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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. Alar is the trade name for what chemical compound?
Initiation - Propagation - Termination
Anomeric
Fructose
Daminozide

2. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Bright green
Carrageenan
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

3. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
Cis
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

4. What is the enzyme that softens tomatoes?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fructose
Pectin Esterase

5. Name a commonly used household chemical leavening agent and the gas it generates.
Pheophytin forms
Gossypol (it is removed during the oil refining process)
Sodium bicarbonate generates CO2
Chitin

6. What does MSG stand for?
Capsaicin
Monosodium Glutamate
They act as catalysts - speeding the polymerization of acrylamide.
Thickener in foods

7. What are colloids that are stabilized by a layer of solvation called?
Bitter
Polyphenol Oxidase
Emulsoids
A concentrate of microfibrillar proteins of fish muscle.

8. What two enzymes degrade pectic substances?
2.5
Linoleic Acid
Fructose
Pectin methylesterase & polygalacturonase

9. What is the major color compound in tomatoes?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Lycopenes
Carrageenan
Negative log of the hydrogen concentration (mol/l).

10. What is the enzyme responsible for browning in apples and lettuce?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Bitter
Polyphenol Oxidase
Pectin Esterase

11. 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)
Gossypol (it is removed during the oil refining process)
Ascorbic Acid and Citric Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

12. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
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
Chitin
Chitin

13. What does MSG stand for?
Monosodium Glutamate
Capsaicin
Capsaicin
Primary butyric acid also caproic acid.

14. What is the main class of color compounds found in raspberries?
Tryptophan
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Anthocyanins

15. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
The speed of a molecule is proportional to the surrounding voltage gradient.
Troponins and Tropomyosin

16. What ketohexose is most significant to food chemists?
14
Anthocyanins
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Fructose

17. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
ERH=100 x Aw
Olive Green

18. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Yellow
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Anthocyanins
Linoleic Acid

19. At low water activity What is the main deteriorative concern?
Fatty Acid (Ester linked) to Fatty Alcohol
Monosodium Glutamate
Lipid oxidation
Tryptophan

20. Name 5 proteins with good foaming properties.
The speed of a molecule is proportional to the surrounding voltage gradient.
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.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Primary butyric acid also caproic acid.

21. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Lycopenes
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.
Osmosis

22. Name two main gluten proteins.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Prolamines
Gliadins and Glutenins

23. Alar is the trade name for what chemical compound?
NaCl (it dissociated to a 2M solution)
Sweet - Salty - Sour - and Bitter
Pectin Esterase - Polygalacturonase - Pectin Layase
Daminozide

24. How many carbon atoms are there in the fatty acid myristic acid?
Thamautin
Arachidonic Acid
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
14

25. Name 3 factors influencing the consistency of commercial fats.
Water
The speed of a molecule is proportional to the surrounding voltage gradient.
V=IR and P=VI or I x I x are
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

26. Are sorbitol and mannitol sweet?
20 carbons and 4 double bonds
Yes
Daminozide
Arachidonic Acid

27. Name three non-nutritive sweeteners approved for use in USA?
Water
Orange Juice
Polyphenol Oxidase
Acsulfame-K - Saccharin - Cyclamate - Aspartame

28. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Browning of freshly cut surfaces of fruits and vegetables.
14
DNA transferred by cell to cell contact (bacterial sex).

29. Will lipid oxidation be higher at a water activity of .05 or .5?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
.05
The speed of a molecule is proportional to the surrounding voltage gradient.

30. What is the structural difference between chlorophyll and chlocophyllide?
Linoleic Acid
Chlocophyllide does not have a phytoltail
.05
Acetoin

31. What does the acronym NPN stand for?
Non-protein nitrogen
Capsaicin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Four

32. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Polyphenol Oxidase
RNA transcribed to DNA
Olive Green
Ammonia - Water - Carbon Dioxide

33. Name one way foam stability can be assessed.
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.
Lycopenes
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.
Ascorbic Acid and Citric Acid

34. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Pectin Esterase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

35. What is the fundamental driving of electrophoresis?
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.
Thamautin
The speed of a molecule is proportional to the surrounding voltage gradient.
Thickener in foods

36. What happens to chlorophyll on heating?
Capsaicin
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
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pheophytin forms

37. When heated ammonium bicarbonate decomposes to form what end products?
The speed of a molecule is proportional to the surrounding voltage gradient.
Ammonia - Water - Carbon Dioxide
Yes
14

38. What is the structural difference between chlorophyll and pheophytia?
Pectin Esterase
Erythorbic Acid
Pheophytia does not have magnesium in porphyrin ring.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

39. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Four
Polyphenoloxidase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Non-protein nitrogen

40. What toxic pigment is found in cottonseed endosperm?
Pectin methyl esterase or galacturonase
Carrageenan
Polyphenol Oxidase
Gossypol (it is removed during the oil refining process)

41. What is the protein efficiency ratio (PER) of casein?
Oil in Water
2.5
It explodes
Initiation - Propagation - Termination

42. 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
.05
Osmosis
Pectin Esterase - Polygalacturonase - Pectin Layase
D: None of the above

43. Contains the lowest content of water
Whole Milk
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin Esterase
Acetoin

44. 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
V=IR and P=VI or I x I x are
Fructose
NaCl (it dissociated to a 2M solution)

45. What are 3 mesomorphic structures associated with lipids in the liquid state?
20 carbons and 4 double bonds
pH below positive charge; pH at no charge; pH above negative charge
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lamellar; Hexagonal I - II; Cubic

46. Name three nonpolar polar - and charged amino acids.
Bitter
Capsaicin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Linoleic Acid

47. What is Ohm's Law and What is Power Equation?
Daminozide
V=IR and P=VI or I x I x are
RNA transcribed to DNA
Fatty Acid (Ester linked) to Fatty Alcohol

48. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Degradation of protein and production of acid from sugar at the same time.
Initiation - Propagation - and Termination
Two aldehydes
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

49. In genetics What is conjugation?
Yellow
Chitin
Lysine - Arginine - and Histidine
DNA transferred by cell to cell contact (bacterial sex).

50. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Ascorbic Acid and Citric Acid
Sodium bicarbonate generates CO2
Milk