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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 HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Polyphenoloxidase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
pH 3-5

2. Name a commonly used household chemical leavening agent and the gas it generates.
Carmelization and Maillard
1 - 3 - 7-trimethylxanthine
Sodium bicarbonate generates CO2
Yes

3. What is the protein efficiency ratio (PER) of casein?
Chitin
2.5
Anomeric
Primary butyric acid also caproic acid.

4. How is pH defined?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Negative log of the hydrogen concentration (mol/l).
Sodium chloride reduces foam stability and sucrose improves foam stability.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

5. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Fructose
Bright green
Two aldehydes
Fructose

6. How does ERH relate to water activity?
ERH=100 x Aw
Phenylketonuria
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Carrageenan

7. How many carbon atoms and how many double bonds are there in arachidonic acid?
Lycopenes
Polyphenol Oxidase
Ascorbic Acid and Citric Acid
20 carbons and 4 double bonds

8. How many carbon atoms are there in the fatty acid myristic acid?
Non-protein nitrogen
Linoleic Acid
14
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.

9. Name 3 physical agents capable of denaturing proteins.
HPLC has higher pressure than FPLC
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Daminozide

10. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Fructose
Yellow
Fatty Acid (Ester linked) to Fatty Alcohol
Sweet - Salty - Sour - and Bitter

11. What is acid proteolysis?
Emulsification
Polyphenoloxidase
Carmelization and Maillard
Degradation of protein and production of acid from sugar at the same time.

12. Name the most common functional property of phospholipids in food systems.
Chitin
Emulsification
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
They act as catalysts - speeding the polymerization of acrylamide.

13. What ketohexose is most significant to food chemists?
Fructose
Polyphenol Oxidase
Gliadins and Glutenins
Chlocophyllide does not have a phytoltail

14. Are sorbitol and mannitol sweet?
Speed of Light
Yes
14
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

15. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
Carrageenan
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Fructose

16. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Lamellar; Hexagonal I - II; Cubic
Onions ( or leeks)
Sodium bicarbonate generates CO2
Pectin Esterase

17. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Tryptophan
Sodium bicarbonate generates CO2
Milk

18. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Polyphenol Oxidase
Pectins
D: None of the above

19. What are the primary secondary - tertiary - and quaternary structures?
Capsaicin
Water
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.
Bright green

20. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Daminozide
Acetoin
Plasmids
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

21. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Daminozide
2.5
Glycosides of anthocyanidins

22. What enzyme is most responsible for browning bananas?
Troponins and Tropomyosin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Polyphenol Oxidase
Orange Juice

23. In what food is butyric acid typically found?
Oil in Water
Pectins
Milk
Anthocyanins

24. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Speed of Light
Olive Green
Daminozide

25. Peptide bond formation results in the formation of what secondary compound?
Water
D: None of the above
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.
Yellow

26. What is the main class of color compounds found in raspberries?
20 carbons and 4 double bonds
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
Anthocyanins
DNA transferred by cell to cell contact (bacterial sex).

27. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Anomeric
Fructose
Prolamines

28. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
Acetoin
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
No
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.

29. What does HLB stand for and What does a high and low HLB value indicate?
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).
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.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

30. What are the three main steps in the autooxidation of lipids?
Emulsoids
Initiation - Propagation - Termination
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
.05 M HCL

31. What is the chemical nature of anthocyanins?
Fatty Acid and Alcohol
Sucrose
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
Glycosides of anthocyanidins

32. Name the three positively charged amino acids.
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.
Covalent (strongest) and Hydrophobic (Weakest)
Lysine - Arginine - and Histidine
Thickener in foods

33. How many polypeptide chains make up an antibody?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Four
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

34. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Gliadins and Glutenins
Fructose
Anomeric
Yellow

35. What are colloids that are stabilized by a layer of solvation called?
Blue pigment in flowers
14
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.
Emulsoids

36. What does HLB stand for and What does a high and low HLB value indicate?
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.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
DNA transferred by cell to cell contact (bacterial sex).
V=IR and P=VI or I x I x are

37. Which two amino acids is the aspartame derived from?
Prolamines
Aspartic Acid and Phenylalanine
Racemic Mixture
Water

38. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenol Oxidase
Polyphenols
Water
Degradation of protein and production of acid from sugar at the same time.

39. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Chitin
.05
Lysine - Arginine - and Histidine

40. Name three effects of protein denaturation.
DNA transferred by cell to cell contact (bacterial sex).
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
.05
DNA transferred by cell to cell contact (bacterial sex).

41. What are the only phenols approved for use in the microbiological preservation of foods?
Degradation of protein and production of acid from sugar at the same time.
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.
Parabens
Carmelization and Maillard

42. What two enzymes degrade pectic substances?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Degradation of protein and production of acid from sugar at the same time.
Lycopenes
Pectin methylesterase & polygalacturonase

43. What effect would the addition of sodium bicarbonate have to chocolate?
Glycosides of anthocyanidins
Bitter
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Orange Juice

44. 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)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Polyphenols
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.

45. How does HPLC differ from FPLC?
Tryptophan
HPLC has higher pressure than FPLC
Capsaicin
No

46. What does the iodine value measure and how is it measured?
Fructose
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Glycosides of anthocyanidins
Polyphenoloxidase

47. Name three non-nutritive sweeteners approved for use in USA?
45% - 52% - 90%
Polyphenols
Negative log of the hydrogen concentration (mol/l).
Acsulfame-K - Saccharin - Cyclamate - Aspartame

48. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Lysine - Arginine - and Histidine
Oil in Water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
.05

49. What is the name of the degradation compound of chlorophyll?
Phenophylin
Lamellar; Hexagonal I - II; Cubic
Phenylketonuria
Polyphenol Oxidase

50. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Polyphenol Oxidase
pH 3-5
pH below positive charge; pH at no charge; pH above negative charge