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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. How does ERH relate to water activity?
ERH=100 x Aw
NaCl (it dissociated to a 2M solution)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
14

2. What is Carboxy-methyl cellulose often used for?
Pheophytin forms
Milk
Initiation - Propagation - and Termination
Thickener in foods

3. How do sodium chloride and sucrose affect foam stability?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Sodium chloride reduces foam stability and sucrose improves foam stability.
It explodes
Oil in Water

4. Name one way foam stability can be assessed.
Pectin methylesterase & polygalacturonase
D: None of the above
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.
Initiation - Propagation - and Termination

5. What toxic pigment is found in cottonseed endosperm?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Sodium bicarbonate generates CO2
Whole Milk
Gossypol (it is removed during the oil refining process)

6. What is the fundamental driving of electrophoresis?
Covalent (strongest) and Hydrophobic (Weakest)
The speed of a molecule is proportional to the surrounding voltage gradient.
Sweet - Salty - Sour - and Bitter
Lysine - Arginine - and Histidine

7. Name 5 chelating agents used in the food industry.
1 - 3 - 7-trimethylxanthine
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
45% - 52% - 90%
Phenylketonuria

8. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Initiation - Propagation - and Termination
Yes
Tryptophan
Sodium chloride reduces foam stability and sucrose improves foam stability.

9. What effect would the addition of sodium bicarbonate have to chocolate?
Bright green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Ammonia - Water - Carbon Dioxide
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

10. What is the name of the degradation compound of chlorophyll?
Yes
Phenophylin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

11. Name 3 factors influencing the consistency of commercial fats.
Lysine - Arginine - and Histidine
Blue pigment in flowers
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Two aldehydes

12. How many carbon atoms are there in the fatty acid myristic acid?
14
Fatty Acid (Ester linked) to Fatty Alcohol
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Cis

13. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Fat Oxidation
Pectin methyl esterase or galacturonase
Fructose
Initiation - Propagation - Termination

14. In the enzyme Taq Polymerase What does Taq stand for?
They act as catalysts - speeding the polymerization of acrylamide.
Thermus Aqauticus
Osmosis
20 carbons and 4 double bonds

15. What does MSG stand for?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Glycosides of anthocyanidins
Monosodium Glutamate
Olive Green

16. What is the main class of color compounds found in raspberries?
.05 M HCL
Thermus Aqauticus
Anthocyanins
Thamautin

17. Name 3 physical agents capable of denaturing proteins.
Pheophytia does not have magnesium in porphyrin ring.
Polyphenols
Sodium bicarbonate generates CO2
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

18. Name the most common functional property of phospholipids in food systems.
Thamautin
V=IR and P=VI or I x I x are
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.
Emulsification

19. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

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20. What enzyme is most responsible for browning bananas?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Thamautin
Polyphenol Oxidase
pH below positive charge; pH at no charge; pH above negative charge

21. 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
Acetoin
Acetoin
Browning of freshly cut surfaces of fruits and vegetables.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

22. What is the structural difference between chlorophyll and pheophytia?
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.
Pheophytia does not have magnesium in porphyrin ring.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Onions ( or leeks)

23. What is the fundamental driving of electrophoresis?
Ascorbic Acid and Citric Acid
They act as catalysts - speeding the polymerization of acrylamide.
The speed of a molecule is proportional to the surrounding voltage gradient.
Phenophylin

24. What is the chemical nature of anthocyanins?
Phenylketonuria
V=IR and P=VI or I x I x are
Four
Glycosides of anthocyanidins

25. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Thamautin
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
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
Water

26. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Acetoin
Bright green
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Linoleic Acid

27. When heated ammonium bicarbonate decomposes to form what end products?
Initiation - Propagation - and Termination
Ammonia - Water - Carbon Dioxide
Acetoin
45% - 52% - 90%

28. Name two non-enzymatic browning reactions.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Tryptophan
Carmelization and Maillard
No

29. Name the strongest biochemical bond and the weakest biochemical bond.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Plasmids
Covalent (strongest) and Hydrophobic (Weakest)

30. What does the acronym NPN stand for?
pH below positive charge; pH at no charge; pH above negative charge
Non-protein nitrogen
Primary butyric acid also caproic acid.
Chlocophyllide does not have a phytoltail

31. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
1 - 3 - 7-trimethylxanthine
2.5
Phenophylin

32. At what pH is benzoic acid most effective?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
pH 3-5
Pectin Esterase - Polygalacturonase - Pectin Layase
Primary butyric acid also caproic acid.

33. What are two common reducing agents that break disulfide bonds in proteins?
Gliadins and Glutenins
Polyphenols
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Browning of freshly cut surfaces of fruits and vegetables.

34. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
V=IR and P=VI or I x I x are
It explodes
Phenophylin

35. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Oil in Water
Monosodium Glutamate
Capsaicin
Thermus Aqauticus

36. Contains the lowest content of water
Thermus Aqauticus
Whole Milk
Water
Lysine - Arginine - and Histidine

37. 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.
Linoleic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Polyphenol Oxidase

38. What does the 'c' stand for in the equation E=mc2?
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.
Speed of Light
HPLC has higher pressure than FPLC

39. Alar is the trade name for what chemical compound?
Daminozide
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Non-protein nitrogen
Acetoin

40. Name three nonpolar polar - and charged amino acids.
Racemic Mixture
14
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
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.

41. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Lipid oxidation
Nucleation or crystal formation and crystal growth.
They act as catalysts - speeding the polymerization of acrylamide.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

42. What are the primary secondary - tertiary - and quaternary structures?
Pectin Esterase - Polygalacturonase - Pectin Layase
Four
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.
Thickener in foods

43. What are the fructose contents in commercial HFCS products.
Pheophytia does not have magnesium in porphyrin ring.
Acetoin
45% - 52% - 90%
Water

44. How is pH defined?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Negative log of the hydrogen concentration (mol/l).
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

45. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Primary butyric acid also caproic acid.
Initiation - Propagation - Termination
20 carbons and 4 double bonds

46. What does MSG stand for?
Gossypol (it is removed during the oil refining process)
DNA transferred by cell to cell contact (bacterial sex).
Monosodium Glutamate
Anomeric

47. What are colloids that are stabilized by a layer of solvation called?
Lipase
Emulsoids
Thamautin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

48. Contains the lowest content of water
V=IR and P=VI or I x I x are
Whole Milk
Browning of freshly cut surfaces of fruits and vegetables.
Polyphenol Oxidase

49. Does kosmotrophil ion discourage water structure?
No
V=IR and P=VI or I x I x are
Pectin Esterase - Polygalacturonase - Pectin Layase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

50. Name 3 factors influencing the rate of lipid oxidation in foods.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Thamautin
Ammonia - Water - Carbon Dioxide
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants