NATS1560 Food Safety Lecture Notes PDF

NATS1560: UNDERSTANDIN G FOOD FOOD GONE BAD Angela Cope [email protected] LEARNING OBJECTIVES:  To define food safety, and identify the leading causes of foodborne illnesses in Canada  To name some common endogenous toxins in vegetables, animals, and mushrooms  To identify the most common an...

NATS1560: UNDERSTANDIN G FOOD FOOD GONE BAD Angela Cope [email protected] LEARNING OBJECTIVES:  To define food safety, and identify the leading causes of foodborne illnesses in Canada  To name some common endogenous toxins in vegetables, animals, and mushrooms  To identify the most common and dangerous biological contaminants  To identify the most effective ways to protect oneself from foodborne illnesses  To identify common chemical contaminants and their sources, and explain bio-amplification  To define allergens and name the most common ones FOOD SAFETY:  Practices of food production, processing, handling, and storage aimed to ensure that the food is free from harmful substances (endogenous toxins and contaminants)  Food-related illness or food poisoning: disease caused by a harmful substance in food or drink TYPES OF FOODBORNE HAZARDS:  Endogenous toxins: substances that are part of the normal growth of an organism, and that are harmful to other  Contaminants: organisms or organisms when substances that infect or invade ingested, inhaled, or other organisms or substances, absorbed making them polluted, spoiled, or impure −Biological contaminants: living organisms or the substances that they produce −Chemical contaminants: chemical substances ENDOGENOUS TOXINS IN VEGETABLES:  Solanine, glycoalkaloid in plants of Solanaceae family (potatoes, tomatoes, eggplants, peppers, etc.)  Alkaloids, e.g., caffeine and theobromine  Oxalic acid (rhubarb, spinach, collards, kale, broccoli, beets, etc.)  Amygdalin and other cyanide- producing compounds (cassava, apricot kernels)  Protease inhibitors (raw beans)  Phytoestrogens (soybeans) TOXINS IN MUSHROOMS AND ANIMALS:  Mushroom toxins  e.g., in Amanita verna aka (“Destroying angel”)  Puffer fish or fugu, (tetrodotoxin) TEST PRACTICE: 1. What is a food source of tetrodotoxin? a. Puffer fish b. Certain species of mushrooms c. Tomatoes d. Cassava TEST PRACTICE: 2. What is a food source of amygdalin? a. Certain species of mushrooms b. eggplants c. Cassava d. Raw beans TEST PRACTICE: 3. What is a food source of solanine? a. Amanita verna b. Potatoes c. Swiss chard d. Coffee TEST PRACTICE: 4. What is a food source of oxalic acid? a. Raw beans b. Green pepper c. Rhubarb leaves d. Apricot kernels BIOLOGICAL CONTAMINANTS: Bacteria Fungi Viruses Parasites Algae Prions CONTAMINATION OF SHELLFISH  Shellfish toxins, or contamination by “red tide” −harmful algal bloom, or harmful phytoplankton  Paralytic Shellfish Poisoning, PSP (saxitoxin)  Amnesic Shellfish Poisoning, ASP  Diarrhetic Shellfish Poisoning, DSP BACTERIA, FUNGI, VIRUSES,  MYCOTOXINS: AND PARASITES:  Ergot (sclerotia in rye)  Aflatoxins  Smuts and rusts BACTERIA:  VIRUSES:  Campylobacter  Clostridium perfringens  Norovirus, or Norwalk  Clostridium botulinum  Hepatitis A  Escherichia coli  Listeria monocytogenes  PARASITES:  Mycobacterium tuberculosis  Salmonella  Roundworms (e.g., Trichinella spiralis)  Shigella  Tapeworms  Staphylococcus aureus  Giardia lamblia (giardiasis, or beaver fever)  Vibrio cholerae  Entamoeba histolytica  Yersinia enterocolitica  Biological Contaminants: HOME REVIEW: e. Tapeworm Hepatitis A Assign the following biological contaminants to f. g. Aflatoxin their categories: h. Staphylococcus aureus i. Salmonella Categories: j. Entamoeba histolytica k. Ergot l. Vibrio cholera a. virus m. Giardia lamblia n. Listeria monocytogenes b. bacterium o. Clostridium botulinum Trichinella spiralis c. mycotoxin p. q. Campylobacter d. parasite r. Escherichia coli s. Yersinia enterocolitica TEST PRACTICE: 5. What is the difference between endogenous toxins and contaminants? a. Contaminants can be found in plants and animals, endogenous toxins only in plants b. Contaminants can be eliminated by cooking, endogenous toxins can’t c. Endogenous toxins are generated within the food source, contaminants infect the food from outside d. Contaminants are living things or produced by living things, endogenous toxins are chemical substances TEST PRACTICE: 6. What is the difference between chemical and biological contaminants? a. Biological contaminants can be eliminated by washing or cooking, chemical contaminants can’t b. Biological contaminants are generated within the food source, chemical contaminants pollute the food from outside c. Biological contaminants are living things or produced by living things, chemical contaminants are chemical substances d. There is no difference   May 2000, E. coli O157:H7 THE WALKERTON TRAGEDY: contamination of Water Public Utility in Walkerton, ON  2300-2500 cases, 7 deaths  Public Utility Commission manager and foreman found guilty of negligence in discharging their duties to keep public water safe ? CANADA’S 2008 LISTERIOSIS OUTBREAK  57 cases of listeriosis, 22 deaths  caused by contaminated packaged meats from a Maple Leaf Foods plant in Toronto 2012 XL FOODS BEEF RECALL “Hand print on a large TSA plate from my 8 1/2 year old son after playing outside”, by Tasha Sturm, Cabrillo College, June 2015. It shows colonies of bacteria and fungi, most of which are harmless, some even beneficial, and some may be harmful. ARE ANTIBACTERIAL PRODUCTS GOOD?  Many antibacterial products (soaps, detergents, wipes, etc.) use triclosan and similar chemicals as active ingredients  There is no evidence that these products are more effective than regular soap and water!  They promote the growth of antibiotic- resistant bacteria  They are harmful to ecosystems and very likely to human health too  The hand-sanitizer Purell™ is an alcohol-based gel. It does not contain triclosan or similar chemicals http://www.smithsonianmag.com/science-nature/five-reasons-why- you-should-probably-stop-using-antibacterial-soap-180948078/?no-ist FOOD SAFETY PRECAUTIONS  Obtain food from a reliable source  Use clean water to drink and to prepare food  Ensure good hygiene practices − avoid handling of food when ill, especially if suffering from diarrhea and/or vomiting − wash hands frequently in warm soapy water while handling foods, especially after handling raw meat and seafood and after using the washroom  Prevent cross contamination − use clean utensils to prepare and serve food − separate raw foods and ready-to-eat foods − clean surfaces used to prepare and serve food − store foods properly − keep cold foods at 4 ⁰C or lower, and hot foods at 60 ⁰C or higher  Cook foods to proper internal temperature, e.g. at least 70 ⁰C for pork and ground beef  Do not use antibacterial products  Demand that food manufacturers and public officials give public health priority over private interests HOME REVIEW: What are the five most common causes of foodborne illnesses in Canada? What can you do to protect yourself from these illnesses? BSE, OR MAD COW DISEASE  Bovine Spongiform Encephalopathy (BSE), one of the Transmissible Spongiform Encephalopathies (TSE), like scrapie in sheep and Creutzfeldt-Jakob Disease (CJD) in humans Human prion protein  caused by prions, self-replicating misfolded proteins in brain and spinal tissue structure. Source: cchem.berkeley.edu  Late1980s-1990s, BSE epidemics in UK caused an outbreak of variant Creutzfeldt-Jakob Disease (vCJD), − 177 cases of vCJD in UK, about 20 in France, several in Ireland, Italy, Spain, USA, and Canada  transmitted to cattle by feed containing protein supplements made from waste sheep and cattle tissue (now banned for ruminants)  transmitted to humans through consumption of infected cattle products containing brain and spinal British Minister of Agriculture in 1990 assuring tissue the public that beef was “completely safe” (Source: BBC News)