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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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1. Name two non-enzymatic browning reactions.
pH 3-5
Carmelization and Maillard
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Initiation - Propagation - Termination

2. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Osmosis
Degradation of protein and production of acid from sugar at the same time.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Pectin methyl esterase or galacturonase

3. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
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.
Glycosides of anthocyanidins
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

4. What are 3 mesomorphic structures associated with lipids in the liquid state?
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.
It explodes
Lamellar; Hexagonal I - II; Cubic
DNA transferred by cell to cell contact (bacterial sex).

5. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Speed of Light
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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.

6. How many carbon atoms are there in the fatty acid myristic acid?
14
Arachidonic Acid
.05 M HCL
Emulsification

7. Are sorbitol and mannitol sweet?
pH below positive charge; pH at no charge; pH above negative charge
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.
Yes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

8. What toxic pigment is found in cottonseed endosperm?
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
Gossypol (it is removed during the oil refining process)
Pheophytia does not have magnesium in porphyrin ring.
Emulsification

9. Name a naturally occurring protein sweetener.
Thamautin
Sucrose
Pectin methyl esterase or galacturonase
It explodes

10. 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
Browning of freshly cut surfaces of fruits and vegetables.
Ascorbic Acid and Citric Acid
Yellow
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

11. Name two main gluten proteins.
2.5
Olive Green
Gliadins and Glutenins
Ammonia - Water - Carbon Dioxide

12. Name 3 factors influencing the rate of lipid oxidation in foods.
Non-protein nitrogen
Sucrose
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Covalent (strongest) and Hydrophobic (Weakest)

13. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Acetoin
V=IR and P=VI or I x I x are
They act as catalysts - speeding the polymerization of acrylamide.

14. How many polypeptide chains make up an antibody?
Sucrose
Four
Capsaicin
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

15. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Chlocophyllide does not have a phytoltail
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
An enzyme that converts hydrogen peroxide to water plus oxygen.
Onions ( or leeks)

16. Which two amino acids is the aspartame derived from?
The speed of a molecule is proportional to the surrounding voltage gradient.
Aspartic Acid and Phenylalanine
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Osmosis

17. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Lamellar; Hexagonal I - II; Cubic
Orange Juice
Fructose
No

18. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fat Oxidation
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
A concentrate of microfibrillar proteins of fish muscle.

19. What does Reichert-Meissert Number measure?
pH below positive charge; pH at no charge; pH above negative charge
They act as catalysts - speeding the polymerization of acrylamide.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Primary butyric acid also caproic acid.

20. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Parabens
Onions ( or leeks)
It explodes

21. How do sodium chloride and sucrose affect foam stability?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Sweet - Salty - Sour - and Bitter
Pectin methylesterase & polygalacturonase
Sodium chloride reduces foam stability and sucrose improves foam stability.

22. At low water activity What is the main deteriorative concern?
Sodium bicarbonate generates CO2
Prolamines
Lipid oxidation
Speed of Light

23. What effect would the addition of sodium bicarbonate have to chocolate?
Capsaicin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Pectin Esterase
Initiation - Propagation - Termination

24. How can a molecular weight of protein - DNA - and RNA be determined?
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Ascorbic Acid and Citric Acid
Fatty Acid (Ester linked) to Fatty Alcohol

25. What is the chemical nomenclature for caffeine?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Ammonia - Water - Carbon Dioxide
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
1 - 3 - 7-trimethylxanthine

26. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Emulsification
Bitter
Prolamines
HPLC has higher pressure than FPLC

27. Name 3 factors influencing the consistency of commercial fats.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
HPLC has higher pressure than FPLC
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Plasmids

28. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Tryptophan
Parabens
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

29. During freezing What are the two stages in the crystallization process?
Bright green
Whole Milk
Bitter
Nucleation or crystal formation and crystal growth.

30. What is a polymorphism?
Sucrose
Non-protein nitrogen
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

31. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Emulsoids

32. What are the primary secondary - tertiary - and quaternary structures?
Osmosis
Sweet - Salty - Sour - and Bitter
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.

33. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
.05 M HCL
Bright green
Tryptophan

34. When heated ammonium bicarbonate decomposes to form what end products?
It explodes
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.
Capsaicin
Ammonia - Water - Carbon Dioxide

35. How does ERH relate to water activity?
ERH=100 x Aw
Phenylketonuria
Ascorbic Acid and Citric Acid
Negative log of the hydrogen concentration (mol/l).

36. What is the enzyme that softens tomatoes?
It explodes
NaCl (it dissociated to a 2M solution)
Pectin Esterase
No

37. What is Ohm's Law and What is Power Equation?
Blue pigment in flowers
Covalent (strongest) and Hydrophobic (Weakest)
Pectin methyl esterase or galacturonase
V=IR and P=VI or I x I x are

38. What are the only phenols approved for use in the microbiological preservation of foods?
No
HPLC has higher pressure than FPLC
Oil in Water
Parabens

39. Alar is the trade name for what chemical compound?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
An enzyme that converts hydrogen peroxide to water plus oxygen.
Daminozide
Water

40. How many carbon atoms and how many double bonds are there in arachidonic 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.
Carrageenan
20 carbons and 4 double bonds
Chlocophyllide does not have a phytoltail

41. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
HPLC has higher pressure than FPLC
Four
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

42. What enzyme causes hyrolytic rancidity in milk?
Lipase
Erythorbic Acid
D: None of the above
Parabens

43. Name the two components that comprise the relaxing factor in muscle fibers.
The speed of a molecule is proportional to the surrounding voltage gradient.
Onions ( or leeks)
Troponins and Tropomyosin
.05 M HCL

44. Name three non-nutritive sweeteners approved for use in USA?
Covalent (strongest) and Hydrophobic (Weakest)
They act as catalysts - speeding the polymerization of acrylamide.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Pectins

45. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Pheophytin forms
Whole Milk
Oil in Water
Milk

46. What are the four basic flavors perceived by the tongue?
Troponins and Tropomyosin
Fat Oxidation
Polyphenols
Sweet - Salty - Sour - and Bitter

47. Name 3 chemical agents capable of denaturing proteins.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
V=IR and P=VI or I x I x are

48. Alar is the trade name for what chemical compound?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Olive Green
Pectin Esterase - Polygalacturonase - Pectin Layase
Daminozide

49. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Monosodium Glutamate
Fructose
Water
Carrageenan

50. Name one way foam stability can be assessed.
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.
D: None of the above
Racemic Mixture
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)