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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 you take 20 ml of .1 M NaOH to titrate 40 mL of an HCL solution to the penolphthalein end point What is the molarity of the HCL solution?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
.05 M HCL
Cis
Covalent (strongest) and Hydrophobic (Weakest)

2. Name 3 physical agents capable of denaturing proteins.
Onions ( or leeks)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Sodium bicarbonate generates CO2
Prolamines

3. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Pectins
45% - 52% - 90%
Oil in Water

4. Name three effects of protein denaturation.
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
Lycopenes
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lamellar; Hexagonal I - II; Cubic

5. What is the protein efficiency ratio (PER) of casein?
pH below positive charge; pH at no charge; pH above negative charge
2.5
Gliadins and Glutenins
Ascorbic Acid and Citric Acid

6. How can a molecular weight of protein - DNA - and RNA be determined?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Nucleation or crystal formation and crystal growth.
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.

7. Name 3 factors influencing the rate of lipid oxidation in foods.
Sodium bicarbonate generates CO2
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin methyl esterase or galacturonase
V=IR and P=VI or I x I x are

8. What are colloids that are stabilized by a layer of solvation called?
Daminozide
Nucleation or crystal formation and crystal growth.
Parabens
Emulsoids

9. What is the name given to a mixture of equal parts of Darel Lisomers?
Olive Green
Sodium chloride reduces foam stability and sucrose improves foam stability.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Racemic Mixture

10. Waxes are composed of what two basic chemical entities?
Ascorbic Acid and Citric Acid
Fatty Acid (Ester linked) to Fatty Alcohol
Cis
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

11. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Water
Covalent (strongest) and Hydrophobic (Weakest)

12. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Browning of freshly cut surfaces of fruits and vegetables.
Water
Gossypol (it is removed during the oil refining process)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

13. Name two main gluten proteins.
Water
Capsaicin
Gliadins and Glutenins
2.5

14. What two enzymes degrade pectic substances?
Milk
Yellow
Pectin methylesterase & polygalacturonase
2.5

15. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Thermus Aqauticus
Emulsification
They act as catalysts - speeding the polymerization of acrylamide.

16. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Oil in Water
Primary butyric acid also caproic acid.
Bitter
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

17. Name 5 chelating agents used in the food industry.
Tryptophan
Lipid oxidation
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectin methylesterase & polygalacturonase

18. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Ammonia - Water - Carbon Dioxide
pH 3-5

19. Are sorbitol and mannitol sweet?
2.5
Phenophylin
Onions ( or leeks)
Yes

20. What is the main class of color compounds found in raspberries?
Pectin methylesterase & polygalacturonase
Pectin Esterase
Anthocyanins
.05

21. What is the Peroxide Value a measure of?
Negative log of the hydrogen concentration (mol/l).
Sweet - Salty - Sour - and Bitter
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
Fat Oxidation

22. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
No
Orange Juice
Anthocyanins

23. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Fructose
Ascorbic Acid and Citric Acid
Racemic Mixture

24. Does kosmotrophil ion discourage water structure?
No
Fatty Acid and Alcohol
Lipase
Yellow

25. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Anthocyanins
Covalent (strongest) and Hydrophobic (Weakest)
14

26. In the enzyme Taq Polymerase What does Taq stand for?
Bitter
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Thermus Aqauticus
Degradation of protein and production of acid from sugar at the same time.

27. What is the structural difference between chlorophyll and chlocophyllide?
Carrageenan
Osmosis
Bitter
Chlocophyllide does not have a phytoltail

28. What is a polymorphism?
Parabens
Parabens
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

29. In genetics What is conjugation?
Water
V=IR and P=VI or I x I x are
Bright green
DNA transferred by cell to cell contact (bacterial sex).

30. Name two main gluten proteins.
Covalent (strongest) and Hydrophobic (Weakest)
Parabens
Gliadins and Glutenins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

31. Name the strongest biochemical bond and the weakest biochemical bond.
Parabens
Covalent (strongest) and Hydrophobic (Weakest)
HPLC has higher pressure than FPLC
Initiation - Propagation - and Termination

32. What metabolic end product does the Voges-Proskauer test detect?
The speed of a molecule is proportional to the surrounding voltage gradient.
Fructose
Thermus Aqauticus
Acetoin

33. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Glycosides of anthocyanidins
Orange Juice
Osmosis
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

34. What is catalase?
Sweet - Salty - Sour - and Bitter
An enzyme that converts hydrogen peroxide to water plus oxygen.
Milk
2.5

35. Is a disaccharide
Gossypol (it is removed during the oil refining process)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Sucrose
Sodium bicarbonate generates CO2

36. Name the most common functional property of phospholipids in food systems.
Orange Juice
Emulsification
Blue pigment in flowers
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

37. Name three non-nutritive sweeteners approved for use in USA?
RNA transcribed to DNA
Capsaicin
Lipase
Acsulfame-K - Saccharin - Cyclamate - Aspartame

38. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Acetoin
Lipid oxidation
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Bright green

39. Name a commonly used household chemical leavening agent and the gas it generates.
2.5
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sodium bicarbonate generates CO2
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

40. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
The speed of a molecule is proportional to the surrounding voltage gradient.
Degradation of protein and production of acid from sugar at the same time.
Oil in Water

41. Give one word for a carbon atom involved in hemiacetal or acetal formation.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Lipid oxidation
Anomeric
Oil in Water

42. What two enzymes degrade pectic substances?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin methylesterase & polygalacturonase
Degradation of protein and production of acid from sugar at the same time.
No

43. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Whole Milk
Erythorbic Acid
Polyphenol Oxidase

44. Name two reasons why fats are hydrogenated.
Initiation - Propagation - and Termination
Sodium chloride reduces foam stability and sucrose improves foam stability.
Monosodium Glutamate
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

45. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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.
Nucleation or crystal formation and crystal growth.

46. At low water activity What is the main deteriorative concern?
Sucrose
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.
Lipid oxidation
Fructose

47. When heated ammonium bicarbonate decomposes to form what end products?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Ammonia - Water - Carbon Dioxide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Racemic Mixture

48. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Ammonia - Water - Carbon Dioxide
Acetoin
Pectin methyl esterase or galacturonase
Erythorbic Acid

49. Alar is the trade name for what chemical compound?
Daminozide
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.
Yes
Bitter

50. Name the most common functional property of phospholipids in food systems.
Emulsification
Bitter
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chitin