Food Technology

Question 1

What is Freeze Drying?

Answer 1

a. Freeze and then vacuum
b. Unfrozen food placed on shelf → temperature is lowered → vacuum pump decreases the pressure → small amount of heating added → ice turns directly into water vapour due to low pressure → water vapour drawn out → placed in airtight vacuum to prevent any moisture from entering
c. Microorganisms need water to survive
d. Freeze-drying removes the water making it safer and easier to transport
e. Rehydrated right before eaten with water or other fluid

Question 2

What is Smoking or dehydration?

Answer 2

a. Pro :
i. Contains phenols (from wood) that contain antioxidants
ii. Enhances taste
b. Cons :
i. Burning wood can cause carcinogens :(
ii. Kills microbes
iii. Loss of vitamin C

Question 3

What is airdrying?

Answer 3

a. Process of evaporating water from surface and making water diffuse from inside food to outside
b. Pro: reduce weight and volume → better for shipping costs

Question 4

How does decreasing the water activity preserve food?

Answer 4

a. salt (seafood, meat, fish, veggies) sugar (fruit) → dries out the food
i. reduces water activity
ii. water that’s drawn out is evaporated
iii. increases osmotic stress on the organisms → unfavorable environment
iv. for this you need 2 concentrations and a semi-permeable membrane
v. salt: Does not need refrigeration, negative effects on your health
b. to increase shelf life/ flavour
c. antioxidants → vitamin C

Question 5

What are the label requirements of the EU?

Answer 5

1. Name
   a. Name of product needs to be in the product
   b. Can’t be misleading
2. Legibility
3. Allergies
   a. Clearly list allergens present in bold
   b. Gluten free:
   i. Anything made near gluten can be contaminated (contain traces)
   ii. 20mg per kilo of gluten may be present
4. Nutrition information
   a. Amount calories, carbs (dietary fiber, total sugar, added sugar), fats, sodium, Quantity of ingredients
   b. Nutrient content claims
   c. RDA / RI
   d. Per 100 grams, per serving
   e. Added vitamins
5. A list of ingredients in order of amount in product or percentage present
6. Origin information
7. Substitute ingredients
8. Storage conditions
9. Date of minimum durability (“ used by”)
10. Name of business
    → Alcohol: alcohol percentage needs to be on there

Question 6

What is does best before mean?

Answer 6

About quality; when food product may lose some of the qualities but is not unsafe to consume. Generally maintains color, texture and flavour however loses some of its quality

Question 7

What does use by mean?

Answer 7

About safety; Regarded as unsafe when the date has passed because there is a build up of bad bacteria. It is illegal for companies to sell products after this date

Question 8

What do E-numbers mean?

Answer 8

E numbers are code numbers to identify food additives that have shown to be safe and approved for use. Across the EU and Switzerland.
○ Pros
■ Used for the intention with which they were created → they are safe
■ They preserve, add flavor, texture, etc
○ Cons:
■ often arouse mistrust in public
■ disrupt food culture