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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. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Chlocophyllide does not have a phytoltail
Two aldehydes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin Esterase

2. What is surimi?
Olive Green
Emulsification
A concentrate of microfibrillar proteins of fish muscle.
Thermus Aqauticus

3. Name 3 physical agents capable of denaturing proteins.
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
V=IR and P=VI or I x I x are
Speed of Light
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

4. Peptide bond formation results in the formation of what secondary compound?
Water
Phenylketonuria
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
.05

5. Name 4 advantages of using enzymes in food processing.
Daminozide
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
Two aldehydes
.05 M HCL

6. What is the structural difference between chlorophyll and chlocophyllide?
Negative log of the hydrogen concentration (mol/l).
Covalent (strongest) and Hydrophobic (Weakest)
Chlocophyllide does not have a phytoltail
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

7. What is the enzyme responsible for browning in apples and lettuce?
A concentrate of microfibrillar proteins of fish muscle.
Polyphenol Oxidase
Thamautin
Primary butyric acid also caproic acid.

8. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
Speed of Light
Lamellar; Hexagonal I - II; Cubic
Browning of freshly cut surfaces of fruits and vegetables.

9. What enzyme causes hyrolytic rancidity in milk?
Lipase
Chlocophyllide does not have a phytoltail
Chitin
V=IR and P=VI or I x I x are

10. Will lipid oxidation be higher at a water activity of .05 or .5?
Chlocophyllide does not have a phytoltail
.05
Carrageenan
HPLC has higher pressure than FPLC

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
Monosodium Glutamate
Water
Lipid oxidation
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

12. What happens to chlorophyll on heating?
Pheophytin forms
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase
Pheophytia does not have magnesium in porphyrin ring.

13. 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
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Browning of freshly cut surfaces of fruits and vegetables.
Linoleic Acid

14. Name two non-enzymatic browning reactions.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Polyphenol Oxidase
Carmelization and Maillard
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

15. Does kosmotrophil ion discourage water structure?
Lipase
The speed of a molecule is proportional to the surrounding voltage gradient.
No
Covalent (strongest) and Hydrophobic (Weakest)

16. What is Carboxy-methyl cellulose often used for?
Gossypol (it is removed during the oil refining process)
Thickener in foods
Phenophylin
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

17. 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?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Water
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
It explodes

18. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Ascorbic Acid and Citric Acid

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.
Chitin
.05
Phenylketonuria

20. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Pectins
They act as catalysts - speeding the polymerization of acrylamide.
.05 M HCL
pH 3-5

21. Does kosmotrophil ion discourage water structure?
NaCl (it dissociated to a 2M solution)
Chlocophyllide does not have a phytoltail
Sodium bicarbonate generates CO2
No

22. Name the two components that comprise the relaxing factor in muscle fibers.
Pheophytia does not have magnesium in porphyrin ring.
Troponins and Tropomyosin
45% - 52% - 90%
Oil in Water

23. What is surimi?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
RNA transcribed to DNA
Arachidonic Acid
A concentrate of microfibrillar proteins of fish muscle.

24. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
V=IR and P=VI or I x I x are
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
ERH=100 x Aw

25. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Fatty Acid (Ester linked) to Fatty Alcohol
RNA transcribed to DNA
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.

26. In the enzyme Taq Polymerase What does Taq stand for?
Ascorbic Acid and Citric Acid
Lycopenes
Thermus Aqauticus
Initiation - Propagation - and Termination

27. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pectin Esterase - Polygalacturonase - Pectin Layase
DNA transferred by cell to cell contact (bacterial sex).
Bright green
pH below positive charge; pH at no charge; pH above negative charge

28. At what pH is benzoic acid most effective?
Emulsification
pH 3-5
Ascorbic Acid and Citric Acid
DNA transferred by cell to cell contact (bacterial sex).

29. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Yellow
ERH=100 x Aw
Covalent (strongest) and Hydrophobic (Weakest)

30. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Degradation of protein and production of acid from sugar at the same time.
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
Plasmids

31. What is the main class of color compounds found in raspberries?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Anthocyanins
Non-protein nitrogen
Fat Oxidation

32. Name two main gluten proteins.
Osmosis
Aspartic Acid and Phenylalanine
Gliadins and Glutenins
Lamellar; Hexagonal I - II; Cubic

33. Name 3 factors influencing the consistency of commercial fats.
ERH=100 x Aw
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Carrageenan

34. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Speed of Light
Capsaicin
Cis
Primary butyric acid also caproic acid.

35. How can a molecular weight of protein - DNA - and RNA be determined?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Pectin Esterase - Polygalacturonase - Pectin Layase
ERH=100 x Aw

36. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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
Water
Carmelization and Maillard

37. 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
D: None of the above
Pheophytia does not have magnesium in porphyrin ring.
Fatty Acid and Alcohol
Pectins

38. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
NaCl (it dissociated to a 2M solution)
Speed of Light
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

39. Define molarity molality - and normality.
Whole Milk
1 - 3 - 7-trimethylxanthine
Lysine - Arginine - and Histidine
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

40. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Osmosis
Gliadins and Glutenins
Thermus Aqauticus

41. What is the winterization process for an oil?
Pectin methyl esterase or galacturonase
Onions ( or leeks)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Milk

42. In what food is butyric acid typically found?
Fatty Acid and Alcohol
45% - 52% - 90%
Milk
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

43. What is the name of the degradation compound of chlorophyll?
Phenylketonuria
DNA transferred by cell to cell contact (bacterial sex).
Phenophylin
Blue pigment in flowers

44. What is the protein efficiency ratio (PER) of casein?
An enzyme that converts hydrogen peroxide to water plus oxygen.
2.5
Blue pigment in flowers
Two aldehydes

45. What does the iodine value measure and how is it measured?
Monosodium Glutamate
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lipase

46. Peptide bond formation results in the formation of what secondary compound?
Fructose
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Polyphenols
Water

47. What is the Peroxide Value a measure of?
Ammonia - Water - Carbon Dioxide
Pectins
Fat Oxidation
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

48. 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
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
No
The speed of a molecule is proportional to the surrounding voltage gradient.

49. Name two enzymes that are involved in softening fruits.
Polyphenol Oxidase
They act as catalysts - speeding the polymerization of acrylamide.
Pectin Esterase - Polygalacturonase - Pectin Layase
Nucleation or crystal formation and crystal growth.

50. Is a disaccharide
Sucrose
Polyphenoloxidase
Bitter
Emulsification