Supplemental Lecture Ch 13NUTR280Spring 2020 PDF

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Spring 2020 NUTR 280 (01 & 02): Supplemental Lecture - How Safe is Our Food Supply? (Ch. 13) The following is an outline of some of the key points from the readings on “Pathogens in Food”, “Agricultural & Industrial Chemicals in Food”, & “Technology for Keeping Food Safe”. NOTE: Additional &/or updated content will appear in “RED”. Reminder: “FYI” is “for your information” only & will not be potential test questions for Exam #1. I.

Pathogens in Food (pp. 410-417) ● Food-borne illness – an illness caused by consumption of contaminated food. ● Pathogen – a biological agent that causes disease. ● Food-borne infection – any food-borne illness caused by pathogens that multiply in the human body. ● Food-borne intoxication – any food-borne illness caused by consuming a food that contains toxins produced by pathogens. ● Symptoms of a typical case of a food-borne illness are flu-like, i.e. abdominal pain, nausea, diarrhea, and vomiting. Some food-borne illnesses cause a fever as well as more severe symptoms such as kidney failure, arthritis, paralysis, miscarriage, and even death. The time in which it takes for the symptoms to manifest (“onset”) and the “duration” of the illness varies. ● FYI: CDC: “Estimates of Foodborne Illnesses in the United States – Burden of Foodborne Illness: Findings (https://www.cdc.gov/foodborneburden/2011-foodborne-estimates.html) (Accessed 1/26/20) o “CDC estimates that each year roughly 1 in 6 Americans (or 48 million people) gets sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases.” o Look at the three tables regarding the pathogens causing the most food-borne illnesses, hospitalizations, and deaths each year. A. Bacteria 1. Salmonella is the most common cause of bacterial food-borne illness. FYI: “CDC estimates Salmonella bacteria cause about 1.35 million infections, 26,500 hospitalizations, and 420 deaths in the United States every year. Food is the source for about 1 million of these illnesses.” (https://www.cdc.gov/salmonella/index.html) (Accessed 1/26/20) FYI: CDC (published 1/02/20) – “Outbreak of Salmonella Infections Linked to Cut Fruit” (https://www.cdc.gov/salmonella/javiana-12-19/index.html) (Accessed 1/26/20) a) Found most in poultry and eggs. Yet, it has been found in a variety of foods ranging from peanut butter, ground meat, fruits, and vegetables to processed foods such as frozen pot pies. “You can contract salmonellosis by consuming raw and undercooked eggs, undercooked poultry and meat, contaminated raw fruits and vegetables (such as sprouts and melons), as well as raw milk and other dairy products that are made with unpasteurized milk. It also can be transmitted through contact with infected animals or infected food handlers who have not washed their hands after using the bathroom.” (http://www.eatright.org/resource/homefoodsafety/safety-tips/food-poisoning/mostcommon-foodborne-pathogens) (Accessed 1/26/20) b) Prevention: Practice safe food handling/storage & thoroughly cook foods. It is destroyed by heat.

2. FYI: Campylobacter is the leading cause of acute bacterial diarrhea in the United States. FYI: “People can get Campylobacter infection by eating raw or undercooked poultry or eating something that touched it. They can also get it from eating other foods, including seafood, meat, and produce, by contact with animals, and by drinking untreated water.” (https://www.cdc.gov/campylobacter/) (Accessed 1/26/20) 3. FYI: Clostridium perfringens – often called the cafeteria germ; storage of food is often in large containers creating a low oxygen environment that allows them to thrive & grow. Difficult to kill because they form heat-resistant spores (a bacterial stage of life; remain dormant until conditions for growth become favorable). 4. Escherichia coli - commonly called E. coli. a) Found naturally in the GI tracts of humans and animals. b) It comes into contact with food through fecal contamination of water or unsanitary handling of food. There are different strains of E. coli. c) Figure 13.3: The strain that can contaminate beef is of particular concern with regard to ground beef. The E. coli found on the outside of the meat can be quickly killed during cooking. However, because the E. coli is mixed throughout the beef during grinding, it is extremely important to thoroughly cook the ground beef. An illness symptom characteristic of this strain is “bloody” diarrhea. Severe cases of such could result in kidney failure. (FYI: The strain is E. coli O157:H7 – produces a toxin.) d) E. coli (and other bacteria) can also contaminate fruits and vegetables. Thoroughly washing fruits and vegetables can reduce the number of this bacterium found on their surfaces but it does not make contaminated produce risk free. FYI: CDC (published 6/19/19): “Outbreak of E. coli Infections Linked to Ground Beef - Final Update” (https://www.cdc.gov/ecoli/2019/o103-04-19/index.html) (Accessed 1/26/20) Food Safety Alert – “This outbreak appears to be over. Ill people in this outbreak ate ground beef from many sources. No single supplier, distributor, or brand of ground beef was identified. Consumers and restaurants should always handle and cook ground beef safely to avoid foodborne illness.” 5. FYI – Listeria monocytogenes can grow at refrigerator temperatures. It can infect ready-toeat foods such as hot dogs. Hence, never eat a “raw” hotdog. Cook it thoroughly. Also, unpasteurized milk is a common source of Listeria; yet, the process of pasteurization heats the milk to a high enough temperature to kill it. FYI: “Eating food contaminated with Listeria monocytogenes bacteria causes listeriosis — a serious infection that primarily affects individuals who are at a high risk for food poisoning: older adults, pregnant women, young children and people with weakened immune systems. Listeria can grow at refrigerator temperatures where most other bacteria cannot grow.” “Prevention: Cook all foods to proper temperatures and reheat pre-cooked foods to 165°F; wash raw fruit and vegetables before peeling, cutting or eating; separate uncooked meats and poultry from foods that are already cooked or ready-to-eat; wash hands thoroughly; store foods safely; maintain a clean refrigerator and kitchen area; and wash reusable grocery totes regularly.”(http://www.eatright.org/resource/homefoodsafety/safety-tips/food-poisoning/mostcommon-foodborne-pathogens) (Accessed 1/26/20) 2

FYI: “Listeria is a harmful germ that can hide in many foods. Outbreaks of Listeria infections in the 1990s were primarily linked to deli meats and hot dogs. Now, Listeria outbreaks are often linked to dairy products and produce. Investigators have traced recent outbreaks to soft cheeses, celery, sprouts, cantaloupe, and ice cream.” “Soft cheeses made with unpasteurized milk are estimated to be 50 to 160 times more likely to cause Listeria infection than when they are made with pasteurized milk. Although pasteurization of milk kills Listeria, products made from pasteurized milk can still become contaminated it they are produce in facilities with unsanitary conditions.” Raw sprouts “need warm and humid conditions to sprout and grow. These conditions are also ideal for the growth of bacteria, including Listeria, Salmonella, and E.coli.” (https://www.cdc.gov/listeria/prevention.html) (Accessed 1/26/20) FYI: CDC (posted 12/27/19) – “Outbreak of Listeria Infections Linked to Hard-boiled Eggs” (https://www.cdc.gov/listeria/outbreaks/eggs-12-19/index.html) (Accessed 1/26/20) “CDC, public health and regulatory officials in several states, and the U.S. Food and Drug Administration (FDA) are investigating a multistate outbreak of Listeria monocytogenes infections linked to hard-boiled eggs produced by Almark Foods.” 6. FYI: Staphylococcus aureus is a common cause of bacterial food-borne intoxication. It resides in the nasal passages of humans and can be transferred to food through coughing or sneezing. Vomiting can occur soon after ingestion of the contaminated food. 7. Deadliest of all bacterial food toxins is produced by Clostridium botulinum. a) Produce heat-resistant spores, which can be found in soil, water, & intestinal tracts of animals. The toxin is produced when the spores grow and develop. When consumed, the toxin blocks nerve function that leads to respiratory failure due to paralysis. b) If untreated, botulism can be fatal; yet, modern medicine has reduced mortality rates. c) This bacterium grows in low-oxygen & low-acid conditions. d) Improperly canned food and casserole-like foods & stews/soups held in large containers with limited oxygen exposure provide an environment favorable for botulism spores to grow. e) Note: Infants under the age of one should never be fed honey due to the lack of intestinal microflora. The honey can be contaminated with botulism spores. B. Viruses Unlike bacteria, the viruses that cause human diseases cannot grow and reproduce in foods. They reproduce inside human cells & make us sick by turning our cells into virus-producing factories. Norovirus, the leading cause of food-borne illness in the United States, are a group of viruses that cause gastroenteritis (“stomach flu”), which is contracted by ingesting fecal contaminated food or water or by touching a contaminated surface and then putting your fingers to your mouth. Cooking will destroy the noroviruses. “Norovirus is the leading cause of illness and outbreaks from contaminated food in the United States. Most of these outbreaks occur in the food service settings like restaurants. Infected food workers are frequently the source of the outbreaks, often by touching ready-to-eat foods, such as raw fruits and vegetables, with their bare hands before serving them. However, any food served raw or handled after being cooked can get contaminated with norovirus.” (http://www.cdc.gov/norovirus/about/transmission.html) (Accessed 1/26/20) 3

FYI: CDC – Common Settings of Norovirus Outbreaks - “Healthcare Facilities”, “Restaurants and at Catered Events”, “Schools and Childcare Centers”, & “Cruise Ships” (https://www.cdc.gov/norovirus/trends-outbreaks/outbreaks.html) (Accessed 1/26/20) FYI: CDC – “Preventing Norovirus” (http://www.cdc.gov/norovirus/preventing-infection.html) (Accessed 1/26/20) C. FYI: Moldy Food – Mold is a type of fungus that can grow on foods such as bread, cheese, and fruit. Molds can produce toxins under favorable conditions. Cooking and freezing stop mold growth but do not destroy toxins that have already been produced. Therefore, discard any foods that are moldy or are in contact with moldy food and properly clean the area where it was stored. D. Preventing Microbial Food-Borne Illness (pp. 417-420) 1. Choose foods carefully when you are grocery shopping (FYI: Table 13.4 on p. 418) 2. Prevent cross-contamination – the transfer of contaminants from one food or object to another. Example of cross-contamination is when uncooked foods containing live microbes come into contact with foods that have already been cooked. Hence, foods that are going to be cooked should not be prepared on the same surfaces as foods that are eaten raw, never return cooked meat to the same dish that held the raw meat, and sauces used to marinade uncooked foods should never be used as sauces on cooked food. 3. Leftover foods should be refrigerated as soon as possible. Large portions of food should be divided and put into shallow containers before refrigeration. Most leftovers should be kept for only 2-3 days. 4. Proper refrigerator temperature = 40° F or below. Proper freezer temperature = 0° F or below. 5. Fresh and frozen foods should be refrigerated or frozen immediately. 6. Never thaw frozen foods on the counter at room temperature. 7. “FIGHT BAC! Keep Food Safe From Bacteria” educational campaign (Figure 13.9) (p. 419) a) Four steps to prevent food-borne illness: clean, separate, cook & chill. b) Leftovers and casseroles should be reheated or cooked to an internal temperature of 165° F or higher. This includes the microwaving of food as well. FYI: “Cook to the safe internal temperature” at http://www.fightbac.org/food-safetybasics/the-core-four-practices/ (Accessed 1/26/20) c) “Danger Zone” – temperatures in this zone, between 40° F & 140° F, allow rapid bacterial growth and production of bacterial toxins. Foods should only be allowed to remain in this temperature range for minimal amounts of time. e) Follow the “two-hour rule” for cooked foods – eat them or refrigerate them within two hours at a refrigerator temperature of 40° F or below. Note, if left out in a room or outdoors where the temperature is 90° F or above, food should be refrigerated or eaten within just one hour or discarded. 8. FYI: “Foodsafety.gov – Your Gateway to Food Safety Information” (Recalls & Alerts”, “Food Safety Charts”...) (https://www.foodsafety.gov/index.html) (Accessed 1/26/20) II.

Agricultural & Industrial Chemicals in Food (pp. 421-426) A. Pesticides: Risks and Benefits ● Pesticides are chemicals used to control insects, diseases, weeds, fungi, and other pests on crops and around animals. Benefits: prevent spoilage & extend shelf life (both help with keeping costs down as well), increase crop yields & increase the quality of the produce. Risks: Potential risks of pesticides to the consumer depend on size, age, and health of the person and on the type and amount consumed. Also, pesticides become contaminates as they 4

enter the soil and water supplies, subsequently entering the food chain. (Refer to Figure 13.11 – “Contamination throughout the food chain”) ● FYI: To decrease the risk of pesticide toxicity, tolerances are established. Tolerances are the maximum amounts of pesticide residues that may remain in or on a food. They are set at least 100 times lower than the highest dose that has no harmful effects in test animals. The FDA and USDA monitor pesticide residues in foods. (Refer to Figure 13.12 – Pesticide tolerances) ● Organic food production a) Organic foods – foods meeting strict USDA production regulations for “organic”, including prohibition of synthetic pesticides, herbicides, fertilizers, drugs, and preservatives and produced without genetic engineering or irradiation. They are produced using methods that minimize the use of synthetic pesticides and promote recycling of resources and conservation of soil and water to protect the environment. b) USDA Seal and Organic Food Label Claim – “100% Organic” stated with the seal must be made exclusively with 100% organic ingredients. “Organic” stated with the seal has to be made with at least 95% organic ingredients. c) FYI: Consuming a diet of organic foods measurably reduces pesticide exposure. However, they are not completely free of pesticides and other agricultural chemicals not approved for organic use. d) FYI: Are organic foods more “nutritious”? In terms of preventing nutrition-related diseases, most studies do not show that eating organic foods to be more beneficial. e) FYI: Do organic foods contain more nutrients? The research on such is ambivalent – some studies show that organic foods contain more nutrients than conventionally grown foods whereas others have shown no consistent differences. Conflicting evidence is not surprising since there are many variables to account for regarding the growing and distribution of food. f) FYI: Pollution is still possible with the growing and distribution of organic foods, i.e. runoff of manure into waterways and the long-distance shipping of organic foods. B. Choosing Wisely to Minimize Agricultural & Industrial Contaminants 1. Eat a variety of foods, thus avoiding excessive consumption of contaminants that may be present in any one food. 2. When possible, choose organic foods or locally grown produce* to reduce exposure to pesticide residues. (*Pesticides to prevent spoilage or extend shelf life during shipping are typically not used.) 3. Properly wash produce. 4. Trim fat from meat, poultry, and fish before cooking. Remove the fatty material and dark meat from fish. Pesticides and other toxins that are ingested by animals collect in the fat. 5. When possible, select saltwater varieties of fish caught offshore in unpolluted waters. 6. Smaller species of fish are safer because they are earlier in the food chain. Small fish within a species are safer because they are younger and have had less time to accumulate contaminants. III.

Technology for Keeping Food Safe (pp. 427-432) A. How Temperature Keeps Food Safe ● “Cooking foods is one of the oldest methods of ensuring that food is safe.” “Other preservation techniques that rely on high temperature to kill microbes include pasteurization, sterilization, and aseptic processing.” Aseptic processing is “the placement of sterilized food in a sterilized package using a sterile process” with an example being juice boxes. 5

● FYI: “The Dangers of Raw Milk: Unpasteurized Milk Can Pose a Serious Health Risk” http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm079516.htm (Accessed 1/26/20) B. How Irradiation Preserves and Protects Food Food irradiation – a process that exposes foods to radiation in order to kill contaminating organisms and retard the ripening and spoilage of fruits and vegetables. It is used relatively infrequently in the United States. FYI: “Food Irradiation: What You Need To Know - Irradiation does not make foods radioactive, compromise nutritional quality, or noticeably change the taste, texture, or appearance of food. In fact, any changes made by irradiation are so minimal that it is not easy to tell if a food has been irradiated.” (http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm261680.htm) (Accessed 1/26/20) C. Food Additives ● Direct food additive is a substance that is intentionally added to food and is regulated by the FDA. Indirect food additive is a substance that is expected to unintentionally enter food during manufacturing or from packaging. They are regulated by the FDA as well. Accidental contaminants, which enter food when it is handled or prepared incorrectly, are not regulated by the FDA. ● Food additives are used for the following reasons: make food safer; maintain palatability & wholesomeness; improve color, flavor, or texture; aid in processing; and enhance nutritional value. ● FYI: To use a new additive, the manufacturer must prove in a petition to the FDA that the additive will be effective for its intended purpose at the proposed level and that it is safe for its intended use. ● FYI: More than 600 chemicals defined as food additives were already in common use when legislation regulating food additives was passed. To accommodate substances that the FDA and UDSA had already determined to be safe, they were designated as prior-sanctioned substances and are exempt from regulation. A second category that is not subject to food additive regulation consists of substances generally recognizes as safe (GRAS) are a group of chemical additives that are considered safe, based on their long-standing presence in the food supply without harmful effects. ● FYI: A substance on the GRAS or prior-sanctioned list can be removed if emerging scientific evidence suggests they are unsafe. IV.

Biotechnology (pp. 432-446) ● Genetic engineering or genetic modification (GM) are a set of techniques used to manipulate DNA for the purpose of changing the characteristics of an organism or creating a new product. Genetically modified organism (GMO) is an organism whose genetic material has been altered using genetic engineering techniques. ● FYI: Applications of Biotechnology & Risks and Regulation of Biotechnology (pp. 434-436) ● FYI: “Consumer Info About Food from Genetically Engineered Plants” (http://www.fda.gov/Food/IngredientsPackagingLabeling/GEPlants/ucm461805.htm) (Accessed 1/26/20) ● FYI: “How FDA Regulates Food from Genetically Engineered Plants” (http://www.fda.gov/Food/IngredientsPackagingLabeling/GEPlants/ucm461831.htm) (Accessed 1/26/20)

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