Week 7

Chapter 3 - The Food Supply
( In the syllabus, this is Week 8)

In A Nut Shell:

	Bacteria and other microbes in food pose the greatest risk for food-borne illness. In the past, salt, sugar, smoke, fermentation, and drying were used to protect against food-borne illness. Today, careful cooking, pasteurization, and keeping hot foods hot and cold foods cold provide additional insurance.
	Major causes of food-borne illness are the bacteria Campylobacter jejuni, Salmonella, Shigella, Staphlococcus aureus, and Clostridium perfrigens. In addition, such bacteria as Clostridium botulinum, Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli have been found to cause illness.
	To protect against bacteria, cook susceptible foods thoroughly. In addition, cover cuts on the hands, do not sneeze or cough on foods, avoid contact between raw meat or poultry products and other food products, rapidly cool and thoroughly reheat leftovers, and use pasteurized dairy products.
	Cross contamination commonly causes food-borne illness. It occurs particularly when bacteria on raw animal products contact foods that can support bacterial growth. Because of the risk of cross-contamination, no perishable food should be kept at room temperature for more than 1 to 2 hours (depending on the environmental temperature), especially if it may have come in contact with raw animal products.
	Treatment for food-borne illness usually requires drinking lots of fluids, avoiding touching food while diarrhea is present, washing hands thoroughly, and getting bed rest. Botulism, hepatitis A infections, and trichinosis are types of food-borne illness that require prompt medical attention.
	Food additives are used primarily to extend shelf life by preventing microbial growth and the destruction of food components by oxygen, metals, and other substances. Food additives are classified as those intentionally added to foods and those that incidentally appear in foods. An intentional additive is limited to no more than one-one-hundredth of the greatest amount that causes no observed symptoms in animals. The Delaney Clause allows the FDA to ban the use of any intentional food additive under its jurisdiction that causes cancer.
	Antioxidants, such as BHA, BHT, vitamins E And C, and sulfites, prevent oxygen and enzyme destruction of food products. Emulsifiers suspend fat in water, improving the uniformity, smoothness, and body of foods such as ice cream. Common preservatives include sodium benzoate and ascorbic acid, which prevent spoilage of food from metal contamination.
	Toxic substances occur naturally in a wide variety of foods, such as green potatoes, raw fish, mushrooms, raw soybeans, and raw egg whites. Cooking foods limits their toxic effects in some cases; others are best to avoid, such as toxic mushrooms species and the green parts of potatoes.
	A variety of environmental contaminants can be found in foods. Because most of them are fat soluble, trimming fat from meats and discarding fat that is rendered during the cooking of meats, fish, and poultry are good steps to minimize exposure. In addition, it's helpful to know which foods pose a special risk, to wash fruits and vegetables thoroughly, and to discard the outer leaves of leafy vegetables.

The latest Dietary Guidelines for Americans, states the following regarding Food Safety:

	To avoid microbial foodborne illness: Clean hands, food contact surfaces, and fruits and vegetables. Meat and poultry should not be washed or rinsed. Separate raw, cooked, and ready-to-eat foods while shopping, preparing, or storing foods. Cook foods to a safe temperature to kill microorganisms. Chill (refrigerate) perishable food promptly and defrost foods properly. Avoid raw (unpasteurized) milk or any products made from unpasteurized milk, raw or partially cooked eggs or foods containing raw eggs, raw or undercooked meat and poultry, unpasteurized juices, and raw sprouts. Some examples of cases of food-borne illness:
	A previously health 5-month-old girl suddenly died at home from contact with a pet iguana infected with Salmonella. Unpasteurized juice products were recalled after 57 cases of Salmonella illness were reported in California and Colorado. Eight people became ill from Salmonella after consuming tiramisu, a dessert that contains raw eggs.
	Six persons were reported ill from a Shigella infection after eating chopped, uncooked parsley that was served on chicken sandwiches and in coleslaw. A cruise ship had to return to port when more than 600 people developed shigellosis and one person died.
	17 people in Florida die of Vibrio vulnificus infections after eating raw oysters.
	A teenage boy and his father experienced abdominal pain, vomiting, and diarrhea within 30 minutes of eating 4-day-old homemade pesto. The pesto had been reheated and left out a number of times during the 4-day period. It was apparently contaminated with Bacillus cereus. As a result the boy died of liver failure.
	In a recent period of 6 months, more than 45 million pounds of hot dogs, luncheon meats, and other ready-to-eat meat products were recalled due to contamination with potentially deadly Listeria bacteria. The food supply is monitored for safety by food manufacturers and regulatory agencies at the international, federal, state, and local levels. Consumers also play an important role in limiting the risks of developing food borne illness. Microbial food-borne illness can be caused by bacteria, viruses, molds, and parasites. Some bacteria cause food-borne infection because they are able to grow in the GI tract when ingested. Others produce toxins in food and cause food-borne intoxication when the toxin is ingested. Viruses ingested in contaminated food cause food-borne illness because they can multiply inside human cells. Molds that grow on foods cause illness because they produce toxins that are harmful when consumed. Parasites that contaminate water or food cause illness when they grow and reproduce inside the body. Food contamination presents a risk to older adults. Poor eyesight and reduced senses of smell and taste may make it harder to spot spoiled food or dirty utensils. Aging itself and an older person's reduced food intake may lead to a weakened immune system. Older adults face further risks because their stomachs may not produce enough hydrochloric acid, which destroys harmful bacteria, and because of poor blood circulation, which can prevent antibodies from reaching sites of infection. The risk of food-borne illness can be reduced by proper food selection, preparation, and storage. Consumers should choose the freshest meats and produce, select frozen foods that have been kept at constant temperatures, and avoid packages with broken seals or contents that appear spoiled. Once in the home, foods should be cooked thoroughly and leftovers stored properly. Kitchen surfaces, hands, and cooking utensils should be cleaned between preparation steps. When traveling to developing countries, it is recommended that you "boil it, peel it, or don't eat it." Ironically, up to 70% of our fruits and vegetables during certain seasons comes from these countries. In other words, you do not have to travel to get traveler's diarrhea. We should carefully inspect and wash produce, as we would in a foreign country. To reduce the risk of bacteria surviving during microwave cooking:
	Cover food with glass or ceramic when possible to decrease evaporation and heat the surface
	stir and rotate food at least once or twice for even cooking. Then, allow micro-waved food to stand, covered, after cooking is completed to help cook the exterior and equalize the temperature throughout.
	Use an oven temperature probe or a meat thermometer to check that food is done. Insert it at several spots.
	If thawing meat in the microwave, use the oven's defrost setting. Ice crystals in frozen foods are not heated well by the microwave oven and can create cold spots, which later cook more slowly. Proposed Egg Safety Warning label: Safe Handling Instructions: Eggs may contain harmful bacteria known to cause serious illness, especially in children, the elderly, and persons with weakened immune systems. For your protection: Keep eggs refrigerated; cook eggs until yolks are firm; and cook foods containing eggs thoroughly. Contaminants, such as pesticides applied to crops and industrial wastes that leach into water, may find their way into the food supply. Industrial pollutants such as dioxins, toxic metals, and radioactive substances contaminate the environment and can make their way into the food supply. As these contaminants move up the food chain, their concentrations increase. Some contaminants are formed in food during cooking. To decrease the potential risk of chemical contaminants, safer pesticides are being developed and farmers are reducing the amounts applied by using integrated pest management and organic methods. Consumers can reduce the amounts of chemical contaminants in food by careful selection and handling of foods. Food additives include all substances that can reasonably be expected to find their way into food during processing. These include direct food additives, which are intentionally added to preserve or enhance the appeal of food, and indirect food additives, which are substances known to find their way into food during production, processing, cooking, and packaging. Direct and indirect food additives are regulated by the FDA. Accidental contaminants that enter food when it is used or prepared incorrectly are not regulated by the FDA.

Study Guide

Questions:
1. To what extent does food poisoning present a real hazard to consumers eating U.S.
     foods? How often does it occur?

2. Distinguish between the two types of food-borne illnesses and provide an example of
     each. Describe measures that help prevent food-borne illnesses.

3. What special precautions apply to meats? To seafood?

4. What is meant by a "persistent" contaminant of foods? Describe how contaminants
     get into foods and build up in the food chain.

5. What dangers do natural toxicants present?

6. How do pesticides become a hazard to the food supply, and how are they monitored?
     In what ways can people reduce the concentrations of pesticides in and on foods
     that they prepare?

7. What is the difference between a GRAS substance and a regulated food additive? Give
     examples of each. Name and describe the different classes of additives.

8. Define the following terms: food-borne illness, food-borne infection, food intoxication,
     and food poisoning. What populations are most vulnerable to food-borne illnesses?
     Name the two most common food-borne infectious agents, the foods that house
     them, and their symptoms. What is the most common food toxin?

9. What percent of reported food-borne illnesses occur in commercial settings? Explain
     the purpose of the Hazard Analysis Critical Control Points (HACCP) system. What 4
     steps can be taken to prevent food-borne illnesses from arising in the kitchen? Why
     should meat be cooked thoroughly? How should meat and poultry be thawed? What is
     a general rule concerning a suspect food? What percent of people who travel to other
     countries contract travelers' diarrhea? Cite ways to avoid food-borne illness while
     traveling. What is irradiation, and what are the consumer concerns regarding the
     process?

10. Define the following terms: contaminant, methylmercury, and polybrominated
      biphenyl (PBB). What is the agency that regulates commercial fishing to help ensure
      safety standards are met?

11. What is solanine? Define the following terms: pesticide, herbicide, insecticide, and
     fungicide. What populations are at risk for pesticide hazards? How can consumers
     minimize risks associated with pesticide use?

12. What is the general function of additives in the food supply?

13. What are the sources of drinking water for the population? What is the source of
     surface water? How does surface water become contaminated? What is the source of
     groundwater? How does groundwater become contaminated?

14. How is bottled water classified by the FDA? What percent of bottled water comes
     from groundwater? What is the disinfectant used in bottled water?

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Becky Alejandre, Professor - Nutrition	Instructor's contact information Email: alejanb@arc.losrios.edu Phone: (916) 484-8145 FAX: (916) 484-8030	ARC Homepage	ARC Library
Office Location: Room #762 Health & Education Division (located between the tennis courts and the gym)		Office Hours: Mon. 8:00-10:00 a.m. Tues. 10:30-11:30 a.m. Wed. 10:30-11:30 a.m. (online) Thurs.10:30-11:30 a.m. Fri. 7:00-8:00 a.m. (online)

Becky Alejandre, Professor - Nutrition

Becky Alejandre,
Professor - Nutrition