Midterm 1

Question 1

World Food Trends/Factors that influence food production + consumption?

Answer 1

• Population
• Availability of agricultural land
• Age distributions
• Climate/environmental factors
• North americanization of diets

Question 2

Role of food processing in overall global perspective?

Answer 2

• 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

Question 3

Factors affecting world’s per capita food supply?

Answer 3

• Population
• Growth rate
• Availability of cultivatable land
• Food losses
• Environmental concerns
• Energy
• Increasing expectations

Question 4

Increasing available protein supply?

Answer 4

• Grains
• Oilseeds + Legumes
• Vegetables
• Animal Proteins - Milk
• Animal Protein - Meat
• Animal Protein - Poultry
• Animal Protein - Fish

Question 5

Magnitude of food borne illnesses impact on economy

Answer 5

• 4 million(ish) food borne illnesses per year
• Norovirus, c. perfingens, campylobacter, salmonella spp., E. coli
• Cyclospora, Hep. A, Listeria

Question 6

Identify main contributors to food-borne illness, nature of the illnesses

Answer 6

• 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”)

Question 7

E. coli 0157:H7

Answer 7

• 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)

Question 8

Common sense procedure to prevent food borne illnesses

Answer 8

• 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

Question 9

Aspects of a food poisoning/product recall case

Answer 9

• Preserve all info you can recall; and save packaging/code
• Seek medical attention
• Report to proper authorities depending on source

Question 10

Food quality factors

Answer 10

• Nutritional value
• Aesthetics (5 senses)
• Functional properties

Question 11

Difference between food safety and quality?

Answer 11

• Quality is subjective, influences how desirable a product is – safety is objective

Question 12

Factors influencing food quality, spoilage

Answer 12

• Raw Materials
• Processing
• Packaging
• Environmental/Transport Factors
• Final Preparation

Question 13

Impact of deterioration and spoilage on nutritional aspects of food

Answer 13

• 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

Question 14

Differences between best before, sell before, use before coding?

Answer 14

• Best Before: optimal quality

Question 15

Perishable categories?

Answer 15

• 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

Question 16

Define absolute sterility

Answer 16

• All the mans are dead (may damage product)

- Common in medical applications

Question 17

Define commercial sterility

Answer 17

• 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

Question 18

Differentiate b/w batch, continuous processes

Answer 18

• 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)

Question 19

Importance of holding times in thermal processing

Answer 19

• 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)

Question 20

Merits/methods of physical contaminant removal?

Answer 20

• Filtration over tiny pores
• Centrifugation
• Flotation
• Electrostatic Attraction
• Ion Exchange
• Charcoal Adsorption (Viruses)

Question 21

Impacts of particle presence on thermal processing?

Answer 21

• Large particles increase time to reach final T – always better to add a safety margin

Question 22

Methods of microorganism destruction?

Answer 22

• Heat
• Chemical Agents
• Irradiation
• Sonication
• High Pressure Processing

Question 23

Factors that influence microbial growth in canned products?

Answer 23

• Species of microorganisms, acidity, anaerobic capability, water activity, thermal resistance of food