Chapter 1 - Food production Flashcards
What are four main types of operations?
1) Separation - Into two or more streams
2) Conversion - changing the composition
3) Structuring - changing ingredient positioning
4) Stabilization - preservation and packaging
Give three processes that are considered separating with an example each
1) Cleaning (dissolving, sieving, rinsing, sedimentation)
- Raw crops
2) Fractionation (Filtration, centrifugation, evaporation, sedimentation)
- Milk - cream + skim milk
3) Purification (Dilution, precipitation + filtration)
- Protein isolate
Give four processes that are considered conversion with an example each
1) Fermentation
- Winemaking
2) Acidification/neutralization (pH change)
- Rennetting of milk for cheese production
3) Reaction (enzyme, heating)
- Gelatinization
4) Inactivation (microbial, enzyme)
- Pasteurization
Give seven structuring processes
1) Mixing
2) Baking (bread)
3) Emulsification (homogenisation)
4) Crystallisation
5) Freezing
6) Churning
7) Drying
–> Phase changes!
Give three processes that are considered stabilization
1) Reduction of water activity
- Salting, drying, fermentation, hurdle technology
2) Thermal preservation
- Heating, cooling, freezing
3) Non-thermal preservation
- High hydrostatic pressure, Pulsed Electric fields, Magnetic fields, UV
How much cheese and whey is produced by 10 kg of raw milk?
1 kg cheese and 9 kg whey
What parameters are used in process analysis?
- Food, Good, ingredient, substance
- Recovery
- Yield
- Footprint indicator (input, output)
How is yield calculated?
Yield is the recovery divided by the theoretical recovery. Yield is used when a biochemical conversion takes place.
Example: Ethanol production from glucose
C6H12O6 –> 2 C2H5OH + 2 CO2
Theoretical recovery = 92/180 = 51 %
If we get a recovery of 47% then yield is 47%/51% = 92%
Overall yield can be calculated by multiplying all yields.
What is the minimum % of heat needed for pasteurization with reuse of heat?
5%
