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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 toxic pigment is found in cottonseed endosperm?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Gossypol (it is removed during the oil refining process)
The speed of a molecule is proportional to the surrounding voltage gradient.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

2. What are the limiting amino acids in corn - potato - and green peas?
Lipid oxidation
Initiation - Propagation - Termination
Daminozide
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

3. Name two non-enzymatic browning reactions.
Thamautin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
D: None of the above
Carmelization and Maillard

4. What does the iodine value measure and how is it measured?
Lipid oxidation
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Troponins and Tropomyosin
A concentrate of microfibrillar proteins of fish muscle.

5. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Yellow
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Orange Juice

6. Name the most common functional property of phospholipids in food systems.
Polyphenoloxidase
Emulsification
Polyphenols
Sucrose

7. What is the winterization process for an oil?
Osmosis
45% - 52% - 90%
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Acetoin

8. Give one word for a carbon atom involved in hemiacetal or acetal formation.
The speed of a molecule is proportional to the surrounding voltage gradient.
Orange Juice
Fatty Acid and Alcohol
Anomeric

9. Name 4 advantages of using enzymes in food processing.
Fatty Acid and Alcohol
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
Glycosides of anthocyanidins
Ascorbic Acid and Citric Acid

10. 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?
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.
Negative log of the hydrogen concentration (mol/l).
Covalent (strongest) and Hydrophobic (Weakest)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

11. What does Reichert-Meissert Number measure?
Emulsoids
14
Primary butyric acid also caproic acid.
pH below positive charge; pH at no charge; pH above negative charge

12. What is the Peroxide Value a measure of?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Fat Oxidation
pH below positive charge; pH at no charge; pH above negative charge
Sucrose

13. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Capsaicin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Two aldehydes
Milk

14. Name two main gluten proteins.
Lipid oxidation
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.
Gliadins and Glutenins
Pectins

15. What are the four basic flavors perceived by the tongue?
NaCl (it dissociated to a 2M solution)
Pheophytia does not have magnesium in porphyrin ring.
Milk
Sweet - Salty - Sour - and Bitter

16. What is surimi?
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.
A concentrate of microfibrillar proteins of fish muscle.
Sodium bicarbonate generates CO2
Thamautin

17. What does Acid Degree Value measure and how is it measured?
Negative log of the hydrogen concentration (mol/l).
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

18. Name one way foam stability can be assessed.
Emulsification
Chitin
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.
.05

19. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
45% - 52% - 90%
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Arachidonic Acid

20. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Blue pigment in flowers
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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

21. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Daminozide
Anomeric
Orange Juice
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.

22. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Thickener in foods
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chlocophyllide does not have a phytoltail

23. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Lycopenes
Pectin Esterase
Linoleic Acid
Monosodium Glutamate

24. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Osmosis
A concentrate of microfibrillar proteins of fish muscle.

25. What does the 'c' stand for in the equation E=mc2?
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
Speed of Light
Degradation of protein and production of acid from sugar at the same time.

26. During freezing What are the two stages in the crystallization process?
Non-protein nitrogen
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.
Lycopenes
Nucleation or crystal formation and crystal growth.

27. What is the enzyme responsible for browning in apples and lettuce?
Water
V=IR and P=VI or I x I x are
Polyphenol Oxidase
.05 M HCL

28. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
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
Emulsification
Racemic Mixture

29. 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
Gossypol (it is removed during the oil refining process)
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
Plasmids

30. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
1 - 3 - 7-trimethylxanthine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Polyphenols

31. How does ERH relate to water activity?
Chitin
ERH=100 x Aw
Chlocophyllide does not have a phytoltail
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

32. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Two aldehydes
DNA transferred by cell to cell contact (bacterial sex).
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Osmosis

33. What charge will a protein have when the pH of its solution is below at - and above its pKa?
D: None of the above
pH below positive charge; pH at no charge; pH above negative charge
Initiation - Propagation - Termination
.05 M HCL

34. Alar is the trade name for what chemical compound?
45% - 52% - 90%
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Daminozide
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

35. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Initiation - Propagation - Termination
Daminozide
Yellow
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

36. Name 5 proteins with good foaming properties.
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.
Polyphenol Oxidase
Nucleation or crystal formation and crystal growth.
Plasmids

37. Name 3 factors influencing the rate of lipid oxidation in foods.
Pectin methylesterase & polygalacturonase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Degradation of protein and production of acid from sugar at the same time.

38. How can a molecular weight of protein - DNA - and RNA be determined?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Sweet - Salty - Sour - and Bitter

39. What compounds oxidize to form brown color in fruits and vegetables?
Lipase
Polyphenols
Olive Green
Polyphenol Oxidase

40. How many carbon atoms and how many double bonds are there in arachidonic acid?
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase
20 carbons and 4 double bonds
It explodes

41. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Carmelization and Maillard
Milk
Fatty Acid (Ester linked) to Fatty Alcohol

42. What happens to chlorophyll on heating?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pheophytia does not have magnesium in porphyrin ring.
Pheophytin forms
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

43. Name a commonly used household chemical leavening agent and the gas it generates.
Bright green
Sodium bicarbonate generates CO2
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Sodium chloride reduces foam stability and sucrose improves foam stability.

44. What is the name given to a mixture of equal parts of Darel Lisomers?
Linoleic Acid
Glycosides of anthocyanidins
Racemic Mixture
Troponins and Tropomyosin

45. How does ERH relate to water activity?
Fatty Acid (Ester linked) to Fatty Alcohol
Chlocophyllide does not have a phytoltail
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
ERH=100 x Aw

46. Name 3 factors influencing the rate of lipid oxidation in foods.
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
Degradation of protein and production of acid from sugar at the same time.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

47. What enzyme causes hyrolytic rancidity in milk?
Lipase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Covalent (strongest) and Hydrophobic (Weakest)
pH 3-5

48. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sucrose
.05

49. What ketohexose is most significant to food chemists?
pH below positive charge; pH at no charge; pH above negative charge
Fructose
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.
Pectin methylesterase & polygalacturonase

50. What is the geometric configuration of double bonds in most natural fatty acids?
HPLC has higher pressure than FPLC
Ascorbic Acid and Citric Acid
Cis
NaCl (it dissociated to a 2M solution)