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Food Chemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. How does ERH relate to water activity?
ERH=100 x Aw
.05 M HCL
Blue pigment in flowers
Polyphenol Oxidase

2. How does ERH relate to water activity?
ERH=100 x Aw
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Two aldehydes
Monosodium Glutamate

3. What is Carboxy-methyl cellulose often used for?
Emulsoids
Thickener in foods
Pectins
pH 3-5

4. Name two reasons why fats are hydrogenated.
Gliadins and Glutenins
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Arachidonic Acid
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

5. Name 4 advantages of using enzymes in food processing.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
They are natural - nontoxic substances - generally catalyze without unwanted side-effects - active under very mild conditions of temperature and pH - active at low concentrations - rate of reaction can be controlled - can be inactivated after reactio
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Carrageenan

6. What is the main class of color compounds found in raspberries?
14
An enzyme that converts hydrogen peroxide to water plus oxygen.
Anthocyanins
Bitter

7. What is the Peroxide Value a measure of?
Negative log of the hydrogen concentration (mol/l).
Phenophylin
Fat Oxidation
Phenophylin

8. What is the winterization process for an oil?
Chitin
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
DNA transferred by cell to cell contact (bacterial sex).

9. Name the two components that comprise the relaxing factor in muscle fibers.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenoloxidase
Troponins and Tropomyosin
Phenylketonuria

10. What is the Peroxide Value a measure of?
Fat Oxidation
Initiation - Propagation - and Termination
HLB (hydrophilic-lipophilic balance); a low value (3-6) promotes water in oil emulsions and a high value (8-18) promotes oil in water emulsions.
Blue pigment in flowers

11. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Chlocophyllide does not have a phytoltail
Linoleic Acid
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

12. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Pectin Esterase - Polygalacturonase - Pectin Layase
Milk
Two aldehydes
Thamautin

13. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
45% - 52% - 90%
Initiation - Propagation - Termination
Racemic Mixture

14. What is the protein efficiency ratio (PER) of casein?
2.5
Arachidonic Acid
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
No

15. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Gliadins and Glutenins
pH below positive charge; pH at no charge; pH above negative charge
Oil in Water

16. What does the acronym NPN stand for?
Non-protein nitrogen
Pheophytin forms
Glycosides of anthocyanidins
Gliadins and Glutenins

17. What are the three stages of oxidative rancidity?
Linoleic Acid
RNA transcribed to DNA
Degradation of protein and production of acid from sugar at the same time.
Initiation - Propagation - and Termination

18. In what food is butyric acid typically found?
Browning of freshly cut surfaces of fruits and vegetables.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Milk

19. What happens to chlorophyll on heating?
An enzyme that converts hydrogen peroxide to water plus oxygen.
14
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Pheophytin forms

20. What does HLB stand for and What does a high and low HLB value indicate?
.05
HLB (hydrophilic-lipophilic balance); a low value (3-6) promotes water in oil emulsions and a high value (8-18) promotes oil in water emulsions.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Degradation of protein and production of acid from sugar at the same time.

21. In genetics What is conjugation?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Capsaicin
.05 M HCL
DNA transferred by cell to cell contact (bacterial sex).

22. Name three effects of protein denaturation.
Gliadins and Glutenins
.05 M HCL
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

23. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Polyphenols
Bitter
Pectins
1 - 3 - 7-trimethylxanthine

24. What are 3 mesomorphic structures associated with lipids in the liquid state?
Pectin Esterase - Polygalacturonase - Pectin Layase
Lamellar; Hexagonal I - II; Cubic
Sucrose
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

25. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Polyphenols
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

26. What are colloids that are stabilized by a layer of solvation called?
Water
Acetoin
Milk
Emulsoids

27. What is the acid present in fish oil?
Sucrose
Browning of freshly cut surfaces of fruits and vegetables.
Arachidonic Acid
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

28. What are the primary secondary - tertiary - and quaternary structures?
Primary-amino acid sequence. Secondary-alpha-helix - beta sheet. Tertiary-one complete protein chain with cross bonds linking it together. Quaternary-four separate protein chains assembled as one.
Orange Juice
An enzyme that converts hydrogen peroxide to water plus oxygen.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

29. Name 5 proteins with good foaming properties.
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Yellow
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

30. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

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31. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Negative log of the hydrogen concentration (mol/l).
Prolamines
Water
Carrageenan

32. What does MSG stand for?
Chlocophyllide does not have a phytoltail
Monosodium Glutamate
Polyphenoloxidase
Thermus Aqauticus

33. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
D: None of the above
Ammonia - Water - Carbon Dioxide
Plasmids

34. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Oil in Water
Two aldehydes
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

35. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
A concentrate of microfibrillar proteins of fish muscle.
They are natural - nontoxic substances - generally catalyze without unwanted side-effects - active under very mild conditions of temperature and pH - active at low concentrations - rate of reaction can be controlled - can be inactivated after reactio
20 carbons and 4 double bonds

36. What does Acid Degree Value measure and how is it measured?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Tryptophan
Thickener in foods
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

37. How can a molecular weight of protein - DNA - and RNA be determined?
pH 3-5
Emulsification
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Sweet - Salty - Sour - and Bitter

38. Name three factors useful in controlling enzyme activity.
Lipase
Acetoin
Phenophylin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

39. What is the chemical nature of anthocyanins?
Anthocyanins
Glycosides of anthocyanidins
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Carrageenan

40. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Covalent (strongest) and Hydrophobic (Weakest)
Thermus Aqauticus
Sodium bicarbonate generates CO2

41. Name two non-enzymatic browning reactions.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Osmosis
Carmelization and Maillard
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

42. What is acid proteolysis?
Non-protein nitrogen
Degradation of protein and production of acid from sugar at the same time.
Polyphenoloxidase
Oil in Water

43. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Linoleic Acid
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti

44. How many carbon atoms are there in the fatty acid myristic acid?
Initiation - Propagation - Termination
Chlocophyllide does not have a phytoltail
14
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

45. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Milk
Initiation - Propagation - Termination
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Yellow

46. Alar is the trade name for what chemical compound?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Pectin Esterase - Polygalacturonase - Pectin Layase
Daminozide

47. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Four
Daminozide
Initiation - Propagation - and Termination
Carrageenan

48. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
Covalent (strongest) and Hydrophobic (Weakest)
Onions ( or leeks)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

49. What is an isomer that is cheaper than Vitamin C?
Lysine - Arginine - and Histidine
Aspartic Acid and Phenylalanine
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Erythorbic Acid

50. Does kosmotrophil ion discourage water structure?
Lysine - Arginine - and Histidine
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
.05
No