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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 does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Fatty Acid and Alcohol
Thickener in foods
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

2. What does HLB stand for and What does a high and low HLB value indicate?
RNA transcribed to DNA
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.
Arachidonic Acid
.05

3. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Erythorbic Acid
DNA transferred by cell to cell contact (bacterial sex).
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.

4. 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
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Chlocophyllide does not have a phytoltail
They act as catalysts - speeding the polymerization of acrylamide.
D: None of the above

5. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Gossypol (it is removed during the oil refining process)

6. What does the iodine value measure and how is it measured?
Anthocyanins
Troponins and Tropomyosin
Thamautin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

7. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Lamellar; Hexagonal I - II; Cubic
2.5
They act as catalysts - speeding the polymerization of acrylamide.
Water

8. Name two reasons why fats are hydrogenated.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Prolamines
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Chlocophyllide does not have a phytoltail

9. How many polypeptide chains make up an antibody?
Onions ( or leeks)
Emulsification
Four
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

10. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Milk
Lysine - Arginine - and Histidine
Lycopenes

11. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Yes
Fructose
Whole Milk
Carrageenan

12. Name the most common functional property of phospholipids in food systems.
Emulsification
14
Polyphenol Oxidase
Lipase

13. What does the 'c' stand for in the equation E=mc2?
Speed of Light
.05
Chlocophyllide does not have a phytoltail
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

14. What is the main class of color compounds found in raspberries?
Speed of Light
14
Non-protein nitrogen
Anthocyanins

15. Which two amino acids is the aspartame derived from?
Negative log of the hydrogen concentration (mol/l).
Yes
Anomeric
Aspartic Acid and Phenylalanine

16. What are the fructose contents in commercial HFCS products.
Whole Milk
HPLC has higher pressure than FPLC
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
45% - 52% - 90%

17. Name 5 proteins with good foaming properties.
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.
HPLC has higher pressure than FPLC
pH 3-5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

18. Name two main gluten proteins.
Degradation of protein and production of acid from sugar at the same time.
Gliadins and Glutenins
.05
Chlocophyllide does not have a phytoltail

19. Name three effects of protein denaturation.
Pectin Esterase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
.05 M HCL

20. What metabolic end product does the Voges-Proskauer test detect?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Acetoin
Emulsification

21. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Glycosides of anthocyanidins
Gliadins and Glutenins
Primary butyric acid also caproic acid.
Pectins

22. What is an isomer that is cheaper than Vitamin C?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Erythorbic Acid
Thickener in foods
V=IR and P=VI or I x I x are

23. What are the only phenols approved for use in the microbiological preservation of foods?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
They act as catalysts - speeding the polymerization of acrylamide.
Phenylketonuria
Parabens

24. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Arachidonic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
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.

25. What enzyme causes hyrolytic rancidity in milk?
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
Lipase
Linoleic Acid
Covalent (strongest) and Hydrophobic (Weakest)

26. What is the acid present in fish oil?
Pectins
Two aldehydes
Arachidonic Acid
Anthocyanins

27. 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?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Gossypol (it is removed during the oil refining process)
Olive Green
Acetoin

28. What are the three stages of oxidative rancidity?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Thamautin
Initiation - Propagation - and Termination
Chlocophyllide does not have a phytoltail

29. What two enzymes degrade pectic substances?
Fructose
Pectin methylesterase & polygalacturonase
Bitter
Oil in Water

30. 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
Linoleic Acid
pH below positive charge; pH at no charge; pH above negative charge
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

31. Name 3 factors influencing the rate of lipid oxidation in foods.
DNA transferred by cell to cell contact (bacterial sex).
Polyphenol Oxidase
45% - 52% - 90%
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

32. Name one way foam stability can be assessed.
Linoleic Acid
HPLC has higher pressure than FPLC
Parabens
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.

33. 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?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bitter
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.

34. What does Reichert-Meissert Number measure?
Carrageenan
Non-protein nitrogen
DNA transferred by cell to cell contact (bacterial sex).
Primary butyric acid also caproic acid.

35. At low water activity What is the main deteriorative concern?
Lipid oxidation
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Prolamines
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

36. What is the name given to a mixture of equal parts of Darel Lisomers?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Osmosis
Thickener in foods
Racemic Mixture

37. Name two non-enzymatic browning reactions.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Carmelization and Maillard
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

38. Is a disaccharide
Water
An enzyme that converts hydrogen peroxide to water plus oxygen.
Thickener in foods
Sucrose

39. 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
Pheophytia does not have magnesium in porphyrin ring.
No
Fructose

40. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
DNA transferred by cell to cell contact (bacterial sex).
Sodium chloride reduces foam stability and sucrose improves foam stability.
Osmosis

41. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Daminozide
An enzyme that converts hydrogen peroxide to water plus oxygen.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

42. Alar is the trade name for what chemical compound?
Daminozide
Initiation - Propagation - and Termination
Fructose
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

43. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Polyphenoloxidase
Covalent (strongest) and Hydrophobic (Weakest)
Bitter
RNA transcribed to DNA

44. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Chitin
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
1 - 3 - 7-trimethylxanthine

45. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
ERH=100 x Aw
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

46. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Pectin Esterase
Lycopenes
Olive Green
Onions ( or leeks)

47. Are sorbitol and mannitol sweet?
Yes
Lysine - Arginine - and Histidine
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
It explodes

48. What compounds oxidize to form brown color in fruits and vegetables?
Chlocophyllide does not have a phytoltail
Polyphenols
.05
Capsaicin

49. What pigment was first designated as anthocyanins?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
No
Blue pigment in flowers

50. In the enzyme Taq Polymerase What does Taq stand for?
Racemic Mixture
HPLC has higher pressure than FPLC
Linoleic Acid
Thermus Aqauticus