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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Orange Juice
Plasmids
Blue pigment in flowers

2. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Plasmids
Tryptophan
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Lamellar; Hexagonal I - II; Cubic

3. What enzyme causes hyrolytic rancidity in milk?
Lipase
Linoleic Acid
Negative log of the hydrogen concentration (mol/l).
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.

4. 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)
pH below positive charge; pH at no charge; pH above negative charge
Browning of freshly cut surfaces of fruits and vegetables.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

5. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Glycosides of anthocyanidins
Aspartic Acid and Phenylalanine

6. What is a polymorphism?
Troponins and Tropomyosin
Phenophylin
V=IR and P=VI or I x I x are
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

7. 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?
.05 M HCL
It explodes
Troponins and Tropomyosin
Fructose

8. 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.
20 carbons and 4 double bonds
Milk
Primary butyric acid also caproic acid.

9. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
1 - 3 - 7-trimethylxanthine
V=IR and P=VI or I x I x are
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

10. Name 5 proteins with good foaming properties.
Aspartic Acid and Phenylalanine
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.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
An enzyme that converts hydrogen peroxide to water plus oxygen.

11. How many carbon atoms and how many double bonds are there in arachidonic acid?
Milk
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
Olive Green
20 carbons and 4 double bonds

12. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.
Polyphenoloxidase

13. What does HLB stand for and What does a high and low HLB value indicate?
Pectins
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.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Orange Juice

14. In the enzyme Taq Polymerase What does Taq stand for?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Thermus Aqauticus
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

15. Will lipid oxidation be higher at a water activity of .05 or .5?
D: None of the above
Aspartic Acid and Phenylalanine
.05
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.

16. What does the iodine value measure and how is it measured?
Water
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Nucleation or crystal formation and crystal growth.
Yes

17. Name three factors useful in controlling enzyme activity.
Water
Bright green
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

18. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Osmosis
Polyphenol Oxidase
Chlocophyllide does not have a phytoltail
Whole Milk

19. 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
Lycopenes
Browning of freshly cut surfaces of fruits and vegetables.
Fatty Acid (Ester linked) to Fatty Alcohol
Onions ( or leeks)

20. Waxes are composed of what two basic chemical entities?
Blue pigment in flowers
Water
Lamellar; Hexagonal I - II; Cubic
Fatty Acid (Ester linked) to Fatty Alcohol

21. What are the three stages of oxidative rancidity?
ERH=100 x Aw
Aspartic Acid and Phenylalanine
Initiation - Propagation - and Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

22. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
An enzyme that converts hydrogen peroxide to water plus oxygen.
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.
Tryptophan
Chlocophyllide does not have a phytoltail

23. What is acid proteolysis?
Daminozide
Degradation of protein and production of acid from sugar at the same time.
RNA transcribed to DNA
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

24. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Osmosis
Fatty Acid and Alcohol
Chlocophyllide does not have a phytoltail

25. Name two non-enzymatic browning reactions.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Carmelization and Maillard
.05 M HCL
Cis

26. What are the primary secondary - tertiary - and quaternary structures?
Fructose
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.
Pectin methylesterase & polygalacturonase
Gossypol (it is removed during the oil refining process)

27. What effect would the addition of sodium bicarbonate have to chocolate?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
V=IR and P=VI or I x I x are
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

28. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Ammonia - Water - Carbon Dioxide
Primary butyric acid also caproic acid.
Plasmids
D: None of the above

29. What two common compounds are used together as an antioxidative system?
Degradation of protein and production of acid from sugar at the same time.
Ascorbic Acid and Citric Acid
A concentrate of microfibrillar proteins of fish muscle.
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

30. What are two common reducing agents that break disulfide bonds in proteins?
Chitin
Aspartic Acid and Phenylalanine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Phenylketonuria

31. Is a disaccharide
Phenophylin
A concentrate of microfibrillar proteins of fish muscle.
Sucrose
Whole Milk

32. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Pectin Esterase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
.05 M HCL

33. How is pH defined?
Pectin methylesterase & polygalacturonase
Negative log of the hydrogen concentration (mol/l).
Milk
Polyphenols

34. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Speed of Light
Capsaicin
Ammonia - Water - Carbon Dioxide
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

35. What is the chemical nomenclature for caffeine?
Four
1 - 3 - 7-trimethylxanthine
Osmosis
Fructose

36. What compounds oxidize to form brown color in fruits and vegetables?
Carrageenan
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Cis
Polyphenols

37. Name a commonly used household chemical leavening agent and the gas it generates.
Thamautin
Daminozide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Sodium bicarbonate generates CO2

38. What is the Peroxide Value a measure of?
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.
HPLC has higher pressure than FPLC
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

39. What is the winterization process for an oil?
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.
14
RNA transcribed to DNA
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

40. Name 3 chemical agents capable of denaturing proteins.
Carmelization and Maillard
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Phenophylin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

41. How can a molecular weight of protein - DNA - and RNA be determined?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Carmelization and Maillard

42. What does HLB stand for and What does a high and low HLB value indicate?
Fatty Acid (Ester linked) to Fatty Alcohol
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.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Tryptophan

43. What is the name of the degradation compound of chlorophyll?
Browning of freshly cut surfaces of fruits and vegetables.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Phenophylin

44. Peptide bond formation results in the formation of what secondary compound?
D: None of the above
Initiation - Propagation - and Termination
Water
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

45. How does HPLC differ from FPLC?
Chlocophyllide does not have a phytoltail
HPLC has higher pressure than FPLC
Gliadins and Glutenins
Thamautin

46. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Arachidonic Acid
Sodium chloride reduces foam stability and sucrose improves foam stability.

47. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Capsaicin
D: None of the above
Bright green

48. What is the main class of color compounds found in raspberries?
Anthocyanins
Capsaicin
Arachidonic Acid
NaCl (it dissociated to a 2M solution)

49. What does the 'c' stand for in the equation E=mc2?
Covalent (strongest) and Hydrophobic (Weakest)
HPLC has higher pressure than FPLC
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.
Speed of Light

50. In what food is butyric acid typically found?
Milk
Phenophylin
.05
pH 3-5