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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 are two common reducing agents that break disulfide bonds in proteins?
Pectin methyl esterase or galacturonase
Erythorbic Acid
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Water

2. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Browning of freshly cut surfaces of fruits and vegetables.
Polyphenols
Two aldehydes

3. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Pheophytin forms
Plasmids
Pectin methyl esterase or galacturonase
20 carbons and 4 double bonds

4. What is an isomer that is cheaper than Vitamin C?
A concentrate of microfibrillar proteins of fish muscle.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
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.

5. What is the structural difference between chlorophyll and chlocophyllide?
Parabens
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Chlocophyllide does not have a phytoltail
Daminozide

6. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin Esterase
Pectin methyl esterase or galacturonase
Polyphenoloxidase
Fat Oxidation

7. What are the four basic flavors perceived by the tongue?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Thamautin
Tryptophan
Sweet - Salty - Sour - and Bitter

8. What compounds oxidize to form brown color in fruits and vegetables?
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
Fructose
Thermus Aqauticus
Polyphenols

9. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Arachidonic Acid
Osmosis
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

10. What are the three stages of oxidative rancidity?
Daminozide
Milk
Initiation - Propagation - and Termination
A concentrate of microfibrillar proteins of fish muscle.

11. What are proteins which are soluble in 50-80% ethanol known as?
Gossypol (it is removed during the oil refining process)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Prolamines

12. Name 5 proteins with good foaming properties.
14
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.
Fatty Acid and Alcohol
Ammonia - Water - Carbon Dioxide

13. If you take 20 ml of .1 M NaOH to titrate 40 mL of an HCL solution to the penolphthalein end point What is the molarity of the HCL solution?
Bright green
Bitter
.05 M HCL
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

14. What is catalase?
Linoleic Acid
Pheophytin forms
An enzyme that converts hydrogen peroxide to water plus oxygen.
Gossypol (it is removed during the oil refining process)

15. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Racemic Mixture
Osmosis
Orange Juice
2.5

16. What are the primary secondary - tertiary - and quaternary structures?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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.
Ammonia - Water - Carbon Dioxide
Chitin

17. 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.
Polyphenols
20 carbons and 4 double bonds
Olive Green

18. What does the saponification value measure and how is it measured?
Racemic Mixture
Covalent (strongest) and Hydrophobic (Weakest)
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Orange Juice

19. What is the fundamental driving of electrophoresis?
Daminozide
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipid oxidation
Orange Juice

20. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Acetoin
It explodes
They act as catalysts - speeding the polymerization of acrylamide.
Yes

21. Define molarity molality - and normality.
D: None of the above
Sodium bicarbonate generates CO2
HPLC has higher pressure than FPLC
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

22. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Chitin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Prolamines

23. Name three effects of protein denaturation.
Sweet - Salty - Sour - and Bitter
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Ammonia - Water - Carbon Dioxide

24. Contains the lowest content of water
Anomeric
Lipid oxidation
Phenylketonuria
Whole Milk

25. How can a molecular weight of protein - DNA - and RNA be determined?
The speed of a molecule is proportional to the surrounding voltage gradient.
Covalent (strongest) and Hydrophobic (Weakest)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Polyphenol Oxidase

26. Alar is the trade name for what chemical compound?
ERH=100 x Aw
Daminozide
Lipid oxidation
Covalent (strongest) and Hydrophobic (Weakest)

27. How can a molecular weight of protein - DNA - and RNA be determined?
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.
Racemic Mixture
Linoleic Acid

28. What is the acid present in fish oil?
Sweet - Salty - Sour - and Bitter
Arachidonic Acid
A concentrate of microfibrillar proteins of fish muscle.
Primary butyric acid also caproic acid.

29. What are 3 mesomorphic structures associated with lipids in the liquid state?
Carrageenan
Browning of freshly cut surfaces of fruits and vegetables.
Lamellar; Hexagonal I - II; Cubic
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

30. What does MSG stand for?
Monosodium Glutamate
Acetoin
HPLC has higher pressure than FPLC
ERH=100 x Aw

31. 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
ERH=100 x Aw
Aspartic Acid and Phenylalanine
Initiation - Propagation - Termination
Browning of freshly cut surfaces of fruits and vegetables.

32. What is the chemical nature of anthocyanins?
Polyphenol Oxidase
Glycosides of anthocyanidins
Initiation - Propagation - Termination
Pectin Esterase

33. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Ammonia - Water - Carbon Dioxide
Thermus Aqauticus
Monosodium Glutamate

34. Name a commonly used household chemical leavening agent and the gas it generates.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Anomeric
Sodium bicarbonate generates CO2
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

35. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
NaCl (it dissociated to a 2M solution)

36. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lamellar; Hexagonal I - II; Cubic
Thamautin
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

37. 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?
Milk
Pectins
It explodes
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

38. 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
Anomeric
Browning of freshly cut surfaces of fruits and vegetables.
Chlocophyllide does not have a phytoltail
Yellow

39. At low water activity What is the main deteriorative concern?
Prolamines
2.5
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lipid oxidation

40. What are the three main steps in the autooxidation of lipids?
Linoleic Acid
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Initiation - Propagation - Termination
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

41. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Water
Yes
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

42. Name three factors useful in controlling enzyme activity.
Oil in Water
Anthocyanins
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fatty Acid (Ester linked) to Fatty Alcohol

43. What is the protein efficiency ratio (PER) of casein?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chitin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
2.5

44. What are the primary secondary - tertiary - and quaternary structures?
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.
Tryptophan
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.
Two aldehydes

45. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Nucleation or crystal formation and crystal growth.
45% - 52% - 90%

46. What are 3 mesomorphic structures associated with lipids in the liquid state?
Yellow
Lamellar; Hexagonal I - II; Cubic
Bitter
Non-protein nitrogen

47. Name the most common functional property of phospholipids in food systems.
Nucleation or crystal formation and crystal growth.
Emulsification
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Milk

48. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Orange Juice
Monosodium Glutamate
Four
Olive Green

49. What does the acronym NPN stand for?
Bright green
Gliadins and Glutenins
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Non-protein nitrogen

50. How does HPLC differ from FPLC?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
HPLC has higher pressure than FPLC
Sweet - Salty - Sour - and Bitter
Polyphenol Oxidase