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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 are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Pheophytin forms
Non-protein nitrogen
Lipid oxidation

2. What are proteins which are soluble in 50-80% ethanol known as?
Cis
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Prolamines
Yes

3. What are the three main steps in the autooxidation of lipids?
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.
Olive Green
Gossypol (it is removed during the oil refining process)
Initiation - Propagation - Termination

4. Alar is the trade name for what chemical compound?
Primary butyric acid also caproic acid.
Daminozide
Lamellar; Hexagonal I - II; Cubic
Speed of Light

5. What are proteins which are soluble in 50-80% ethanol known as?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
RNA transcribed to DNA
Glycosides of anthocyanidins
Prolamines

6. What are the fructose contents in commercial HFCS products.
Daminozide
Browning of freshly cut surfaces of fruits and vegetables.
45% - 52% - 90%
Ascorbic Acid and Citric Acid

7. What is the structural difference between chlorophyll and chlocophyllide?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chlocophyllide does not have a phytoltail
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lamellar; Hexagonal I - II; Cubic

8. When heated ammonium bicarbonate decomposes to form what end products?
Osmosis
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
.05
Ammonia - Water - Carbon Dioxide

9. What are two common reducing agents that break disulfide bonds in proteins?
Four
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Phenophylin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

10. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Prolamines
Lipid oxidation
Pectin methyl esterase or galacturonase
NaCl (it dissociated to a 2M solution)

11. What ketohexose is most significant to food chemists?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
A concentrate of microfibrillar proteins of fish muscle.
Oil in Water
Fructose

12. Waxes are composed of what two basic chemical entities?
Lycopenes
Fatty Acid (Ester linked) to Fatty Alcohol
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.
Yes

13. What is acid proteolysis?
Racemic Mixture
Milk
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Degradation of protein and production of acid from sugar at the same time.

14. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
1 - 3 - 7-trimethylxanthine
Yes

15. What does the iodine 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.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lysine - Arginine - and Histidine
Oil in Water

16. What is the geometric configuration of double bonds in most natural fatty acids?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Cis
Yellow
Oil in Water

17. Name the strongest biochemical bond and the weakest biochemical bond.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
ERH=100 x Aw
Covalent (strongest) and Hydrophobic (Weakest)
Aspartic Acid and Phenylalanine

18. 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?
Yes
Troponins and Tropomyosin
Speed of Light
It explodes

19. What is surimi?
HPLC has higher pressure than FPLC
A concentrate of microfibrillar proteins of fish muscle.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Pheophytin forms

20. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
A concentrate of microfibrillar proteins of fish muscle.
Pheophytia does not have magnesium in porphyrin ring.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
RNA transcribed to DNA

21. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Nucleation or crystal formation and crystal growth.
D: None of the above
Non-protein nitrogen

22. What effect would the addition of sodium bicarbonate have to chocolate?
Chlocophyllide does not have a phytoltail
2.5
Onions ( or leeks)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

23. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Onions ( or leeks)
Plasmids
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.

24. Name the three positively charged amino acids.
Daminozide
Pheophytia does not have magnesium in porphyrin ring.
Lysine - Arginine - and Histidine
Onions ( or leeks)

25. What are the primary secondary - tertiary - and quaternary structures?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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.
Phenylketonuria
Tryptophan

26. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fructose
Pectin methyl esterase or galacturonase
NaCl (it dissociated to a 2M solution)

27. Name three factors useful in controlling enzyme activity.
ERH=100 x Aw
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
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.

28. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
14
Onions ( or leeks)
Water
Oil in Water

29. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Primary butyric acid also caproic acid.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectins
DNA transferred by cell to cell contact (bacterial sex).

30. 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.
Sweet - Salty - Sour - and Bitter
Lycopenes
Whole Milk

31. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
.05
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.
RNA transcribed to DNA
Sodium chloride reduces foam stability and sucrose improves foam stability.

32. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenoloxidase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

33. Name two non-enzymatic browning reactions.
Acetoin
Bright green
Carmelization and Maillard
No

34. What is the fundamental driving of electrophoresis?
Pectin methyl esterase or galacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.
Pectin methyl esterase or galacturonase
Polyphenoloxidase

35. Name 3 factors influencing the consistency of commercial fats.
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.
.05 M HCL
Carrageenan

36. What does HLB stand for and What does a high and low HLB value indicate?
Nucleation or crystal formation and crystal growth.
Pheophytin forms
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
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.

37. Name 3 factors influencing the rate of lipid oxidation in foods.
Oil in Water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectins
2.5

38. What enzyme causes hyrolytic rancidity in milk?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Lipase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

39. What are colloids that are stabilized by a layer of solvation called?
Sweet - Salty - Sour - and Bitter
Polyphenol Oxidase
Thamautin
Emulsoids

40. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Lycopenes
Bitter
Whole Milk

41. What does MSG stand for?
Whole Milk
Milk
Monosodium Glutamate
It explodes

42. In what food is butyric acid typically found?
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
Pheophytin forms
Milk
Fat Oxidation

43. What does the acronym NPN stand for?
Non-protein nitrogen
Initiation - Propagation - Termination
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Orange Juice

44. Peptide bond formation results in the formation of what secondary compound?
Water
Yellow
Glycosides of anthocyanidins
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

45. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
pH below positive charge; pH at no charge; pH above negative charge
Daminozide
Parabens
They act as catalysts - speeding the polymerization of acrylamide.

46. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
2.5
D: None of the above
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

47. Name one way foam stability can be assessed.
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.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
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.
Pectins

48. Name three nonpolar polar - and charged amino acids.
Bitter
Arachidonic Acid
Pheophytin forms
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

49. What is the winterization process for an oil?
Polyphenol Oxidase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Polyphenol Oxidase

50. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Olive Green
Whole Milk