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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What pigment was first designated as anthocyanins?
Nucleation or crystal formation and crystal growth.
Blue pigment in flowers
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Covalent (strongest) and Hydrophobic (Weakest)

2. Alar is the trade name for what chemical compound?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.
Daminozide
Sucrose

3. Name three factors useful in controlling enzyme activity.
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.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Two aldehydes

4. 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
V=IR and P=VI or I x I x are
Four
Polyphenol Oxidase
Browning of freshly cut surfaces of fruits and vegetables.

5. What enzyme causes hyrolytic rancidity in milk?
Lipase
Daminozide
Pectin methyl esterase or galacturonase
Pectin Esterase - Polygalacturonase - Pectin Layase

6. When heated ammonium bicarbonate decomposes to form what end products?
Covalent (strongest) and Hydrophobic (Weakest)
Degradation of protein and production of acid from sugar at the same time.
Ammonia - Water - Carbon Dioxide
Pectin Esterase

7. What enzyme causes hyrolytic rancidity in milk?
Lipase
NaCl (it dissociated to a 2M solution)
Fructose
They act as catalysts - speeding the polymerization of acrylamide.

8. 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
The speed of a molecule is proportional to the surrounding voltage gradient.
Browning of freshly cut surfaces of fruits and vegetables.
Degradation of protein and production of acid from sugar at the same time.
Glycosides of anthocyanidins

9. In what food is butyric acid typically found?
Fat Oxidation
Olive Green
Thickener in foods
Milk

10. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
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.
Prolamines
Polyphenoloxidase
No

11. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Carrageenan
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Prolamines
Bright green

12. How does ERH relate to water activity?
ERH=100 x Aw
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lamellar; Hexagonal I - II; Cubic
Bitter

13. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Primary butyric acid also caproic acid.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pheophytin forms
2.5

14. Name 3 factors influencing the rate of lipid oxidation in foods.
Initiation - Propagation - and Termination
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Carrageenan
Cis

15. What are the limiting amino acids in corn - potato - and green peas?
Initiation - Propagation - Termination
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Pectin Esterase
Gliadins and Glutenins

16. What is the Peroxide Value a measure of?
Racemic Mixture
ERH=100 x Aw
Pectin Esterase - Polygalacturonase - Pectin Layase
Fat Oxidation

17. Is a disaccharide
Pectin methyl esterase or galacturonase
Whole Milk
Sucrose
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

18. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Pectin Esterase
Two aldehydes
Yes
Water

19. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Chlocophyllide does not have a phytoltail
1 - 3 - 7-trimethylxanthine

20. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Bright green
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Anthocyanins
Polyphenol Oxidase

21. Name 4 advantages of using enzymes in food processing.
Bright green
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
Primary butyric acid also caproic acid.
HPLC has higher pressure than FPLC

22. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Anthocyanins
Osmosis
Pheophytin forms

23. What is the enzyme that softens tomatoes?
Fructose
Pheophytin forms
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectin Esterase

24. Name 5 proteins with good foaming properties.
Degradation of protein and production of acid from sugar at the same time.
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.
Polyphenols
Acetoin

25. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Blue pigment in flowers
Prolamines
Pectin methyl esterase or galacturonase
Pectin Esterase - Polygalacturonase - Pectin Layase

26. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Milk
Chitin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

27. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
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
Olive Green
V=IR and P=VI or I x I x are
Primary butyric acid also caproic acid.

28. What is the name given to a mixture of equal parts of Darel Lisomers?
Gossypol (it is removed during the oil refining process)
Fatty Acid (Ester linked) to Fatty Alcohol
Racemic Mixture
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.

29. During freezing What are the two stages in the crystallization process?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Nucleation or crystal formation and crystal growth.
Speed of Light
Whole Milk

30. Name a naturally occurring protein sweetener.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pheophytia does not have magnesium in porphyrin ring.
20 carbons and 4 double bonds
Thamautin

31. Name the most common functional property of phospholipids in food systems.
Gliadins and Glutenins
Onions ( or leeks)
Emulsification
RNA transcribed to DNA

32. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Sweet - Salty - Sour - and Bitter
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
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

33. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Browning of freshly cut surfaces of fruits and vegetables.
Daminozide
Negative log of the hydrogen concentration (mol/l).

34. How can a molecular weight of protein - DNA - and RNA be determined?
Bitter
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Osmosis

35. Name 3 chemical agents capable of denaturing proteins.
14
Thickener in foods
20 carbons and 4 double bonds
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

36. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
1 - 3 - 7-trimethylxanthine
Lipid oxidation
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

37. What does HLB stand for and What does a high and low HLB value indicate?
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenoloxidase
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

38. Name three effects of protein denaturation.
Pectins
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

39. What happens to chlorophyll on heating?
Nucleation or crystal formation and crystal growth.
Pectin methylesterase & polygalacturonase
Pheophytin forms
Pectin methyl esterase or galacturonase

40. What are the primary secondary - tertiary - and quaternary structures?
Fatty Acid (Ester linked) to Fatty Alcohol
Lipase
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.
Carrageenan

41. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Anthocyanins
2.5
pH below positive charge; pH at no charge; pH above negative charge
Pheophytia does not have magnesium in porphyrin ring.

42. What is the enzyme responsible for browning in apples and lettuce?
Yes
It explodes
Polyphenol Oxidase
Milk

43. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Acsulfame-K - Saccharin - Cyclamate - Aspartame
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

44. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Fatty Acid and Alcohol
V=IR and P=VI or I x I x are
pH 3-5

45. Name three nonpolar polar - and charged amino acids.
Thamautin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Carmelization and Maillard
No

46. How do sodium chloride and sucrose affect foam stability?
Plasmids
Sodium chloride reduces foam stability and sucrose improves foam stability.
Carmelization and Maillard
Pheophytia does not have magnesium in porphyrin ring.

47. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Erythorbic Acid
Carrageenan
Sodium chloride reduces foam stability and sucrose improves foam stability.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

48. What does the saponification value measure and how is it measured?
Fat Oxidation
NaCl (it dissociated to a 2M solution)
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
They act as catalysts - speeding the polymerization of acrylamide.

49. Waxes are composed of what two basic chemical entities?
Fat Oxidation
Polyphenol Oxidase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Fatty Acid (Ester linked) to Fatty Alcohol

50. What is Ohm's Law and What is Power Equation?
Polyphenol Oxidase
V=IR and P=VI or I x I x are
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lamellar; Hexagonal I - II; Cubic