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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. In genetics What is conjugation?
Gossypol (it is removed during the oil refining process)
Speed of Light
Browning of freshly cut surfaces of fruits and vegetables.
DNA transferred by cell to cell contact (bacterial sex).

2. Name three nonpolar polar - and charged amino acids.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
A concentrate of microfibrillar proteins of fish muscle.
Cis
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

3. Name three nonpolar polar - and charged amino acids.
Yes
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Lamellar; Hexagonal I - II; Cubic

4. Name one way foam stability can be assessed.
Emulsification
Milk
NaCl (it dissociated to a 2M solution)
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.

5. Does kosmotrophil ion discourage water structure?
No
Pectin methylesterase & polygalacturonase
45% - 52% - 90%
NaCl (it dissociated to a 2M solution)

6. Name 4 advantages of using enzymes in food processing.
1 - 3 - 7-trimethylxanthine
Pectin methylesterase & polygalacturonase
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 3-5

7. What is Carboxy-methyl cellulose often used for?
Thickener in foods
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.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Orange Juice

8. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Two aldehydes
Polyphenol Oxidase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

9. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Onions ( or leeks)
Capsaicin
Fat Oxidation

10. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Phenylketonuria
Pectin methyl esterase or galacturonase
Four

11. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
It explodes
No
Phenylketonuria

12. What does the saponification value measure and how is it measured?
Initiation - Propagation - Termination
Nucleation or crystal formation and crystal growth.
Cis
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

13. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
It explodes
.05
Carrageenan
Oil in Water

14. Alar is the trade name for what chemical compound?
14
Ammonia - Water - Carbon Dioxide
Daminozide
Plasmids

15. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Daminozide
Linoleic Acid
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

16. Name 3 factors influencing the rate of lipid oxidation in foods.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Bitter

17. 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
RNA transcribed to DNA
Thickener in foods

18. What is surimi?
ERH=100 x Aw
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Anthocyanins
A concentrate of microfibrillar proteins of fish muscle.

19. What are the four basic flavors perceived by the tongue?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipase
Prolamines
Sweet - Salty - Sour - and Bitter

20. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Erythorbic Acid
Pectin Esterase
Primary butyric acid also caproic acid.
Bright green

21. 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)
Polyphenoloxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

22. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
Anthocyanins
Sweet - Salty - Sour - and Bitter
Phenophylin

23. Name 3 factors influencing the rate of lipid oxidation in foods.
Carrageenan
Fat Oxidation
Sodium bicarbonate generates CO2
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

24. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Negative log of the hydrogen concentration (mol/l).
NaCl (it dissociated to a 2M solution)
Phenylketonuria
Tryptophan

25. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Carrageenan
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Capsaicin
Gossypol (it is removed during the oil refining process)

26. Name 5 proteins with good foaming properties.
Phenophylin
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.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

27. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
Blue pigment in flowers
Racemic Mixture
Anomeric

28. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Water
pH below positive charge; pH at no charge; pH above negative charge
Racemic Mixture
An enzyme that converts hydrogen peroxide to water plus oxygen.

29. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
pH 3-5
Non-protein nitrogen
Blue pigment in flowers

30. How many polypeptide chains make up an antibody?
Four
Pheophytin forms
V=IR and P=VI or I x I x are
Osmosis

31. What is catalase?
Chitin
Ascorbic Acid and Citric Acid
An enzyme that converts hydrogen peroxide to water plus oxygen.
Orange Juice

32. What does HLB stand for and What does a high and low HLB value indicate?
Yes
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.
Browning of freshly cut surfaces of fruits and vegetables.
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.

33. What is acid proteolysis?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
45% - 52% - 90%
Degradation of protein and production of acid from sugar at the same time.

34. What are the fructose contents in commercial HFCS products.
Anthocyanins
Fatty Acid (Ester linked) to Fatty Alcohol
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
45% - 52% - 90%

35. What is the protein efficiency ratio (PER) of casein?
45% - 52% - 90%
2.5
Pectins
Emulsoids

36. What toxic pigment is found in cottonseed endosperm?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Gossypol (it is removed during the oil refining process)
Negative log of the hydrogen concentration (mol/l).
20 carbons and 4 double bonds

37. Peptide bond formation results in the formation of what secondary compound?
Ammonia - Water - Carbon Dioxide
The speed of a molecule is proportional to the surrounding voltage gradient.
2.5
Water

38. What is the structural difference between chlorophyll and chlocophyllide?
Fat Oxidation
Chlocophyllide does not have a phytoltail
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty Acid (Ester linked) to Fatty Alcohol

39. Name a commonly used household chemical leavening agent and the gas it generates.
Lysine - Arginine - and Histidine
NaCl (it dissociated to a 2M solution)
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
Sodium bicarbonate generates CO2

40. How many carbon atoms are there in the fatty acid myristic acid?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
.05
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
14

41. What happens to chlorophyll on heating?
Pheophytin forms
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Plasmids
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

42. What does the iodine value measure and how is it measured?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
An enzyme that converts hydrogen peroxide to water plus oxygen.
V=IR and P=VI or I x I x are
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

43. Name 3 chemical agents capable of denaturing proteins.
Cis
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Bitter
pH 3-5

44. Name two main gluten proteins.
Polyphenols
Whole Milk
Emulsoids
Gliadins and Glutenins

45. Contains the lowest content of water
Tryptophan
Whole Milk
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

46. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
HPLC has higher pressure than FPLC
20 carbons and 4 double bonds
DNA transferred by cell to cell contact (bacterial sex).

47. What is the major color compound in tomatoes?
Lycopenes
No
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
D: None of the above

48. What is the name given to a mixture of equal parts of Darel Lisomers?
Sodium bicarbonate generates CO2
Racemic Mixture
Tryptophan
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

49. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Thermus Aqauticus
Orange Juice
Anomeric

50. What does HLB stand for and What does a high and low HLB value indicate?
Non-protein nitrogen
An enzyme that converts hydrogen peroxide to water plus oxygen.
Carrageenan
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.