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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. Name two enzymes that are involved in softening fruits.
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.
Thermus Aqauticus
Plasmids
Pectin Esterase - Polygalacturonase - Pectin Layase

2. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Milk
Olive Green
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

3. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
The speed of a molecule is proportional to the surrounding voltage gradient.
Olive Green
Pectin Esterase

4. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Sucrose
Phenylketonuria
Capsaicin
Aspartic Acid and Phenylalanine

5. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Acetoin
Bitter
Polyphenoloxidase
Degradation of protein and production of acid from sugar at the same time.

6. Give one word for a carbon atom involved in hemiacetal or acetal formation.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Carrageenan
Anomeric
Carmelization and Maillard

7. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anthocyanins
Cis
Yellow
Anomeric

8. What are colloids that are stabilized by a layer of solvation called?
Pheophytia does not have magnesium in porphyrin ring.
Orange Juice
Nucleation or crystal formation and crystal growth.
Emulsoids

9. What is the Peroxide Value a measure of?
Polyphenol Oxidase
Polyphenoloxidase
Bright green
Fat Oxidation

10. What is the winterization process for an oil?
V=IR and P=VI or I x I x are
Gliadins and Glutenins
Prolamines
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

11. What is Ohm's Law and What is Power Equation?
Olive Green
Plasmids
Capsaicin
V=IR and P=VI or I x I x are

12. What toxic pigment is found in cottonseed endosperm?
Troponins and Tropomyosin
Bright green
14
Gossypol (it is removed during the oil refining process)

13. In genetics What is conjugation?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Monosodium Glutamate
DNA transferred by cell to cell contact (bacterial sex).
Pectin methylesterase & polygalacturonase

14. What are two common reducing agents that break disulfide bonds in proteins?
Sodium chloride reduces foam stability and sucrose improves foam stability.
2.5
Blue pigment in flowers
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

15. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Four
Lipase
Anthocyanins

16. During freezing What are the two stages in the crystallization process?
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.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Nucleation or crystal formation and crystal growth.
Anthocyanins

17. What is the structural difference between chlorophyll and pheophytia?
Parabens
Pheophytia does not have magnesium in porphyrin ring.
Browning of freshly cut surfaces of fruits and vegetables.
Fructose

18. Are sorbitol and mannitol sweet?
Emulsification
Gliadins and Glutenins
Pectins
Yes

19. What enzyme causes hyrolytic rancidity in milk?
It explodes
Lipase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Plasmids

20. 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?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lipase
Fat Oxidation
.05 M HCL

21. Will lipid oxidation be higher at a water activity of .05 or .5?
Water
.05
2.5
Anomeric

22. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Non-protein nitrogen
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. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Capsaicin
45% - 52% - 90%
They act as catalysts - speeding the polymerization of acrylamide.
Sweet - Salty - Sour - and Bitter

24. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
D: None of the above
Erythorbic Acid
Oil in Water

25. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Aspartic Acid and Phenylalanine
Degradation of protein and production of acid from sugar at the same time.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

26. Name a commonly used household chemical leavening agent and the gas it generates.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sodium bicarbonate generates CO2
Thamautin
Pectins

27. What is the structural difference between chlorophyll and chlocophyllide?
Troponins and Tropomyosin
Chlocophyllide does not have a phytoltail
Fatty Acid (Ester linked) to Fatty Alcohol
pH 3-5

28. Name three nonpolar polar - and charged amino acids.
Glycosides of anthocyanidins
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
V=IR and P=VI or I x I x are

29. 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.
Lysine - Arginine - and Histidine
Water
Degradation of protein and production of acid from sugar at the same time.

30. What enzyme is most responsible for browning bananas?
Chlocophyllide does not have a phytoltail
Lycopenes
20 carbons and 4 double bonds
Polyphenol Oxidase

31. Waxes are composed of what two basic chemical entities?
Phenophylin
Fatty Acid (Ester linked) to Fatty Alcohol
Thermus Aqauticus
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.

32. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Gliadins and Glutenins

33. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Parabens
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fat Oxidation
Bright green

34. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Osmosis
Fatty Acid (Ester linked) to Fatty Alcohol
Onions ( or leeks)

35. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lamellar; Hexagonal I - II; Cubic
ERH=100 x Aw
Capsaicin

36. In genetics What is conjugation?
Fructose
An enzyme that converts hydrogen peroxide to water plus oxygen.
DNA transferred by cell to cell contact (bacterial sex).
Capsaicin

37. How many polypeptide chains make up an antibody?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Sucrose
Four
Fructose

38. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Fatty Acid (Ester linked) to Fatty Alcohol
The speed of a molecule is proportional to the surrounding voltage gradient.
Linoleic Acid
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

39. What pigment was first designated as anthocyanins?
Water
ERH=100 x Aw
Plasmids
Blue pigment in flowers

40. What happens to chlorophyll on heating?
V=IR and P=VI or I x I x are
Pheophytin forms
DNA transferred by cell to cell contact (bacterial sex).
Anthocyanins

41. Is a disaccharide
Glycosides of anthocyanidins
Monosodium Glutamate
Sucrose
Sodium bicarbonate generates CO2

42. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
1 - 3 - 7-trimethylxanthine
Racemic Mixture
Emulsification

43. What is a polymorphism?
pH 3-5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

44. Peptide bond formation results in the formation of what secondary compound?
Water
Daminozide
Anthocyanins
Speed of Light

45. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
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.
Two aldehydes
Yellow
Pectin methyl esterase or galacturonase

46. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Negative log of the hydrogen concentration (mol/l).
RNA transcribed to DNA
Erythorbic Acid

47. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Fructose
Carrageenan
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lycopenes

48. Alar is the trade name for what chemical compound?
Daminozide
Yellow
Anomeric
Plasmids

49. Name two enzymes that are involved in softening fruits.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Pectin Esterase - Polygalacturonase - Pectin Layase
Nucleation or crystal formation and crystal growth.

50. Alar is the trade name for what chemical compound?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Phenophylin
Daminozide
Osmosis