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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 is the chemical nature of anthocyanins?
2.5
Bright green
20 carbons and 4 double bonds
Glycosides of anthocyanidins

2. Name 3 factors influencing the rate of lipid oxidation in foods.
2.5
Initiation - Propagation - and Termination
20 carbons and 4 double bonds
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

3. What is the structural difference between chlorophyll and pheophytia?
Fat Oxidation
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
Bright green
Pheophytia does not have magnesium in porphyrin ring.

4. How many carbon atoms are there in the fatty acid myristic acid?
Negative log of the hydrogen concentration (mol/l).
14
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

5. What is the main class of color compounds found in raspberries?
Initiation - Propagation - and Termination
Monosodium Glutamate
Anthocyanins
Daminozide

6. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
An enzyme that converts hydrogen peroxide to water plus oxygen.
They act as catalysts - speeding the polymerization of acrylamide.
2.5
45% - 52% - 90%

7. Will lipid oxidation be higher at a water activity of .05 or .5?
Orange Juice
Two aldehydes
Olive Green
.05

8. In genetics What is conjugation?
D: None of the above
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
DNA transferred by cell to cell contact (bacterial sex).
Lysine - Arginine - and Histidine

9. Alar is the trade name for what chemical compound?
Sucrose
Daminozide
Onions ( or leeks)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

10. What are two common reducing agents that break disulfide bonds in proteins?
Polyphenol Oxidase
Phenophylin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

11. 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
V=IR and P=VI or I x I x are
Onions ( or leeks)
Tryptophan

12. Name the strongest biochemical bond and the weakest biochemical bond.
Oil in Water
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Covalent (strongest) and Hydrophobic (Weakest)
Daminozide

13. What is the chemical nature of anthocyanins?
Polyphenols
Emulsification
Glycosides of anthocyanidins
Troponins and Tropomyosin

14. What is the chemical nomenclature for caffeine?
An enzyme that converts hydrogen peroxide to water plus oxygen.
1 - 3 - 7-trimethylxanthine
Gliadins and Glutenins
Polyphenoloxidase

15. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Arachidonic Acid
No
Water
Lycopenes

16. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Onions ( or leeks)
45% - 52% - 90%
Two aldehydes

17. 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
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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.

18. Contains the lowest content of water
Sucrose
Polyphenol Oxidase
Whole Milk
1 - 3 - 7-trimethylxanthine

19. Peptide bond formation results in the formation of what secondary compound?
Capsaicin
Thickener in foods
Water
Prolamines

20. Name one way foam stability can be assessed.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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.

21. What are the only phenols approved for use in the microbiological preservation of foods?
Lysine - Arginine - and Histidine
Parabens
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
.05 M HCL

22. Name three factors useful in controlling enzyme activity.
NaCl (it dissociated to a 2M solution)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Daminozide
Tryptophan

23. What does the saponification value measure and how is it measured?
Fatty Acid and Alcohol
Acetoin
Daminozide
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

24. What is the protein efficiency ratio (PER) of casein?
Chitin
Polyphenoloxidase
Gossypol (it is removed during the oil refining process)
2.5

25. Does kosmotrophil ion discourage water structure?
Tryptophan
Fatty Acid (Ester linked) to Fatty Alcohol
Blue pigment in flowers
No

26. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Prolamines
Racemic Mixture
Carrageenan

27. Name a commonly used household chemical leavening agent and the gas it generates.
Polyphenol Oxidase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Sodium bicarbonate generates CO2
Capsaicin

28. What does the 'c' stand for in the equation E=mc2?
Phenylketonuria
Sucrose
Speed of Light
The speed of a molecule is proportional to the surrounding voltage gradient.

29. In genetics What is conjugation?
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
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
DNA transferred by cell to cell contact (bacterial sex).
Thickener in foods

30. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Nucleation or crystal formation and crystal growth.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

31. 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
Polyphenols
Lipid oxidation
D: None of the above
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

32. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Monosodium Glutamate
Anthocyanins

33. What is the name of the degradation compound of chlorophyll?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Daminozide
Phenophylin
Gliadins and Glutenins

34. What is a polymorphism?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
NaCl (it dissociated to a 2M solution)
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Ascorbic Acid and Citric Acid

35. What does MSG stand for?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Monosodium Glutamate
Primary butyric acid also caproic acid.
Anthocyanins

36. What is the enzyme responsible for browning in apples and lettuce?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Anomeric
Yellow
Polyphenol Oxidase

37. Name one way foam stability can be assessed.
Blue pigment in flowers
Lipid oxidation
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.
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.

38. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Capsaicin
Yellow
45% - 52% - 90%

39. What ketohexose is most significant to food chemists?
Fructose
.05
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Speed of Light

40. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Anthocyanins
DNA transferred by cell to cell contact (bacterial sex).
It explodes

41. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Onions ( or leeks)
Initiation - Propagation - Termination
Oil in Water

42. What is the enzyme that softens tomatoes?
Phenophylin
Pectin Esterase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

43. Name three non-nutritive sweeteners approved for use in USA?
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Orange Juice

44. What is an isomer that is cheaper than Vitamin C?
Carrageenan
Lysine - Arginine - and Histidine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Erythorbic Acid

45. Alar is the trade name for what chemical compound?
Polyphenol Oxidase
Daminozide
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Primary butyric acid also caproic acid.

46. What are the primary secondary - tertiary - and quaternary structures?
No
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.
Gliadins and Glutenins
Oil in Water

47. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Non-protein nitrogen
45% - 52% - 90%
Erythorbic Acid

48. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Four
Speed of Light
Two aldehydes

49. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Fat Oxidation
.05 M HCL
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.

50. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Thickener in foods
Primary butyric acid also caproic acid.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.