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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. What is a polymorphism?
Aspartic Acid and Phenylalanine
An enzyme that converts hydrogen peroxide to water plus oxygen.
Pheophytin forms
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

2. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

3. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
RNA transcribed to DNA
Capsaicin
They act as catalysts - speeding the polymerization of acrylamide.
Pectin Esterase - Polygalacturonase - Pectin Layase

4. 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?
Lamellar; Hexagonal I - II; Cubic
ERH=100 x Aw
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It explodes

5. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
Lysine - Arginine - and Histidine
pH 3-5
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

6. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Gossypol (it is removed during the oil refining process)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

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

8. How does HPLC differ from FPLC?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
HPLC has higher pressure than FPLC
ERH=100 x Aw

9. What does MSG stand for?
Prolamines
Monosodium Glutamate
Polyphenol Oxidase
Speed of Light

10. How is pH defined?
Racemic Mixture
Pectin Esterase
Negative log of the hydrogen concentration (mol/l).
Tryptophan

11. Alar is the trade name for what chemical compound?
Gossypol (it is removed during the oil refining process)
Daminozide
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
An enzyme that converts hydrogen peroxide to water plus oxygen.

12. Define molarity molality - and normality.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

13. What is the name of the degradation compound of chlorophyll?
Phenophylin
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
Yellow
Prolamines

14. In what food is butyric acid typically found?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
It explodes
Milk
Pheophytin forms

15. What is the protein efficiency ratio (PER) of casein?
Phenophylin
2.5
Initiation - Propagation - Termination
Degradation of protein and production of acid from sugar at the same time.

16. Name three effects of protein denaturation.
Acetoin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Ascorbic Acid and Citric Acid
Oil in Water

17. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Capsaicin
.05
Gliadins and Glutenins

18. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water
Racemic Mixture
Yellow

19. How many carbon atoms and how many double bonds are there in arachidonic 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.
20 carbons and 4 double bonds
Anthocyanins
.05 M HCL

20. How can a molecular weight of protein - DNA - and RNA be determined?
Glycosides of anthocyanidins
Pheophytin forms
Pectins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

21. Name three non-nutritive sweeteners approved for use in USA?
Gliadins and Glutenins
Acsulfame-K - Saccharin - Cyclamate - Aspartame
RNA transcribed to DNA
Water

22. What is the acid present in fish oil?
Water
Whole Milk
Initiation - Propagation - Termination
Arachidonic Acid

23. What toxic pigment is found in cottonseed endosperm?
Browning of freshly cut surfaces of fruits and vegetables.
Pheophytin forms
Gossypol (it is removed during the oil refining process)
Racemic Mixture

24. Define molarity molality - and normality.
Lipase
Sodium bicarbonate generates CO2
Water
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

25. How many polypeptide chains make up an antibody?
Troponins and Tropomyosin
Speed of Light
Four
Chitin

26. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Bitter
Plasmids
Capsaicin

27. What is the structural difference between chlorophyll and pheophytia?
Oil in Water
Pheophytia does not have magnesium in porphyrin ring.
Blue pigment in flowers
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

28. Is a disaccharide
Erythorbic Acid
Carrageenan
Negative log of the hydrogen concentration (mol/l).
Sucrose

29. What is the main class of color compounds found in raspberries?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin methyl esterase or galacturonase
Anthocyanins

30. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Carmelization and Maillard
Yellow
Anomeric
Orange Juice

31. What is an isomer that is cheaper than Vitamin C?
Lysine - Arginine - and Histidine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Erythorbic Acid
Monosodium Glutamate

32. Name 3 chemical agents capable of denaturing proteins.
Ascorbic Acid and Citric Acid
ERH=100 x Aw
20 carbons and 4 double bonds
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

33. At low water activity What is the main deteriorative concern?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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
Lipid oxidation
Acetoin

34. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Pheophytia does not have magnesium in porphyrin ring.
Blue pigment in flowers
Pheophytin forms

35. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Orange Juice
.05
Monosodium Glutamate

36. What are the primary secondary - tertiary - and quaternary structures?
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Pectin methyl esterase or galacturonase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

37. What charge will a protein have when the pH of its solution is below at - and above its pKa?
It explodes
Daminozide
Negative log of the hydrogen concentration (mol/l).
pH below positive charge; pH at no charge; pH above negative charge

38. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Sodium bicarbonate generates CO2
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lipase

39. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Yellow
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Lysine - Arginine - and Histidine

40. 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)
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
DNA transferred by cell to cell contact (bacterial sex).

41. Which two amino acids is the aspartame derived from?
Non-protein nitrogen
Aspartic Acid and Phenylalanine
Acetoin
Polyphenol Oxidase

42. Name 4 advantages of using enzymes in food processing.
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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Emulsification
Glycosides of anthocyanidins

43. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phenylketonuria
Yellow
Non-protein nitrogen

44. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Blue pigment in flowers
Pectin Esterase - Polygalacturonase - Pectin Layase
Oil in Water
RNA transcribed to DNA

45. What is the Peroxide Value a measure of?
Ammonia - Water - Carbon Dioxide
Fat Oxidation
Emulsoids
Yes

46. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Polyphenol Oxidase
Carmelization and Maillard

47. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Pheophytia does not have magnesium in porphyrin ring.
Monosodium Glutamate
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bitter

48. 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.
.05 M HCL
Degradation of protein and production of acid from sugar at the same time.
Arachidonic Acid

49. How can a molecular weight of protein - DNA - and RNA be determined?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Initiation - Propagation - and Termination
Degradation of protein and production of acid from sugar at the same time.
Lycopenes

50. 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
Degradation of protein and production of acid from sugar at the same time.
Carrageenan
Olive Green