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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. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
Troponins and Tropomyosin
Carmelization and Maillard
They act as catalysts - speeding the polymerization of acrylamide.

2. Name two main gluten proteins.
Gliadins and Glutenins
Four
Aspartic Acid and Phenylalanine
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

3. What effect would the addition of sodium bicarbonate have to chocolate?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
45% - 52% - 90%
Tryptophan

4. Waxes are composed of what two basic chemical entities?
Pectins
2.5
Chlocophyllide does not have a phytoltail
Fatty Acid (Ester linked) to Fatty Alcohol

5. What are the three stages of oxidative rancidity?
Gossypol (it is removed during the oil refining process)
Initiation - Propagation - and Termination
Fructose
Polyphenols

6. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
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
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Non-protein nitrogen

7. Name two non-enzymatic browning reactions.
D: None of the above
Carmelization and Maillard
Water
Anthocyanins

8. Name 3 factors influencing the rate of lipid oxidation in foods.
A concentrate of microfibrillar proteins of fish muscle.
Pheophytin forms
Water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

9. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
ERH=100 x Aw
Thickener in foods
No
Tryptophan

10. Name two enzymes that are involved in softening fruits.
Parabens
Plasmids
Pectin Esterase - Polygalacturonase - Pectin Layase
.05 M HCL

11. Name two non-enzymatic browning reactions.
Daminozide
Two aldehydes
Carmelization and Maillard
DNA transferred by cell to cell contact (bacterial sex).

12. What is the structural difference between chlorophyll and pheophytia?
Initiation - Propagation - Termination
Pheophytia does not have magnesium in porphyrin ring.
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.
Sweet - Salty - Sour - and Bitter

13. What does the acronym NPN stand for?
Thamautin
Fatty Acid and Alcohol
Emulsoids
Non-protein nitrogen

14. What happens to chlorophyll on heating?
Arachidonic Acid
Fat Oxidation
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pheophytin forms

15. At what pH is benzoic acid most effective?
Lipase
.05
pH 3-5
Pectin methyl esterase or galacturonase

16. 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.
Polyphenol Oxidase
Pheophytia does not have magnesium in porphyrin ring.
A concentrate of microfibrillar proteins of fish muscle.

17. At low water activity What is the main deteriorative concern?
Fat Oxidation
Water
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lipid oxidation

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?
It explodes
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
Polyphenol Oxidase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

19. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Browning of freshly cut surfaces of fruits and vegetables.
Initiation - Propagation - Termination
RNA transcribed to DNA
Thamautin

20. When heated ammonium bicarbonate decomposes to form what end products?
Bright green
Ammonia - Water - Carbon Dioxide
ERH=100 x Aw
Lamellar; Hexagonal I - II; Cubic

21. 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?
Speed of Light
.05 M HCL
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.
Racemic Mixture

22. What are the three stages of oxidative rancidity?
Emulsification
Initiation - Propagation - and Termination
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Thamautin

23. How do sodium chloride and sucrose affect foam stability?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Fructose
Sodium chloride reduces foam stability and sucrose improves foam stability.
Degradation of protein and production of acid from sugar at the same time.

24. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
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.
Anomeric
Blue pigment in flowers

25. What are the four basic flavors perceived by the tongue?
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.
Negative log of the hydrogen concentration (mol/l).
Anomeric
Sweet - Salty - Sour - and Bitter

26. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

27. What is the enzyme responsible for browning in apples and lettuce?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Prolamines
Polyphenol Oxidase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

28. What is the structural difference between chlorophyll and chlocophyllide?
Covalent (strongest) and Hydrophobic (Weakest)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Chlocophyllide does not have a phytoltail
Ammonia - Water - Carbon Dioxide

29. What two types of compounds are joined with an ester bond to make a wax?
NaCl (it dissociated to a 2M solution)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fatty Acid and Alcohol
Pectin Esterase

30. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Tryptophan
Bitter
Pectin Esterase - Polygalacturonase - Pectin Layase
Speed of Light

31. What is catalase?
Water
An enzyme that converts hydrogen peroxide to water plus oxygen.
A concentrate of microfibrillar proteins of fish muscle.
Lysine - Arginine - and Histidine

32. What is the main class of color compounds found in raspberries?
Sodium bicarbonate generates CO2
Anthocyanins
Parabens
Orange Juice

33. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Anomeric
Ammonia - Water - Carbon Dioxide
RNA transcribed to DNA

34. What does Acid Degree Value measure and how is it measured?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Degradation of protein and production of acid from sugar at the same time.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Chitin

35. 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
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.
Prolamines
D: None of the above
Olive Green

36. Name one way foam stability can be assessed.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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

37. What is the name given to a mixture of equal parts of Darel Lisomers?
Daminozide
Pectin Esterase - Polygalacturonase - Pectin Layase
Racemic Mixture
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.

38. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Parabens
Carrageenan
Phenylketonuria
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

39. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Yellow
Polyphenoloxidase

40. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Fatty Acid and Alcohol

41. What happens to chlorophyll on heating?
Daminozide
Pectin Esterase
Pheophytin forms
Troponins and Tropomyosin

42. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Primary butyric acid also caproic acid.
They act as catalysts - speeding the polymerization of acrylamide.
Sucrose
Yes

43. What are the primary secondary - tertiary - and quaternary structures?
Sweet - Salty - Sour - and Bitter
ERH=100 x Aw
Pectin Esterase - Polygalacturonase - Pectin Layase
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.

44. Name the strongest biochemical bond and the weakest biochemical bond.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Thickener in foods
Covalent (strongest) and Hydrophobic (Weakest)
V=IR and P=VI or I x I x are

45. What two common compounds are used together as an antioxidative system?
pH below positive charge; pH at no charge; pH above negative charge
Gliadins and Glutenins
Ascorbic Acid and Citric Acid
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

46. Name a naturally occurring protein sweetener.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Thamautin
Pectin methyl esterase or galacturonase
Sucrose

47. Name one way foam stability can be assessed.
pH 3-5
Racemic Mixture
Bright green
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.

48. What are 3 mesomorphic structures associated with lipids in the liquid state?
Pectins
Lamellar; Hexagonal I - II; Cubic
Water
Pectin Esterase

49. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Chitin
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.
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.

50. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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