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Here's the final part. Kindly let me know should any corrections be required.
Part I: Separation and Concentration Technologies in Food Processing
Section A: Please match the correct term with its definition:
Terms: Single Extraction Apparatus | Vibrator Separator | Pneumatic Separator
|Magnetic Separator | Filtration Method| Conventional Filtration | Reverse Osmosis |
Ultra Filtration |Centrifuge| Pervaporation | Electro-dialysis | Ion exchange materials
separators | Bleed and Feed | Filtration | Centrifugation | Crystallization | Multi-stage
Extraction Apparatus | SFE |
Evaporation | Climbing film evaporator | Falling film evaporator
Microfiltration Offer significant advantages such as higher recovery and purity.
Ultra Filtration Is a membrane-type electrochemical process whereby membranes are used to
separate ionic molecules from non-ionic one using electric field as the driving force for
separation.
Falling film evaporator. A thin liquid film of uniform thickness moves downwards by gravity
inside tubes.
Filtration Removal of insoluble particles from a suspension by passing it across a porous
material, retaining particles according to their sizes- and shape to some extent.
Climbing film evaporator Liquid moves rapidly upwards by percolation along vertical tubes
and upon reaching the top, the concentrates and vapors produced are sent to a separator.
Vibrator Separator Relies on vibration to move particles through different screens separating
solids by their sizes or masses.
Centrifugation. Provide solid-liquid and liquid- liquid separations, such as in milk processing,
in which milk fat (i.e. cream) removal and clarification can occur simultaneously.
SFE Low in operating cost; however, it produces diluted solutions.
Evaporation Is used in food system to obtain partial separation of a volatile solvent, commonly
water, from non-volatile components
Centrifugation This method includes the conventional filtration and mechanical expression (i.e.
juice extraction from fruits and vegetables)
Pneumatic Separator Used to compressed gases to separate particles according to their masses
SFE Use CO2 to complete separation of food components
Magnetic separator Applied magnetic fields to remove metallic particles
Pervaporation Three-step process that is pressure driven membrane where the permeate
generated is a low-pressure vapor, not a liquid, that can be condensed and collected or
further concentrated.
Crystallization The process by which solid crystals of a solute, are formed from a
solution
Conventional Filtration relies on gravity, pressure or vacuum to create the driving force
necessary for the liquid phase to pass throughout different kinds of filters.
Ion exchange materials separators Is the continuous process by feeding the solution to
be treated at the same rate as the concentrate removed.
Pneumatic Separator. A device that separates particles from suspensions, or even
macro-molecules from solutions, according to their size, shape and density
Part II: Dehydration
1. What is a method that Aw can be controlled other than dehydration? Name two
examples of this type of drying?
- Pervaporation.
2. Describe the differences between absorption and adsorption?
- Absorption is the process in which a fluid is dissolved by a liquid or a solid while
adsorption is the process in which atoms, ions or molecules from a substance adhere
to a surface of the adsorbent.
3. Describe the differences between direct heating and indirect heating
- Direct heat means to heating the food directly over the heat source (whether
charcoal, gas, or wood), while indirect cooking refers to cooking adjacent to the heat
source.
4. What are the modes of heating in the dehydration process?
5. Name and describe two types of batch drying?
6. Name and describe two types of continuous drying systems?
7. What is psychrometric? And, how does it relate to dehydration? (You may have to
do a little research for this question, but make your answer 2-3 sentences long)
Part III: Deep Frying
The Chemistry behind Deep Frying:
8. When food is fried in heated oil, the moisture form steams, which evaporates with a
bubbling action and gradually subsides as the foods are ready.
9. Water, steam, and oxygen initiate the chemical reactions in the frying oil and food.
10. Frying is more preferable in oil with short and unsaturated fatty acids than oil with
long and saturated fatty acids. Oil with short and unsaturated fatty acid are more
volatile in water than longer and saturated fatty acids are.
11. The moisture in deep-fat frying reacts with oil.
12. Free fatty acids and their oxidized compounds are extremely important to the flavor
qualities of frying oil and fried foods.
13. The flavor of oil formed during deep-fat frying is described as the following:
a. Fruity b. Grassy c. Buttery d. Burnt e. Nutty
f. Fishy
14. Does the type of fryer affect the oil deterioration? True or False
- True.
15. Do carotenes protect the oil from thermal oxidation in the absence of other
antioxidant? True or False
- False.
16. Does the Maillard Rxn cause nutrient loss and browning in deep frying? True or
False
- True
17. The rate of vitamin E or tocopherol decomposition during deep-fat frying depends
on the frying time and oil. True or False
-
True
18. What is the normal temperature range for deep frying in food service?
- 100 ◦C
19. What is the highest temperature range for deep frying in food service?
20. Hot oil requires careful handling to avoid possible damage to fryer and shortening.
21. Why are antioxidants added to edible oils?
180 ◦C
Part IV: Ice Cream
22. What is the purpose of using milk?
- Milk provides fats whose creaminess and richness contributes to its melting
characteristics.
23. What is the purpose of rock salt?
- Salt effectively lowers the freezing/melting point of water. By packing salt solution
around the ice-cream base, the rock salt solution provides a base cool enough to
allow freezing and thickening before ice melts completely.
24. What is the purpose of ice?
- It provides a cooler environment to allow the ice cream to get colder.
25. Why do we cook the milk?
- Cooking the milk gets rid of the microorganisms that may be present. These
organisms might ruin the ice cream once prepared
26. Why do you freeze the cream prior to churning?
- To prevent smaller ice crystals melt and then refreeze into larger ice crystals, which
increases the overall crystal size in the mix.
27. Why is sugar and a pinch of salt added to ice cream?
- Adding salt lowers the freezing temperature of the water and for wintery roads, it
means that the water won't freeze as easily.
- A pinch of sugar added and dissolved into the cream base to reduce the time it takes
to freeze.
28. Why is whipping cream added in making ice cream?
29. What is the purpose of vanilla extract? Or any extract added to ice cream?
- Vanilla
30. Why is pectin and stabilizer added? Give an example of each.
- Pectin is able to reduce the interfacial tension between an oil phase and a water
phase and can be efficient for the preparation of emulsions.
- Types of pectin include Citrus and Beet.
31. Why is carrageenan added to ice cream?
- Carrageenan is an additive that when added to ice cream, It thickens, binds and
prevents the ingredients from separating.
32. What is overrun? And, why it’s important to determine its percentage in ice cream?
- This refers to the amount of air pushed into the ice cream while it is being made.
33. What is the equation used to determine overrun?
-
Percentage Overrun = (
𝑉𝑜𝑙𝑢𝑚𝑒.𝑂𝑓 𝑖𝑐𝑒 𝑐𝑟𝑒𝑎𝑚 –𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑚𝑖𝑥 𝑢𝑠𝑒𝑑
Volume of mix used
) x 100
34. What is the purpose of churning and freezing ice cream?
- During the churning, the base is being frozen whilst air simultaneously i...