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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is an isomer that is cheaper than Vitamin C?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Erythorbic Acid
Lamellar; Hexagonal I - II; Cubic
.05 M HCL

2. What is the enzyme that softens tomatoes?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
pH below positive charge; pH at no charge; pH above negative charge
Pectin Esterase
Initiation - Propagation - and Termination

3. 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.
Tryptophan
Sweet - Salty - Sour - and Bitter
Monosodium Glutamate

4. What metabolic end product does the Voges-Proskauer test detect?
Sweet - Salty - Sour - and Bitter
Browning of freshly cut surfaces of fruits and vegetables.
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.
Acetoin

5. 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.
Chitin
Blue pigment in flowers
Gliadins and Glutenins

6. Name two non-enzymatic browning reactions.
Thermus Aqauticus
Water
Nucleation or crystal formation and crystal growth.
Carmelization and Maillard

7. 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)
Aspartic Acid and Phenylalanine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

8. What is a polymorphism?
Anomeric
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Ascorbic Acid and Citric Acid

9. What ketohexose is most significant to food chemists?
Racemic Mixture
They act as catalysts - speeding the polymerization of acrylamide.
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.
Fructose

10. 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.
Osmosis
Anthocyanins
It explodes

11. Name two reasons why fats are hydrogenated.
Anomeric
Browning of freshly cut surfaces of fruits and vegetables.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Ascorbic Acid and Citric Acid

12. During freezing What are the two stages in the crystallization process?
Bitter
Nucleation or crystal formation and crystal growth.
Fat Oxidation
V=IR and P=VI or I x I x are

13. What are colloids that are stabilized by a layer of solvation called?
Glycosides of anthocyanidins
Emulsoids
Chlocophyllide does not have a phytoltail
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

14. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
Covalent (strongest) and Hydrophobic (Weakest)
Bright green
Osmosis

15. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Negative log of the hydrogen concentration (mol/l).
Lamellar; Hexagonal I - II; Cubic
1 - 3 - 7-trimethylxanthine
Olive Green

16. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Onions ( or leeks)
Pectin methylesterase & polygalacturonase
Osmosis
Gossypol (it is removed during the oil refining process)

17. What is the major color compound in tomatoes?
Pectin methylesterase & polygalacturonase
Water
Lycopenes
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

18. What is an isomer that is cheaper than Vitamin C?
Emulsoids
Erythorbic Acid
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Two aldehydes

19. Contains the lowest content of water
1 - 3 - 7-trimethylxanthine
Linoleic Acid
They act as catalysts - speeding the polymerization of acrylamide.
Whole Milk

20. Peptide bond formation results in the formation of what secondary compound?
Water
Glycosides of anthocyanidins
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.
Emulsification

21. In the enzyme Taq Polymerase What does Taq stand for?
Bright green
Initiation - Propagation - Termination
Thermus Aqauticus
Emulsification

22. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Prolamines
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Onions ( or leeks)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

23. Alar is the trade name for what chemical compound?
Phenylketonuria
Phenophylin
Daminozide
Monosodium Glutamate

24. What two enzymes degrade pectic substances?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
ERH=100 x Aw
Pectin methylesterase & polygalacturonase
Water

25. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Fructose
Sweet - Salty - Sour - and Bitter
Pectin methyl esterase or galacturonase

26. What is the protein efficiency ratio (PER) of casein?
Four
Initiation - Propagation - Termination
2.5
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

27. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
No
V=IR and P=VI or I x I x are
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

28. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Thamautin
Acetoin
Acsulfame-K - Saccharin - Cyclamate - Aspartame

29. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Orange Juice
Yellow

30. At low water activity What is the main deteriorative concern?
Whole Milk
Lipid oxidation
Emulsoids
Yellow

31. 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
Erythorbic Acid
Yellow
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

32. How do sodium chloride and sucrose affect foam stability?
Fructose
Sodium chloride reduces foam stability and sucrose improves foam stability.
14
D: None of the above

33. What is the name of the degradation compound of chlorophyll?
Osmosis
Bitter
It explodes
Phenophylin

34. Define molarity molality - and normality.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Browning of freshly cut surfaces of fruits and vegetables.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
1 - 3 - 7-trimethylxanthine

35. During freezing What are the two stages in the crystallization process?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
2.5
Nucleation or crystal formation and crystal growth.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

36. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Troponins and Tropomyosin
Thamautin
Oil in Water
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

37. What is Ohm's Law and What is Power Equation?
Nucleation or crystal formation and crystal growth.
Carrageenan
Emulsification
V=IR and P=VI or I x I x are

38. In genetics What is conjugation?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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
DNA transferred by cell to cell contact (bacterial sex).
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. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Two aldehydes
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
20 carbons and 4 double bonds

40. What is the main class of color compounds found in raspberries?
Anthocyanins
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Daminozide

41. 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
Pectin Esterase - Polygalacturonase - Pectin Layase
D: None of the above
Thamautin
.05

42. 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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Chitin
Bright green
Sodium bicarbonate generates CO2

43. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectin Esterase - Polygalacturonase - Pectin Layase
Blue pigment in flowers

44. How many polypeptide chains make up an antibody?
Four
Initiation - Propagation - Termination
Orange Juice
Acsulfame-K - Saccharin - Cyclamate - Aspartame

45. What does the iodine value measure and how is it measured?
DNA transferred by cell to cell contact (bacterial sex).
Capsaicin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
They act as catalysts - speeding the polymerization of acrylamide.

46. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pectins
Pectin methylesterase & polygalacturonase
Anomeric
Monosodium Glutamate

47. 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.
V=IR and P=VI or I x I x are
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

48. Waxes are composed of what two basic chemical entities?
Phenophylin
Fatty Acid (Ester linked) to Fatty Alcohol
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Ammonia - Water - Carbon Dioxide

49. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pheophytia does not have magnesium in porphyrin ring.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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
pH below positive charge; pH at no charge; pH above negative charge

50. How is pH defined?
Yes
Lipase
Negative log of the hydrogen concentration (mol/l).
Chitin