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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 3 physical agents capable of denaturing proteins.
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
Sodium chloride reduces foam stability and sucrose improves foam stability.
Polyphenol Oxidase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

2. What is surimi?
Thamautin
No
.05 M HCL
A concentrate of microfibrillar proteins of fish muscle.

3. What are the three stages of oxidative rancidity?
Water
Onions ( or leeks)
Initiation - Propagation - and Termination
1 - 3 - 7-trimethylxanthine

4. What is the geometric configuration of double bonds in most natural fatty acids?
Thamautin
Cis
Tryptophan
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

5. What is the fundamental driving of electrophoresis?
Polyphenol Oxidase
The speed of a molecule is proportional to the surrounding voltage gradient.
Cis
Thamautin

6. Is a disaccharide
Sucrose
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Nucleation or crystal formation and crystal growth.
pH below positive charge; pH at no charge; pH above negative charge

7. What toxic pigment is found in cottonseed endosperm?
Degradation of protein and production of acid from sugar at the same time.
Pectin methylesterase & polygalacturonase
Gossypol (it is removed during the oil refining process)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

8. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
Chlocophyllide does not have a phytoltail
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

9. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Fat Oxidation
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.
Nucleation or crystal formation and crystal growth.

10. What is the chemical nomenclature for caffeine?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin methylesterase & polygalacturonase
1 - 3 - 7-trimethylxanthine

11. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Emulsoids
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Tryptophan
Racemic Mixture

12. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
ERH=100 x Aw
pH 3-5
Capsaicin
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.

13. Name two non-enzymatic browning reactions.
Initiation - Propagation - and Termination
Pectin Esterase - Polygalacturonase - Pectin Layase
Carmelization and Maillard
Cis

14. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Four
Gliadins and Glutenins

15. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
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.
Plasmids
Thamautin

16. What is the main class of color compounds found in raspberries?
Monosodium Glutamate
Anthocyanins
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Yes

17. In what food is butyric acid typically found?
Milk
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
1 - 3 - 7-trimethylxanthine
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

18. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenol Oxidase
Water
Polyphenols
Emulsoids

19. 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.
Pheophytia does not have magnesium in porphyrin ring.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Polyphenol Oxidase

20. Name 3 chemical agents capable of denaturing proteins.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Polyphenol Oxidase
Thamautin

21. Contains the lowest content of water
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
V=IR and P=VI or I x I x are
Polyphenol Oxidase
Whole Milk

22. What is acid proteolysis?
Thamautin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Degradation of protein and production of acid from sugar at the same time.
Bright green

23. What is the name given to a mixture of equal parts of Darel Lisomers?
Milk
Sweet - Salty - Sour - and Bitter
Racemic Mixture
Plasmids

24. How does HPLC differ from FPLC?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Daminozide
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
HPLC has higher pressure than FPLC

25. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Emulsification
Anomeric
Polyphenols
Two aldehydes

26. What happens to chlorophyll on heating?
Pectin Esterase - Polygalacturonase - Pectin Layase
Pheophytin forms
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Daminozide

27. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Pectin methylesterase & polygalacturonase
Blue pigment in flowers
Linoleic Acid
Pectins

28. Name two enzymes that are involved in softening fruits.
Bright green
Pectin Esterase - Polygalacturonase - Pectin Layase
Initiation - Propagation - Termination
Carrageenan

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

30. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Bitter
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Yes

31. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Non-protein nitrogen
Water
Prolamines
Carrageenan

32. What are the only phenols approved for use in the microbiological preservation of foods?
Thickener in foods
Parabens
Speed of Light
Chlocophyllide does not have a phytoltail

33. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

34. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
HPLC has higher pressure than FPLC
Two aldehydes
Phenylketonuria
Chlocophyllide does not have a phytoltail

35. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Non-protein nitrogen
14

36. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Chlocophyllide does not have a phytoltail
NaCl (it dissociated to a 2M solution)
Polyphenol Oxidase
Sodium bicarbonate generates CO2

37. What is the major color compound in tomatoes?
ERH=100 x Aw
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pheophytia does not have magnesium in porphyrin ring.
Lycopenes

38. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Osmosis
Pheophytia does not have magnesium in porphyrin ring.
Pectin Esterase
Pectin methyl esterase or galacturonase

39. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Bitter
Thickener in foods
Pectins

40. Name the two components that comprise the relaxing factor in muscle fibers.
Fat Oxidation
Acetoin
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.
Troponins and Tropomyosin

41. What pigment was first designated as anthocyanins?
V=IR and P=VI or I x I x are
Blue pigment in flowers
HPLC has higher pressure than FPLC
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

42. Peptide bond formation results in the formation of what secondary compound?
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.
Yes
Water
14

43. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Prolamines
Polyphenoloxidase
Osmosis

44. What is the chemical nature of anthocyanins?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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.
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.
Glycosides of anthocyanidins

45. What are the three stages of oxidative rancidity?
pH 3-5
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Initiation - Propagation - and Termination
Whole Milk

46. What are the primary secondary - tertiary - and quaternary structures?
Four
Prolamines
2.5
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.

47. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
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
Sweet - Salty - Sour - and Bitter
Parabens

48. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Negative log of the hydrogen concentration (mol/l).
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
RNA transcribed to DNA

49. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Water
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

50. What ketohexose is most significant to food chemists?
Nucleation or crystal formation and crystal growth.
Lamellar; Hexagonal I - II; Cubic
Chitin
Fructose