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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 degradative enzyme causes browning in apples - pears - bananas - and peaches?
Nucleation or crystal formation and crystal growth.
Bright green
Polyphenol Oxidase
Polyphenoloxidase

2. What is the major color compound in tomatoes?
Polyphenols
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Lycopenes
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

3. What is a polymorphism?
Parabens
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
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Speed of Light

4. Name the two components that comprise the relaxing factor in muscle fibers.
Acetoin
Troponins and Tropomyosin
Milk
Pectin Esterase

5. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Ascorbic Acid and Citric Acid
Water
An enzyme that converts hydrogen peroxide to water plus oxygen.
Racemic Mixture

6. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Pectin methylesterase & polygalacturonase
HPLC has higher pressure than FPLC
Onions ( or leeks)

7. What enzyme is most responsible for browning bananas?
Olive Green
Polyphenol Oxidase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

8. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
1 - 3 - 7-trimethylxanthine
Two aldehydes
Chitin
Phenylketonuria

9. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Milk
Troponins and Tropomyosin
Milk

10. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Whole Milk
pH 3-5

11. What is the major color compound in tomatoes?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.
Lycopenes

12. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Non-protein nitrogen
45% - 52% - 90%

13. What is the structural difference between chlorophyll and chlocophyllide?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chlocophyllide does not have a phytoltail
Lipase
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

14. Name two reasons why fats are hydrogenated.
Yes
20 carbons and 4 double bonds
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

15. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Tryptophan
Thamautin
Racemic Mixture

16. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Degradation of protein and production of acid from sugar at the same time.
NaCl (it dissociated to a 2M solution)
Pectin methyl esterase or galacturonase

17. What is the winterization process for an oil?
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
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Osmosis

18. What are the three main steps in the autooxidation of lipids?
Aspartic Acid and Phenylalanine
Initiation - Propagation - Termination
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).

19. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
Fatty Acid (Ester linked) to Fatty Alcohol
Fatty Acid (Ester linked) to Fatty Alcohol
Yellow

20. Name 3 chemical agents capable of denaturing proteins.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Covalent (strongest) and Hydrophobic (Weakest)

21. What does Reichert-Meissert Number measure?
HPLC has higher pressure than FPLC
Fatty Acid (Ester linked) to Fatty Alcohol
Primary butyric acid also caproic acid.
Cis

22. What is the protein efficiency ratio (PER) of casein?
2.5
Troponins and Tropomyosin
Pheophytin forms
45% - 52% - 90%

23. During freezing What are the two stages in the crystallization process?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Daminozide
Thamautin
Nucleation or crystal formation and crystal growth.

24. What enzyme causes hyrolytic rancidity in milk?
Speed of Light
Polyphenols
Lipase
D: None of the above

25. Name two main gluten proteins.
Pectins
Pectin Esterase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Gliadins and Glutenins

26. What is Ohm's Law and What is Power Equation?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
V=IR and P=VI or I x I x are
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

27. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Ammonia - Water - Carbon Dioxide
Phenophylin
Acsulfame-K - Saccharin - Cyclamate - Aspartame

28. What is the fundamental driving of electrophoresis?
Lysine - Arginine - and Histidine
The speed of a molecule is proportional to the surrounding voltage gradient.
A concentrate of microfibrillar proteins of fish muscle.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

29. What does the acronym NPN stand for?
Phenylketonuria
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
Capsaicin
Non-protein nitrogen

30. Name two main gluten proteins.
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
Gliadins and Glutenins
Pectins

31. How many polypeptide chains make up an antibody?
Four
RNA transcribed to DNA
An enzyme that converts hydrogen peroxide to water plus oxygen.
NaCl (it dissociated to a 2M solution)

32. What metabolic end product does the Voges-Proskauer test detect?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Acetoin
Emulsoids
Polyphenoloxidase

33. In genetics What is conjugation?
Daminozide
D: None of the above
DNA transferred by cell to cell contact (bacterial sex).
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

34. Alar is the trade name for what chemical compound?
Prolamines
Glycosides of anthocyanidins
The speed of a molecule is proportional to the surrounding voltage gradient.
Daminozide

35. What enzyme causes hyrolytic rancidity in milk?
Aspartic Acid and Phenylalanine
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.
Lipase
Capsaicin

36. 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
D: None of the above
It explodes
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Prolamines

37. In genetics What is conjugation?
Sodium chloride reduces foam stability and sucrose improves foam stability.
DNA transferred by cell to cell contact (bacterial sex).
Bitter
Pectin Esterase

38. Name 5 proteins with good foaming properties.
Parabens
Pheophytin forms
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.
Water

39. Name the most common functional property of phospholipids in food systems.
Emulsoids
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
Emulsification
Sweet - Salty - Sour - and Bitter

40. What happens to chlorophyll on heating?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pheophytin forms
Anthocyanins
It explodes

41. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Speed of Light
Speed of Light
The speed of a molecule is proportional to the surrounding voltage gradient.

42. How can a molecular weight of protein - DNA - and RNA be determined?
Chlocophyllide does not have a phytoltail
It explodes
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Phenylketonuria

43. How many carbon atoms and how many double bonds are there in arachidonic acid?
Lipid oxidation
pH below positive charge; pH at no charge; pH above negative charge
20 carbons and 4 double bonds
Pectin methylesterase & polygalacturonase

44. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
2.5
DNA transferred by cell to cell contact (bacterial sex).
Yellow
Chlocophyllide does not have a phytoltail

45. Name a commonly used household chemical leavening agent and the gas it generates.
Gliadins and Glutenins
Prolamines
14
Sodium bicarbonate generates CO2

46. What is the geometric configuration of double bonds in most natural fatty acids?
Sodium bicarbonate generates CO2
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Cis
Water

47. What two common compounds are used together as an antioxidative system?
Primary butyric acid also caproic acid.
14
DNA transferred by cell to cell contact (bacterial sex).
Ascorbic Acid and Citric Acid

48. What are the limiting amino acids in corn - potato - and green peas?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Chlocophyllide does not have a phytoltail
.05 M HCL

49. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
No
Water
DNA transferred by cell to cell contact (bacterial sex).

50. What is the chemical nomenclature for caffeine?
Fatty Acid and Alcohol
1 - 3 - 7-trimethylxanthine
Arachidonic Acid
Emulsoids