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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. 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?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Emulsification
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

2. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Sucrose
Lysine - Arginine - and Histidine
Yellow
Emulsification

3. What is acid proteolysis?
V=IR and P=VI or I x I x are
Degradation of protein and production of acid from sugar at the same time.
Sucrose
Water

4. Name one way foam stability can be assessed.
Polyphenols
Pectin Esterase - Polygalacturonase - Pectin Layase
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

5. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
V=IR and P=VI or I x I x are

6. Name three factors useful in controlling enzyme activity.
Sweet - Salty - Sour - and Bitter
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

7. Name three non-nutritive sweeteners approved for use in USA?
Polyphenol Oxidase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
A concentrate of microfibrillar proteins of fish muscle.
An enzyme that converts hydrogen peroxide to water plus oxygen.

8. In what food is butyric acid typically found?
Erythorbic Acid
Fructose
Sodium bicarbonate generates CO2
Milk

9. At what pH is benzoic acid most effective?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
pH 3-5
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phenophylin

10. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Troponins and Tropomyosin
pH 3-5
Acetoin

11. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phenylketonuria
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.
Onions ( or leeks)

12. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Emulsoids
Daminozide
Yes
Carrageenan

13. What happens to chlorophyll on heating?
Water
Pheophytin forms
Lamellar; Hexagonal I - II; Cubic
Sodium chloride reduces foam stability and sucrose improves foam stability.

14. What is the acid present in fish oil?
Arachidonic Acid
Carmelization and Maillard
The speed of a molecule is proportional to the surrounding voltage gradient.
Pectin Esterase

15. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Initiation - Propagation - Termination
.05
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Yellow

16. Name 5 chelating agents used in the food industry.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
It explodes
Browning of freshly cut surfaces of fruits and vegetables.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

17. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Water

18. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Pectin Esterase - Polygalacturonase - Pectin Layase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Bitter

19. What metabolic end product does the Voges-Proskauer test detect?
.05
Polyphenoloxidase
Blue pigment in flowers
Acetoin

20. Name 3 physical agents capable of denaturing proteins.
Initiation - Propagation - and Termination
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Aspartic Acid and Phenylalanine
Osmosis

21. Waxes are composed of what two basic chemical entities?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Osmosis
Fatty Acid (Ester linked) to Fatty Alcohol
Daminozide

22. What are the three main steps in the autooxidation of lipids?
Anthocyanins
It explodes
Initiation - Propagation - Termination
Covalent (strongest) and Hydrophobic (Weakest)

23. What does Reichert-Meissert Number measure?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Fatty Acid (Ester linked) to Fatty Alcohol
Primary butyric acid also caproic acid.
Thamautin

24. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Emulsoids
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Glycosides of anthocyanidins

25. What are the only phenols approved for use in the microbiological preservation of foods?
Polyphenoloxidase
Parabens
Lamellar; Hexagonal I - II; Cubic
Speed of Light

26. What are the fructose contents in commercial HFCS products.
Acetoin
Fat Oxidation
45% - 52% - 90%
Onions ( or leeks)

27. Name the two components that comprise the relaxing factor in muscle fibers.
Lysine - Arginine - and Histidine
2.5
Troponins and Tropomyosin
Thamautin

28. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
NaCl (it dissociated to a 2M solution)
The speed of a molecule is proportional to the surrounding voltage gradient.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Polyphenoloxidase

29. What is the main class of color compounds found in raspberries?
Oil in Water
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Anthocyanins
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.

30. What is the Peroxide Value a measure of?
Polyphenols
2.5
Fat Oxidation
2.5

31. What is the major color compound in tomatoes?
Sodium chloride reduces foam stability and sucrose improves foam stability.
2.5
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

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

33. Contains the lowest content of water
Daminozide
Whole Milk
Chitin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

34. Name 3 chemical agents capable of denaturing proteins.
Phenophylin
Tryptophan
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

35. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Gossypol (it is removed during the oil refining process)
Primary butyric acid also caproic acid.
Fructose

36. What is the fundamental driving of electrophoresis?
.05
Ascorbic Acid and Citric Acid
The speed of a molecule is proportional to the surrounding voltage gradient.
Monosodium Glutamate

37. What is a polymorphism?
It explodes
Olive Green
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Lycopenes

38. Does kosmotrophil ion discourage water structure?
No
Lycopenes
NaCl (it dissociated to a 2M solution)
Plasmids

39. Will lipid oxidation be higher at a water activity of .05 or .5?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Polyphenoloxidase
.05

40. What are the limiting amino acids in corn - potato - and green peas?
Nucleation or crystal formation and crystal growth.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Parabens
An enzyme that converts hydrogen peroxide to water plus oxygen.

41. What is the acid present in fish oil?
Lysine - Arginine - and Histidine
Thermus Aqauticus
Thickener in foods
Arachidonic Acid

42. 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.
Lipase
An enzyme that converts hydrogen peroxide to water plus oxygen.
.05

43. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pectin methylesterase & polygalacturonase
Anomeric
Thamautin
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

44. 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?
20 carbons and 4 double bonds
It explodes
Gossypol (it is removed during the oil refining process)
Fructose

45. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Sodium bicarbonate generates CO2
Tryptophan
Whole Milk
D: None of the above

46. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Carrageenan
Monosodium Glutamate
NaCl (it dissociated to a 2M solution)
Yes

47. 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
Whole Milk
Fatty Acid (Ester linked) to Fatty Alcohol
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
D: None of the above

48. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Pheophytia does not have magnesium in porphyrin ring.
Whole Milk
Aspartic Acid and Phenylalanine

49. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
45% - 52% - 90%
Carmelization and Maillard
ERH=100 x Aw

50. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Chitin
Chitin
Phenylketonuria
Thermus Aqauticus