- Maple Leaf meats sold cold cuts contaminated w listeria - a screw inside the cutting machine contained bacteria - cantaloupes should be washed before cutting - cantaloupes grow on the ground full of bacteria which sticks to its rough surface - outbreaks of cantaloupe poisoning (from E. Coli & salmonella ) Video 4 - Staphylococci bacteria found in our skin & nasal secretions produces a heat-stable toxin - ex. potato salad easily contaminated with straphylococci bc ingredients are handled a lot - often stored in unstable temps where bacteria can multiply - onset of symptoms within hours but pass quickly - Clostridium botulinum is most dangerous - 0.0000001 grams botulinum toxin can cause paralysis & kill; there is an antitoxin - the bacteria is anaerobic so it multiplies most effectively in absence of air - bottled carrot juice, garlic bottled in oil - if garlic not properly washed then bottled in oil, spores of bacteria produce toxin - Botox is solution of Botulinim toxin à paralyzes muscles - Botox eases headaches & chronic anal fissures - E. Coli O157:H7 causes “ Hamburger Disease ” à 3 kids killed in Western US - humans have E. Coli in body but one type found in animal’s intestines is deadly - if intestine contacts meat, it becomes contaminated - hamburgers are riskier because all parts are not completely cooked like steak - cook burger to 70 C or 160 F so bacteria are killed - but cooking at high temps gives rise to amines which are known carcinogens - 1996 Scotland - world’s worst E. Coli poisoning à 21 Deaths - reputable butcher John Barr & Sons; used knife for cutting raw meat to cut cooked meat - 1996 outbreak in Japan - food irradiation of hamburger meat could curb the E. Coli problem - the radiation is not radioactive but public has hard time accepting it - sprouts can get salmonella & E. Coli ; they’re grown in moist enviro & bacteria loves moistures - must wash sprouts well - Hepatitis A incubation period 15-50 days à very long & can last for months
- flu-like symptoms, diarrhea, jaundice (yellowing of eyes & skin) - Chi-Chi’s restaurants had outbreak from scallions fertilized by manure & not properly washed - don’t cross-contaminate in kitchen; don’t use same plates & utensils for raw & cooked food - cannibal sandwich à Raw meat w onions popular in Wisconsin - don’t let food sit between 20 ° & 60 ° for more than 2 hours - if between 5 ° -20 ° multiplication of bacteria is not as quick, so can leave it for 4 hrs Lesson 3: Cooking Video1 - Catching Fire by Richard Wrangham, “How Cooking Made Us Human” - “The Potato Eaters” by Van Gough 1885 - chemical change during cooking foods - Maillard Reaction à carbs & proteins heated & toasted, they combine & lose water - amino acids & sugars react to cause browning - acrylamides are formed, but generally not harmful - more powerful changes when meats cooked; fat drips from meat & immediately vapourized & comes back in altered form & sticks to the meat - water lost & meat dehydrates à polycyclic aromatic hydrocarbons (PAH) are deposited à causes charring of meat - 2 PAH molecules ( Benzopyrene & Methylbenzanthracene
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- Spring '11
- pH, Pesticide, E number, Food additive