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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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1. What two types of compounds are joined with an ester bond to make a wax?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Yellow
Anomeric
Fatty Acid and Alcohol

2. What are the only phenols approved for use in the microbiological preservation of foods?
Erythorbic Acid
Parabens
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.
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.

3. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Polyphenols
Sucrose
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

4. What is the major color compound in tomatoes?
Emulsoids
Lycopenes
Emulsoids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

5. In what food is butyric acid typically found?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Milk

6. Name one way foam stability can be assessed.
Gliadins and Glutenins
Prolamines
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.
Onions ( or leeks)

7. Alar is the trade name for what chemical compound?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
1 - 3 - 7-trimethylxanthine
Daminozide
Monosodium Glutamate

8. Name the three positively charged amino acids.
Carmelization and Maillard
Oil in Water
Thermus Aqauticus
Lysine - Arginine - and Histidine

9. Alar is the trade name for what chemical compound?
Daminozide
Phenylketonuria
Capsaicin
Olive Green

10. What charge will a protein have when the pH of its solution is below at - and above its pKa?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH below positive charge; pH at no charge; pH above negative charge
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

11. What is the protein efficiency ratio (PER) of casein?
14
Fat Oxidation
Pheophytin forms
2.5

12. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Polyphenols
Lycopenes
Fructose

13. What is a polymorphism?
Ammonia - Water - Carbon Dioxide
Pectin Esterase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Milk

14. Give one word for a carbon atom involved in hemiacetal or acetal formation.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Anomeric
Lamellar; Hexagonal I - II; Cubic
Emulsification

15. What is the enzyme that softens tomatoes?
Phenophylin
Pectin Esterase
Yellow
Pheophytin forms

16. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Monosodium Glutamate
20 carbons and 4 double bonds
Four
Polyphenoloxidase

17. Name 5 chelating agents used in the food industry.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Polyphenol Oxidase
Daminozide
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

18. Name two reasons why fats are hydrogenated.
Lycopenes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Yes
Erythorbic Acid

19. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Oil in Water
Daminozide
Sodium chloride reduces foam stability and sucrose improves foam stability.

20. 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
Ascorbic Acid and Citric Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
D: None of the above

21. What is the major color compound in tomatoes?
Troponins and Tropomyosin
.05
Pectin methylesterase & polygalacturonase
Lycopenes

22. What two enzymes degrade pectic substances?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Water
Pectin methylesterase & polygalacturonase
.05 M HCL

23. 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?
Initiation - Propagation - and Termination
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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).

24. How many carbon atoms are there in the fatty acid myristic acid?
Phenophylin
14
Daminozide
RNA transcribed to DNA

25. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Fat Oxidation
Plasmids

26. What is the protein efficiency ratio (PER) of casein?
Negative log of the hydrogen concentration (mol/l).
2.5
Milk
Monosodium Glutamate

27. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
.05 M HCL
pH below positive charge; pH at no charge; pH above negative charge
The speed of a molecule is proportional to the surrounding voltage gradient.

28. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
NaCl (it dissociated to a 2M solution)
RNA transcribed to DNA
Troponins and Tropomyosin

29. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Orange Juice
Oil in Water
Degradation of protein and production of acid from sugar at the same time.

30. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Glycosides of anthocyanidins
Yellow
Acetoin

31. What are the three main steps in the autooxidation of lipids?
Plasmids
Fatty Acid (Ester linked) to Fatty Alcohol
Monosodium Glutamate
Initiation - Propagation - Termination

32. 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?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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.
Yes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

33. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
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.
Monosodium Glutamate
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

34. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Lipase
Phenylketonuria
Two aldehydes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

35. What are the four basic flavors perceived by the tongue?
Pectin methyl esterase or galacturonase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Sweet - Salty - Sour - and Bitter

36. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Troponins and Tropomyosin
Pectin methylesterase & polygalacturonase
Orange Juice
Phenylketonuria

37. What is surimi?
45% - 52% - 90%
Pectin Esterase - Polygalacturonase - Pectin Layase
Gliadins and Glutenins
A concentrate of microfibrillar proteins of fish muscle.

38. How does ERH relate to water activity?
Tryptophan
Troponins and Tropomyosin
ERH=100 x Aw
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

39. What does MSG stand for?
Monosodium Glutamate
Ammonia - Water - Carbon Dioxide
Orange Juice
20 carbons and 4 double bonds

40. What is the fundamental driving of electrophoresis?
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.
The speed of a molecule is proportional to the surrounding voltage gradient.
Sodium bicarbonate generates CO2
Anomeric

41. What does the saponification value measure and how is it measured?
Emulsoids
Sodium bicarbonate generates CO2
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin methylesterase & polygalacturonase

42. At what pH is benzoic acid most effective?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
pH 3-5
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

43. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Bitter
Sodium bicarbonate generates CO2
Plasmids
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.

44. Is a disaccharide
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Browning of freshly cut surfaces of fruits and vegetables.
Sucrose
No

45. Contains the lowest content of water
Whole Milk
Daminozide
Phenophylin
Chitin

46. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Pheophytin forms
Polyphenol Oxidase
Four

47. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Whole Milk
Anthocyanins
They act as catalysts - speeding the polymerization of acrylamide.

48. Name 3 chemical agents capable of denaturing proteins.
Pectin methyl esterase or galacturonase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Polyphenols
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

49. What is the chemical nature of anthocyanins?
Pheophytia does not have magnesium in porphyrin ring.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Glycosides of anthocyanidins
.05 M HCL

50. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Orange Juice
Blue pigment in flowers
NaCl (it dissociated to a 2M solution)
Pectins