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all the lecture notes we did in class are inside this document this will help you for exam and some of the questions she chooses is from here,...

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What is Food Science? A combination of biology (plant tissues, muscle foods, nutrition, diet and disease), chemistry (antioxidants, oxidation, nonenzymatic/enzymatic browning, food colours and additives) and physics (food processing, food safety, packaging techniques, storage stability and shelf-life) Nonenzymatic browning: rxn of variety of sugar w/amino source key: heat - toasting english muffin vs. Enzymatic browning: cut into it and expose the tissue oxidation - sliced apple turning brown Food Science Careers: product development, Quality Assurance, management, research, teaching Food Science Research: chemistry & nutrition, quality & sensory evaluations, diet & health/disease Functional Foods - super foods (e.g., blueberries and antioxidants, flaxseeds) - reduce risks of osteoporosis, heart disease, diabetes, cancer - consumed as part of regular diet, similar in appearance to conventional foods - demonstrated physiological benefits, reduces risk of chronic disease beyond nutritional functions  flaxseeds, improve immune function, oxidative status Bioactive Compounds - casein phosphopeptides dairy enhance mineral absorption from food - polyunsaturated oils fish and flax oil, omega 3 and long chain amino brain function - phytoestrogens isoflavones, lignans  bone strength, reducing risk of heart disease Physical Chemistry of Fats - fat crystal structure - spreadability of butter making it easier to spread - chocolate melting point is key to richness - bloom/whiteness on chocolate is a physical state imperfection Foodborne Illness: mostly associated with bacteria; some with viruses, but only in the winter months Bacteria = 90% Viruses = 6% Chemicals = 3% Parasites = 1%, if not properly stored or cleaned… e.g., hunted food 6.5-33M people/yr in U.S., 13% of CDN population become ill from contaminated food e.g., E-coli: hamburgers Costs - costs can be high, depending on the length of the illness ($10-83B USD / $100M CDN) - a lot of cases aren’t reported, because many people do not report a food born illness - an outbreak = several individuals going to the doctor reporting a illness and all having a common source confirmation of source found by culturing the food that is thought to be the problem - can only become public record if illness is reported to a doctor  the number isn’t very exact

Canadian Statistics - 60% unspecified agents (2.4M/yr), 40% were attributed to 30 known pathogens (1.6M/yr) - majority of foodborne illnesses (70%) come from outside the home (e.g., restaurants, fast food) - smaller amounts come from the household (11%) or retail/grocery stores (4%) - most people can't find exact cause of illness, because source is gone before symptoms show Top 4 Domestic Pathogens - majority of pathogens norovirus or Norwalk virus!!!! (1.05M 65%) - second major pathogen clostridium perfringens (0.18M11%) - third major pathogen campylobacter spp. (0.14M 8%) - fourth major pathogen salmonella (0.09M 5%) Who is the most susceptible to foodborne illnesses? - pregnant and lactating mothers - very young infants and children - elderly nursing homes close down, often due to Norwalk virus - immune compromised patients reduced ability to fight off infections - cruise ships Norwalk virus, since it’s a very small area with a lot of people Spread of Foodborne Illness - poor personal hygiene must wash hands, clean / sterilize food prep surfaces and utensils - many bacteria already present in body in gut flora, mucus membranes and skin surfaces - cross-contamination associated with transfer of bacteria from handlers to raw/cooked foods - temperature abuse, related to improper storage of raw/cooked foods - keep cold foods cold, and hot foods hot - avoid the danger zone 4° - 60°C - fridges should be set to 4 degrees  don’t want fresh food to freeze - linked to transfer from raw foods to cooked foods during preparation/storage raw foods have potential contaminants/bacteria that could 'infect' cooked food if it dripped or leaked through condensation, etc. don't store raw above cooked ...soils that uncooked fruits and veggies were grown in might have come in contact with / be ridden with bacteria, etc. Danger Zone for Foods 100 - 74°C, cooking temperatures 74 - 60°C, growth inhibited for most bacteria **EXCEPT thermophiles organism that thrives at a temperature of 50°C or higher 60 - 4°C, DANGER ZONE growth of bacteria and toxin production, depends on species 4 - 0°C, slow growth < 0°C, freezing stops growth, cells can still survive

KNOW METRIC CONVERSIONS IN BOLD (next page) and KNOW HOW to SPELL BACTERIA NAMES for MIDTERMS

SEROTYPE is a particular/specific variety of a bacteria Sources of Contamination environment: soil, water, air, micro flora, food handlers, utensils contact surfaces: equipment, food handler - must sanitize between batches/production runs - clean with chlorine (Cl2, H2O2, Ozone) Raw Food Ingredients •Poultry Salmonella spp. •Beef Escherichia coli O157:H7 - responsible for hamburger diseases and Walkerton •Seafood Fecal coliforms - coliform is general term for colon/GI tract bacteria Hepatitis A: viral disease of liver, common in developing countries generally due to poor sanitation and poor hygiene raw oysters are potential risk water they're harvested in can contain bacteria •Eggs, milk, dairyListeria monocytogenes: bacteria involved with lunch meat recall associated with dairy/chocolate Chlorine - good oxidizing agent - starts with Cl2 (chlorine gas) + H2O (aqueous base) products are HCl + HOCl - the hypochloride ion (OCl- ) interacts with membrane and kills it Cl2(g) + H2O  HOCl + HCl chlorine (gas) + water  hypochloric acid (weak acid) + hydrochloric acid (strong acid)

NaOCl + H2O  HOCl + Na+ + OHsodium hypochloride (store bought bleach) + water (add to bleach in bucket)  hypochloric acid + sodium + hydroxide ion (Javex)

HOCl + OH-  OCl - + H2 O hypochloric acid + hydroxide ion  hypochloride ion + water

**it is the hypochloride ion that is responsible for the actual sanitizing (kills/inactivates bacteria) KNOW THESE PATHWAYS for MIDTERM Common Symptoms of Foodborne Illness - nausea - vomiting - abdominal pain - diarrhea - fever - headache - fatigue

Classification of Foodborne Illness Bacterial infection: effect of microorganism on gut wall (extreme cases may involve bacteremia) •Salmonellosis - name of illness caused by salmonella •Listeriosis - name of illness caused by listeria Intoxication: bacteria makes toxin in the food •Staphylcoccus aureus (intoxification) - bacteria IN food (e.g., raw ground beef exposed to sun) •Clostridia spp. (intoxification) - general form is clostridia botulinum bacterial intoxication  neurotoxin produced, causes tingling in the mouth or lips Toxin-mediated infection: has effect of toxin, but not from food item  bacteria sets up house in body - toxin produced by micro-organism, either in food, itself, or released from food activated in body •Escherichia coli O157: H7 (toxin-mediated infection) toxicity caused by component of cell wall Foods of Concern for Transmission of Foodborne Illness •can easily be passed through soil fruits are grown near a farm, where there is cattle possibility of bacteria, if not pasteurized and cleaned •low acid foods - low acid is not the same as low pH - some presence of acid, pH greater or equal to 4.5 - potatoes, garlic, cream of broccoli soup  low acid - tomatoes are borderline - citrus juice is high acid  pH around 2-3 •high moisture content foods - easy place for bacteria to grow - protein - fresh products •protein-rich foods - meat - poultry - dairy-based foods HIGHEST RISK: chicken, ground beef HIGH RISK: beef (other), steak, turkey MEDIUM RISK: deli meat, BBQ, pork, roast beef LOW RISK: chicken nuggets, ham, sausage (products that have been preserved) -

chicken/ground beef are highest risk of foodborne illnesses (more surfaces/more exposure time) the smaller the pieces, the more surface exposed, therefore increase in likelihood of contamination

HACCP - Hazard Analysis Critical Control Points: food safety mgmnt system (Campbell’s soup) analysis and control of biological, chemical and physical hazards from raw material production, procurement & handling, to manufacturing, distribution & consumption of finished product designed for use in all segments of the food industry (growing, harvesting, processing, manufacturing, distributing, merchandising, preparing food for consumption) has programs for training, sanitation, pest control and recall 1. look at controls  ingredients (ingredient inspection) 2. look at temperatures keeping ingredients/food out the danger zone 3. look at foodborne illness looking for a growth of bacteria 4. look at a total coliform looking for < 500 cfu/g (cfu= colony forming units) 5. look at E.coli look for 100 cfu/g (smaller number, because it’s a specific bacteria) 6. look at viscosity, weight, salt, colour, organoleptic (food properties experienced through senses)

How Bacteria is Identified and/or Classified MORPHOLOGY (how they look) - Shape:  bacilli (e.g., Salmonella spp.) - flagella follicles which help them move - seen with electromicrograph - cells that are joined end to end, rod-like  cocci (e.g., Enterococci) - spheres or round cells, individual or paired up - associated with the intestinal or gut flora SELF-LIMITING  organism or colony of organisms that limits its own growth (e.g., single organism may have a maximum size determined by genetics, or a colony of organisms may release waste which is ultimately toxic to the colony once it exceeds a certain population)  self-limiting nature of a colony may be advantageous to the continued survival (e.g., parasites -if numbers become too high, host would die and so too, eventually, would the parasites) REACTION to STAINING  gram positive - purple (absorbing crystal violet)  gram negative - pink (not absorbing as much) METABOLISM - Respiration Requirements: Composition of oxygen = 75% nitrogen, 20% O2, 1% CO2 + other gases  aerobic bacteria require O2  anaerobic bacteria (Clostridia spp.) don't require O2 (higher performance from CO2)  facultative anaerobic bacteria (Salmonella spp., E.coli) can grow in presence, or absence of O2  microaerophilic bacteria (Campylobacter jejuni) very specific O2 concentration required 3-6% ENVIRONMENTAL TOLERANCES  thermophile: can grow at high temperature, not as common, found at bottom of ocean/heat vent  halophile (Vibrio cholera): grow at high salt concentrations, natural disasters/earthquakes/war epidemics disturbing water system can present issues when ocean waters seep in Serotypes of Bacteria Campylobacter jejuni  gram negative, microaerophilic, spiral or S-shaped cells  self-limiting diseases if healthy only lasts few days, immune system should be able to fight it off Duration: lasts about 2-7 days Symptoms: onset 2-5 days after you consume product  abdominal pain  diarrhea  generally after you recover there shouldn’t be any problems  back to normal, if generally healthy Source and mode of transmissions:  raw milk, poultry and meats  only a small number of cells are required for infection  usually wide spread... often mistaken for salmonella poisoning, unless it is extremely bad Mode of transmission:

 cross-contamination Escherichia coli O157: H7  gram negative, facultative anaerobic, rod-shaped cells, toxin-mediated infection - consume bacteria and it sets up house in your body - not made/ synthesize until it's in your body  self-limiting disease Duration 1-3 days (health individual) Symptoms (could be longer than 3 days): onset 12-72 hours  severe abdominal pain  nausea, vomiting  bloody diarrhea  kidney failure (Hemolytic Uremic Syndrome - worst case scenario in Walkertons water) Mode of transmission  intestines of cattle  orchard apples where animals are kept grazing (fecal contamination)  cross contamination from handlers/ contact surfaces/ utensils How E.coli Gets into Water  dung holding tanks leak  liquid or dry dung is spread over the fields as fertilized  heavy rain carried bacteria down to water table water taken from well, not treatment plant  staff at water treatment plant were not properly trained  bacteria entered water system through a crack in the pipe thought they were treating the water properly but they weren’t E. coli went through the system inadequate treatment  chlorination / sanitation at treatment plant was not working well (not dosing correctly)  townspeople were bathing/cooking/drinking contaminated water Walkerton Costs  2,500 became ill 7 deaths 9,275 claims  greater than $72M in compensation  those with acute gastroenteritis are more likely to develop hypertension, renal problems or cardiovascular event (long term consequences) Listeria monocytogenes  intoxication - infection by bacteria  not self-limiting  gram positive, facultative anaerobic, short rod-shaped motile cells  refrigeration does not inhibit growth, can also grow in salted or acidic foods Duration: indefinite Symptoms: onset 1 day- 3 weeks  nausea, vomiting  fever, headache, chills  backache  flu-like symptoms in healthy adults complications can be life threatening Complications (especially in pregnant women and at risk population):  septicemia  meningitis / encephalitis (backache)  birth defects (stillbirth, miscarriage, abortion, meningitis - transferred to fetus stillborn) Sources:  raw meat, raw poultry, seafood

 dairy products (cheese, ice cream, raw milk)  raw vegetables (soil contamination) Mode of transmission:  naturally present in environment  cross-contamination during or post-processing  insufficient cooking of raw foods Salmonella spp.  gram negative, facultative anaerobic, short rod-shaped cells  self-limiting bacterial infection Duration: 2 - 3 days Symptoms: onset 6 - 48 hrs  abdominal pain  fever, headache  nausea, vomiting  diarrhea Sources:  raw meats (e.g., pork, raw poultry)  eggs, milk, dairy products  chocolate  cream-filled desserts Mode of transmission:  cross-contamination with fecal material, particularly a problem with central processing facilities in food production (usually when they do recalls they will list where products were sent and sold)  can trace outbreaks and see where it all started (e.g., Lunchables in Ontario towards children were able to identify location and farm the outbreak came from and what other companies were involved  able to identify the primary infection (person who ate Lunchable) and secondary infection (infected by someone who ate Lunchable), which came from the outbreak Staphylococcus aureus  gram positive, facultative anaerobic, cocci (spherical cell, in clusters of 4)  bacterial intoxication  heat stable Enterotoxin (bacteria grows with heat) Duration: 1 - 2 days Symptoms: onset 1 - 6 hrs (2 - 4 hrs)  severe nausea, vomiting  acute abdominal pain  diarrhea Sources:  naturally present in nasal passages of healthy people  may also infect cuts and wounds  present on hands, hair, nose and throat of people Common foods:  found in cooked ready-to-serve foods, due to cross-contamination  ready-to-eat luncheon meats (egg salad)  meat, poultry  vegetable and egg salads

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custards, milk and dairy foods

Modes of transmission:  contamination from food handlers (particularly hands)  particularly a problem with foods requiring large amounts of pre-preparation and handling  e.g., Steak Tar Tar  bacteria are also spread through aerosol droplets (talking, coughing, sneezing near food)  improper usage of tasting spoons and ladles can transfer bacteria Clostridia spp.  gram positive, anaerobic, spore forming bacilli  spore formation allows the bacterium to withstand harsh environmental stresses (heat treatment, freezing, high salt conditions, dehydration and/or high acidity).  spore coat lets it within stand environmental stresses by making it a different form  rod shape cells (vegetative cells) or spore shaped form  see a combination of the two forms, not just one on their own  main species of concern include environmental and soil bacteria - Clostridia perfringens - Clostridia botulinum - Clostridia difficile (hospital related illnesses) Clostridium perfringens Duration: 1 day or less Symptoms: onset 8 - 22 hrs  abdominal pain  diarrhea Sources and mode of transmission:  widely distributed and may be found in most foods including:  meat products which have been boiled, steamed, braised, stewed or inadequately roasted, then allowed to cool slowly and served cold or poorly reheated  cooling rapidly and portioning it out (smaller pieces increases surface area) Common foods:  spices, gravy  improperly cooled foods (e.g., temperature abused foods which are then reheated) Costridium botulinum  gram positive, anaerobic, spore forming bacilli, bacterial intoxication  neurotoxin produced (heat labile heat sensitive) Duration: days year (last a year if paralysis complications) Symptoms: onset 12 - 36 hrs  fatigue  headache, dizziness  vision problems  trouble swallowing  respiratory paralysis Sources and mode of transmission:  low-acid foods ( > pH 4.6) which are improperly heat-processed and then packaged in an anaerobic atmosphere and held in the danger zone (compounds the problem)  problem with home-canning or even industrial type of products

Common foods:  home-canned green beans, meats, fish,  garlic or onions stored in oil or butter  one of the most common is preserved garlic  we alter the acid levels in food to avoid Clostridium botulinum  decrease the pH Other Foodborne Illnesses VIRUSES:  viral infection specific type of virus, self-limiting  acute viral gastroenteritis, 'winter vomiting disease' - genus: Norovirus - family: Caliciviridae  Norwalk-like virus (found mostly on cruise ships, in senior homes)  round, nonenveloped, 27-32 nm virion Duration: 2-3 days Symptoms: onset 24-48hrs, symptoms can persist for several weeks  abrupt onset of non-bloody diarrhea  abdominal cramps  headache  nausea  low-grade fever Sources and Mode of Transmission:  fecal-oral route  contamination by infected fecal matter from sick food handlers  raw sewage in water  water, shellfish, salads MOLDS: Aflatoxin - Aspergillus flavus (toxin)  associated with liver cancer in humans PARASITES: Cyclosporidia – Cyclospora  prolonged diarrhea associated with fresh berries Trichinellosis - Trichinella spiralis  associated with insufficiently cooked meats  associated with game from hunting bear meat, moose meat risk decreased by freezing the product properly before eating  round worm infection - nausea - vomiting - diarrhea sweats - fever - muscle pains

What is Fermentation?  will produce a new food product from raw materials (grapes to wine, milk to cheese)  involves conversion of food components into more stable form through microorganisms; - longer shelf life  produces amino acids, acids, alcohols, gases and other small organic compounds - changes flavour and odour of products Results of Fermentation?  generally reduces likelihood of pathogens growing in food: - related to acid production; decreases pH, much less friendly environment  can also extend shelf-life of product: - related to inhibition of spoilage organisms due to acid or alcohol production  grapes wine  milk  cheese  cabbage  sauerkraut  wheat  bread Types of Fermentation I. Natural or ‘wild’ fermentations:  microorganism of interest is naturally present on starting material food: - sauerkraut, pickles, olives II. Controlled or ‘inoculated’ fermentations:  an inoculum or ‘starter culture’ is added to the starting food material: - cheese, yogurt: bacteria + raw materials - beer, wine, vinegar: yeast + juice - bread: yeast + flour + water +sugar - sausage KNOW HOMOFERMENTATIVE REACTION HOMOfermentative: lactic acid is the only product produced C6H12O6 (glucose)  2CH3CHOHCOOH HETEROfermentative: ethanol, lactic acid and CO 2 are all produced C6H12O6 (glucose)  C2H5OH + CH3CHOHCOOH + CO2

Lactic Acid Bacteria (acidity factor): Most important bacteria in desirable fermentations:  non-sporeformers  gram positive, cocci or rods  microaerophilic (need small amount of O2) ...