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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. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Gossypol (it is removed during the oil refining process)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Blue pigment in flowers
Bitter

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

3. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Lipase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Plasmids

4. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Linoleic Acid
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

5. What does Acid Degree Value measure and how is it measured?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Bitter
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.

6. What are two common reducing agents that break disulfide bonds in proteins?
Phenylketonuria
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Sucrose
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

7. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Blue pigment in flowers
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
RNA transcribed to DNA
Tryptophan

8. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
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.
Water
Arachidonic Acid
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

9. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
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
Emulsification

10. Name 3 factors influencing the rate of lipid oxidation in foods.
HPLC has higher pressure than FPLC
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Troponins and Tropomyosin

11. 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
Lipid oxidation
Water
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Initiation - Propagation - Termination

12. Name 3 physical agents capable of denaturing proteins.
Emulsoids
RNA transcribed to DNA
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Negative log of the hydrogen concentration (mol/l).

13. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
They act as catalysts - speeding the polymerization of acrylamide.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

14. What are the three stages of oxidative rancidity?
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.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Initiation - Propagation - and Termination
It explodes

15. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
20 carbons and 4 double bonds
Sweet - Salty - Sour - and Bitter
Non-protein nitrogen

16. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Tryptophan
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Lipid oxidation

17. Name one way foam stability can be assessed.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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.
Negative log of the hydrogen concentration (mol/l).
Chlocophyllide does not have a phytoltail

18. What is the main class of color compounds found in raspberries?
Daminozide
Anthocyanins
Two aldehydes
Onions ( or leeks)

19. What does Reichert-Meissert Number measure?
Prolamines
Primary butyric acid also caproic acid.
ERH=100 x Aw
Parabens

20. In what food is butyric acid typically found?
Milk
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Water
They act as catalysts - speeding the polymerization of acrylamide.

21. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Thamautin
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
pH below positive charge; pH at no charge; pH above negative charge

22. What enzyme is most responsible for browning bananas?
Water
Polyphenol Oxidase
HPLC has higher pressure than FPLC
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

23. What is the fundamental driving of electrophoresis?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Initiation - Propagation - and Termination
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

24. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Linoleic Acid
It explodes
Onions ( or leeks)

25. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
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
Whole Milk
RNA transcribed to DNA

26. What ketohexose is most significant to food chemists?
Racemic Mixture
Fructose
Anomeric
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

27. Name two main gluten proteins.
Linoleic Acid
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
Gliadins and Glutenins
Daminozide

28. Name 3 chemical agents capable of denaturing proteins.
Sucrose
Ascorbic Acid and Citric Acid
Anomeric
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

29. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
pH below positive charge; pH at no charge; pH above negative charge
Polyphenoloxidase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

30. Name 3 factors influencing the consistency of commercial fats.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Thermus Aqauticus
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

31. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Sweet - Salty - Sour - and Bitter
Linoleic Acid
pH 3-5

32. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
45% - 52% - 90%
Daminozide
Lycopenes

33. Name three factors useful in controlling enzyme activity.
pH below positive charge; pH at no charge; pH above negative charge
Degradation of protein and production of acid from sugar at the same time.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

34. Name 5 proteins with good foaming properties.
Fructose
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.
Sucrose
D: None of the above

35. What are the limiting amino acids in corn - potato - and green peas?
Fatty Acid and Alcohol
.05 M HCL
Tryptophan
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

36. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Ascorbic Acid and Citric Acid
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Polyphenol Oxidase

37. What does the 'c' stand for in the equation E=mc2?
Parabens
Speed of Light
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.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

38. In what food is butyric acid typically found?
Pectins
Pectin Esterase - Polygalacturonase - Pectin Layase
Milk
Erythorbic Acid

39. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
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.
Negative log of the hydrogen concentration (mol/l).
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

40. Name two non-enzymatic browning reactions.
No
Fat Oxidation
Carmelization and Maillard
Four

41. Alar is the trade name for what chemical compound?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Daminozide
Pectin Esterase - Polygalacturonase - Pectin Layase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

42. Name a naturally occurring protein sweetener.
Fat Oxidation
Primary butyric acid also caproic acid.
Thamautin
Acetoin

43. Name the two components that comprise the relaxing factor in muscle fibers.
Arachidonic Acid
Troponins and Tropomyosin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Plasmids

44. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
They act as catalysts - speeding the polymerization of acrylamide.
DNA transferred by cell to cell contact (bacterial sex).
pH 3-5

45. Name two enzymes that are involved in softening fruits.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Aspartic Acid and Phenylalanine
Four
Pectin Esterase - Polygalacturonase - Pectin Layase

46. What are the four basic flavors perceived by the tongue?
Lipase
Polyphenoloxidase
Water
Sweet - Salty - Sour - and Bitter

47. Name two reasons why fats are hydrogenated.
Orange Juice
Yellow
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

48. Name two enzymes that are involved in softening fruits.
Monosodium Glutamate
Arachidonic Acid
pH below positive charge; pH at no charge; pH above negative charge
Pectin Esterase - Polygalacturonase - Pectin Layase

49. What compounds oxidize to form brown color in fruits and vegetables?
Plasmids
Polyphenols
20 carbons and 4 double bonds
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.

50. What is the chemical nomenclature for caffeine?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Water
1 - 3 - 7-trimethylxanthine
Racemic Mixture