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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 pigment was first designated as anthocyanins?
Blue pigment in flowers
.05 M HCL
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Initiation - Propagation - Termination

2. What is the acid present in fish oil?
45% - 52% - 90%
Speed of Light
Arachidonic Acid
Fructose

3. Peptide bond formation results in the formation of what secondary compound?
Pheophytia does not have magnesium in porphyrin ring.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Water
Osmosis

4. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
2.5
Parabens
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

5. What are soluble polymers of anhydro-galacturonic acid and its esters called?
1 - 3 - 7-trimethylxanthine
Pectins
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

6. What is the structural difference between chlorophyll and chlocophyllide?
20 carbons and 4 double bonds
Two aldehydes
pH 3-5
Chlocophyllide does not have a phytoltail

7. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
Monosodium Glutamate
Fat Oxidation
D: None of the above

8. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Thamautin
Two aldehydes
Linoleic Acid
Bitter

9. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Pectin Esterase - Polygalacturonase - Pectin Layase
Erythorbic Acid
Bitter

10. What is Carboxy-methyl cellulose often used for?
Capsaicin
Troponins and Tropomyosin
Thickener in foods
Fatty Acid and Alcohol

11. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Blue pigment in flowers
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Emulsoids
Osmosis

12. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Milk
Troponins and Tropomyosin
Emulsoids

13. What does the acronym NPN stand for?
Phenophylin
Non-protein nitrogen
Plasmids
Thamautin

14. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
1 - 3 - 7-trimethylxanthine
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

15. What effect would the addition of sodium bicarbonate have to chocolate?
Lamellar; Hexagonal I - II; Cubic
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Erythorbic Acid
Browning of freshly cut surfaces of fruits and vegetables.

16. What effect would the addition of sodium bicarbonate have to chocolate?
Fatty Acid (Ester linked) to Fatty Alcohol
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.
Yellow

17. What is Ohm's Law and What is Power Equation?
A concentrate of microfibrillar proteins of fish muscle.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Milk
V=IR and P=VI or I x I x are

18. 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.
.05
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Four

19. What is Carboxy-methyl cellulose often used for?
Thickener in foods
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

20. 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
Fatty Acid (Ester linked) to Fatty Alcohol
Browning of freshly cut surfaces of fruits and vegetables.
Chitin
pH 3-5

21. What is the enzyme responsible for browning in apples and lettuce?
A concentrate of microfibrillar proteins of fish muscle.
Sodium chloride reduces foam stability and sucrose improves foam stability.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Polyphenol Oxidase

22. During freezing What are the two stages in the crystallization process?
14
Yes
Bright green
Nucleation or crystal formation and crystal growth.

23. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
No
Pectin methyl esterase or galacturonase
Thickener in foods
Anomeric

24. At what pH is benzoic acid most effective?
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
They act as catalysts - speeding the polymerization of acrylamide.
pH 3-5
Parabens

25. Name 4 advantages of using enzymes in food processing.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Ammonia - Water - Carbon Dioxide
Oil in Water
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

26. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Degradation of protein and production of acid from sugar at the same time.
Bright green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

27. What is Ohm's Law and What is Power Equation?
Initiation - Propagation - and Termination
Emulsification
Aspartic Acid and Phenylalanine
V=IR and P=VI or I x I x are

28. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Monosodium Glutamate
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
V=IR and P=VI or I x I x are

29. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Chitin
Fructose

30. Which two amino acids is the aspartame derived from?
Browning of freshly cut surfaces of fruits and vegetables.
Aspartic Acid and Phenylalanine
Lipase
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.

31. What is the structural difference between chlorophyll and pheophytia?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Phenophylin
Pheophytia does not have magnesium in porphyrin ring.

32. What are 3 mesomorphic structures associated with lipids in the liquid state?
Pectins
Lamellar; Hexagonal I - II; Cubic
pH below positive charge; pH at no charge; pH above negative charge
Acsulfame-K - Saccharin - Cyclamate - Aspartame

33. What compounds oxidize to form brown color in fruits and vegetables?
Emulsification
HPLC has higher pressure than FPLC
Polyphenols
Browning of freshly cut surfaces of fruits and vegetables.

34. Name one way foam stability can be assessed.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Arachidonic Acid
Fatty Acid (Ester linked) to Fatty Alcohol
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.

35. 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)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Fructose
Sucrose

36. Are sorbitol and mannitol sweet?
Pheophytin forms
Yes
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

37. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Negative log of the hydrogen concentration (mol/l).
Linoleic Acid
Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

38. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Chlocophyllide does not have a phytoltail
Browning of freshly cut surfaces of fruits and vegetables.
Plasmids

39. 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?
Prolamines
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
NaCl (it dissociated to a 2M solution)
Olive Green

40. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Covalent (strongest) and Hydrophobic (Weakest)
Pectin methyl esterase or galacturonase
Polyphenol Oxidase

41. What is the main class of color compounds found in raspberries?
Anthocyanins
Yellow
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

42. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Ammonia - Water - Carbon Dioxide
Bitter
Pheophytin forms
1 - 3 - 7-trimethylxanthine

43. What are proteins which are soluble in 50-80% ethanol known as?
2.5
Prolamines
Aspartic Acid and Phenylalanine
Onions ( or leeks)

44. What enzyme is most responsible for browning bananas?
1 - 3 - 7-trimethylxanthine
Polyphenol Oxidase
An enzyme that converts hydrogen peroxide to water plus oxygen.
Non-protein nitrogen

45. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Daminozide
Onions ( or leeks)
No

46. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Linoleic Acid
pH below positive charge; pH at no charge; pH above negative charge
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

47. Name three non-nutritive sweeteners approved for use in USA?
Fatty Acid and Alcohol
Acsulfame-K - Saccharin - Cyclamate - Aspartame
They act as catalysts - speeding the polymerization of acrylamide.
Chitin

48. Define molarity molality - and normality.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
The speed of a molecule is proportional to the surrounding voltage gradient.
Glycosides of anthocyanidins
.05 M HCL

49. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Bitter
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

50. What happens to chlorophyll on heating?
Pheophytin forms
Polyphenoloxidase
Tryptophan
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.