Midterm 1 Flashcards
World Food Trends/Factors that influence food production + consumption?
- Population
- Availability of agricultural land
- Age distributions
- Climate/environmental factors
- North americanization of diets
Role of food processing in overall global perspective?
- Matching supply/demand
- Extending shelf life
- Improving edibility and safety
- Fitting into people’s lifestyles (time)
- Accounting for demographics
- Fighting chemical, biological and physical degredation
- Adding extra convenience
Factors affecting world’s per capita food supply?
- Population
- Growth rate
- Availability of cultivatable land
- Food losses
- Environmental concerns
- Energy
- Increasing expectations
Increasing available protein supply?
- Grains
- Oilseeds + Legumes
- Vegetables
- Animal Proteins - Milk
- Animal Protein - Meat
- Animal Protein - Poultry
- Animal Protein - Fish
Magnitude of food borne illnesses impact on economy
- 4 million(ish) food borne illnesses per year
- Norovirus, c. perfingens, campylobacter, salmonella spp., E. coli
- Cyclospora, Hep. A, Listeria
Identify main contributors to food-borne illness, nature of the illnesses
- Improper handling of food (can be innocent)
- e.g inadequate refrigeration of the cronut burger maple jam –> staph. aureus
- e.g bird droppings in food at restaurant
- Vomitting, diarrhea, pain, joint aches, nausea, fever…
- Consumer trends and fads can influence this (e.g “raw water” and “minimally processed foods”)
E. coli 0157:H7
- Nobody fucks with this shit
- Can cause colitis (fucks your intestines) / hemolytic uremic syndrome (fucks your kidneys)
- If intestine is affected, have to surgically remove it
- Can definitely die from this
- Easily killed by heat but found in a lot of stuff (raw meats, veggies, raw milk, unpasteurized juices even)
Common sense procedure to prevent food borne illnesses
- Wash hands
- Rubber gloves if you cut
- Wash dishes ASAP
- Clean sponges n dishcloths frequently
- Clean work surfaces frequently
- Put perishables in the fridge
- Cook food to >160F
- Cook hamburger till clear juices, no undercooking
- Avoid recontamination
Aspects of a food poisoning/product recall case
- Preserve all info you can recall; and save packaging/code
- Seek medical attention
- Report to proper authorities depending on source
Food quality factors
- Nutritional value
- Aesthetics (5 senses)
- Functional properties
Difference between food safety and quality?
- Quality is subjective, influences how desirable a product is – safety is objective
Factors influencing food quality, spoilage
- Raw Materials
- Processing
- Packaging
- Environmental/Transport Factors
- Final Preparation
Impact of deterioration and spoilage on nutritional aspects of food
- Can be physical, chemical or biological
- Time, T, Moisture, Enzymatic Reactions
- Contaminants, radiation, geo. constraints
- Vitamins: go down with time, storage
- Proteins: don’t deteriorate (to some extent)
- Carbs just kinda stay there
- Elements and fibre are pretty robust
- Moisture over time
- Fats/Lipids definitely degrade time-dependent, oxidation
Differences between best before, sell before, use before coding?
- Best Before: optimal quality
Perishable categories?
- Perishable: [1,30 days] –> 0 to 2 C refrigerated
- Semi-perishable: [30, 90 days] –> 0 to 2C refrigerated
- Shelf-stable food [90, 365 days] –> canned food at RT, dried food
Define absolute sterility
- All the mans are dead (may damage product)
- Common in medical applications
Define commercial sterility
- Growth halted under certain conditions (T, pH, etc.)
- All pathogenic/toxin-forming organisms have been destroyed
- May be some spores which cannot grow under conditions
Differentiate b/w batch, continuous processes
- Batch: large kettles/other vessels
- “Time-to-temperature” is affected by size, insulation of vessel, and if too high, can damage food in the process of getting there
- Continuous: Uses pumps, HX’s to heat and cool product; holding tubes positioned between the heating and cooling stages of the process
- Allows tighter control of holding time and come-up/come-down time, less chance of food damage (basically a step-change)
Importance of holding times in thermal processing
- Affected by boundary layer – fluid on the outer wall of a tube flows slightly slower than what’s in centre (viscous drag)
- Product may be processed uniformly – rule of thumb is to hold product for 2x as long as hold time calculated for average moving particle
- (Avg Vel * Holding Time) = Tube Length, then double your tube length
- Can use coloured dye injection, salt injection tests to see holding times experimentally (how fast a particle moves through tube system)
Merits/methods of physical contaminant removal?
- Filtration over tiny pores
- Centrifugation
- Flotation
- Electrostatic Attraction
- Ion Exchange
- Charcoal Adsorption (Viruses)
Impacts of particle presence on thermal processing?
- Large particles increase time to reach final T – always better to add a safety margin
Methods of microorganism destruction?
- Heat
- Chemical Agents
- Irradiation
- Sonication
- High Pressure Processing
Factors that influence microbial growth in canned products?
- Species of microorganisms, acidity, anaerobic capability, water activity, thermal resistance of food
