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Food Chemistry

Instructions:

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 is an isomer that is cheaper than Vitamin C?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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
Lamellar; Hexagonal I - II; Cubic
Erythorbic Acid

2. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Gossypol (it is removed during the oil refining process)
Pheophytin forms
Linoleic Acid

3. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Oil in Water
Fatty Acid and Alcohol
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

4. What are two common reducing agents that break disulfide bonds in proteins?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Lipase
Non-protein nitrogen
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

5. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
pH 3-5
Arachidonic Acid
Oil in Water

6. Does kosmotrophil ion discourage water structure?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
No
Covalent (strongest) and Hydrophobic (Weakest)
Polyphenol Oxidase

7. What is the acid present in fish oil?
Pheophytin forms
Arachidonic Acid
Initiation - Propagation - and Termination
Olive Green

8. Are sorbitol and mannitol sweet?
Yes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Carmelization and Maillard
They act as catalysts - speeding the polymerization of acrylamide.

9. Are sorbitol and mannitol sweet?
Olive Green
The speed of a molecule is proportional to the surrounding voltage gradient.
Yes
Four

10. What does MSG stand for?
Monosodium Glutamate
RNA transcribed to DNA
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.
Daminozide

11. What does HLB stand for and What does a high and low HLB value indicate?
1 - 3 - 7-trimethylxanthine
Water
Pectin methylesterase & polygalacturonase
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.

12. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Capsaicin
Ascorbic Acid and Citric Acid
Lipid oxidation

13. What is the structural difference between chlorophyll and pheophytia?
Erythorbic Acid
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
1 - 3 - 7-trimethylxanthine
Pheophytia does not have magnesium in porphyrin ring.

14. Alar is the trade name for what chemical compound?
Daminozide
Milk
1 - 3 - 7-trimethylxanthine
Polyphenol Oxidase

15. How can a molecular weight of protein - DNA - and RNA be determined?
Bright green
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Nucleation or crystal formation and crystal growth.
HPLC has higher pressure than FPLC

16. What compounds oxidize to form brown color in fruits and vegetables?
Plasmids
Polyphenols
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Pectin Esterase

17. What are the primary secondary - tertiary - and quaternary structures?
Oil in Water
Anthocyanins
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.
D: None of the above

18. Name 5 chelating agents used in the food industry.
Plasmids
Thermus Aqauticus
Polyphenol Oxidase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

19. How does ERH relate to water activity?
Tryptophan
Racemic Mixture
Parabens
ERH=100 x Aw

20. What ketohexose is most significant to food chemists?
Fructose
Thickener in foods
Osmosis
Whole Milk

21. What is acid proteolysis?
Sucrose
Aspartic Acid and Phenylalanine
Onions ( or leeks)
Degradation of protein and production of acid from sugar at the same time.

22. What is surimi?
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
D: None of the above
ERH=100 x Aw
A concentrate of microfibrillar proteins of fish muscle.

23. How many carbon atoms and how many double bonds are there in arachidonic acid?
Four
.05 M HCL
No
20 carbons and 4 double bonds

24. What does Reichert-Meissert Number measure?
Capsaicin
Pectin methyl esterase or galacturonase
Primary butyric acid also caproic acid.
Water

25. What is the chemical nomenclature for caffeine?
Browning of freshly cut surfaces of fruits and vegetables.
Lycopenes
1 - 3 - 7-trimethylxanthine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

26. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Initiation - Propagation - Termination
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
RNA transcribed to DNA

27. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Linoleic Acid
Pectins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

28. Is a disaccharide
Thermus Aqauticus
Carrageenan
ERH=100 x Aw
Sucrose

29. Name the two components that comprise the relaxing factor in muscle fibers.
Pectin methylesterase & polygalacturonase
Troponins and Tropomyosin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
HPLC has higher pressure than FPLC

30. Name two non-enzymatic browning reactions.
Aspartic Acid and Phenylalanine
Fatty Acid and Alcohol
Pheophytin forms
Carmelization and Maillard

31. What is the main class of color compounds found in raspberries?
It explodes
Anthocyanins
Gliadins and Glutenins
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

32. 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
Two aldehydes
Carmelization and Maillard
Osmosis
Browning of freshly cut surfaces of fruits and vegetables.

33. What are the limiting amino acids in corn - potato - and green peas?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Yellow
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

34. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
Daminozide
No
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

35. What is Ohm's Law and What is Power Equation?
Plasmids
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
V=IR and P=VI or I x I x are
An enzyme that converts hydrogen peroxide to water plus oxygen.

36. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Covalent (strongest) and Hydrophobic (Weakest)
Oil in Water

37. Will lipid oxidation be higher at a water activity of .05 or .5?
Fatty Acid and Alcohol
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Tryptophan
.05

38. 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
Water
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

39. What are the three main steps in the autooxidation of lipids?
Osmosis
Initiation - Propagation - Termination
Aspartic Acid and Phenylalanine
Emulsoids

40. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Prolamines
They act as catalysts - speeding the polymerization of acrylamide.
Milk
ERH=100 x Aw

41. What is the geometric configuration of double bonds in most natural fatty acids?
14
Nucleation or crystal formation and crystal growth.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Cis

42. What does the iodine value measure and how is it measured?
D: None of the above
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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
Plasmids

43. What are the fructose contents in commercial HFCS products.
It explodes
Cis
Thamautin
45% - 52% - 90%

44. What does the saponification value measure and how is it measured?
pH 3-5
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Gossypol (it is removed during the oil refining process)
Water

45. How many polypeptide chains make up an antibody?
Fructose
Troponins and Tropomyosin
Four
Acsulfame-K - Saccharin - Cyclamate - Aspartame

46. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Lamellar; Hexagonal I - II; Cubic
Emulsification
Plasmids

47. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Phenophylin
Tryptophan
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

48. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Cis
Erythorbic Acid
Non-protein nitrogen

49. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Osmosis
Daminozide
Polyphenoloxidase

50. Name the three positively charged amino acids.
Thermus Aqauticus
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lysine - Arginine - and Histidine
An enzyme that converts hydrogen peroxide to water plus oxygen.