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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. How does ERH relate to water activity?
Lysine - Arginine - and Histidine
Ammonia - Water - Carbon Dioxide
Onions ( or leeks)
ERH=100 x Aw

2. Waxes are composed of what two basic chemical entities?
.05
Fatty Acid (Ester linked) to Fatty Alcohol
Browning of freshly cut surfaces of fruits and vegetables.
Pectin Esterase

3. When heated ammonium bicarbonate decomposes to form what end products?
Bitter
Water
Ammonia - Water - Carbon Dioxide
No

4. 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?
1 - 3 - 7-trimethylxanthine
V=IR and P=VI or I x I x are
It explodes
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

5. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Fatty Acid (Ester linked) to Fatty Alcohol
14
Chitin
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

6. Name 4 advantages of using enzymes in food processing.
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
HPLC has higher pressure than FPLC
Linoleic Acid
Speed of Light

7. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
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
Racemic Mixture
V=IR and P=VI or I x I x are

8. What is acid proteolysis?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lamellar; Hexagonal I - II; Cubic
Degradation of protein and production of acid from sugar at the same time.
Cis

9. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
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
Pectins
Yes

10. At what pH is benzoic acid most effective?
Lipid oxidation
2.5
Pectin Esterase - Polygalacturonase - Pectin Layase
pH 3-5

11. What is acid proteolysis?
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.
NaCl (it dissociated to a 2M solution)
Degradation of protein and production of acid from sugar at the same time.
Bright green

12. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Pheophytia does not have magnesium in porphyrin ring.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Glycosides of anthocyanidins

13. What ketohexose is most significant to food chemists?
Speed of Light
Troponins and Tropomyosin
Fructose
NaCl (it dissociated to a 2M solution)

14. What is the enzyme that softens tomatoes?
Covalent (strongest) and Hydrophobic (Weakest)
Aspartic Acid and Phenylalanine
Pectin Esterase
Chlocophyllide does not have a phytoltail

15. What metabolic end product does the Voges-Proskauer test detect?
Anomeric
Fatty Acid and Alcohol
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Acetoin

16. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Polyphenol Oxidase
Pectin methylesterase & polygalacturonase
Bitter
Thermus Aqauticus

17. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bitter
Bright green
Cis
Pectin Esterase - Polygalacturonase - Pectin Layase

18. Name the three positively charged amino acids.
Thermus Aqauticus
.05 M HCL
Anomeric
Lysine - Arginine - and Histidine

19. What compounds oxidize to form brown color in fruits and vegetables?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Oil in Water
Polyphenols
Pectin methylesterase & polygalacturonase

20. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Pectin methylesterase & polygalacturonase
Sucrose
It explodes

21. What is catalase?
Primary butyric acid also caproic acid.
Bright green
D: None of the above
An enzyme that converts hydrogen peroxide to water plus oxygen.

22. What are the primary secondary - tertiary - and quaternary structures?
Arachidonic Acid
Acetoin
Prolamines
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.

23. Is a disaccharide
Fructose
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Water
Sucrose

24. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Fat Oxidation
Lysine - Arginine - and Histidine
Polyphenoloxidase

25. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Chlocophyllide does not have a phytoltail
Fructose
Ammonia - Water - Carbon Dioxide

26. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Browning of freshly cut surfaces of fruits and vegetables.
An enzyme that converts hydrogen peroxide to water plus oxygen.
ERH=100 x Aw

27. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
V=IR and P=VI or I x I x are
Plasmids
Polyphenoloxidase

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

29. What enzyme causes hyrolytic rancidity in milk?
Acetoin
Lipase
Aspartic Acid and Phenylalanine
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

30. What is the winterization process for an oil?
Negative log of the hydrogen concentration (mol/l).
Pectin Esterase
Monosodium Glutamate
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

31. Name three factors useful in controlling enzyme activity.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Prolamines
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lycopenes

32. 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
Pectin Esterase - Polygalacturonase - Pectin Layase
D: None of the above
Lycopenes
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

33. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Sodium bicarbonate generates CO2
20 carbons and 4 double bonds
Erythorbic Acid

34. How many carbon atoms are there in the fatty acid myristic acid?
It explodes
14
1 - 3 - 7-trimethylxanthine
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

35. What does the 'c' stand for in the equation E=mc2?
Onions ( or leeks)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Speed of Light
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

36. During freezing What are the two stages in the crystallization process?
Lamellar; Hexagonal I - II; Cubic
Sodium chloride reduces foam stability and sucrose improves foam stability.
Acetoin
Nucleation or crystal formation and crystal growth.

37. What is the protein efficiency ratio (PER) of casein?
Pectin Esterase
2.5
A concentrate of microfibrillar proteins of fish muscle.
ERH=100 x Aw

38. In the enzyme Taq Polymerase What does Taq stand for?
Polyphenoloxidase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Thermus Aqauticus
Linoleic Acid

39. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
.05 M HCL
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water

40. What are two common reducing agents that break disulfide bonds in proteins?
Osmosis
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fatty Acid (Ester linked) to Fatty Alcohol
D: None of the above

41. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Pectin Esterase - Polygalacturonase - Pectin Layase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
NaCl (it dissociated to a 2M solution)
Plasmids

42. What enzyme causes hyrolytic rancidity in milk?
Lipid oxidation
Lipase
Degradation of protein and production of acid from sugar at the same time.
Monosodium Glutamate

43. Name the two components that comprise the relaxing factor in muscle fibers.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
V=IR and P=VI or I x I x are
Chitin
Troponins and Tropomyosin

44. Name the most common functional property of phospholipids in food systems.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Emulsification
Carrageenan
Lipase

45. Name a naturally occurring protein sweetener.
Thamautin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
pH 3-5
pH below positive charge; pH at no charge; pH above negative charge

46. Name a commonly used household chemical leavening agent and the gas it generates.
It explodes
Sodium bicarbonate generates CO2
Covalent (strongest) and Hydrophobic (Weakest)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

47. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
RNA transcribed to DNA
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
A concentrate of microfibrillar proteins of fish muscle.

48. What is an isomer that is cheaper than Vitamin C?
Primary butyric acid also caproic acid.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Erythorbic Acid
Speed of Light

49. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Capsaicin
Anomeric
Olive Green
It explodes

50. What are colloids that are stabilized by a layer of solvation called?
Anomeric
Emulsoids
Erythorbic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.