Food Safety and Technology: Impact on Consumers
Hope, a young mother, grocery shopping with her 15-month-old son, Owen, doesn’t think twice as he contentedly gnaws on a cucumber. A few hours later, Owen starts projectile vomiting. After a frantic call to the pediatrician, Hope follows directions to keep him hydrated and to wait until whatever is irritating Owen’s digestive system is gone: the diagnosis is food poisoning. She thinks back to everything her son has eaten in the past twenty-four hours and realizes that the cucumber in the grocery store wasn’t washed.
Was it the pesticides used on the cucumber that made Owen sick—or could it have been the wax coating applied to keep vegetables firm and crisp? Would an organic cucumber have caused the same reaction? What is food poisoning? How common is it and what causes it? Is organic food healthier and safer than non-organic? What’s the difference? How is our food kept fresh and safe?
In every process of food production safeguards must be in place to ensure food safety. In this chapter, you will learn about possible contaminants that can enter our food supply and simple ways to prevent yourself from getting sick. You will also learn the difference between organic and non-organic farming practices and other food technologies such as aseptic packaging, food irradiation, and genetic modification; and how these methods contribute to our food’s safety.
<H1> Why Is Food Safety Important?
Modern science and technology have given us a wide array of techniques to grow, produce, and preserve food. With these advances, there are also risks. Food safety remains a major public health issue in the United States, as contamination can occur at any point from farm to table. According to The Centers for Disease Control and Prevention (CDC) approximately seventy-five million Americans report experiencing foodborne illness each year. Typically caused by food contaminated by bacteria or bacterial toxins that causes acute symptoms of gastrointestinal distress, foodborne illness can also be caused by many other sources. It is estimated that over half the population of the United States have had symptoms of foodborne illness without ever knowing or reporting it. Of those afflicted by foodborne illness, 300,000 are hospitalized, and 5,000 die each year (CDC 2003).
<H2> Foodborne Illness
Foodborne illness is a term used to encompass any illness or symptom that arises from ingesting food or water that may contain pathogens, natural toxins, or proteins that precipitate a reaction. Food poisoning is considered a foodborne illness, since the inherent toxins in some foods cause sickness. A food allergy, which is an immunological reaction involving an antibody response, is also considered a foodborne illness.
People most affected by foodborne illnesses are those with compromised immune systems, the elderly, children under the age of ten, and pregnant women. However, foodborne illness can affect anyone. The most common symptoms of foodborne illness are diarrhea and abdominal cramping, sometimes accompanied by nausea and vomiting. Usually these symptoms are shrugged off as "it must have been something I ate," and never given a second thought. In fact, many foodborne illnesses are not diagnosed by medical professionals. It’s only when symptoms become severe, such as the projectile vomiting (like Owen suffered), double vision, loss of muscle control, and excessive or blood diarrhea, that medical attention is sought.
To diagnose a foodborne illness, specifically those caused by a pathogen, a specimen must be obtained and cultured. Stool cultures are usually indicated, especially if diarrhea is a symptom. Blood is cultured if the patient has a high fever. A physician who suspects that a patient is suffering from a foodborne illness should take a detailed history including a 24-hour dietary recall. Pathogenic causes of foodborne illness must be reported to the state health department. The state health department reports these illnesses to the Centers for Disease and Control and Prevention (CDC), who assist local and state agencies with any epidemics caused by pathogens. Most treatment protocols involve keeping the person hydrated and comfortable, as most foodborne illness tends to be self-limiting; the body is very adept at ridding itself of the offending microbe by rapidly clearing the gastrointestinal system.
<H2> Food Spoilage
The majority of our food is derived from living plants and animals. Because living cells usually die and decompose after being separated from their nutrient source, it makes sense that food starts to spoil over time. When food spoils it usually changes in appearance. Many vegetables will become limp and wilted-looking, meats will turn brown, and dairy products such as milk, will start to curdle and sometimes take on a yellow tinge. Taste, smell, and texture also change as a food spoils. The taste and smell of soured milk or an apple that is mealy is very distinct to anyone who has the misfortune of consuming them.
Foods that are most likely to spoil include those that are fresh picked, unrefrigerated, or not properly packaged. Oxygen, heat, and light are the three primary factors often responsible for spoilage in many foods. That is why packaging and storage is so important in keeping foods safe to eat and enjoy. Foods that contain fats spoil quicker than those without fat. Any product that contains oil or fat may become rancid when exposed to heat, light, or oxygen. Proteins also begin to spoil when exposed to heat, as heat causes chemical changes that start decomposition.
Fresh fruits and vegetables also should be refrigerated to discourage decomposition, which is typically attributed to microbial growth. As you learned in Chapter 4, fruits and vegetables contain natural sugars. As these foods age and lose water, these natural sugars become more concentrated, attracting sugar-hungry microbes. Even in a refrigerated environment, many fruits and vegetables last only a week or two before starting to spoil.
Processed foods, although they are often very different in appearance from their original ingredients’ structure, have the same potential for spoiling as unprocessed foods. Many foods that we consider to be processed include breakfast cereals and snack foods. As they age many processed foods don’t change in color, but flavor and smell does change as these foods age. Stale potato chips, for example, have a very distinct and unpleasant smell and flavor.
<H2> Other Concerns Related to Food Safety
In addition to foodborne illnesses, food additives, preservatives, and pesticides are also common concerns related to food safety. Many consumer groups have recently scrutinized many additives, preservatives, and pesticides, leading to new research and discussions regarding their use. Food preservatives are used in a variety of foods. Their primary use is to help foods maintain their freshness and appearance longer. Food additives, such as food coloring, can also cause adverse reactions in people. Pesticides are a family of chemicals used in both the field and storage areas to decrease the destruction caused by insects and fungus. Food additives, preservatives, and pesticides are all are discussed in greater detail later in this chapter.
Other technological advances that contribute to food safety concerns are genetic modification and irradiation. Irradiation utilizes gamma rays to sterilize foods and kill microorganisms that might be present. Genetic modification is a more time consuming process, as the DNA of an organism is altered to bring about specific changes that can make the plant or animal more resistant to normal spoilage. Genetic modification has been debated world wide, and many concerns revolve around altering DNA and how it might disrupt other crops, even those many miles from where the altered ones are growing, through pollen contamination.
<H1> What Causes Foodborne Illness?
Microbes or their toxic by-products most typically cause foodborne illness. Of all the foodborne complaints reported, bacterial causes are at the top of the list followed by viral, parasitic, and fungal contamination. The Centers for Disease Control and Prevention (CDC) reported that between 1987 and 1992, 79% of reported foodborne illnesses of known causes were due to bacteria; Salmonella being at the top of the list. Table 14.1 shows foodborne illness rates.
Although bacteria are the predominate cause of foodborne illness, other microbes can cause disease, such as the Hepatitis A virus. Every now and then you will hear on the news, or read in the newspaper of a local restaurant notifying its patrons of potential exposure to this virus by one of their employees. In November of 2003 over five hundred people were infected by Hepatitis A, leading to three deaths, after they ate at a western Pennsylvania restaurant where contaminated onions were used (MSNBC 2003).
Another foodborne illness that has had front-page exposure is mad cow disease, or bovine spongiform encephalopathy (BSE). Cattle contract this disease from eating feed contaminated with tissue and blood from other infected animals. First discovered in the early 1980’s in Britain, this neurological disorder is caused by a prion, a protein that is closely related to a virus. The word prion is derived from proteinaceous infectious particle (Tortora, Funke & Case 2003). The first reported case in the United States was in December of 2003 in Washington State, when an animal tested positive for the disease after it was slaughtered. Prion proteins are not destroyed with cooking, and are only found in the tissue of the central nervous system, retina, and lower intestines; not the milk, or muscle meats. The disease can be passed to humans who consume contaminated meat or tissue that is usually ground into items such as sausages.
<H2> Harmful Microbes Can Multiply in Foods
Given the correct conditions, microbes can thrive and multiply in many types of food. Depending on the temperature, moisture content, acidity and oxygen content, different microbes grow at different rates. Many bacteria will also compete with each other for the optimum environment. Rinds and shells can protect a food from microbial invasion. Eggshells are a good example of a barrier that keeps bacteria, such as Salmonella from entering the nutrient rich environment within. Many microbes cannot tolerate acidic foods, for example Clostridium botulinum does not grow or produce its toxin in an acidic environment below a pH of 4.5, so the risk of botulism is decreased in acidic fruits like oranges and lemons or foods like pickles. pH refers to the acidic or alkaline nature of the food, the pH scale runs from 1-14 with 7 being neutral. Milk has a neutral pH; citrus fruit would rate a low number and a more alkaline food, like a fresh egg would score higher on the scale.
<H2> Foodborne Microbes Can Release Toxins
Although many microbes can directly cause illness by contamination, many give off a by-product or toxin that is responsible for the many different symptoms attributed to acute illness. Some bacteria produce proteins called exotoxins, which can bind to body cells and cause serious problems such as paralysis, diarrhea, and vomiting. One of the most common is the exotoxin produced by Clostridium botulinum. The botulism exotoxin blocks nerve transmission to muscle cells causing paralysis. Exotoxins can be categorized depending on the type of cell they bind to; the two primary types of exotoxins associated with foodborne illness are neurotoxins and enterotoxins. Neurotoxins damage the nervous system, usually causing paralysis, while enterotoxins target the gastrointestinal system, with severe diarrhea and vomiting being the primary symptoms.
<H2> Our Bodies Respond to Foodborne Microbes and Toxins with Acute Illness
Any irritant identified by the gastrointestinal system will immediately cause symptoms such as vomiting or diarrhea in an attempt to quickly rid the system of the offending material. If the substance survives the harsh environment of the gastrointestinal tract and crosses into the body, the white blood cells will be activated, and any number of symptoms may arise, as the body starts to defend itself. These symptoms may include fatigue, fever, and nausea as the body attempts to restrain the individual from activity until the system is cleared from the offending substance. Other symptoms that may arise are from the microbe, its toxins, or the body’s response to the invasion can take many forms depending on the type of microbe or toxin. Table 14.1 gives many possible symptoms from common bacterial pathogens.
<H2> Mercury and Other Substances Can Also Cause Foodborne Illness
Many different chemicals are released into the atmosphere as a result of industry, agriculture, automobile emissions and improper waste disposal being the primary causes, these are referred to as persistent organic pollutants (POP). They all eventually enter the food supply through the soil or water. If a pollutant gets into the soil, a plant can absorb the chemical into its structure, and can pass it on as part of the food chain. Animals can also absorb pollutants into their tissues, with fat-soluble substances being more of a problem, as they tend to accumulate in body tissues; and are easily absorbed when the animal is used as a food source. It has been found that POP residues are present in virtually all categories of foods, including baked goods, fruit, vegetables, meat, poultry and dairy products. These chemicals can travel long distance in trade winds and water currents, moving from tropical and temperate regions to concentrate in the northern latitudes. It is believed that all living organisms on Earth carry a measurable level of POPs in their tissues (Schafer 2002).
Mercury and lead are two important and common pollutants that Americans are exposed to. Mercury, a naturally occurring element, is found in soil and rocks, lakes, streams, and oceans. It is also released into the environment by pulp and paper processing and the burning of garbage and fossil fuels. As mercury is released into the environment, it falls from the air, eventually finding its way to streams, lakes and the ocean, where it accumulates. Fish absorb mercury as they feed on aquatic organisms. Large predatory fish, such as swordfish, shark, King mackerel, tilefish and fresh and frozen tuna tend to contain the highest levels of mercury. Freshwater fish caught in local lakes and rivers, have variable levels of mercury, and local and state governments routinely monitor mercury levels, and post advisories when levels are too high. As mercury accumulates in the body, it has been shown to be toxic to the developing nervous system and can damage the developing brains of fetuses and growing children. Pregnant and nursing women and young children are advised to avoid eating these types of fish. (Environmental News Network 2003) Canned tuna, salmon, cod, Pollock, sole, shrimp, mussels and scallops do not contain high levels of mercury and are safe to consume. To learn more about the risks of mercury in seafood, visit the FDA’s food safety website www.cfsan.fda.gov or call their 24 hour Information Line 1(888) SAFEFOOD.
Lead, another naturally occurring element, can be found in the soil, water, air, and many foods. Excessive lead exposure can lead to learning and behavioral impediments in children, and cardiovascular and kidney disease in adults. It is impossible to avoid lead completely, but because of its health implications, everyone should try to limit their exposure.
Polychlorinated biphenyls (PCBs) and dioxins are just two industrial pollutants that have been found in food worldwide. Dioxins from discarded transformers and PCBs, which are byproducts of waste incineration, enter the soil and can persist in the environment for years, easily accumulating in fatty tissues. Many studies done in Belgian show that chicken, pork and eggs have been found to have concentrations of these chemicals in excess of international standards (Larebeke et al 2002). PCBs and dioxins along with other POPs have been linked to cancer, learning disorders, impaired immune function and infertility (Schafer 2002).
International agreements sponsored by the United Nations such as the Stockholm Convention seek to ban or restrict many chemicals and require the backing of many countries for realization. The Stockholm Convention, originally drafted in May 2001, is intended to enable the international community to collaborate on an agreeable solution to reducing and eventually phase out the use of POPs. Its mandate is to reduce POP use, and develop alternatives as well as ensure safe and environmentally sound disposal of POPs. As a global treaty, it’s the intention of the United Nations to involve as many countries in the dialogue involving scientific findings, education, and the socio-economic impact of
reducing POP use and their disposal. Anyone interested in the full text of the Stockholm Convention can access it at http:www.pops.int.
<H1> How Can You Prevent Foodborne Illness?
Foods that are most commonly associated with foodborne illness are those of animal origin, such as raw meat, poultry, eggs, shellfish, and nonpasterized milk. Foods that may be the products of multiple animals (such as ground beef) can be especially hazardous. A pathogen present in one animal has the potential to contaminate the whole batch. Fruits and vegetables can also cause problems when they are not cleaned well and consumed raw. Washing decreases, but cannot eliminate all contaminants and the quality of the water used in washing is sometimes a factor. Unpasteurized fruit juice may also be contaminated if there are pathogens in or on the fruit used to make it (CDC 2003).
<H2> When Preparing Foods at Home
When you prepare foods at home, you can prevent food borne illness by following four basic rules:
1. Wash your hands and kitchen surfaces often.
2. Separate foods to prevent cross contamination. Cross contamination is an easy way for bacteria or other microbes to spread from one food to another, as they travel from one source to another.
3. Cook foods to their proper temperatures.
4. Chill foods to prevent microbes from growing.
<Insert Figure 14.1 FightBac logo of USDA>
<H3> Keep Your Hands and Kitchen Clean
One of the easiest and most effective ways to prevent foodborne illness is to always wash your hands before and after preparing food. A clean area and tools are also essential in reducing cross contamination. Wash utensils, containers, and cutting boards in the dishwasher or with hot soapy water before and after contact with food; especially raw and cooked meat, seafood, and poultry (Food Marketing Institute 2003). It’s also important to wash counter tops and utensils with hot soapy water after preparing each food type to reduce the chance of cross contamination. Use a non-porous, plastic or stone, cutting board instead of a wooden one, because they are less likely to absorb any juices and harbor bacteria. Dishtowels, cloths and aprons should be washed in hot water often. It’s a good idea to wash sponges in the dishwasher each time you run it, and to replace them regularly. If you don’t have a dishwasher, put sponges in boiling water for three minutes to sterilize them on a routine basis. Remember that the most effective way to prevent cross contamination is to always clean surfaces, utensils, and hands after working with a food and before progressing to the next one.
<H3> Keep Raw Foods Separate
Remember, cross contamination is an easy way for bacteria or other microbes to spread from one food to another. Raw meat, poultry, and seafood carry a large array of microbes, and can easily contaminate other foods through direct contact, by their juices or surfaces (including hands) that are not cleaned after each food’s preparation. Contact between food that won’t be cooked, like salad ingredients, with these foods or their juices can cause cross contamination, and potential foodborne illness. Be careful not to place cooked food on a plate that previously held raw meat, seafood, or poultry. When preparing meals with a marinade, make sure you reserve some of the marinade in a clean container before adding raw ingredients, so you will have some non-contaminated marinade to use later in the cooking process. Remember to always marinate raw food in the refrigerator.
<H3> Keep Cold Foods Cold
Different microbes thrive in different environments. The majority of bacteria that cause food related illness prefer temperatures between 60 – 130° F, (15 – 50° C), with the majority growing best in temperatures between 80 –100° F (25-40° C) (Tortora, Funke, Case, 2003). Because of this, refrigeration has become one of the most reliable methods of diminishing bacteria’s ability to cause illness. Not all bacteria in cool environments are killed, but the rate at which they reproduce is drastically reduced. Freezing is also an effective way of preventing bacterial and fungal growth in food. Naturally occurring enzymes that cause food decomposition are stopped at freezing temperatures, which is why it’s a great way to store fresh berries for use out of season.
A simple consumer tip to remember about foods that are typically stored in cold temperatures is to purchase them last. When you are buying meats, poultry, seafood, and dairy products at a grocery store or market, look for the "sell by" or "use by" date on their packaging. The "sell by" date indicates the last day a product can be sold and still maintain its quality during normal home storage and consumption. The "use by" date tells you how long a product will maintain optimum quality before eating (Food Marketing Institute 2003). After you purchase these perishable foods, you should get them home and into the refrigerator or freezer within one hour. If your trip home will be longer than an hour, bring along a cooler to transport them in.
Once you get home, meat, poultry and seafood should be put in the coldest part of the refrigerator. They should also be properly wrapped so their juices do not drip onto any other foods. If you are not going to use meat, poultry or seafood within 48 hours of purchase, you should store them in the freezer (Food Marketing Institute 2003). Remember that eggs are also considered perishable and should be kept refrigerated. Try not to overstock your refrigerator or freezer, as air needs to circulate around food to cool it quickly and discourage microbial growth.
Have you ever taken cheese out of the refrigerator and noticed that it had a blue growth on it? Interestingly, cool temperatures do not slow the growth of some molds; in fact some prefer refrigerated temperatures. Applesauce, leftover coffee, and spaghetti sauce are common foods that easily grow mold. The cool temperatures in addition to the acidic nature of these foods make them a hospitable environment for mold growth. So how did the mold get into the sealed, refrigerated package? Mold spores are common in the atmosphere, and they randomly land on food either in the processing plant, or in open containers at your home. If the temperature and pH of the food is correct they will grow.
Most people throw away moldy foods, as their taste has changed. Not too many foodborne illnesses have arisen from moldy food, probably due to the unpalatable nature of them. But molds and other members of the fungus family are used in the food industry; the distinct flavor of Roquefort and Blue cheese can be attributed to the use of molds in their ripening process. Molds and yeast are also used to give distinct flavors to such foods as sourdough bread, miso and the many varieties of beer, wine and distilled beverages available.
After a meal, leftovers should be promptly refrigerated to discourage microbial growth. The standard rule for storing leftovers is 2 hours/2 inches/4 days. Food should be refrigerated within 2 hours of serving. If the temperature is 90°F or higher, like at a picnic, then foods should be refrigerated within one hour (USDA 2003). Because a larger quantity of food takes longer to cool and will allow more microbes to thrive, food should be stored at a depth of no greater than 2 inches. Leftovers should only be refrigerated for up to 4 days. If you don’t plan on using the food within 4 days, freeze it (CSPI 2003).
Small amounts of food are preferable for cooling and freezing as well as for thawing. Sufficient thawing will ensure adequate cooking throughout, which is essential to preventing foodborne illness. Raw poultry is a good example of a food item that needs to be carefully contained as it thaws, so its juices don’t contaminate other foods. The perfect place to thaw poultry is on the bottom shelf of the refrigerator, in a large bowl to catch any of its juices. Table 14-2 shows recommended poultry thawing times based on weight. Never thaw frozen meat, poultry, or seafood on a kitchen counter. Room temperatures allow growth of bacteria on the surface of food, although the inside may still be frozen (Food Marketing Institute 2003). A microwave is also useful for thawing, but be sure to read your microwave’s instructions carefully first.
<H3> Keep Hot Foods Hot
Thoroughly cooking food is a sure way to kill microbes. Raw meat, poultry, seafood, and eggs must be heated long and hot enough to kill any microbes. The color of cooked meat can be deceiving. The only way to be sure meat is thoroughly cooked is with a food thermometer. Grilled meat and poultry often brown very quickly on the outside, but may not be thoroughly cooked on the inside. Test your food in several places to be sure it’s cooked evenly, and remember to wash the thermometer after each use. If you don’t have a thermometer available, do not eat beef that is still pink inside, as the CDC links eating undercooked, pink beef with a higher risk of foodborne illness (USDA 2003).
Frozen foods take twice as long to cook than thawed foods, don’t be impatient! Remember to allow yourself more time and don’t interrupt the cooking process, as bacterial growth may be encouraged, not discouraged. Microwave cooking is convenient, but you need to be sure your food is thoroughly cooked, and there are no cold spots in the food where bacteria can thrive. For best results when microwaving, remember to cover food, stir often, and rotate for even cooking (USDA 2003). If you are cooking meat or poultry, use a thermometer to check internal temperatures in several spots; as temperatures vary in different parts of food more in microwave cooking than in conventional ovens (Food Marketing Institute 2003).
When cooked properly, fish should be opaque and flake easily with a fork. Eggs should be cooked until the yolk and whites are firm, and scrambled eggs should not be runny. If you are using eggs in a casserole or custard make sure that the internal temperature reaches at least 160° F (CSPI 2003).
Insert Figure 14.2 Thermy USDA mascot for teaching children about food safety
<H2> When Eating Out
Eating out is one of life’s simple pleasures. It shouldn’t be a time when you have to question the safety of the food being served. One way to protect yourself when dining out is to choose an eating establishment that is clean. However, being clean on the surface won’t guarantee that the kitchen is clean. That is why health inspections are important. Many local governments have health inspectors that randomly visit and inspect the food preparation areas of all businesses that serve food, whether eat in or dine out. You can usually find the results of these inspections in the local newspaper or by contacting your local health department.
A way to protect yourself when dining out is by ordering foods to be cooked as you would at home. If you order a hamburger or steak, and it comes pink in the middle, send it back and asked for it to be cooked thoroughly. If you order something made with eggs, ask if the eggs are pasteurized, if not, you might want to pass on that item, and order something else.
<H2> When Traveling to Other Countries
When traveling abroad, care should be taken in selecting food and beverages. All raw food has the potential for contamination, especially in areas where hygiene and sanitation are inadequate. All travelers are cautioned to avoid salads, uncooked vegetables, and nonpasteurized dairy products. Depending on which area of the world you are visiting, different food choices may be available. If fish is a common delicacy, be aware that many tropical species from the insular areas of the Caribbean and Pacifica and Indian Oceans, can contain poisonous biotoxins, even when well cooked (CDC 2003).
Water is not always a safe option, even if chlorinated, as chlorine doesn’t always kill enteric viruses and parasitic organisms that can cause tenacious gastrointestinal disease. In regions where hygiene and sanitation are suspect, only consume the following: canned or bottled carbonated beverages such as bottled water and soft drinks, beverages made with boiled water and fermented drinks such as beer and wine, as their processing will neutralize any potential pathogens. Also, remember to ask for drinks without ice, as freezing contaminated water does not kill microbes and parasites. If you think the water may be contaminated, don’t brush your teeth with it, use bottled water or boil the water for one minute, then allow the water to return to room temperature before brushing. You can find more information about food and water safety when traveling by visiting the CDC’s Website: www.cdc.gov.travel.food-drink-risks.htm or by contacting your local health department.
Preservatives help extend the shelf life of many foods, decreasing costs and allowing consumers to buy items in bulk. Some preservatives such as Vitamin C also enhance the nutrient quality of foods. There is a small segment of the population sensitive to preservatives and other additives found in processed foods. These people have to be careful of the amount of preservatives ingested to avoid reactions such as asthma or headaches.
Most processed foods contain preservatives, unless the package touts that it is ‘preservative free’. All preservatives must be listed in the ingredients, but you must know a wide array of chemical names to know and understand which are preservatives. Table 14.3 lists some common preservatives and which types of foods you would expect to find them in.
<H2> Natural Techniques Have Been Used for Centuries to Preserve Foods
Preservatives, as explained earlier, help prevent microbial spoilage and chemical deterioration. Some methods of preserving foods has have been used for thousands of years, and employ naturally derived substances such as salt, sugars, and vinegar. Early populations used these methods in addition to heat and drying to preserve food for the winter and travel. These methods are still used in homemade jellies (high sugar content) and smoking fish (heat). Vinegar (acetic acid) is used primarily in pickling.
<H3> Salting and Sugaring
The use of salt and sugar to preserve food works by drawing the water out of the food substance by a process known as osmosis, as discussed in Chapter 7 (see Figure 7.4). The water is drawn to the surface, dehydrating the food, making it an inhospitable environment for microbes, especially bacteria. A good way to see how effectively salt draws water from food, and to understand osmosis, is to liberally rub salt on cucumber slices and leave it for an hour or so. When the hour has passed, you will see the surface will have become covered with water ‘sweated’ out of the cucumber.
Salt, one of the oldest and most effective preservatives is especially good at drawing water from food. The amount of salt required to be effective as a preservative is much higher than normally used for seasoning. Traditionally, salt was the primary preservative used in all meats and seafood, but because of a population very conscious of highly salted foods, this method is not used as it was in the past. Some meat jerkys still rely on salting, but not many other products do.
Salt has been traditionally used for curing pork products. Many countries have specialty hams that rely on regional customs to produce a unique and quality meat. A good example is the Parma Ham from Italy, it is dry salted with sea salt during the winter for a bout a month then wiped clean and hung in huge curing rooms in long rows where plenty of fresh air can circulate around them. The curers must constantly adjust windows to accommodate changing winds. It takes almost nine months for a Parma ham to mature. (Shepard 2000)
Sugar has a remarkable ability to preserve foods while retaining much of its shape, color, and texture, because some of the sugar is absorbed into the food, replacing any water drawn out in cooking. The downside to using sugar is that fungus tends to flourish in sweet, acidic environments, such as jam. Sugar also adds calories, as well as can contribute to dental caries.
Honey, a natural sweetener, is also a most effective preserver. Used long before white or cane sugar, honey was used to preserve meats and fruits as far back as pre-Roman times (Shepard 2000). Hams are often covered in honey to create an anti-bacterial coat to protect them during storage.
Drying is an ancient method of preserving food, used by many cultures in a variety of climates. There is evidence that the Egyptians dried fish and poultry in the hot desert sun as early as 12,000BC (Shepard 2000). By removing water from food, it is no longer a hospitable environment for bacteria or other potential pathogens. Also the absence of moisture in food prevents most chemical deterioration of food from occurring. However, depending on the method used, foods change color, texture and flavor and their vitamin content can be decreased.
The foods that are best adapted to drying are legumes, as they are dried naturally. As long as the moisture content of the environment stays low, no problems will arise. In some instances, moist conditions will encourage fungi to grow on the surface of crops and a chemical called aflatoxin is produced by the mold Aspergillus flavus. Aflatoxin has been associated with peanuts, and if ingested can cause illness, in both livestock and humans.
Another method of drying food is called freeze-drying; this is a rapid and complete drying of food. The food is first flash-frozen and any water is rapidly converted to fine ice crystals, which are evaporated in a vacuum. The product is then immediately packaged and sealed to ensure no penetration of moisture occurs. At no time does the temperature go higher than freezing, helping preserve flavor, color and texture. This method allows for a shelf life of several years, as long as the seal is not broken. Freeze-drying is used for products such as coffee, tea, dried milk, gravy, and soup powders. This method is also used to make dehydrated camper’s food.
<H3> Smoked Foods
Smoking foods, especially meats, is a natural food preservation technique that has been used for many years. If food was not drying well, it would be hung near the campfire of around the chimney so the smoke of the fire would permeate the food, partly cooking and further drying it. Depending on the heat of the smoke, smoking is either cold – smoked, which is a short-term preservation method, or hot-smoked, which keeps food for a long time. When food is cold-smoked the temperature is no higher then 85oF (29oC). The smoke will give a mild, smoky flavor as it slightly dries, but does not cook the food. This method is good for meat or fish, but will only preserve it for a limited time before starting to spoil. This method is used for foods that are eaten raw such as beef fillets or smoked salmon.
Hot-smoked food uses temperatures above 130oF (55oC). This process is used for foods such as venison, poultry, smoked trout, pork, lamb and beef. Originally using heavy salting with the smoking, modern "hot-smoked" food uses much less salt. The type of wood used to smoke foods also contributes to the foods’ flavor. Birch, hickory, apple, juniper and willow are woods that have distinctive flavors. Smoked foods still need to be covered and stored in areas where air, heat, and insects cannot have easy access to them.
Storing food in cool cellars, running streams, or underground is a way to preserve foods that has been used for centuries. As mentioned earlier, many bacterial metabolic activities are optimum in higher temperatures. As the temperature of a food is lowered, the bacteria’s metabolism is slowed, and it becomes less able to reproduce or give off toxic by-products. The use of refrigeration has been a great addition to modern life, and has allowed many fresh foods to remain viable and nutritious for days. Although refrigeration will not stop spoilage, it slows it down remarkably.
The use of cold via ice to ship and store food is thought to go back to the second century with records of Chinese royalty using icehouses to store food. Thirteenth and fourteenth century Egyptian royalty were also storing food in icehouses, stocked with ice brought from the mountains of Lebanon (Shephard 2000). The transport of freshly caught fish using ice is also first attributed to the Chinese, and European merchants fascinated with the idea soon perfected the use of cold to design and build refrigerated vessels to transport all types of food stuffs. Ice was important commodity in the early nineteenth century. A Massachusetts company developed the forerunner of our refrigerator, the miniature icehouse, in the early 1800’s.
A successful form of preserving food is deep-freezing. At temperatures between 18 and –23o C, bacteria and fungi stop growing, but do not die. Enzymatic processes that are usually associated with normal decomposition of food are also stopped. When freezing items, remember the smaller the package the quicker the cooling. Care must be taken if the electrical supply is cut off. Try not to open the freezer until the power is restored. When the power comes back on, check to make sure the temperature is at least –5oC on the top shelf. If it is warmer, you should inspect your freezer’s contents and discard any items that are not firmly frozen, thus lessening chances of an overgrowth of bacteria.
Insert Figure 14.3 a refrigerator door with temperatures, graduated like a thermometer, of foods and their proper storage temperatures
<H2> Synthetic Food Preservative Techniques Are Used in Industry
After World War II, the use of industrial techniques to enhance our food supply expanded with the new technologies being discovered. As more and more households acquired refrigerators and freezers, food scientists found ways to enhance and expand American food choices.
<Insert Table 14.3 Common Preservatives Found in Food>
BHT (butylated hydroxytoulene) and BHA (butylated hydroxyanisole) are two commonly used antioxidants in foods. BHT and BHA are found in a wide variety of products, and are used to keep oils and fats from going rancid; BHT is frequently added to many breakfast cereal packages to decrease spoilage. BHA is stable at high temperatures and is often used in products such as soup bases, ice cream, potato flakes, gelatin desserts, dry mixes for desserts, unsmoked dry sausage and chewing gum. Propyl gallate, another antioxidant, works synergistically with both BHA and BHT and enhance each other’s effectiveness when paired together. Propyl gallate is used in products such as mayonnaise, mashed potato flakes, fruits, spice flavorings for beverages, ice cream, baked goods, and gelatin desserts.
<H3> Mold Inhibitors
Mold, along with bacteria, is found everywhere in nature. All of the food we buy or grow houses a variety of microbes. Mold, fungus, and bacteria cause the majority of food spoilage. Molds and fungus, unlike bacteria, like dark, damp, and acidic environments—for example, they would love that open jar of apple sauce in the back of your refrigerator! Mold grows quickly on baked goods and dairy products. The bread you bought, left on the counter, and finally got around to eating a week later would start to mold if it wasn’t treated with mold inhibitors such as calcium propionate, sodium propionate or propionic acid. Propionic acid occurs naturally in apples, strawberries, and tea and is used to prevent mold growth in baked goods and processed cheese. Sodium propionate and calcium propionate are salts synthesized from propionic acid and are used as mold inhibitors in a variety of foods. Sodium propionate is primarily used as a mold inhibitor in baked goods, frostings, confections, and gelatin; while calcium propionate is used in breads, rolls, poultry stuffing, chocolate products, and processed cheeses.
Sulfur dioxide is also used to control mold growth on fresh fruits and vegetables in combination with cold temperatures. The growth of molds and fungus causes the loss of much fruit. For example, it has become standard commercial practice to fumigate stored grapes every ten days to prevent the spread of a fungus (CC&PA 1980). Because of these procedures, it’s important to remember to wash all fresh fruit and vegetables before eating.
Sulfiting agents such as sodium bisulfite and sulfur dioxide are effective preservatives, antioxidants, and antibrowning agents. Sulfites have antibacterial properties, and are used as a bleaching agent for flour. They are also used in the beer and wine industry, as well as in dehydrated foods, maraschino cherries, and processed potatoes. Sulfites are not used in enriched grain products because of their capacity to bind with thiamin (Vitamin B1), making it unavailable for absorption. The FDA has banned the use of sulfites as a preservative in salad bars, because some people have had adverse asthmatic reactions. All foods that contain added sulfites must be labeled to warn those with sensitivities.
Nitrates and nitrites are additives commonly used in food processing. Both forms have been used in the processed meat industry for many years as antibacterial agents and color enhancers. They give ham, hot dogs, and bologna their familiar pink color. Nitrites can easily be converted to nitrosamines during the cooking process. Nitrosamines have been found to be carcinogenic in animals, so the FDA has required all foods with nitrites to contain additional antioxidants to decrease the formation of nitrosamines.
Pasteurization was developed in 1864 by Louis Pasteur to destroy unwanted microorganisms in wine. Its quick use of heat to eliminate pathogens without altering the taste or quality of the food product makes it particularly useful and important process in the dairy and juice industry. Heating it to 72°C for fifteen seconds pasteurizes milk, while ice cream, which is higher in fat, requires pasteurization at 82°C for twenty seconds. Pasteurization does not eliminate all microbes, but significantly decreases the numbers of heat sensitive microorganisms, which tend to be the most pathogenic.
<H3> Industrial Canning
Canned foods, consumed in the United States at a rate of 20 million per day (Shephard 2000) are a convenient and quick way for many to consume a variety of foods on a daily basis. A French inventor, Nicolas Appert, first developed the canning process in the late 1700’s, and modern techniques have contributed to the retention of flavor, texture, and nutrients.
The canning process requires that the endospores of Clostridium botulinium be destroyed. This especially lethal organism can grow and multiply in canned food items. The process that ensures that C. botulinium is eliminated also kills other microorganisms that have food poisoning potential. The food canning process involves several steps. First the food to be canned is sorted, removing any spoiled food. Then the food is washed and blanched. Blanching involves the use of hot water or steam to parboil or scald the food, thereby stopping enzymatic processes. It can also be used to help remove skins from certain fruit and vegetables. Blanching also kills any microorganisms on the food’s surface. After blanching, cans are filled and heated, air is siphoned out, and they are sealed. After sealing, the cans are heated by steam under pressure, and then cooled in a water bath. Canned food has an average shelf life of at least two years from the date of purchase. It is recommended that all canned food be stored in moderate temperatures (75° F and below).
The U.S. Army has found that canned meats, vegetables and jam were in "excellent states of preservation" after 46 years. However, long storage of canned foods is not recommended. For high quality (versus safety), the broadest guideline given by the U.S.D.A. is to use high-acid canned food (fruits, tomatoes and pickled products) in 18 to 24 months, and low-acid (meats and vegetables) in two to five years (WSU 2003).
<H3> Other Preservative Packaging
Many different packaging techniques have arisen over the past several decades. The newest and most environmentally sound one is Aseptic Packaging. You probably know it best as juice boxes. Widely used in Europe and Asia, aseptic packaging was first introduced in the United States in the 1980s. Food and beverages that are packaged in aseptic containers are first sterilized in a flash-heating and cooling process, which sterilizes the food before it is immediately placed in the sterile container, using less energy than traditional canning processes. Nutrients as well as food quality is high without the need for preservatives, or refrigeration. The packaging material consists of six layers of paper (70%), polyethylene (24%) and aluminum (6%) in the following order: polyethylene, paper, polyethylene, aluminum foil, polyethylene and polyethylene. The polyethylene makes the package liquid tight from the inside and out. The paper gives strength and shape while the aluminum’s ultra thin layer eliminates the need for refrigeration and preservatives by forming a barrier against light and oxygen (Aseptic Packaging Council 2003).
Although the six layers sounds like a lot of packaging, there is actually less packaging material used than any other comparable containers. A typical single serving aseptic package provides a product-to-package ratio that is 96% product to only 4% packaging by weight. Aseptic cartons use less energy to manufacture, fill, ship, and store; and are recyclable. By not needing refrigeration or preservatives, aseptic packaging eliminates additional energy and any potential environmental burden (Aseptic Packaging Council 2003).
Insert figure 14.4 – a photo of a few juice cartons/organic milk/soy milk in aseptic packaging to show different sizes and varieties
Irradiation is an effective process for eliminating harmful bacteria often found in foods, such as Trichinella spiralis and Salmonella in meats and poultry. It also inhibits spoilage by fungus. It involves the use of x-rays, beams of high-energy electrons produced by electron accelerators, or gamma rays from cobalt 60 or cesium 137. In the United States, gamma rays are typically used for irradiation. Energy from gamma rays penetrate food and its packaging. Most of this energy simply passes through the food, similar to microwaves, leaving no residue (Extoxnet 1997). While the food remains unchanged, bacteria and parasites are killed or left unable to reproduce, thus decreasing their ability to spoil food or cause food borne illness.
In the United States, many foods are preserved using irradiation; among them spices, grains, pork products, fresh fruits and poultry. NASA uses irradiated foods for space flights (Loaharanu 2003). Although irradiation rids foods of most pathogenic microbes, it does not change the food; frozen foods remain frozen and raw foods stay raw through the process. While many foods can be safely irradiated without any noticeable changes, dairy products do not. The flavor of milk and dairy products becomes unpalatable after irradiation, making them inappropriate for this process. A recent consumer report on irradiated meat did note that the flavor of both beef and chicken had a subtle off-taste and smell, but one that many consumers might not be able to notice (Consumer Reports 2003). Food’s nutritional quality is unaltered and only a few nutrients, including vitamins A, E, K, and thiamin seem to be affected by irradiation. Losses of these nutrients are comparable to what would be lost in conventional processing and preparation. Although irradiated food has been shown to be safe, the FDA requires that all irradiated foods be labeled with a "radura" symbol and the words "treated by irradiation, do not irradiate again" or "treated with radiation, do not irradiate again" must accompany the symbol. Irradiated food can be re-infected by inadequate handling and preparation practices, so consumers still need to be diligent in their storage and preparation practices. Irradiation has been approved for use by fifty countries and endorsed by the World Health Organization (WHO), the Food and Agricultural Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA).
Insert Figure 14.5 the Radura symbol
<H2> Government Regulations Control Food Safety
Many government agencies such as the United States Department of Agriculture (USDA), The Food and Drug Administration (FDA), The Centers for Disease Control and Prevention (CDC), and The Environmental Protection Agency (EPA) monitor and regulate food production and help to set standards to ensure food safety. Information about these agencies and how to access them is in Table 14.4.
Additives, while regulated by the FDA have been a constant source of controversy. Their use has increased over the past fifty years, allowing the consumer more variety at lower costs. Additives increase shelf life, as well help keep many common processed foods uniform from batch to batch. Without additives such as flavorings strawberry ice cream would only be available for a
short time in the early summer in limited quantities. And without added preservatives, that loaf of bread you were reading the ingredients of would go stale within a day or so.
<H1> Why Are Food Allergies a Growing Concern?
The ancient saying, "one man’s meat is another man’s poison" has a good deal of truth behind it. As discussed earlier in this chapter, different microbes can cause foodborne illness. However, our bodies can also experience negative reactions to food unrelated to foodborne illness. Sometimes, when a person eats or even touches a particular protein, starch, or additive, they can have an allergic reaction resulting in a variety of symptoms from headaches, to diarrhea to more life-threatening situations such as anaphylaxis. Anaphylaxis is a quick occurring reaction, in which smooth muscles contract and swelling occurs; most commonly of the respiratory system causing obstruction of the airways. Common foods that can cause food allergies include nuts, citrus fruit, seafood, wheat, and dairy. A food allergy is an adverse response to a substance that causes our immune systems to respond. The body responds to the food component as if it is harmful, like a microbe, and releases antibodies, immune system proteins, to surround and hold the food component, until it can be broken down and removed from the system. Although people can have food allergies to starches or additives, 90% of all food allergies are related to proteins (Emsley & Fell 2002).
Many people talk about food allergies and intolerance in the same breath. Although food allergies and intolerance may seem similar, they are not the same thing. Food intolerance can have many of the same symptoms as a food allergy, but does not cause an immune response; it causes the digestive system to react to rid the body of the food. Sometimes it’s hard to tell the two apart. Many who think they have a food allergy, when tested, discover that they actually have a food intolerance. For example, people who are lactose intolerance, sometimes mistakenly think they are allergic to milk. In fact, they are not allergic—rather they lack an adequate amount of lactose enzymes to properly digest the sugar in milk.
Food allergies can cause immediate reactions, such as hives, eczema, asthma, or even anaphylaxis. These reactions can occur within minutes or hours. Some delayed allergic reactions can even occur days later. Delayed reaction allergy symptoms are not as dramatic or life threatening as immediate reactions. Symptoms include migraines, rashes, and diarrhea. Evidence suggests that 40% of migraine headaches are caused by reactions to food (Mansfield 1988). These types of delayed reactions most commonly occur in adults, although many children display immediate reactions.
Children’s delayed reactions to food allergens are often different than adults’. Some common allergy symptoms in children include chronic ear infections, bed-wetting, dark circles under the eyes, irritability, and eczema. Interestingly enough, many young children "grow out" of their allergies. Over 50% of children under the age of three who were diagnosed with a food allergy to eggs or milk became tolerant of these foods when their gastrointestinal tracts matured (Emsley & Fell 2002).
Food allergies can either be fixed or cyclic. A fixed food reaction occurs whenever an offending food is eaten. People with fixed food allergies need to avoid foods that cause a reaction. A cyclic allergic response, which accounts for 85% of food allergies, develops slowly over time. If the offending food is avoided for at least four months, then it can be reintroduced into the diet in small, infrequent amounts without any reactions (Pizzorno & Murray 1985).
It’s estimated that one out of five Americans experiences some symptoms related to their diet (Emsley & Fell 2002). Although most people do not have food allergies, with repeated exposure to the same food components, many people may develop allergic reactions. Some theories as to why we react to food or its components are:
<H1> What Are Food Additives and Are They Safe?
Have you ever picked up a loaf of bread and started reading its ingredients? You’d expect to see flour, yeast, water, and some sugar, but what are all those other items? And why does it feel like you have to have a degree in chemistry to understand what they are? They are collectively called food additives, and additives are in almost every processed food. Without additives, that loaf of bread you were holding would go stale within a day or so. It’s estimated that over three thousand different additives are currently used in the United States and the U.S. Food and Drug Administration (FDA) regulates their use.
Additives, while regulated by the FDA have been a constant source of controversy. Their use has increased over the past fifty years, allowing the consumer more variety at lower costs.
<H2> Additives Can Enhance a Food’s Taste, Appearance, or Nutrition
An additive is a substance or mixture of substances intentionally put into food to enhance its appearance, palatability, and quality. Many of the additives used by the food industry come from natural sources. Beet juice, a natural food coloring, and citric acid, are common, naturally derived food additives. In cases when supply or cost would prohibit using naturally derived additives, additives can be synthesized to supplement natural supplies. Vanillin, the main flavoring substance in vanilla beans, is synthesized at a cost considerably lower than the cost of the natural products. It is doubtful that natural sources of vanillin could meet consumer demands (CCPA 1980). Many additives help stop the growth of microbes and decrease food deterioration due to light, heat, or exposure to oxygen or metals. Most additives can be categorized as preservatives, colorings, flavorings, bleaching agents, humectants, desiccants, texturizers, emulsifiers or stabilizers. Vitamins and minerals can also be added to improve the nutritive value of certain foods (CC&PA 1980). Roughly half of all additives are flavorings used to replace the natural flavor lost during food processing (Winter 1994).
Flavoring agents can be obtained from natural or synthetic sources. Essential oils, extracts, and spices supply most of the naturally derived flavorings. Flavorings are typically found in soft drinks, baked goods, and frozen confections. Flavor enhancers are also widely used. These additives have little or no flavor of their own, but accentuate the natural flavor of foods. They are often added when very little of a natural ingredient is used (CSPI 2003). The most common flavor enhancers used are maltol and MSG (monosodium glutamate). MSG is the sodium salt of one of twenty standard amino acids: glutamic acid, which also serves as a neurotransmitter. Originally derived from sea kelp by the Japanese and introduced to Americans during World War II, MSG is found in many processed foods. However, a small fraction of the population is sensitive to MSG, and suffers symptoms such as headaches, difficulty breathing, and heart palpitations. It has been demonstrated that the glutamate portion of MSG can cross the blood brain barrier and cause over stimulation of neurons, especially in the young. Because of this research, Congress mandated in the 1960’s that MSG be removed from baby food (Blaylock 1996).
Food colorings, derived from both natural and synthetic origins, are used extensively in processed foods. Many food colorings are made from coal-tar, a thick or semisolid tar derived from bituminous coal whose derivatives have been found to cause cancer in animals and need to be tested and certified safe by the FDA before use (Winters 1994). Natural colorings such as beet juice, which gives a red color, or carotenes, a yellow color, do not need to be tested for safety. Over the years many of the coal-tar colors have been banned from use, as they are carcinogens.
<insert figure 14.6 Photos of skittles or fruit loops or another colorful food product>
<H3> Vitamins and Other Nutrients
Antioxidants such as tocopherals (vitamin E) and ascorbic acid (Vitamin C) can be naturally derived. Vitamin E is usually found in fat based products and ascorbic acid is commonly added to food such as frozen fruit, dry milk, apple juice, soft drinks, candy and meat products containing sodium nitrates. Sodium ascorbate is vitamin C with sodium added to produce a salt, and is also used as an antioxidant in foods such as concentrated milk products, cereals and cured meats.
Iodine, and Vitamin D are nutritive additives. Their function in foods is to reduce the occurrence of disease. Iodine was originally added to table salt to help decrease the incidence of goiter, a condition that causes the thyroid gland to enlargen. Vitamin D is added to milk, because in the northern states during the late fall and winter many people do not get enough sun exposure, and vitamin D is naturally derived from exposing our skin to the sun. Vitamin D is necessary for calcium metabolism and has been found to be important in impeding osteoporosis.
<H3> Texturizers, Stabilizers, and Emulsifiers
Texturizers, such as calcium chloride are added to foods to improve their texture, such as canned tomatoes and potatoes so they don’t fall apart. Stabilizers are added to products to give them "body" and maintain a desired texture or color. For example, sodium nitrate is often added to meat to help control its pink color. Thickening agents are naturally or chemically modified carbohydrates that "stabilize" processed food by partially absorbing water and keeping the complex mixtures of oils, water, acids, and solids in foods well mixed (CSPI 2003). Natural thickeners include pectin, which is used in jams and jellies; and alginate and carrageen, which are obtained from seaweed and used in ice cream and salad dressings.
Emulsifiers, like thickening agents and stabilizers, help to keep fats evenly dispersed within foods. They make chocolate more mixable with milk and keep pudding from separating. The most widely used emulsifiers are lecithin and polysorbate 60. Lecithin can be isolated from eggs, soybeans, and corn, and is also used as an antioxidant. As you may remember from Chapter 8, antioxidants are compounds that protect cells from the damage caused by oxygen damage. Polysorbate 60 is used in powdered foods, nondairy whipped cream and creamers, salad dressing made without egg yolks, and vitamin supplements (Winter 1994).
<H3> Humectants & Desiccants
Moisture content is a critical component to food, and humectants and desiccants are added to maintain the correct levels. Humectants help retain moisture in food, keeping things like marshmallows, chewing gum, and shredded coconut, soft and stretchy. Common humectants are glycerin, sorbitol, and propylene glycol. Waxes used on produce also help maintain moisture content, just like the wax that was on Owen’s cucumber. Waxing agents can be from sources such as beeswax, carnauba wax, or from petroleum based products such as paraffin, or mineral oil. The best ways to remove these products are to peel the outerlayer off or scrub with hot, soapy water and rinse well. Desiccants prevent moisture absorption from the air; examples include sodium ferrocyanide and calcium silicate, which is used to prevent table salt from forming clumps.
<H3> Bleaching Agents
Bleaching Agents are used primarily in baked goods. Fresh ground flour is pale yellow, and when stored it slowly becomes white. Processors have added bleaching agents to flour to speed this process and decrease the possibility of spoilage or insect infestation. Benzoyl peroxide is a commonly used to bleach flour as well as blue and Gorgonzola cheeses (Winter 1994).
<H2> Intentional versus Incidental Food Additives
Trace amounts of substances can get into our food during harvesting, processing, storage, or packaging such as insects, fragments of packaging materials, pesticides, hormones or antibiotics given to livestock. These are called unintentional or incidental additives and do not have to be included on the label. This small amount of incidental food additives present in food has not been shown to cause any problems with quality.
<H2> The GRAS List
It is estimated that by1958 the food industry in the United States was using over six hundred natural and synthetic additives. Federal legislation was passed to regulate food additives, and the Generally Recognized as Safe (GRAS) list was established. This list contains all six hundred plus additives and any new ones, with assurances that all additives would be tested, and if found to be harmful to the body, would be removed from the list, and from use in the food industry. The Delaney Clause was also enacted in 1958, stating "no additive may be permitted in any amount if tests show that it produces cancer when fed to man or animals of by other appropriate tests."
In 1985, the FDA established the Adverse Reaction Monitoring System (ARMS). Under this system, the FDA investigates complaints from consumers, physicians or food companies. Many of the complaints are about artificial sweeteners and sulfite preservatives, causing headaches, asthmatic reactions and in some cases anaphylaxis. Because of these complaints and the investigations that followed, the FDA has banned the use of sulfites on raw fruit and vegetables, with the exception of potatoes, while continuing to monitor sulfite use on other foods (NCRP 1993).
<H2> Are Food Additives Safe?
Although there is much controversy over food additives, they have allowed our food supply to increase and diversify. Their use has increased over the past fifty years, allowing consumers more variety at lower costs. Without additives such as flavorings, strawberry ice cream would only be available for a short time and only in limited quantities during the early summer. Most additives are used to improve the appearance and shelf life of foods. They also keep processed foods uniform from batch to batch. The average American consumes approximately 150 pounds of food additives a year (NCRP 1993). If you are interested in reducing the amount of food additives in your diet, you should start by comparing food labels of different brands of the same foods. Some brands use fewer additives than others, and some brands are additive free.
Nutrition Label Activity box here comparing different food labels
<H1> What are Pesticides?
Pesticides are used to help protect food crop losses due to weeds, insects, fungus and other organisms including birds and mammals. Rodents, for example, in addition to consuming food, also contaminate large quantities of food with their excreta. Pesticides also help reduce the potential of disease by decreasing the amount of microorganisms on crops. They increase overall crop yield, and more crop diversity. The three most common types of pesticides used in food production are insecticides, herbicides, and fungicides. Insecticides are used to control insects that can infest crops; herbicides are used to control weeds and other unwanted plant growth; and fungicides are used to control plant destroying mold and fungal growth. It is estimated that 65% of all pesticides produced in the United States are herbicides.
Many plants naturally produce pesticides to help protect themselves from predators and disease. Man has found a way to use naturally derived or synthetic analogs of this protective mechanism for agricultural use. Despite the negative connotations associated with pesticides, many pesticides used today are naturally derived, and/or have a low impact on the environment. Gardeners and farmers are starting to use biopesticides, which are primarily insecticides. Biopesticides are less toxic to humans and the environment. They are species-specific, and work to suppress a pest’s population, not eliminate it. Biopesticides do not leave residues on crops--most degrade rapidly and are easily washed away with water. There are two types of biopesticides: microbial and biochemical. Pheromones are a type of biochemical pesticide. Naturally, insects use pheromones to attract mates. Man-made pheromones are used to disrupt insect mating by attracting males into traps. Microbial biopesticides are derived from naturally occurring or genetically altered microorganisms like bacteria, viruses, or fungus; and produce toxins or cause disease in the selected microbe. A widely used microbial biopesticide is Bacillus thuringiensis or "Bt". This is a common soil bacterium that is genetically altered to be toxic to several species of insects.
Aside from biopesticides, there are other categories of organic or "natural" pesticides that are commonly used by farmers. Many minerals such as boric acid or diatomaceous earth are used as pesticides. Another example is a Pacific Northwest remedy for decreasing the damage to gardens by slugs: sprinkling table salt around the perimeter of the garden, which deters slugs from entering. The salt dehydrates the slug, slowly killing it. However, salt can also change a soil’s pH and interfere with roots’ ability to absorb water and nutrients.
Pesticides can also be synthetically derived. Many are made from petroleum-based products. Examples of commonly used synthetic pesticides include thiabendazole, which is a fungicide used on potatoes, and fungicides commonly used to prevent apple diseases such as dithane, manzate and polyram.
<H2> Do Pesticides Threaten Human Health?
Years of studies show that chemicals, whether natural or synthetic, can linger on food, and affect immune system function in those whose systems are already compromised and may even cause cancer and birth defects (Rothacker 2001). The liver is responsible for detoxifying the chemicals that enter our bodies. If diseases or other toxins, such as alcohol, already stress it, then the liver isn’t as effective at removing pesticide residues. Many pesticides are fat-soluble and can be deposited in body tissues. Others target nervous system and endocrine system cells. Originally intended for other organisms, these pesticides have the potential to cause problems in humans.
Children may be more susceptible to pesticide residues as they consume more food and water per unit of body weight than adults and may have a limited ability to detoxify these substances. Because of the potential risks from chemicals to a developing child; pregnant and nursing women should always consider peeling fruit and vegetable rinds to decrease their exposure to residues. This is also a sensible precaution when preparing fruit or vegetables for small children, though removing the rinds may also reduce the nutritional content of the food (Heaton 2003).
Any pesticide, naturally or synthetically derived, can pose an unnecessary risk to both the environment and the consumer through soil and water contamination. All are potential toxins. Pesticides are a necessary component of agricultural practice. It is in the consumer’s best interest to be aware of pesticide use and carefully clean all produce.
<H2> Government Regulations Control the Use of Pesticides
The Environmental Protection Agency (EPA) is the government agency responsible for regulating the sale, distribution, and use of all pesticides in the United States. The EPA also sets a tolerance level, which is the maximum residue level of a pesticide permitted in or on food or feed grown in the United States or imported into the United States from other countries (EPA 2003). The EPA is also responsible for overseeing the labeling, packaging, and disposal of pesticides. Pesticide tolerances and exemptions are enforced by the U.S. Food and Drug Administration (for most foods), the U.S. Department of Agriculture (for meat, poultry, and some egg products), and the individual states. The EPA reviews every registered pesticide on a fifteen-year cycle (EPA 2003).
Once the EPA has certified a pesticide, states can set their own regulations for its use. Regulation of pesticide use varies from state to state, but all states require the collection of information such as how much and where pesticides have been applied. Canadian regulation of pesticides closely resembles American laws with provinces and territories given free range to limit pesticide use.
Synthesizing a new pesticide and proving its safety so it can be registered with the EPA can take fifteen to twenty years and an investment of millions of dollars. Before a pesticide can be accepted by the EPA for use, it must be determined that it performs its intended function with minimal impact to the environment. Due to the cost of registering a pesticide with the EPA, only products that have a large potential market are produced.
<H2> Are Organic Foods More Healthful?
The term organic is commonly used to describe foods that are grown without the use of synthetic pesticides. The thought of organic food used to conjure up images of hippies and bean sprouts. Now organic food has a reputation of being healthier for both humans and the environment and has become part of the mainstream food supply. Organic food sales in the United States have more than quadrupled in the past two decades, with sales estimated to reach $3.6 billion in 2003 (Kortbech-Olesen 2002). Many small organic companies have been acquired by large corporations, resulting in many processed and junk foods carrying an organic label.
<Figure 14.7 Insert photo of organic cheetos here>
The National Organic Program (NOP) of the USDA came into law in October of 2002. The organic industry itself had asked for national standards on organic labeling, as different U.S. states had different requirements for organic food labels, and some had no rules at all. The European Union enforced a common standard for organic plant produce in 1991. Without a national standard, it was feared that European countries might seek to exclude U.S. organic exports.
The new Organic Standards established uniform definitions for all organic products. Any label or product claiming to be organic must comply with the following definitions:
<Insert Figure 14.9 Organic Food Labels>
The USDA regulates organic farming standards and farms must be certified as organic by a government-approved certifier who inspects the farm and verifies that the farmer is following all USDA organic standards. Companies that handle or process organic food before it arrives at your local supermarket or restaurant must be certified too (Aiyana 2002). Organic farming methods are strict and require farmers to find natural alternatives to many common problems such as weeds and insects. Contrary to common belief, organic farmers can use pesticides as a final option for pest control when all other methods have failed or are known to be ineffective, but are restricted to a limited number that have been approved for use based on their origin, environmental impact and potential to persist as residues (Heaton 2003). Organic farmers emphasize the use of renewable resources and the conservation of soil and water to enhance environmental and nutritional quality. Once a crop is harvested, a winter crop (usually of a legume origin) is planted to help fix nitrogen in the soil and decrease erosion, which also lessens the need for fertilizers.
Organic meat, poultry, eggs, and dairy products come from animals fed only organic feed, and if ill are removed from the others until well again. None of these animals are given growth hormones to increase their size or ability to produce milk (Growth hormones will be discussed in greater depth later in this chapter). Irradiation is also prohibited in organic production
Recent studies at the University of California, Davis and other institutions have indicating that organic foods were 2 ½ times more nutritious than their non-organic counterparts, and that organic plants were lower in the toxic metals (ACS 2003). For example, organic plants are generally 29% lower in lead, 25% lower in mercury, and 40% lower in land aluminum than plants not grown organically (Spectrum 1995). On average, vitamin C content in many organically grown crops is found in higher concentrations than similar non-organically grown crops. Differences range from an increase of 6 to 100 % depending on the type of plant (potatoes versus carrots) (Heaton 2003). Other studies have shown higher values of antioxidants as well as vitamins A & B1 in organically grown produce, compared to conventionally grown food (ACS 2003). Higher mineral content has also been found in organically grown crops.
<Insert Highlight: labels on loose fruits and vegetables and what they mean>
<H1> Why Are Growth Hormones Added to Foods, and Are They Harmful?
Introduced in the United States food supply in 1994, Recombinant Bovine Growth Hormone (rBGH), also known as Recombinant Bovine Somatotropin (rBST) is a genetically engineered growth hormone extracted from cows' pituitary glands that increases milk output by as much as 20 to 30%. This hormone is injected into a third of U.S. dairy cows, whose milk and milk products are shipped throughout the country. . Currently, there are no labeling requirements for products containing rBGH.
Although the FDA has allowed the use of rBGH in the United States, Canada and the European Union have banned its use due to long range studies showing that rats who were orally administered rBGH over a ninety day period produced antibodies to the hormone and had weakened immune systems (Lyman 2001). Another protein, IGF-1, which is an insulin-like growth factor, is also found in higher amounts in milk of cows receiving rBGH. This protein can easily pass into the bloodstream of humans who drink milk from cows who receive IGF-1. Studies have shown an elevated level of IGF-1 in humans may increase breast and prostate cancer risk. Other studies have linked it to higher incidence of diabetes in humans (OCA 1998).
While the risks of rBGH to humans are still being studied, dairy cows
subject to this chemical have an increased tendency to mastitis (udder
swelling), which requires medical treatment, and administering antibiotics.
These antibiotics commonly find their way into the milk supply and into
the consumer, possibly adding to antibiotic resistant strains of bacteria.
References and Web-Links
Aiyana, J What Consumers Should Know about the New USDA Organic Labeling Standard. The Pulse of Oriental Medicine. November 2002
Aseptic Packaging Council. http://www.aspectic.org/main.shtml Accessed 11/06/03
A Study by the Committee on Chemistry and Public Affairs, 1980 Chemistry and the Food System American Chemical Society
Associated Press. PA hepatitis cases rise past 500. MSNBC news. wysowug://5http://www.msnbc.com/news/993541.asp?Osi=&cpI=I. Accessed 11/27/03
Blaylock. 1996. Excitoxins: The Taste That Kills Health Press
Centers for Disease Control and Prevention (CDC). Diagnosis and Management of Foodborne Illness: A Primer for Physicians. January 2001.
Centers for Disease Control and Prevention (CDC). wysiwyg://77http://www.cdc.gov.mmwr/preview/mmwrhtml/rr5002a1.htm. accessed 11/15/03
Centers for Disease Control and Prevention (CDC) Foodborne Illness Disease Information
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Table 14-1 Common Bacterial Causes of Foodborne Illness
|Bacteria||Incubation Period||Duration||Symptoms||Foods Most Commonly Affected||Usual Source of
|Steps for Prevention|
(over 2300 types)
|12-24 hours||4-7 days||Diarrhea
|Raw or undercooked eggs
Undercooked poultry & meat
Raw milk & dairy products
Fruits and vegetables
|Intestinal tract & feces of poultry
Salmonella enteritidis in raw shell eggs
Avoid cross contamination
Use sanitary practice
(0157:H7 and other strains that can cause human illness)
|2-4 days||5-10 days||Diarrhea [may be bloody]
Can lead to kidney and blood
Raw or rare ground beef, sausages
Un-pasteurized apple juice or cider
Uncooked fruits and vegetables
|Intestinal tracts of cattle
|Thoroughly cook meat
Avoid cross contamination
|1-7 days||7-10 days||Fever
Headache & muscle pain followed by diarrhea (sometimes bloody)
|Raw & undercooked meat, poultry or shellfish
|Intestinal tracts of animals & birds
Untreated water & sewage sludge
|Only drink pasteurized milk
Cook foods properly
Avoid cross contamination
|Clostridium botulinum||12-36 hours||1-8 days||Nausea
Muscle paralysis [droopy eyelids]
Difficulty speaking & swallowing
|Improperly canned or vacuum-packed food
Garlic in oil
|Widely distributed in nature
Soil, water, on plants & intestinal tracts of animals & fish.
Grows only in little or no oxygen
|Properly can foods following recommended procedures
Cook foods properly
Children under 16 months should not consume raw honey
|Staphylococcus||1-6 hours||2-3 days||Severe nausea & vomiting, abdominal cramps and diarrhea||Custard or cream filled baked goods
Mayonnaise based salads & sandwiches
Noses and throats
Use sanitary practices
(over 30 types)
|12-50 hours||2 days -2 weeks||Bloody & mucus containing diarrhea
Abdominal cramps, chills & vomiting
Milk and dairy products
|Human intestinal tract
Rarely found in other animals
|Use sanitary practices|
Source: Iowa State University Extension Food Safety Project (2002),
FDA and CDC (2003)
Table 14.2 A Guide to Thawing Poultry
|Method Needed||Size of Poultry||Approximate Length of Time|
|Refrigerator||1 to 3 pounds, small chickens, pieces
3 to 6 pounds, large chickens, ducks, small turkeys
6 to 12 pounds, large turkeys
12 to 16 pounds, whole turkey
16 to 20 pounds, whole turkey
3 to 4 days
4 to 5 days
|1 to 3 pounds, small chickens, pieces
3 to 6 pounds, large chickens, ducks, small turkeys
|8 – 15 minutes*
(standing time 10 minutes)
[Cindy, what does "standing" time mean?]
(standing time 20 minutes)
*Approximate, read microwave’s instructions
Note: Turkeys purchased stuffed and frozen with the USDA or state mark of inspection on the packaging are safe because they have been processed under controlled conditions. These turkeys should not be thawed before cooking. Follow package directions for handling.
Sources: Lacey (1994), USDA (2000)
Table 14.3 Common Preservatives Found in Food
|Preservative||Foods Found In|
|Alpha –Tocopheral (Vitamin E)||Vegetable Oils|
|Ascorbic Acid (Vitamin C)||Breakfast cereal, cured meat, fruit drinks|
|Calcium Proprionate / Sodium Proprionate||Bread, cakes, pies, rolls|
|BHT||Breakfast cereal, chewing gum, oil, potato chips|
|BHA||Breakfast coral packaging, chewing gum, oil, potato chips|
|EDTA||Canned shellfish, margarine, mayonnaise, processed fruits and vegetables, salad dressings, sandwich spreads, soft drinks|
|Propyl Gallate||Chewing gum, chicken soup base, vegetable oil, meat products, potato sticks|
|Sorbic Acid / Potassium Sorbate||Cake, cheese, dried fruit, jelly syrup wine|
|Sodium Nitrate / Sodium Nitrite||Bacon, corned beef, ham, luncheon meta, hot dogs, smoked fish|
|Sodium Benzoate||Carbonated drinks, fruit juice, pickles, preserves|
|Sodium Chloride (salt)||Most processed foods|
|Sulfites (Sodium Bisulfite, Sulfur Dioxide)||Dried fruit, processed potatoes, wine|
Table 14.4 Government Agencies
|Name of Agency||Year Established||Role in Food Regulations||Web site|
|United States Department of Agriculture (USDA)||1785||Oversees safety of meat, poultry, and eggs sold across state lines. Also regulates which drugs can be used to treat sick cattle and poultry.||www.usda.gov|
|Centers for Disease Control (CDC)||1946||Works with public health officials to promote and educate health and safety. Able to track information needed in identifying foodborne illness outbreaks.||www.cdc.gov|
|Environmental Protection Agency (EPA)||1970||Regulates use of pesticides and which crops they can be applied to. Establishes standards for water quality.||www.epa.gov|
|Food & Drug Administration
|1862||Regulates food standards of all food products (except meat, poultry and eggs) and bottled water. Regulates food labeling and enforces pesticide use as established by EPA.||www.fda.gov|
Box 14.1 Highlight: How Typhoid Mary Earned Her Place in History
"Typhoid Mary" is a name commonly given to someone who has a contagious disease, but not many people know much about the real Typhoid Mary. The real Typhoid Mary was an Irish immigrant Mary Mallon. In 1868, Mallon came to the United States and found work as a cook. She first came into the public eye after working for the Warren family at their summer home on Oyster Bay, Long Island. Soon after settling in for a summer vacation, one of the children became ill with typhoid fever, followed by her mother, a sister and three of the hired help.
Typhoid fever’s symptoms include a high fever (104O f) and continuous headaches, followed by diarrhea. It is caused by Salmonella typhi, and is passed through food and water contaminated by an infected person’s feces. An investigation into the Warren family’s outbreaks caused the investigator to stumble across Mary Mallon’s employment history, which revealed that she had worked at seven previous jobs in which twenty-two people had contracted typhoid fever, with one death, after Mary began cooking for them (Leavitt, 1996). When first approached as a suspect, Mary grew defensive, and refused to submit blood and fecal samples, which are necessary to confirm infection. The persistent health investigator returned to Mary’s place of employment with additional New York City Health Department personnel, police and an ambulance. Mary was apprehended after a struggle and taken to a local hospital where it was confirmed that she was indeed a carrier. But she had no symptoms; and so she became the US’s first ‘healthy carrier’, a designation she refused to believe. A healthy carrier is someone who seems healthy but carries a contagious form of a disease that can infect others. Mary was then sent to North Brother Island, part of the Riverside’s Hospital’s facilities, in the East River to live in isolation. Mary believed she was unfairly persecuted sued the health department. The judgment was found in favor of the health department, and Mary stayed on North Brother Island for another year, until a new health commissioner decided to release Mary on the condition that she never work as a cook again. Unfortunately, no one ever explained to Mary how she could be a ‘healthy carrier’, as some people can have a weak case of typhoid fever that resembles the common flu, and never know they were infected.
Mary, using the pseudonym, Mrs. Brown eventually went back to being a cook, and five years after her release from North Brother Island, caused another outbreak of typhoid fever at the Sloan Maternity Hospital in Manhattan, twenty-five people became ill, two of which died. When it was discovered that Mrs. Brown was really Mary Mallon, she was immediately sent back to confinement where she lived the remainder of her life. In all, it is believed that Typhoid Mary was the cause of 53 outbreaks including the 1903 Ithaca, NY epidemic in which 1400 people were infected, including 3 deaths. (Cunningham, 2002)
Highlight box 2
What do the codes mean on the loose fruits and vegetables you buy?
4 digits: conventionally grown
5 digits: starting with 8 means genetically modified
5 digits: starting with a 9 means organically grown
Nutrition Debate Box
Genetically Modified Organisms: A Blessing or a Curse?
Current advances in biotechnology have opened the door to one of the most controversial topics in food science, genetically modified organisms (GMO). GMOs are organisms that are created through genetic engineering. Genetically Engineered (GE) is the standard U.S. term for a process in which foreign genes are spliced into a non-related species, creating an entirely new organism. Genetically Modified (GM) is the same as GE, but is more widely used in Europe, as it translates easily among the different languages. Bio-tech foods, gene foods, bioengineered food, gene-altered foods, and transgenic foods are all terms used to describe foods that have been created through genetic engineering. The new 11th edition of the Merriam-Webster Collegiate Dictionary added the word "Frankenfood" as another term to describe genetically engineered food.
Any plant, animal or living organism (such as bacteria or yeast) that has had its DNA altered in a laboratory to enhance or change certain characteristics falls is considered genetically engineered. For example, Bacillus thuringiensis is a genetically engineered bacterium that is used as a pesticide. Research labs at UC Berkeley and Stanford University led the process of genetic engineering in the early 1970s. Developing GMOs is a lengthy, tedious, and costly process; requiring years of research and testing. After carefully selecting cultivated cells, genes are removed and scientists are able to identify individual genes that code for specific functions. Using bacteria to transfer these genes, scientists incorporated them into new cells where the introduced genes trigger chosen functions. By using bacteria as the selected medium, DNA can be easily and efficiently produced and incorporated into any cell. Several important medical therapeutics have been developed using this process including human insulin, human growth factor, and factor VIII (a protein needed for blood clotting in hemophiliacs).
Genetically engineered plants and animals may have the potential to solve many food production problems encountered worldwide by improving nutrient content, increasing yield, decreasing the need to for pesticides, and allowing plants to grow in inhospitable soils. Animals, in addition to plants, have also been genetically modified to grow quicker and bigger. In 1994, the Flavr Savr tomato became the first commercially sold GMO (Figure 14.X). add a photo of the Flovr Savr tomato hereThe process involved in developing this tomato involved identifying the gene that codes for an enzyme called polygalacturonace, which causes ripening in the tomato. This gene was removed, and inserted back in reverse orientation. As a result, polygalacturonase was not synthesized, and ripening slowed dramatically—making the tomato appear "fresh" longer, and enabling it to maintain a longer shelf life (McHughen 2000). Since 1994, hundreds of plants and animals have been genetically modified and incorporated into our current food market. In the United States soy, corn, canola and cotton crops make up nearly all the genetically modified crop acreage (Margulis 2003). In 2000, approximately 54% of all soybeans and 25% of all the corn grown in the United States were GMOs (Whitman 2000).
Many proponents of genetic modification argue that genetic engineering is an extension of plant and animal breeding methods, producing a superior organism by only transferring the desired traits. Indeed, in traditional farming practices, plants have been selected for desired traits such as higher yield, better taste, size, and color by saving seeds. Sometimes one plant is crossed with another plant in a process call called hybridization. Hybridization is when a plant or animal is paired with another of a different but similar species—such as tangelos, which are a hybrid of grapefruit and tangerines, or nectarines, which are modified peaches.
Many animals have been targeted by genetic engineering leading to the development of cattle, sheep, pigs and poultry that grow quicker, with a higher disease resistance and lower fat levels. Fish, such as salmon, have also been genetically modified. Transgenic salmon are significantly larger than their wild relatives, producing a higher yield of meat. They are also manipulated for other traits including disease resistance.
Opponents to genetic engineering argue that hybridization is a safer and a more natural way of manipulating plants and animals. Their concerns regarding GMOs include environmental hazards, human health risks, and economic concerns. Gene transfer to non-target species is a concern, especially if plants that are engineered for herbicide tolerance are crossbred with non-altered plants. One result could be a "super weed;" a plant tolerant to herbicides, thereby requiring that newer and stronger chemicals be produced.
The risk of allergens being introduced or created by GMOs is another legitimate concern. Introducing a gene into a plant may create a new allergen or cause an allergic reaction in a susceptible individual (Whitman 2000). In the United States, legislation was passed in 1992 that requires all new GMOs to be tested and labeled for allergy sensitivity if the DNA introduced is from any food containing a common allergen. It is estimated that it will take several generations before the full impact of genetically modified organisms will be known.
Genetically modified organisms are welcomed in some countries and outlawed in others. In the United States, many processed foods already contain GMOs, and do not require labeling to indicate their presence. The regulation of GMOs in the United States is shared by several governmental agencies including the National Institutes of Health (NIH), USDA, FDA and EPA. Many U.S. consumer groups are pressuring the government to require labeling for all foods containing GMOs.
There are many potential benefits to GMOs, but there are also many potential
risks to their development and use. Only time will tell if Genetically
Modified Organisms are a blessing or a curse.