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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 are the only phenols approved for use in the microbiological preservation of foods?
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.
Parabens
45% - 52% - 90%
pH 3-5

2. What is the acid present in fish oil?
Arachidonic Acid
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
It explodes
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

3. 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
Emulsoids
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
D: None of the above
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

4. Name 3 factors influencing the rate of lipid oxidation in foods.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Glycosides of anthocyanidins
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Phenylketonuria

5. Will lipid oxidation be higher at a water activity of .05 or .5?
Lysine - Arginine - and Histidine
.05
Negative log of the hydrogen concentration (mol/l).
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

6. What is Ohm's Law and What is Power Equation?
Fatty Acid (Ester linked) to Fatty Alcohol
Lipid oxidation
Water
V=IR and P=VI or I x I x are

7. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sodium chloride reduces foam stability and sucrose improves foam stability.
HPLC has higher pressure than FPLC
Gossypol (it is removed during the oil refining process)

8. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Emulsoids
Phenylketonuria
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Plasmids

9. Name two enzymes that are involved in softening fruits.
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
Thamautin
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Pectin Esterase - Polygalacturonase - Pectin Layase

10. What metabolic end product does the Voges-Proskauer test detect?
Oil in Water
Acetoin
Pectin methyl esterase or galacturonase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

11. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Monosodium Glutamate
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Olive Green
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

12. In the enzyme Taq Polymerase What does Taq stand for?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Thermus Aqauticus
Carrageenan
Emulsification

13. Is a disaccharide
Bitter
Sucrose
Nucleation or crystal formation and crystal growth.
Polyphenoloxidase

14. What does Acid Degree Value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Tryptophan

15. Name three factors useful in controlling enzyme activity.
20 carbons and 4 double bonds
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Pectins
Carmelization and Maillard

16. In genetics What is conjugation?
Gliadins and Glutenins
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
DNA transferred by cell to cell contact (bacterial sex).
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

17. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Gliadins and Glutenins
HPLC has higher pressure than FPLC
Sweet - Salty - Sour - and Bitter
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

18. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
V=IR and P=VI or I x I x are
NaCl (it dissociated to a 2M solution)
Thamautin

19. What is Carboxy-methyl cellulose often used for?
Sweet - Salty - Sour - and Bitter
Parabens
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Thickener in foods

20. What is acid proteolysis?
Polyphenoloxidase
Glycosides of anthocyanidins
HPLC has higher pressure than FPLC
Degradation of protein and production of acid from sugar at the same time.

21. How does ERH relate to water activity?
ERH=100 x Aw
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Non-protein nitrogen
Pectin methyl esterase or galacturonase

22. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Phenylketonuria
Erythorbic Acid
Pectin Esterase - Polygalacturonase - Pectin Layase

23. Contains the lowest content of water
Browning of freshly cut surfaces of fruits and vegetables.
Whole Milk
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Fatty Acid and Alcohol

24. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Degradation of protein and production of acid from sugar at the same time.
They act as catalysts - speeding the polymerization of acrylamide.
Fatty Acid (Ester linked) to Fatty Alcohol

25. Name 5 chelating agents used in the food industry.
Onions ( or leeks)
Anthocyanins
V=IR and P=VI or I x I x are
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

26. Alar is the trade name for what chemical compound?
Glycosides of anthocyanidins
Fat Oxidation
ERH=100 x Aw
Daminozide

27. Are sorbitol and mannitol sweet?
No
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
Phenophylin
Yes

28. What effect would the addition of sodium bicarbonate have to chocolate?
Daminozide
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Browning of freshly cut surfaces of fruits and vegetables.

29. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
No
Oil in Water
Two aldehydes
Pectins

30. What is the acid present in fish oil?
Osmosis
1 - 3 - 7-trimethylxanthine
Arachidonic Acid
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

31. Waxes are composed of what two basic chemical entities?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Linoleic Acid
Fatty Acid (Ester linked) to Fatty Alcohol
Phenophylin

32. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pectin methyl esterase or galacturonase
Pectins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH below positive charge; pH at no charge; pH above negative charge

33. What does HLB stand for and What does a high and low HLB value indicate?
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.
Fatty Acid (Ester linked) to Fatty Alcohol
Ammonia - Water - Carbon Dioxide
.05

34. What compounds oxidize to form brown color in fruits and vegetables?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Polyphenols
Phenylketonuria
2.5

35. What enzyme is most responsible for browning bananas?
V=IR and P=VI or I x I x are
Polyphenol Oxidase
D: None of the above
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.

36. What metabolic end product does the Voges-Proskauer test detect?
Phenylketonuria
Acetoin
Anomeric
Monosodium Glutamate

37. What does Reichert-Meissert Number measure?
Lysine - Arginine - and Histidine
Carmelization and Maillard
Primary butyric acid also caproic acid.
Chlocophyllide does not have a phytoltail

38. What does MSG stand for?
Monosodium Glutamate
Orange Juice
They act as catalysts - speeding the polymerization of acrylamide.
pH below positive charge; pH at no charge; pH above negative charge

39. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Two aldehydes
Water
Primary butyric acid also caproic acid.

40. Name three effects of protein denaturation.
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.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Fatty Acid (Ester linked) to Fatty Alcohol
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

41. What is the winterization process for an oil?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
They act as catalysts - speeding the polymerization of acrylamide.
Sodium chloride reduces foam stability and sucrose improves foam stability.

42. What is the main class of color compounds found in raspberries?
Anthocyanins
Initiation - Propagation - Termination
Parabens
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.

43. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Carrageenan
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
Orange Juice

44. What is the main class of color compounds found in raspberries?
Linoleic Acid
Anthocyanins
Pectins
Ascorbic Acid and Citric Acid

45. What is the chemical nomenclature for caffeine?
Bitter
Phenophylin
1 - 3 - 7-trimethylxanthine
D: None of the above

46. What does HLB stand for and What does a high and low HLB value indicate?
They act as catalysts - speeding the polymerization of acrylamide.
Water
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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.

47. What is the chemical nomenclature for caffeine?
Tryptophan
1 - 3 - 7-trimethylxanthine
Lysine - Arginine - and Histidine
Thickener in foods

48. 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?
It explodes
Tryptophan
Whole Milk
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

49. What enzyme is most responsible for browning bananas?
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenol Oxidase
Troponins and Tropomyosin
Yes

50. What is the name given to a mixture of equal parts of Darel Lisomers?
Chlocophyllide does not have a phytoltail
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Racemic Mixture
Emulsification