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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 two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Primary butyric acid also caproic acid.
Cis
Pectin methyl esterase or galacturonase

2. Contains the lowest content of water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Yes
Whole Milk
Ammonia - Water - Carbon Dioxide

3. What compounds oxidize to form brown color in fruits and vegetables?
Water
Anomeric
Polyphenols
ERH=100 x Aw

4. Does kosmotrophil ion discourage water structure?
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.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
No
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

5. What is the protein efficiency ratio (PER) of casein?
Thermus Aqauticus
Plasmids
2.5
Pectin methyl esterase or galacturonase

6. When heated ammonium bicarbonate decomposes to form what end products?
Pectins
Ammonia - Water - Carbon Dioxide
Anomeric
Sodium bicarbonate generates CO2

7. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
20 carbons and 4 double bonds
DNA transferred by cell to cell contact (bacterial sex).

8. What is Carboxy-methyl cellulose often used for?
Thamautin
Acetoin
Thickener in foods
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

9. Name 5 proteins with good foaming properties.
Pectin methylesterase & polygalacturonase
An enzyme that converts hydrogen peroxide to water plus oxygen.
Pectin methyl esterase or galacturonase
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.

10. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Blue pigment in flowers
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Initiation - Propagation - Termination
Negative log of the hydrogen concentration (mol/l).

11. How many carbon atoms and how many double bonds are there in arachidonic acid?
Gliadins and Glutenins
20 carbons and 4 double bonds
Negative log of the hydrogen concentration (mol/l).
Lamellar; Hexagonal I - II; Cubic

12. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Phenylketonuria
Two aldehydes
Chitin
1 - 3 - 7-trimethylxanthine

13. What is the Peroxide Value a measure of?
Linoleic Acid
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Plasmids

14. 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
Gossypol (it is removed during the oil refining process)
Initiation - Propagation - Termination
Pectins

15. 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
Gliadins and Glutenins
Browning of freshly cut surfaces of fruits and vegetables.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Phenophylin

16. In genetics What is conjugation?
Pectin Esterase - Polygalacturonase - Pectin Layase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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.
DNA transferred by cell to cell contact (bacterial sex).

17. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Olive Green
Pectin methylesterase & polygalacturonase
Polyphenoloxidase
Water

18. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Thermus Aqauticus
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.
Pectins

19. What are the three stages of oxidative rancidity?
Pectin methylesterase & polygalacturonase
Ammonia - Water - Carbon Dioxide
Polyphenol Oxidase
Initiation - Propagation - and Termination

20. What is the Peroxide Value a measure of?
Fat Oxidation
Non-protein nitrogen
Phenylketonuria
Lycopenes

21. What toxic pigment is found in cottonseed endosperm?
Bright green
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.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

22. What is acid proteolysis?
D: None of the above
Degradation of protein and production of acid from sugar at the same time.
Pectin Esterase
A concentrate of microfibrillar proteins of fish muscle.

23. What metabolic end product does the Voges-Proskauer test detect?
Lipase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Acetoin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

24. 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.
Arachidonic Acid
Onions ( or leeks)
Troponins and Tropomyosin

25. What does the 'c' stand for in the equation E=mc2?
Parabens
Nucleation or crystal formation and crystal growth.
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.
Speed of Light

26. In the enzyme Taq Polymerase What does Taq stand for?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pectins
Thermus Aqauticus
Ascorbic Acid and Citric Acid

27. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Whole Milk
Emulsification
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

28. What is the main class of color compounds found in raspberries?
Polyphenols
45% - 52% - 90%
Anthocyanins
Ascorbic Acid and Citric Acid

29. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Yes
Initiation - Propagation - and Termination
Oil in Water

30. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Pheophytin forms
Blue pigment in flowers
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Aspartic Acid and Phenylalanine

31. What is the geometric configuration of double bonds in most natural fatty acids?
D: None of the above
Cis
Osmosis
Bright green

32. During freezing What are the two stages in the crystallization process?
Prolamines
Nucleation or crystal formation and crystal growth.
Non-protein nitrogen
Carmelization and Maillard

33. How is pH defined?
Emulsoids
Negative log of the hydrogen concentration (mol/l).
Linoleic Acid
Initiation - Propagation - and Termination

34. What is the winterization process for an oil?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Browning of freshly cut surfaces of fruits and vegetables.
A concentrate of microfibrillar proteins of fish muscle.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

35. What is the structural difference between chlorophyll and chlocophyllide?
Negative log of the hydrogen concentration (mol/l).
Browning of freshly cut surfaces of fruits and vegetables.
Chlocophyllide does not have a phytoltail
Sucrose

36. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
HPLC has higher pressure than FPLC
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Erythorbic Acid
Carrageenan

37. How is pH defined?
Two aldehydes
Plasmids
Negative log of the hydrogen concentration (mol/l).
Lamellar; Hexagonal I - II; Cubic

38. Name three effects of protein denaturation.
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.
Thermus Aqauticus
Tryptophan
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

39. 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
Water
Lycopenes
Daminozide
D: None of the above

40. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
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 below positive charge; pH at no charge; pH above negative charge
Gossypol (it is removed during the oil refining process)

41. What is catalase?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
2.5
An enzyme that converts hydrogen peroxide to water plus oxygen.

42. 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)
Ascorbic Acid and Citric Acid
Phenylketonuria
Carrageenan

43. Name 3 factors influencing the rate of lipid oxidation in foods.
Lycopenes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
.05 M HCL
Polyphenoloxidase

44. In genetics What is conjugation?
Erythorbic Acid
Covalent (strongest) and Hydrophobic (Weakest)
Pectins
DNA transferred by cell to cell contact (bacterial sex).

45. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
Ammonia - Water - Carbon Dioxide
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Four

46. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Emulsification
DNA transferred by cell to cell contact (bacterial sex).
Osmosis
Sweet - Salty - Sour - and Bitter

47. Does kosmotrophil ion discourage water structure?
Daminozide
No
Nucleation or crystal formation and crystal growth.
Lipase

48. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Anomeric
Thamautin
Tryptophan

49. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Cis
Anthocyanins

50. What is acid proteolysis?
Lipase
It explodes
Two aldehydes
Degradation of protein and production of acid from sugar at the same time.