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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. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Four
Carrageenan
Sweet - Salty - Sour - and Bitter
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

2. Name the most common functional property of phospholipids in food systems.
Browning of freshly cut surfaces of fruits and vegetables.
Pectin methyl esterase or galacturonase
Emulsification
Pectin Esterase - Polygalacturonase - Pectin Layase

3. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Four
V=IR and P=VI or I x I x are
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.

4. Name 5 proteins with good foaming properties.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Browning of freshly cut surfaces of fruits and vegetables.
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.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

5. Name the strongest biochemical bond and the weakest biochemical bond.
Plasmids
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Initiation - Propagation - Termination
Covalent (strongest) and Hydrophobic (Weakest)

6. What are the three stages of oxidative rancidity?
Thermus Aqauticus
Two aldehydes
Initiation - Propagation - and Termination
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

7. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Phenylketonuria
Blue pigment in flowers
Gossypol (it is removed during the oil refining process)

8. What does HLB stand for and What does a high and low HLB value indicate?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Acsulfame-K - Saccharin - Cyclamate - Aspartame
A concentrate of microfibrillar proteins of fish muscle.
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.

9. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Gliadins and Glutenins
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.

10. What does MSG stand for?
Monosodium Glutamate
Gliadins and Glutenins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin Esterase - Polygalacturonase - Pectin Layase

11. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Fructose
Pectin methyl esterase or galacturonase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Racemic Mixture

12. What are the primary secondary - tertiary - and quaternary structures?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.
Arachidonic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

13. Name two main gluten proteins.
Gliadins and Glutenins
Lipid oxidation
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Oil in Water

14. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Oil in Water
Chlocophyllide does not have a phytoltail
Fat Oxidation
pH below positive charge; pH at no charge; pH above negative charge

15. Peptide bond formation results in the formation of what secondary compound?
45% - 52% - 90%
.05
Initiation - Propagation - and Termination
Water

16. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Orange Juice
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

17. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Pectin methyl esterase or galacturonase
Erythorbic Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

18. What happens to chlorophyll on heating?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Pheophytin forms
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Lysine - Arginine - and Histidine

19. Does kosmotrophil ion discourage water structure?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
.05 M HCL
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
No

20. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
V=IR and P=VI or I x I x are
Gliadins and Glutenins
Fructose

21. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
Four
Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

22. What is the name of the degradation compound of chlorophyll?
Gossypol (it is removed during the oil refining process)
Phenophylin
Fructose
RNA transcribed to DNA

23. In the enzyme Taq Polymerase What does Taq stand for?
Lipase
Thermus Aqauticus
Plasmids
Anomeric

24. How do sodium chloride and sucrose affect foam stability?
Speed of Light
Pheophytin forms
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Sodium chloride reduces foam stability and sucrose improves foam stability.

25. What is the acid present in fish oil?
Browning of freshly cut surfaces of fruits and vegetables.
45% - 52% - 90%
Two aldehydes
Arachidonic Acid

26. What is Carboxy-methyl cellulose often used for?
Bitter
Degradation of protein and production of acid from sugar at the same time.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Thickener in foods

27. What toxic pigment is found in cottonseed endosperm?
Phenylketonuria
Gossypol (it is removed during the oil refining process)
Lysine - Arginine - and Histidine
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

28. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Covalent (strongest) and Hydrophobic (Weakest)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

29. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Bitter
Tryptophan
Olive Green
Ascorbic Acid and Citric Acid

30. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Yes
Non-protein nitrogen
Prolamines

31. Contains the lowest content of water
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Whole Milk
Pectins
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.

32. What pigment was first designated as anthocyanins?
Thickener in foods
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Blue pigment in flowers
Daminozide

33. In what food is butyric acid typically found?
Milk
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.
Lycopenes
Sweet - Salty - Sour - and Bitter

34. When heated ammonium bicarbonate decomposes to form what end products?
It explodes
Water
Prolamines
Ammonia - Water - Carbon Dioxide

35. What is the chemical nomenclature for caffeine?
Blue pigment in flowers
DNA transferred by cell to cell contact (bacterial sex).
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.
1 - 3 - 7-trimethylxanthine

36. Name two enzymes that are involved in softening fruits.
Emulsoids
Lycopenes
Pectin Esterase
Pectin Esterase - Polygalacturonase - Pectin Layase

37. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Anomeric
Bright green
20 carbons and 4 double bonds
Polyphenoloxidase

38. What is the major color compound in tomatoes?
Lycopenes
Lipase
Fat Oxidation
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

39. Name two enzymes that are involved in softening fruits.
Bitter
14
Pectin Esterase - Polygalacturonase - Pectin Layase
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

40. What is the chemical nature of anthocyanins?
Blue pigment in flowers
Linoleic Acid
Glycosides of anthocyanidins
Parabens

41. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Troponins and Tropomyosin
D: None of the above
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

42. What is the structural difference between chlorophyll and chlocophyllide?
Pectin Esterase - Polygalacturonase - Pectin Layase
Chlocophyllide does not have a phytoltail
pH 3-5
Yellow

43. Name three effects of protein denaturation.
Fructose
The speed of a molecule is proportional to the surrounding voltage gradient.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

44. What compounds oxidize to form brown color in fruits and vegetables?
V=IR and P=VI or I x I x are
Pectin methylesterase & polygalacturonase
Thickener in foods
Polyphenols

45. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
Polyphenols
No
Fatty Acid (Ester linked) to Fatty Alcohol

46. 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
Browning of freshly cut surfaces of fruits and vegetables.
.05
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pheophytin forms

47. What effect would the addition of sodium bicarbonate have to chocolate?
Thickener in foods
Sodium chloride reduces foam stability and sucrose improves foam stability.
.05
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

48. What does the 'c' stand for in the equation E=mc2?
Parabens
A concentrate of microfibrillar proteins of fish muscle.
Speed of Light
Sodium bicarbonate generates CO2

49. What enzyme causes hyrolytic rancidity in milk?
Lipase
Phenylketonuria
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

50. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Aspartic Acid and Phenylalanine
Lysine - Arginine - and Histidine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)