Food Safety - Chapter 8

FOOD SAFETY HOW CAN FOOD MAKE US SICK? Foodborne illness is caused by consuming food that is contaminated by pathogens or toxins, and these harmful substances have reached their threshold effect. Food contamination can occur when food is grown or produced, during processing or storage, at retail f...

FOOD SAFETY HOW CAN FOOD MAKE US SICK? Foodborne illness is caused by consuming food that is contaminated by pathogens or toxins, and these harmful substances have reached their threshold effect. Food contamination can occur when food is grown or produced, during processing or storage, at retail facilities or at home. Cross-contamination IDENTIFYING POTENTIAL PROBLEMS AND TRACKING FOOD BORNE ILLNESS The National Food Safety Initiative established Hazard Analysis Critical Control Point (HACCP) A national computer network  (Establish records and documentation) (Establish procedures for verification) (Conduct a Hazard Analysis) (Establish the corrective action) (Determine the critical control points). (Establish a system to monitor and control of CCP) (Establish Critical limit(s) 4 KEEPING FOOD SAFE—THE ROLE OF FOOD MANUFACTURERS AND RETAILERS Manufacturers are responsible for Establishing and implementing a HAACP system Proper labeling their products Restaurants and other retail businesses are responsible for preventing contaminated food from reaching the consumers KEEPING FOOD SAFE—THE ROLE OF THE CONSUMER Actively involved in preventing foodborne illness Using HACCP at home Reporting harmful incidents  PATHOGENS IN FOOD Food pathogens include Bacteria, viruses, molds, parasites, and prions A foodborne infection: consuming food contaminated with pathogens that grow in the GI tract or other parts of the body. A foodborne intoxication: consuming food containing toxins produced by a pathogen. SPOREFORMING BACTERIA (PATHOGENS) Clostridium botulinum Proteolytic Nonproteolytic Clostridium perfringens Bacillus cereus NONSPOREFORMING BACTERIA
Campylobacter spp.
Pathogenic Escherichia coli (e.g., E. coli O157:H7)
Listeria monocytogenes
Salmonella spp. (e.g., S. typhimurium, S. enteriditis)
Shigella spp. (e.g., S. dysinteriae)
Pathogenic Staphylococcus aureus (e.g., coagulase positive S. aureus)
Vibrio spp. (e.g., V. cholerae, V. parahaemolyticus, V. vulnificus) vulnificus
Yersinia enterocolitica VIRUSES IN FOODS—NOROVIRUSES Include caliciviruses and Norwalk-like viruses Cause gastroenteritis, or “stomach flu” Spread primarily from one infected person to another, but can also be spread through contaminated food or cross-contamination Common sources include water, raw shellfish, and salads VIRUSES IN FOODS—HEPATITIS A Highly contagious viral disorder that causes inflammation of the liver, even permanent liver damage It can be contracted from eating contaminated food, or raw or undercooked, sewage- contaminated shellfish Cooking and good sanitation can prevent its spread MOLDS IN FOOD Molds produce toxins that can lead to food intoxication. Aflatoxin: a potent mutagen and carcinogen Ergot: a natural source of LSD Cooking and freezing do not destroy toxins. Moldy food should be discarded. PARASITES IN FOOD May be transmitted through consumption of contaminated food and water Common types of parasites Giardia lamblia: from contaminated water Crytosporidium parvum: also contaminated water Trichinella spiralis: in raw and undercooked pork Anisakis simplex: found in raw fish Thorough cooking can kill parasites. REDUCING THE RISK OF MICROBIAL FOODBORNE ILLNESS Proper handling of food is the key REDUCING THE RISK—STORE FOOD PROPERLY The goal is to keep food from setting at temperatures that promote bacterial growth OTHER STRATEGIES TO KEEP FOOD SAFE Store Food Properly Prevent cross-contamination Cook food thoroughly and refrigerate leftovers as soon as possible after serving Keep food safe away from home CHEMICAL CONTAMINANTS IN FOOD RISKS AND BENEFITS OF PESTICIDES Crops grown using pesticides generally produce higher yields and look more appealing. Residues of pesticides can enter food supply, although they are not considered a major concern by FDA. Regulating pesticides EPA regulates the use of pesticides and establishes tolerances FDA and USDA monitor pesticide levels in food  REDUCING PESTICIDE RISKS Genetic engineering aims to produce naturally pest- resistant crops. Integrated Pest Management (IPM) combines chemical and non-chemical methods and emphasizes the use of natural toxins and effective pesticide applications. ANTIBIOTICS IN FOOD Animals are given antibiotics to prevent disease and to promote growth. The FDA regulates which drug can be used The USDA monitors tissue samples for drug residues. Concerns of creating antibiotic-resistant “super bacteria”. HORMONES IN FOOD Hormones are used to increase weight gain in sheep and cattle, and increase milk production in dairy cows. Bovine somatotropin (bST) is of concern to some people. FDA concluded that no long-term effects had been observed in cows given bST. CONTAMINATION FROM INDUSTRIAL WASTES Polychlorinated biphenyls (PCBs) Carcinogenic Found in contaminated water and other environment Can accumulate in human adipose tissue A particular concern for pregnant and lactating women Other contaminants Chlordane, radioactive substances, toxic metals Large fish on the top of the food chain and shellfish contain high amounts of industrial contaminants. CHEMICAL HAZARDS – FOOD ADDITIVES Direct (allowable limits under Food Regulations) Preservatives (e.g., nitrite and sulfiting agents) Nutritional additives (e.g., niacin, vitamin A) Color additives (e.g., FD&C Yellow No. 5) FOOD ADDITIVES Intentially added to food Food additives can be used to: Maintain or enhance the sensory characteristics of food Facilitate food processing or food preparation Maintain, restore or improve the nutritional quality of foods Maintain food quality by preventing spoilage or disease of foods FOOD TECHNOLOGY FOOD SPOILAGE It occurs when the taste, texture, or nutritional value changes due to the presence of natural enzymes, bacteria or mold. Food spoilage is a serious financial problem, since world-wide about 40% of all food grown for humans is lost to some pest or microorganism, not to mention the money spent on pesticides and health hazards associated with pesticide contamination FOOD SPOILAGE Microorganism In addition to microorganisms that cause food-borne illnesses, there are a "host“ of bacteria and fungi that cause food spoilage Biochemical reaction Enzyme in fruit ripening
skin soften, undesirable color changes Pest Bird (grain), squirrel (fruits), rats (all kinds of foods), etc FOOD TECHNOLOGY Advances in food and agricultural technology
improved the safety and availability of foods. Includes techniques to Preserve food Allows food to be stored for long periods Ensure that food is available even if the local growing season is not ideal Develop new food products Adds nutrients lacking in the diet Creates disease-resistant high-yield crops FOOD TECHNOLOGY Preservation techniques relying on temperature Cooking, cooling, canning, pasteurization, sterilization, and aseptic processing ASEPTIC PROCESSING UHT: Ultra-high Temperature Processing (T>135oC, for 1- 2 seconds) Lose some of the nutrients Shelf life about 6-9 months at room temperature HTST: High temperature short time pasteurization (T=72oC for at least 15 s) Retain higher amount of nutrients Shelf life about 1 month at refrigerated temperature (4oC)  BY-PRODUCTS OF HEAT PROCESSING  3-Monochloropropane-1,2-diol (3-MCPDl) A carcinogenic contaminant in a wide range of foods and ingredients in high fat, low pH, high salt content, long storage life foods in toasted cereal products.  formed in foods by the reaction: chloride + lipids, trace amounts.  in foods and food ingredients at low levels as a result of processing, migration from packaging materials during storage, or in domestic cooking.  common in acid-hydrolized vegetable protein (HVP) when produced using hydrochloride acid. BY-PRODUCTS OF HEAT PROCESSING Polycyclic aromatic hydrocarbons (PAHs) Carcinogenic substances formed when fat drips onto the flame of a grill Grilled or charred meats are therefore high in PAHs. Acrylamide Substances cause cancer and reproductive problems in animals and as a neurotoxin in human Formed during high-temperature baking or frying particularly in carbohydrate-rich foods. The highest level s are found in french fries and snack chips FOOD TECHNOLOGY Food Irradiation (cold pasteurization) Using high dose of x-rays, gamma radiation, or high-energy electrons to kill microorganism and insects, and retard ripening and spoilage of fruits and vegetables Irradiated foods must be labeled. Does not make food radioactive. FOOD IRRADIATION It increases the safety and shelf life of foods and does not compromise or noticeably change food texture, taste, or appearance. Irradiation can benefit the environment by reducing the use of chemical to kill microbes and insects It can decrease the amounts of certain nutrients but losses are similar to those that occur with canning or cold storage It is treated as a food additive since irradiation produces unique compounds in irradiated foods. FOOD TECHNOLOGY Food additives—direct or indirect Purposes of food additives To prevent spoilage To improve nutrient content, color, texture, and flavor See “Off The Shelf” Table for commonly used additives. FOOD ADDITIVES CATEGORIES 1. Antimicrobial agents prevent spoilage by inhibiting the growth of microbes. Historically salt and sugar in concentration were the most common antimicrobial agents. Concentrated salt and sugar osmotically inhibit bacterial growth. Antimicrobial agents: Increase shelf life of food items Protect color and flavor of food Examples: Citric acid used in acidic foods Propionates used in breads Nitrates or nitrites used in cured meats Sorbates used in cheese, fruit products, syrups, beverages Sulfites are used in dried fruits and alcoholic beverages FOOD ADDITIVES CATEGORIES 2. Antioxidants, prevent oxidation of foods. Many antioxidants are added to the packaging materials rather than the food. Antioxidants include: BHA (Butylated hydroxyanisole) BHT (Butylated hydroxytoluene EDTA Tocopherols (Vitamin E) Vitamin C FOOD ADDITIVES CATEGORIES 3. Additives That Improve the Sensory Features of Foods A. Food Colorings are added to improve the appearance of food. In some cases, colors are added because we associate certain colors with certain flavors. We think green treats are either lime flavored or mint flavored. Butterscotch candy that was green would be "peculiar". We are more likely to eat a visually appealing food. FOOD ADDITIVES CATEGORIES 3. Additives That Improve the Sensory Features of Foods B. Flavor Enhancers are used to have food taste more like an expected taste or to mask a bland or distasteful substance. Sugar, salt and MSG are common flavor enhancers. Most herbs and spices are used for flavor as well as a host of fruit flavors. FOOD ADDITIVES CATEGORIES 4. Additives That Facilitate Food Processing or Preparation A. Emulsifiers are substances that keep food ingredients from separating during processing and in storage. These additives are commonly added to ice cream, salad dressings, margarines, peanut butter and almost anything in which fat and water- soluble ingredients might separate. Examples of emulsifiers are: Lecithin Mono- and di-glycerides Propylene glycol  FOOD ADDITIVES CATEGORIES 4. Additives That Facilitate Food Processing or Preparation B. Stabilizers maintain or improve the texture of food. They are added to puddings, canned meats, all types of spreads, syrups and ice cream. Some ice creams are so stabilized they don't melt. Examples of stabilizers include: Gums Starches Carrageen Alginate Agar Pectin FOOD ADDITIVES CATEGORIES 4. Additives That Facilitate Food Processing or Preparation C. Other Processing or Preparation Additives Humectants retain moisture of foods Firming Agents keep things, especially vegetables, crispy Chelating agents bind metals to prevent clouding and precipitation pH agents maintain appropriate pH (and sometimes taste) Anti-caking agents prevent lumps in crystalline foods Leavening Agents alter texture and volume of food. FOOD ADDITIVES CATEGORIES 5. Additives That Maintain or Improve Nutritional Quality Used to enrich or fortify foods to improve their nutritional quality and, originally, to prevent nutrient deficiency diseases, such as goiter and scurvy. Enrichment restores nutrients lost in processing of foods. Fortification: add nutrients to foods that would be otherwise difficult to obtain in typical diet; used to market foods by appealing to our desire to obtain vitamins and minerals without choosing nutrient dense whole foods. FOOD ADDITIVES & SAFETY Nitrites are used to prevent spoilage and microbial contamination of cured meats, such as bacon, ham and lunch meats. Nitrites can prevent botulism. Nitrites combine with digestion products of proteins to form nitrosamines. High temperature also promote nitrosamine formation Nitrosamines are potential carcinogens and have been linked to bladder tumors in some animals. FOOD ADDITIVES & SAFETY Sulfites and sulfur compounds maintain freshness and prevent discoloration of fruits and vegetables. They are also used in wine, beer and other alcohol distillations. Some people, especially those with asthma and similar problems, are allergic to the sulfiting agents so sulfite use on foods intended to be consumed fresh (raw) is prohibited. FOOD PACKAGING Packaging can protect food from spoilage It keeps mold and bacteria out, keeps moisture in, and protects food from physical damage E.g. Fresh refrigerated foods are sealed in plastic pouches, the air is vacuumed out, and the pouch and its contents are partially precooked and immediately refrigerated. Enable better preserve of flavor and nutrients  FOOD PACKAGING Modified atmosphere packaging (MAP) The oxygen in the package is replaced with a gas such as carbon dioxide or nitrogen, in which microbes are unlikely to grow. Consumer should follow the instruction of storage and cooking strictly refer to the information printed on the package. CHEMICAL HAZARDS – FOOD PACKAGING Foods prepared in the microwave are exposed to high temperatures for short periods of time. Substances in packaging may undergo vaporization or chemical alteration if exposed for too long in a microwave oven. Some materials, such as Styrofoam and many plastics are not intended for microwave use and may release harmful substances when they "melt" and volatilize their hydrocarbons. WORLD HUNGER AND THE GLOBAL ENVIRONMENT THE TWO FACES OF MALNUTRITION Undernutrition Almost 852 million people around the world are chronically undernourished. Over half of all the deaths in children under 5 years of age are due to undernutrition. Overnutrition Rates of illness related to overconsumption and overweight soar in recent years NUTRITIONAL TRANSITION THE CYCLE OF MALNUTRITION WORLD FOOD CRISIS & HUNGER High food prices leading to food and nutrition insecurity for poor people around the globe. In this risky and changing environment, the Global Hunger Index (GHI) highlights key trends and the geographic areas of greatest vulnerability GLOBAL HUNGER INDEX PROBLEMS ASSOCIATED WITH MALNUTRITION Low birth weight and high infant mortality rate Stunning growth of children Prevalence of infectious diseases 18-9 PROBLEMS ASSOCIATED WITH MALNUTRITION CAUSES OF UNDERNUTRITION— FOOD SHORTAGE The most obvious example is famine Food shortage can be caused by poverty POVERTY IS THE MAIN CAUSE OF FOOD INSECURITY The poor have less access to affordable food. Lack of education. Limits access to health care. Cause homelessness FEDERAL PROGRAMS TO PREVENT MALNUTRITION Providing people with food Targeting at-risk populations Providing nutrition education Controlling food costs MORE CAUSES OF FOOD SHORTAGE Overpopulation Cultural practices Limited environmental resources The demands, the methods used to increase food production have damaging long-term effects on the environment CAUSES OF UNDERNUTRITION— POOR QUALITY DIETS Deficiencies of protein, iron, iodine, and vitamin A are common ELIMINATING WORLD HUNGER— SHORT TERM Many organizations provide emergency aid ELIMINATING WORLD HUNGER— SHORT TERM LONG-TERM SOLUTIONS: 1) PROVIDING ENOUGH FOOD The number of people = the amount of food that can be produced! 2) Controlling Population Growth Family planning (Indirectly reducing population growth through increasing general level of education and providing economic security) 3) GROWING AND IMPORTING ADEQUATE FOOD—IMPROVING FOOD SELF-SUFFICIENCY Agricultural technology Increase food production International trade A country that has few natural resources may have access to the international trade system. Subsistence crops vs. cash crops 4) MAINTAINING THE ENVIRONMENT Sustainable agriculture Using food production methods that prevent damage to the environment and allow the land to restore itself so food can be produced indefinitely Sustainable agriculture: crop rotation prevent the depletion of nutrients in the soil, reduce the use of fertilizer (use resources and increase water pollution), pollution of the water reduces the amount available to irrigateProgress the crops and toward nourishFood Sustainable theProduction population.. Advantages to soil quality and biodiversity. Sustainable choices Personal choices can influence the environmental impact of both the local and the global food production 5) ELIMINATING POVERTY Hunger will always exist as long as there is poverty. Even when food is plentiful in a region, the poor do not have access to enough of the right food. Essential economic development. 6) ENSURING A NUTRITIOUS FOOD SUPPLY Food fortification Increasing the protein quality of the diet and eliminating micronutrient deficiencies Supplementation Supplementing specific nutrients to at-risk segments of the population can help reducing the prevalence of malnutrition 7) PROVIDING EDUCATION Teach what foods to eat, how to prepare these food safely, and how to grow them Education to encourage breast-feeding and education about nutritious breast milk substitutes and their safe preparation can improve nutritional status and health in infants.