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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 enzyme is most responsible for browning bananas?
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
Polyphenol Oxidase
Thamautin
Gossypol (it is removed during the oil refining process)

2. What is the major color compound in tomatoes?
DNA transferred by cell to cell contact (bacterial sex).
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lycopenes
Polyphenol Oxidase

3. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sweet - Salty - Sour - and Bitter
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
NaCl (it dissociated to a 2M solution)

4. Will lipid oxidation be higher at a water activity of .05 or .5?
Degradation of protein and production of acid from sugar at the same time.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
.05

5. What is the Peroxide Value a measure of?
Nucleation or crystal formation and crystal growth.
Fat Oxidation
Gliadins and Glutenins
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

6. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Arachidonic Acid
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fatty Acid (Ester linked) to Fatty Alcohol

7. What is the enzyme responsible for browning in apples and lettuce?
.05
Aspartic Acid and Phenylalanine
Phenylketonuria
Polyphenol Oxidase

8. What is the main class of color compounds found in raspberries?
A concentrate of microfibrillar proteins of fish muscle.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Blue pigment in flowers
Anthocyanins

9. Name two enzymes that are involved in softening fruits.
Milk
Pectin Esterase - Polygalacturonase - Pectin Layase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Sweet - Salty - Sour - and Bitter

10. At low water activity What is the main deteriorative concern?
Pheophytin forms
.05 M HCL
Two aldehydes
Lipid oxidation

11. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Lipase
Chitin

12. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
No
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
Non-protein nitrogen

13. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
RNA transcribed to DNA
45% - 52% - 90%
Browning of freshly cut surfaces of fruits and vegetables.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

14. What does the saponification value measure and how is it measured?
Arachidonic Acid
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Pheophytia does not have magnesium in porphyrin ring.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

15. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Erythorbic Acid
Two aldehydes
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.

16. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
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.
NaCl (it dissociated to a 2M solution)
Orange Juice
14

17. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
It explodes
Chitin
No
Anthocyanins

18. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Anomeric
Fat Oxidation
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Osmosis

19. How does ERH relate to water activity?
Orange Juice
Pectin methyl esterase or galacturonase
Water
ERH=100 x Aw

20. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Blue pigment in flowers
DNA transferred by cell to cell contact (bacterial sex).
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Carrageenan

21. Name three factors useful in controlling enzyme activity.
The speed of a molecule is proportional to the surrounding voltage gradient.
1 - 3 - 7-trimethylxanthine
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Oil in Water

22. How does HPLC differ from FPLC?
Chlocophyllide does not have a phytoltail
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
Carmelization and Maillard
HPLC has higher pressure than FPLC

23. How many polypeptide chains make up an antibody?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Fatty Acid and Alcohol
Two aldehydes
Four

24. Which two amino acids is the aspartame derived from?
Emulsification
Pectin methylesterase & polygalacturonase
Aspartic Acid and Phenylalanine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

25. Name two reasons why fats are hydrogenated.
Blue pigment in flowers
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
Milk
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

26. What does the 'c' stand for in the equation E=mc2?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Speed of Light
Polyphenol Oxidase
RNA transcribed to DNA

27. Is a disaccharide
Carrageenan
Sucrose
Parabens
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

28. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
Parabens
Browning of freshly cut surfaces of fruits and vegetables.
Pectin methylesterase & polygalacturonase
They act as catalysts - speeding the polymerization of acrylamide.

29. What are 3 mesomorphic structures associated with lipids in the liquid state?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lamellar; Hexagonal I - II; Cubic
Orange Juice
Polyphenoloxidase

30. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Linoleic Acid

31. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
ERH=100 x Aw
Acsulfame-K - Saccharin - Cyclamate - Aspartame
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

32. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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.
20 carbons and 4 double bonds

33. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Plasmids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Arachidonic Acid

34. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Onions ( or leeks)
Water

35. What is a polymorphism?
Lycopenes
The speed of a molecule is proportional to the surrounding voltage gradient.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fatty Acid and Alcohol

36. How many carbon atoms are there in the fatty acid myristic acid?
Chitin
14
Olive Green
Fat Oxidation

37. Contains the lowest content of water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Blue pigment in flowers
Whole Milk
Fatty Acid and Alcohol

38. When heated ammonium bicarbonate decomposes to form what end products?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Ammonia - Water - Carbon Dioxide
Lipase
Whole Milk

39. Name two enzymes that are involved in softening fruits.
Chitin
Bitter
Whole Milk
Pectin Esterase - Polygalacturonase - Pectin Layase

40. Name two non-enzymatic browning reactions.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Carmelization and Maillard
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Pheophytia does not have magnesium in porphyrin ring.

41. At what pH is benzoic acid most effective?
pH 3-5
Fatty Acid and Alcohol
Gliadins and Glutenins
Four

42. What are two common reducing agents that break disulfide bonds in proteins?
Pheophytin forms
Gossypol (it is removed during the oil refining process)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Arachidonic Acid

43. Name the three positively charged amino acids.
Blue pigment in flowers
Lysine - Arginine - and Histidine
Acetoin
Onions ( or leeks)

44. Alar is the trade name for what chemical compound?
No
Daminozide
Arachidonic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

45. What does HLB stand for and What does a high and low HLB value indicate?
Nucleation or crystal formation and crystal growth.
Pectin methyl esterase or galacturonase
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.
20 carbons and 4 double bonds

46. What is the main class of color compounds found in raspberries?
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.
Milk
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.
Anthocyanins

47. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Onions ( or leeks)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Thamautin

48. What is the major color compound in tomatoes?
It explodes
Initiation - Propagation - Termination
Lycopenes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

49. How many carbon atoms are there in the fatty acid myristic acid?
14
Cis
Nucleation or crystal formation and crystal growth.
Pectin methyl esterase or galacturonase

50. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Four
Polyphenols
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)