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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. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Glycosides of anthocyanidins
.05 M HCL
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

2. What is acid proteolysis?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
They act as catalysts - speeding the polymerization of acrylamide.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Degradation of protein and production of acid from sugar at the same time.

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

4. What is the chemical nature of anthocyanins?
V=IR and P=VI or I x I x are
Fatty Acid (Ester linked) to Fatty Alcohol
Glycosides of anthocyanidins
Degradation of protein and production of acid from sugar at the same time.

5. What is the major color compound in tomatoes?
14
Glycosides of anthocyanidins
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Lycopenes

6. What effect would the addition of sodium bicarbonate have to chocolate?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Carrageenan

7. What is the name given to a mixture of equal parts of Darel Lisomers?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Racemic Mixture
Non-protein nitrogen
Polyphenol Oxidase

8. How does ERH relate to water activity?
.05
Gliadins and Glutenins
ERH=100 x Aw
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

9. What two types of compounds are joined with an ester bond to make a wax?
Olive Green
Yes
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty Acid and Alcohol

10. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Browning of freshly cut surfaces of fruits and vegetables.
pH below positive charge; pH at no charge; pH above negative charge
Thermus Aqauticus
No

11. What two types of compounds are joined with an ester bond to make a wax?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Nucleation or crystal formation and crystal growth.
Fatty Acid and Alcohol
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

12. Name the three positively charged amino acids.
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).
Lysine - Arginine - and Histidine
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

13. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase
Olive Green

14. What compounds oxidize to form brown color in fruits and vegetables?
Orange Juice
Polyphenols
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

15. Name three effects of protein denaturation.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chitin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Phenophylin

16. At low water activity What is the main deteriorative concern?
Glycosides of anthocyanidins
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.
Pheophytin forms
Lipid oxidation

17. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenoloxidase
Degradation of protein and production of acid from sugar at the same time.

18. Name 5 chelating agents used in the food industry.
Thamautin
DNA transferred by cell to cell contact (bacterial sex).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

19. In what food is butyric acid typically found?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Milk
Phenophylin

20. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Daminozide
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
An enzyme that converts hydrogen peroxide to water plus oxygen.

21. How is pH defined?
An enzyme that converts hydrogen peroxide to water plus oxygen.
It explodes
Negative log of the hydrogen concentration (mol/l).
.05

22. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
D: None of the above
Yellow
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
14

23. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Monosodium Glutamate
Bitter
Pheophytin forms

24. How many carbon atoms are there in the fatty acid myristic acid?
14
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
pH below positive charge; pH at no charge; pH above negative charge
Pheophytia does not have magnesium in porphyrin ring.

25. Name three nonpolar polar - and charged amino acids.
Polyphenol Oxidase
Phenylketonuria
Carmelization and Maillard
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

26. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
1 - 3 - 7-trimethylxanthine
No
Fat Oxidation
Orange Juice

27. Alar is the trade name for what chemical compound?
Chlocophyllide does not have a phytoltail
Daminozide
Aspartic Acid and Phenylalanine
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

28. What is Carboxy-methyl cellulose often used for?
45% - 52% - 90%
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Thickener in foods
Pheophytia does not have magnesium in porphyrin ring.

29. 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
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.
Browning of freshly cut surfaces of fruits and vegetables.
Polyphenol Oxidase
Polyphenol Oxidase

30. During freezing What are the two stages in the crystallization process?
Water
Nucleation or crystal formation and crystal growth.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pheophytin forms

31. 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?
Water
Orange Juice
Nucleation or crystal formation and crystal growth.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

32. How many carbon atoms and how many double bonds are there in arachidonic acid?
Lamellar; Hexagonal I - II; Cubic
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
20 carbons and 4 double bonds
Fatty Acid and Alcohol

33. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
Erythorbic Acid
Polyphenols
.05 M HCL

34. Name 3 chemical agents capable of denaturing proteins.
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.
Whole Milk
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

35. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
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.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pectins

36. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Thermus Aqauticus
Onions ( or leeks)
Pectin methyl esterase or galacturonase

37. 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 methylesterase & polygalacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.
Water
Sucrose

38. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Carmelization and Maillard
The speed of a molecule is proportional to the surrounding voltage gradient.

39. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Pheophytia does not have magnesium in porphyrin ring.
Ammonia - Water - Carbon Dioxide
Capsaicin

40. What does Acid Degree Value measure and how is it measured?
Daminozide
Four
Yes
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

41. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Fructose
Carrageenan
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

42. What is the chemical nature of anthocyanins?
Cis
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Glycosides of anthocyanidins

43. Contains the lowest content of water
Troponins and Tropomyosin
Polyphenols
Non-protein nitrogen
Whole Milk

44. What toxic pigment is found in cottonseed endosperm?
Bitter
Gossypol (it is removed during the oil refining process)
Arachidonic Acid
Chitin

45. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Phenophylin
Parabens
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

46. During freezing What are the two stages in the crystallization process?
Daminozide
Sucrose
HPLC has higher pressure than FPLC
Nucleation or crystal formation and crystal growth.

47. 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?
pH 3-5
Nucleation or crystal formation and crystal growth.
It explodes
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

48. 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.
Whole Milk
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
DNA transferred by cell to cell contact (bacterial sex).

49. Is a disaccharide
Bright green
Sucrose
Pheophytin forms
It explodes

50. What toxic pigment is found in cottonseed endosperm?
Pectin methyl esterase or galacturonase
Phenophylin
Gossypol (it is removed during the oil refining process)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.