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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. How many carbon atoms are there in the fatty acid myristic acid?
V=IR and P=VI or I x I x are
Pectins
14
Pheophytia does not have magnesium in porphyrin ring.

2. Name two main gluten proteins.
NaCl (it dissociated to a 2M solution)
Nucleation or crystal formation and crystal growth.
Gliadins and Glutenins
ERH=100 x Aw

3. Contains the lowest content of water
Lipid oxidation
Emulsification
Whole Milk
Non-protein nitrogen

4. What does the acronym NPN stand for?
45% - 52% - 90%
The speed of a molecule is proportional to the surrounding voltage gradient.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Non-protein nitrogen

5. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Chitin
Lysine - Arginine - and Histidine
DNA transferred by cell to cell contact (bacterial sex).

6. What does MSG stand for?
Monosodium Glutamate
Bitter
They act as catalysts - speeding the polymerization of acrylamide.
Phenophylin

7. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Olive Green
Browning of freshly cut surfaces of fruits and vegetables.
pH below positive charge; pH at no charge; pH above negative charge

8. What does Acid Degree Value measure and how is it measured?
Phenylketonuria
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Acetoin
Gliadins and Glutenins

9. What is Carboxy-methyl cellulose often used for?
No
Thickener in foods
Acetoin
Anomeric

10. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Ascorbic Acid and Citric Acid
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

11. What does MSG stand for?
Pectins
Phenylketonuria
Lysine - Arginine - and Histidine
Monosodium Glutamate

12. Name one way foam stability can be assessed.
Polyphenol Oxidase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Initiation - Propagation - Termination
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.

13. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Olive Green
Prolamines
Chlocophyllide does not have a phytoltail

14. Name three factors useful in controlling enzyme activity.
Pectins
Anthocyanins
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

15. Is a disaccharide
Negative log of the hydrogen concentration (mol/l).
Ammonia - Water - Carbon Dioxide
Sucrose
No

16. What two types of compounds are joined with an ester bond to make a wax?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Fatty Acid and Alcohol
Racemic Mixture
Ascorbic Acid and Citric Acid

17. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Oil in Water
Nucleation or crystal formation and crystal growth.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

18. Are sorbitol and mannitol sweet?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
HPLC has higher pressure than FPLC
Yes
Two aldehydes

19. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Whole Milk
Thickener in foods
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

20. 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
Arachidonic Acid
Ammonia - Water - Carbon Dioxide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

21. Name 4 advantages of using enzymes in food processing.
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
Polyphenoloxidase
Pectin methylesterase & polygalacturonase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

22. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Pectin methylesterase & polygalacturonase
Plasmids
Milk

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

24. 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?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Polyphenol Oxidase
Non-protein nitrogen
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

25. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the 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.
Pectin methyl esterase or galacturonase
Daminozide

26. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
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
It explodes
Lipase
Carmelization and Maillard

27. Name three effects of protein denaturation.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Emulsoids
Osmosis
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

28. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Onions ( or leeks)
Polyphenoloxidase
Cis
Tryptophan

29. Alar is the trade name for what chemical compound?
Lysine - Arginine - and Histidine
Acetoin
Daminozide
Polyphenol Oxidase

30. At what pH is benzoic acid most effective?
Polyphenols
Water
Fructose
pH 3-5

31. What does the iodine value measure and how is it measured?
Carmelization and Maillard
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Milk
Daminozide

32. What toxic pigment is found in cottonseed endosperm?
Degradation of protein and production of acid from sugar at the same time.
Gossypol (it is removed during the oil refining process)
.05
Carrageenan

33. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
They act as catalysts - speeding the polymerization of acrylamide.
Carmelization and Maillard
Water

34. Will lipid oxidation be higher at a water activity of .05 or .5?
Monosodium Glutamate
2.5
.05
V=IR and P=VI or I x I x are

35. Name three effects of protein denaturation.
Bitter
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Covalent (strongest) and Hydrophobic (Weakest)

36. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
2.5
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

37. What effect would the addition of sodium bicarbonate have to chocolate?
Tryptophan
Gossypol (it is removed during the oil refining process)
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

38. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pectins
Blue pigment in flowers
NaCl (it dissociated to a 2M solution)

39. What compounds oxidize to form brown color in fruits and vegetables?
Non-protein nitrogen
Polyphenols
Cis
Anthocyanins

40. Does kosmotrophil ion discourage water structure?
Linoleic Acid
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
No
Prolamines

41. Name 5 chelating agents used in the food industry.
Pectin Esterase - Polygalacturonase - Pectin Layase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Acetoin
Chlocophyllide does not have a phytoltail

42. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Thickener in foods

43. What metabolic end product does the Voges-Proskauer test detect?
Pectin Esterase
Lipase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Acetoin

44. What are the only phenols approved for use in the microbiological preservation of foods?
Lipase
Parabens
Phenophylin
Carmelization and Maillard

45. What is the enzyme that softens tomatoes?
Fatty Acid and Alcohol
Pectin Esterase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Gossypol (it is removed during the oil refining process)

46. What two common compounds are used together as an antioxidative system?
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
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Ascorbic Acid and Citric Acid

47. What happens to chlorophyll on heating?
Pheophytin forms
Pectin Esterase - Polygalacturonase - Pectin Layase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Plasmids

48. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Orange Juice
Olive Green
Parabens

49. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
2.5
Phenophylin
pH 3-5

50. Name three nonpolar polar - and charged amino acids.
Pheophytia does not have magnesium in porphyrin ring.
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.
Cis
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)