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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. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
pH below positive charge; pH at no charge; pH above negative charge
Sodium bicarbonate generates CO2
D: None of the above

2. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Arachidonic Acid
A concentrate of microfibrillar proteins of fish muscle.

3. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Linoleic Acid
Pectin methyl esterase or galacturonase
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.
Polyphenols

4. What two types of compounds are joined with an ester bond to make a wax?
Fructose
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fatty Acid and Alcohol
Nucleation or crystal formation and crystal growth.

5. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Orange Juice
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Water
Anomeric

6. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Sodium bicarbonate generates CO2
Capsaicin
Carrageenan

7. Name the two components that comprise the relaxing factor in muscle fibers.
Erythorbic Acid
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
Pectin methyl esterase or galacturonase
Troponins and Tropomyosin

8. At low water activity What is the main deteriorative concern?
Lipid oxidation
.05
Pheophytin forms
Acsulfame-K - Saccharin - Cyclamate - Aspartame

9. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
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.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lamellar; Hexagonal I - II; Cubic
It explodes

10. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Lysine - Arginine - and Histidine
Erythorbic Acid
Bright green
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

11. What are the primary secondary - tertiary - and quaternary structures?
Cis
Pectin Esterase - Polygalacturonase - Pectin Layase
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.

12. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin methylesterase & polygalacturonase
Nucleation or crystal formation and crystal growth.

13. What compounds oxidize to form brown color in fruits and vegetables?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Linoleic Acid
Polyphenols
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. Name one way foam stability can be assessed.
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.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
A concentrate of microfibrillar proteins of fish muscle.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

15. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Sucrose
Nucleation or crystal formation and crystal growth.
They act as catalysts - speeding the polymerization of acrylamide.
Glycosides of anthocyanidins

16. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
Thermus Aqauticus
ERH=100 x Aw
Pectin Esterase

17. Name 5 proteins with good foaming properties.
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.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

18. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Tryptophan
Chitin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

19. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Two aldehydes
Anomeric
pH below positive charge; pH at no charge; pH above negative charge
1 - 3 - 7-trimethylxanthine

20. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Oil in Water
Browning of freshly cut surfaces of fruits and vegetables.
Lysine - Arginine - and Histidine

21. What is the main class of color compounds found in raspberries?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Anthocyanins
DNA transferred by cell to cell contact (bacterial sex).

22. What is Ohm's Law and What is Power Equation?
Thickener in foods
V=IR and P=VI or I x I x are
Linoleic Acid
Plasmids

23. Name 3 factors influencing the consistency of commercial fats.
Lycopenes
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Oil in Water
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

24. How does HPLC differ from FPLC?
Tryptophan
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
HPLC has higher pressure than FPLC
Sodium chloride reduces foam stability and sucrose improves foam stability.

25. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Gliadins and Glutenins
Lamellar; Hexagonal I - II; Cubic
Capsaicin
It explodes

26. How many polypeptide chains make up an antibody?
Water
Four
Pheophytia does not have magnesium in porphyrin ring.
pH 3-5

27. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
NaCl (it dissociated to a 2M solution)
Thickener in foods
Pectin Esterase

28. Will lipid oxidation be higher at a water activity of .05 or .5?
Primary butyric acid also caproic acid.
Erythorbic 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.
.05

29. Name three nonpolar polar - and charged amino acids.
Negative log of the hydrogen concentration (mol/l).
V=IR and P=VI or I x I x are
Lipase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

30. What is the enzyme responsible for browning in apples and lettuce?
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase

31. What are two common reducing agents that break disulfide bonds in proteins?
Anthocyanins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fatty Acid and Alcohol
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

32. What is a polymorphism?
2.5
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Cis
Browning of freshly cut surfaces of fruits and vegetables.

33. 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
Racemic Mixture
ERH=100 x Aw
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

34. 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
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Thamautin
Primary butyric acid also caproic acid.
Browning of freshly cut surfaces of fruits and vegetables.

35. Alar is the trade name for what chemical compound?
Water
Daminozide
Fatty Acid and Alcohol
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

36. What is the geometric configuration of double bonds in most natural fatty acids?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenol Oxidase
Cis
.05 M HCL

37. What is acid proteolysis?
Polyphenols
Troponins and Tropomyosin
Degradation of protein and production of acid from sugar at the same time.
.05

38. In the enzyme Taq Polymerase What does Taq stand for?
D: None of the above
Degradation of protein and production of acid from sugar at the same time.
Thermus Aqauticus
The speed of a molecule is proportional to the surrounding voltage gradient.

39. What is the enzyme that softens tomatoes?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Daminozide
Fatty Acid and Alcohol
Pectin Esterase

40. Name 4 advantages of using enzymes in food processing.
Covalent (strongest) and Hydrophobic (Weakest)
Lipid oxidation
Initiation - Propagation - and Termination
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

41. 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.
A concentrate of microfibrillar proteins of fish muscle.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
DNA transferred by cell to cell contact (bacterial sex).

42. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lysine - Arginine - and Histidine
Ammonia - Water - Carbon Dioxide
Plasmids

43. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
2.5
Degradation of protein and production of acid from sugar at the same time.
HPLC has higher pressure than FPLC

44. What is the Peroxide Value a measure of?
Fat Oxidation
Carmelization and Maillard
No
Anomeric

45. What are the three stages of oxidative rancidity?
Pheophytin forms
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Initiation - Propagation - and Termination
2.5

46. What is the geometric configuration of double bonds in most natural fatty acids?
Browning of freshly cut surfaces of fruits and vegetables.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Speed of Light
Cis

47. Name two reasons why fats are hydrogenated.
20 carbons and 4 double bonds
It explodes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

48. Name two main gluten proteins.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sodium bicarbonate generates CO2
Anomeric
Gliadins and Glutenins

49. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Negative log of the hydrogen concentration (mol/l).
Two aldehydes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

50. How do sodium chloride and sucrose affect foam stability?
Bitter
Pectin methylesterase & polygalacturonase
.05 M HCL
Sodium chloride reduces foam stability and sucrose improves foam stability.