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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 3 chemical agents capable of denaturing proteins.
Monosodium Glutamate
Plasmids
Speed of Light
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

2. What is the enzyme responsible for browning in apples and lettuce?
Pheophytin forms
Polyphenol Oxidase
Aspartic Acid and Phenylalanine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

3. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Troponins and Tropomyosin
1 - 3 - 7-trimethylxanthine
pH 3-5

4. Name the strongest biochemical bond and the weakest biochemical bond.
NaCl (it dissociated to a 2M solution)
Two aldehydes
Covalent (strongest) and Hydrophobic (Weakest)
Troponins and Tropomyosin

5. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
pH below positive charge; pH at no charge; pH above negative charge
Milk
It explodes

6. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Chlocophyllide does not have a phytoltail
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
A concentrate of microfibrillar proteins of fish muscle.

7. What are the three stages of oxidative rancidity?
Lysine - Arginine - and Histidine
Initiation - Propagation - and Termination
Covalent (strongest) and Hydrophobic (Weakest)
A concentrate of microfibrillar proteins of fish muscle.

8. What ketohexose is most significant to food chemists?
Fructose
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Capsaicin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

9. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Ammonia - Water - Carbon Dioxide
Ascorbic Acid and Citric Acid
Daminozide

10. Alar is the trade name for what chemical compound?
Milk
Gliadins and Glutenins
Daminozide
Carmelization and Maillard

11. What are the primary secondary - tertiary - and quaternary structures?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Sodium bicarbonate generates CO2
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
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.

12. Name a naturally occurring protein sweetener.
Negative log of the hydrogen concentration (mol/l).
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Thamautin

13. How can a molecular weight of protein - DNA - and RNA be determined?
Water
Oil in Water
Sucrose
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

14. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Sodium bicarbonate generates CO2
Initiation - Propagation - Termination
Negative log of the hydrogen concentration (mol/l).

15. Waxes are composed of what two basic chemical entities?
Four
Fatty Acid (Ester linked) to Fatty Alcohol
2.5
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

16. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Yellow

17. What is a polymorphism?
Emulsoids
Negative log of the hydrogen concentration (mol/l).
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Monosodium Glutamate

18. What does Reichert-Meissert Number measure?
Gossypol (it is removed during the oil refining process)
Negative log of the hydrogen concentration (mol/l).
Pectin methyl esterase or galacturonase
Primary butyric acid also caproic acid.

19. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
Pectin methylesterase & polygalacturonase
Daminozide
14
Browning of freshly cut surfaces of fruits and vegetables.

20. Is a disaccharide
Sucrose
Emulsification
Non-protein nitrogen
Arachidonic Acid

21. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Polyphenol Oxidase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acetoin
Parabens

22. Name the three positively charged amino acids.
Thamautin
Lysine - Arginine - and Histidine
Oil in Water
Orange Juice

23. What is Carboxy-methyl cellulose often used for?
Thickener in foods
14
Tryptophan
Bitter

24. What is the protein efficiency ratio (PER) of casein?
2.5
Oil in Water
14
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.

25. How can a molecular weight of protein - DNA - and RNA be determined?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
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
Sucrose
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

26. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
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
Polyphenol Oxidase
Pectin methyl esterase or galacturonase
Aspartic Acid and Phenylalanine

27. What are two common reducing agents that break disulfide bonds in proteins?
Pheophytin forms
They act as catalysts - speeding the polymerization of acrylamide.
A concentrate of microfibrillar proteins of fish muscle.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

28. Name one way foam stability can be assessed.
The degree of liquid drainage or foam collapse (foam reduction) after a given time - the time for total or half-drainage (or half-reduction in volume) - or the time before drainage starts.
Sucrose
Initiation - Propagation - and Termination
Milk

29. Name 5 chelating agents used in the food industry.
Carrageenan
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lycopenes
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

30. Alar is the trade name for what chemical compound?
Carmelization and Maillard
They act as catalysts - speeding the polymerization of acrylamide.
Chlocophyllide does not have a phytoltail
Daminozide

31. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Olive Green
Acetoin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

32. In genetics What is conjugation?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
DNA transferred by cell to cell contact (bacterial sex).
NaCl (it dissociated to a 2M solution)
Tryptophan

33. In what food is butyric acid typically found?
Milk
pH 3-5
They act as catalysts - speeding the polymerization of acrylamide.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

34. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Negative log of the hydrogen concentration (mol/l).

35. What is the name of the degradation compound of chlorophyll?
Browning of freshly cut surfaces of fruits and vegetables.
Thamautin
pH 3-5
Phenophylin

36. What enzyme causes hyrolytic rancidity in milk?
Fatty Acid (Ester linked) to Fatty Alcohol
Emulsification
Lipase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

37. Name 3 physical agents capable of denaturing proteins.
Pectin Esterase - Polygalacturonase - Pectin Layase
Blue pigment in flowers
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

38. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Acetoin
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Chlocophyllide does not have a phytoltail

39. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Gliadins and Glutenins
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
pH 3-5
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

40. Are sorbitol and mannitol sweet?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Yes
Water
Pectin methylesterase & polygalacturonase

41. What is the Peroxide Value a measure of?
Fat Oxidation
Anomeric
Pheophytia does not have magnesium in porphyrin ring.
Sweet - Salty - Sour - and Bitter

42. Name the two components that comprise the relaxing factor in muscle fibers.
Chitin
Chitin
Troponins and Tropomyosin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

43. Name the most common functional property of phospholipids in food systems.
It explodes
Emulsification
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Initiation - Propagation - and Termination

44. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Initiation - Propagation - Termination
45% - 52% - 90%
Cis
Oil in Water

45. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
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
pH below positive charge; pH at no charge; pH above negative charge
Water

46. What are the four basic flavors perceived by the tongue?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Sweet - Salty - Sour - and Bitter
Pectin methyl esterase or galacturonase
Olive Green

47. What is the winterization process for an oil?
pH 3-5
D: None of the above
.05 M HCL
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

48. How is pH defined?
Prolamines
Pheophytia does not have magnesium in porphyrin ring.
Cis
Negative log of the hydrogen concentration (mol/l).

49. What is catalase?
Bright green
Orange Juice
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
An enzyme that converts hydrogen peroxide to water plus oxygen.

50. What ketohexose is most significant to food chemists?
Daminozide
Sodium chloride reduces foam stability and sucrose improves foam stability.
Yellow
Fructose