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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 does the iodine value measure and how is it measured?
Yellow
Lysine - Arginine - and Histidine
V=IR and P=VI or I x I x are
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

2. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Capsaicin
NaCl (it dissociated to a 2M solution)
Olive Green

3. Name the most common functional property of phospholipids in food systems.
Emulsification
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.
Speed of Light
ERH=100 x Aw

4. Name a naturally occurring protein sweetener.
Chitin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Thamautin
Daminozide

5. What is an isomer that is cheaper than Vitamin C?
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
2.5
Erythorbic Acid
Parabens

6. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Prolamines
Thamautin
V=IR and P=VI or I x I x are

7. What are the three stages of oxidative rancidity?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Gliadins and Glutenins
Initiation - Propagation - and Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

8. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Primary butyric acid also caproic acid.
Chitin
It explodes
Osmosis

9. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pectin methylesterase & polygalacturonase
Onions ( or leeks)
.05 M HCL

10. What is Ohm's Law and What is Power Equation?
Chitin
Pheophytia does not have magnesium in porphyrin ring.
V=IR and P=VI or I x I x are
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

11. Name two enzymes that are involved in softening fruits.
Arachidonic Acid
Lamellar; Hexagonal I - II; Cubic
Pectin Esterase - Polygalacturonase - Pectin Layase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

12. Name three factors useful in controlling enzyme activity.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
2.5
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Emulsification

13. Contains the lowest content of water
Pectin methyl esterase or galacturonase
DNA transferred by cell to cell contact (bacterial sex).
Whole Milk
Covalent (strongest) and Hydrophobic (Weakest)

14. 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
It explodes
D: None of the above
Phenophylin
Carrageenan

15. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Sucrose
Degradation of protein and production of acid from sugar at the same time.

16. How is pH defined?
Glycosides of anthocyanidins
Negative log of the hydrogen concentration (mol/l).
Bitter
Emulsification

17. Name two non-enzymatic browning reactions.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Ammonia - Water - Carbon Dioxide
Carmelization and Maillard
Browning of freshly cut surfaces of fruits and vegetables.

18. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Monosodium Glutamate
Speed of Light
Sucrose

19. What does MSG stand for?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Pectin methyl esterase or galacturonase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Monosodium Glutamate

20. What is surimi?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pectin Esterase
A concentrate of microfibrillar proteins of fish muscle.
Four

21. Is a disaccharide
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Sucrose
.05
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

22. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin Esterase - Polygalacturonase - Pectin Layase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lycopenes

23. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
Phenophylin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Emulsoids

24. 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
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Anomeric
Gliadins and Glutenins

25. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Yes
Lipid oxidation
Milk

26. Name a commonly used household chemical leavening agent and the gas it generates.
NaCl (it dissociated to a 2M solution)
Arachidonic Acid
Nucleation or crystal formation and crystal growth.
Sodium bicarbonate generates CO2

27. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Troponins and Tropomyosin
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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.

28. How many carbon atoms and how many double bonds are there in arachidonic acid?
Water
20 carbons and 4 double bonds
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.
Water

29. In the enzyme Taq Polymerase What does Taq stand for?
Oil in Water
Osmosis
Thermus Aqauticus
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

30. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Covalent (strongest) and Hydrophobic (Weakest)
Phenylketonuria
Sucrose
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

31. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
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
Daminozide

32. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectin methyl esterase or galacturonase
Polyphenol Oxidase
Polyphenoloxidase

33. During freezing What are the two stages in the crystallization process?
Sodium chloride reduces foam stability and sucrose improves foam stability.
V=IR and P=VI or I x I x are
Nucleation or crystal formation and crystal growth.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

34. What are the three main steps in the autooxidation of lipids?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Troponins and Tropomyosin
Initiation - Propagation - Termination
Whole Milk

35. Contains the lowest content of water
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Whole Milk
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
They act as catalysts - speeding the polymerization of acrylamide.

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

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37. What is the structural difference between chlorophyll and chlocophyllide?
.05
Chlocophyllide does not have a phytoltail
V=IR and P=VI or I x I x are
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

38. What is the enzyme that softens tomatoes?
Water
1 - 3 - 7-trimethylxanthine
Pectin Esterase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

39. Name two non-enzymatic browning reactions.
Initiation - Propagation - and Termination
Carmelization and Maillard
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
No

40. Name three nonpolar polar - and charged amino acids.
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.
Lysine - Arginine - and Histidine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
45% - 52% - 90%

41. Will lipid oxidation be higher at a water activity of .05 or .5?
Arachidonic Acid
Acsulfame-K - Saccharin - Cyclamate - Aspartame
.05
No

42. What is the structural difference between chlorophyll and pheophytia?
Pectin Esterase
45% - 52% - 90%
Pheophytia does not have magnesium in porphyrin ring.
14

43. What effect would the addition of sodium bicarbonate have to chocolate?
Chlocophyllide does not have a phytoltail
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
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

44. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
HPLC has higher pressure than FPLC
Onions ( or leeks)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

45. Is a disaccharide
Carmelization and Maillard
Parabens
Sucrose
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

46. What happens to chlorophyll on heating?
Pheophytin forms
pH 3-5
Emulsification
Water

47. What are the only phenols approved for use in the microbiological preservation of foods?
Fructose
Milk
Pectin methyl esterase or galacturonase
Parabens

48. What is the major color compound in tomatoes?
Lycopenes
Bitter
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pectin methyl esterase or galacturonase

49. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Phenophylin
Primary butyric acid also caproic acid.
RNA transcribed to DNA
Acetoin

50. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
.05
Phenophylin
Thermus Aqauticus