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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. Will lipid oxidation be higher at a water activity of .05 or .5?
V=IR and P=VI or I x I x are
.05
Pheophytia does not have magnesium in porphyrin ring.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

2. What two enzymes degrade pectic substances?
Oil in Water
Pectin methylesterase & polygalacturonase
Pectin Esterase
Onions ( or leeks)

3. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Lipase
Pectin methyl esterase or galacturonase
Capsaicin

4. What is the geometric configuration of double bonds in most natural fatty acids?
Pheophytia does not have magnesium in porphyrin ring.
Cis
Degradation of protein and production of acid from sugar at the same time.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

5. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Blue pigment in flowers
pH below positive charge; pH at no charge; pH above negative charge
.05
Prolamines

6. What does the iodine value measure and how is it measured?
14
Thamautin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenols

7. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Non-protein nitrogen
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.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Polyphenoloxidase

8. Are sorbitol and mannitol sweet?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Yes
Fatty Acid (Ester linked) to Fatty Alcohol
Sweet - Salty - Sour - and Bitter

9. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Pectin Esterase
.05
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.

10. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Troponins and Tropomyosin
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

11. What toxic pigment is found in cottonseed endosperm?
Troponins and Tropomyosin
Gossypol (it is removed during the oil refining process)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

12. What does Acid Degree Value measure and how is it measured?
It explodes
Carmelization and Maillard
Daminozide
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

13. If you take 20 ml of .1 M NaOH to titrate 40 mL of an HCL solution to the penolphthalein end point What is the molarity of the HCL solution?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
.05 M HCL
Degradation of protein and production of acid from sugar at the same time.
Monosodium Glutamate

14. What does HLB stand for and What does a high and low HLB value indicate?
Gossypol (it is removed during the oil refining process)
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.
pH 3-5
Lysine - Arginine - and Histidine

15. Waxes are composed of what two basic chemical entities?
Polyphenol Oxidase
Fatty Acid (Ester linked) to Fatty Alcohol
Lipase
1 - 3 - 7-trimethylxanthine

16. What is the protein efficiency ratio (PER) of casein?
NaCl (it dissociated to a 2M solution)
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.
2.5
Negative log of the hydrogen concentration (mol/l).

17. When heated ammonium bicarbonate decomposes to form what end products?
Linoleic Acid
Ammonia - Water - Carbon Dioxide
ERH=100 x Aw
Carmelization and Maillard

18. What is the enzyme that softens tomatoes?
Oil in Water
Carmelization and Maillard
Pectin Esterase
Milk

19. What does MSG stand for?
Two aldehydes
Pectin methyl esterase or galacturonase
Monosodium Glutamate
NaCl (it dissociated to a 2M solution)

20. At what pH is benzoic acid most effective?
Onions ( or leeks)
pH 3-5
Bright green
Anthocyanins

21. In the enzyme Taq Polymerase What does Taq stand for?
Prolamines
Primary butyric acid also caproic acid.
Thermus Aqauticus
Polyphenol Oxidase

22. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Phenophylin
Water
Ammonia - Water - Carbon Dioxide

23. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Blue pigment in flowers
Sucrose
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.
Onions ( or leeks)

24. Define molarity molality - and normality.
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
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.
Chitin
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. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
A concentrate of microfibrillar proteins of fish muscle.
Lycopenes
Lycopenes

26. What is the name of the degradation compound of chlorophyll?
Non-protein nitrogen
Phenophylin
.05
.05

27. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
D: None of the above
Chitin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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.

28. Contains the lowest content of water
Lipid oxidation
Whole Milk
Daminozide
Phenophylin

29. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
Yes
Chitin
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

30. What two enzymes degrade pectic substances?
Non-protein nitrogen
Pectin methylesterase & polygalacturonase
Phenophylin
Anomeric

31. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Pheophytia does not have magnesium in porphyrin ring.
Emulsification
Tryptophan

32. What are the three main steps in the autooxidation of lipids?
Polyphenols
Anomeric
Initiation - Propagation - Termination
Four

33. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Sweet - Salty - Sour - and Bitter
Bright green
Chitin

34. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Capsaicin
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Pheophytin forms

35. What effect would the addition of sodium bicarbonate have to chocolate?
.05
Carrageenan
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Ascorbic Acid and Citric Acid

36. What is the main class of color compounds found in raspberries?
Phenylketonuria
Anthocyanins
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
The speed of a molecule is proportional to the surrounding voltage gradient.

37. Peptide bond formation results in the formation of what secondary compound?
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
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.
Osmosis
Water

38. What effect would the addition of sodium bicarbonate have to chocolate?
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).
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Cis

39. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Pectin methylesterase & polygalacturonase
Polyphenols
Nucleation or crystal formation and crystal growth.

40. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
.05
They act as catalysts - speeding the polymerization of acrylamide.
Yes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

41. Name two non-enzymatic browning reactions.
.05
Lycopenes
Carmelization and Maillard
Polyphenols

42. How many polypeptide chains make up an antibody?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Blue pigment in flowers
Four
Lipid oxidation

43. Name two main gluten proteins.
Emulsification
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Lipid oxidation
Gliadins and Glutenins

44. Give one word for a carbon atom involved in hemiacetal or acetal formation.
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.
Sodium bicarbonate generates CO2
Anomeric
Degradation of protein and production of acid from sugar at the same time.

45. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Two aldehydes
.05
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

46. At low water activity What is the main deteriorative concern?
RNA transcribed to DNA
Lipid oxidation
Pectin methylesterase & polygalacturonase
Aspartic Acid and Phenylalanine

47. In genetics What is conjugation?
Acetoin
Milk
Daminozide
DNA transferred by cell to cell contact (bacterial sex).

48. Is a disaccharide
Sucrose
Acetoin
Bitter
Ascorbic Acid and Citric Acid

49. At what pH is benzoic acid most effective?
Fatty Acid (Ester linked) to Fatty Alcohol
Daminozide
Troponins and Tropomyosin
pH 3-5

50. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Phenophylin
Pectin Esterase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Chitin