Food Safety and Technology: Microbial Threats and Genetic Engineering BIOL 103, Chapter 14

Today’s Topic Food Safety Food Technology Genetically Modified Foods

Food Safety Harmful substances in foods – Pathogens (disease-causing) – Foodborne illness: 1.Infection from pathogen 2.Toxin produced by microorganism CDC: “48 million Americans become sick, 128,000 require hospitalization, and 3,000 die from foodborne illnesses).”

Food Safety Harmful substances in food pathogens (Table 14.1: Common Foodborne Pathogens and Illnesses): PathogensCommon SourceIllnessSymptoms S. aureusVomiting, abdominal cramps C. botulinum Fatal to infants SalmonellaDiarrhea, Vomiting, Abdominal cramps E. coliWatery or bloody diarrhea, Death

Food Safety Prions: self-reproducing protein particles that can cause a disease such as… – Mad Cow Disease or Bovine spongiform encephalopathy (BSE): a chronic degenerative disease that affects the CNS of cattle. – Cooking and irradiation do not kill or deactivate abnormal prions.

Food Safety- Harmful Substances in Food Chemical contamination – Pesticides Important role in food production Concerns: 1.Pollution of soil and water 2.Threatens wildlife FDA collects samples and analyzes food samples and animal feeds for illegal pesticide residues.

Food Safety Organic alternatives to chemical contamination in foods – There is no scientific evidence that genetic engineering and irradiation of foods present unacceptable risks – “USDA Organic” seal – Concerns regarding natural fertilizer – Can use approved synthetic and natural pesticides to control weeds and insects – Microbial contaminants still found

Food Safety Animal drugs 1.Antibiotics to maintain animal well-being, but overuse can develop antibiotic-resistant microorganisms  illness in humans 2.However, drug residues may enter human food  drug allergies or illness in humans Pollutants – Animal manure, factories wastes/dioxins, human sewage can contaminate food production areas

Food Safety: Harmful Toxins Natural Toxins – Aflatoxins: – Ciguatera: Cooking does not destroy these toxins. – Methyl mercury: – Poisonous mushrooms: – Solanine:

Figure 14.5 Toxins in the food chain As toxins travel up the food chain, they become concentrated in larger fish.

Figure 14.7 Government agencies that help protect our food supply Although the FDA has primary responsibility for the safety of much of our food supply, many government agencies provide oversight.

Keeping Food Safe: Government Agencies (Pg ) 1.FDA: enforces laws governing safety of ____________________ food, except meat and poultry. 2.CDC: monitors/investigates outbreaks of ________ _______________and determines proper prevention 3.USDA FSIS: enforces laws governing safety of domestic and imported ________________ product. 4.USDA CSREES: develops research and education programs on ______________for farmers/consumers 5.EPA: regulates public ___________, approves _________________and other chemicals used in the environment.

Keeping Food Safe: Consumer Keep hot foods hot and cold foods cold 1.Clean 2.Separate 3.Cook 4.Chill (refrigerate promptly)

Risk for Foodborne Illness 1.Immune disorders (e.g. HIV infection) 2.Cancer 3.Diabetes 4.Long-term steroid use, such as for asthma or arthritis 5.Liver disease 6.Hemochromatosis (iron storage disorder that affects the liver) 7.Stomach problems (e.g. low stomach acid)

Food Technology Food preservation – Preservatives 1.Salt, sugar – Most common antimicrobial agents 2.Antioxidants – prevents changes in color/flavor caused by air exposure

Food Technology Other preservation techniques 1.Salting 2.Fermenting 3.Drying 4.Canning 5.Heating (e.g. pasteurization) 6.Irradiation – controversial

Food Technology Irradiation – food is exposed to measured doses of radiation to reduce or eliminate pathogens and kill insects, reduce spoilage, and in certain fruits/vegetables, inhibit sprouting and delay ripening. Why are food manufacturers reluctant to use this method of preservation?

Food Technology: Irradiation

Food Technology Bacteriophage – “Bacteria eaters” – viruses that infect bacteria – Sprayed on ready-to-eat meats and poultry products to protect people from bacterial infections Infect only bacteria and do not bother mammalian or plant cells – Must declare “bacteriophage preparation” on label of meat/poultry product

Genetically Modified Foods Traditional Breeding Cross two plants and develop hybrids Takes time Genetic Engineering Transform specific genes Less time needed to get desired effects

Figure Genetic engineering and traditional breeding Genetic engineering can fast-track crop development that can take years with traditional breeding practices.

GM foods: Pros and Cons Benefits 1.Enhanced plant growth 2._________ pesticide and fertilizer use 3.Enhanced ___________ composition 4.Enhanced _____________ Risks Potential for new ________ Herbicide-resistant weeds Loss of ________________ – Biggest con of unmonitored GM crops

Genetically Modified Foods Regulation – FDA oversees genetically modified foods – Label requirements if food is significantly different Examples: – Changes in nutritional properties – Presence of allergen that consumers would not expect in the food – Any property that would require special handling, storage, cooking, or preservations.