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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. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Monosodium Glutamate
Yellow
Anomeric
Racemic Mixture

2. Name 3 physical agents capable of denaturing proteins.
Fat Oxidation
Negative log of the hydrogen concentration (mol/l).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

3. Name two enzymes that are involved in softening fruits.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
14
Pectin Esterase - Polygalacturonase - Pectin Layase
RNA transcribed to DNA

4. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Lipid oxidation
Linoleic Acid
Pectin methyl esterase or galacturonase
2.5

5. What is the fundamental driving of electrophoresis?
Covalent (strongest) and Hydrophobic (Weakest)
The speed of a molecule is proportional to the surrounding voltage gradient.
Pheophytin forms
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.

6. Which two amino acids is the aspartame derived from?
Plasmids
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Daminozide
Aspartic Acid and Phenylalanine

7. What effect would the addition of sodium bicarbonate have to chocolate?
Blue pigment in flowers
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
RNA transcribed to DNA
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

8. What is the enzyme that softens tomatoes?
Blue pigment in flowers
Pectin Esterase
Thamautin
NaCl (it dissociated to a 2M solution)

9. At what pH is benzoic acid most effective?
pH 3-5
Carmelization and Maillard
pH below positive charge; pH at no charge; pH above negative charge
Four

10. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
Nucleation or crystal formation and crystal growth.
V=IR and P=VI or I x I x are
Carrageenan

11. How many carbon atoms and how many double bonds are there in arachidonic acid?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
20 carbons and 4 double bonds
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
HPLC has higher pressure than FPLC

12. Is a disaccharide
Capsaicin
pH 3-5
Water
Sucrose

13. What is the structural difference between chlorophyll and chlocophyllide?
No
Emulsoids
Chlocophyllide does not have a phytoltail
Olive Green

14. What does the saponification value measure and how is it measured?
HPLC has higher pressure than FPLC
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Whole Milk
Ammonia - Water - Carbon Dioxide

15. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
.05 M HCL
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

16. Name three non-nutritive sweeteners approved for use in USA?
Emulsoids
It explodes
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Chlocophyllide does not have a phytoltail

17. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Degradation of protein and production of acid from sugar at the same time.
Glycosides of anthocyanidins
Parabens

18. 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
An enzyme that converts hydrogen peroxide to water plus oxygen.
Blue pigment in flowers
Bitter

19. What toxic pigment is found in cottonseed endosperm?
Parabens
Lycopenes
Troponins and Tropomyosin
Gossypol (it is removed during the oil refining process)

20. What does Acid Degree Value measure and how is it measured?
Polyphenol Oxidase
45% - 52% - 90%
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

21. Name three effects of protein denaturation.
D: None of the above
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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Polyphenols

22. What is the geometric configuration of double bonds in most natural fatty acids?
Thermus Aqauticus
Chlocophyllide does not have a phytoltail
Cis
Chitin

23. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
ERH=100 x Aw
Polyphenoloxidase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

24. What is the chemical nomenclature for caffeine?
Lipase
1 - 3 - 7-trimethylxanthine
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
An enzyme that converts hydrogen peroxide to water plus oxygen.

25. What metabolic end product does the Voges-Proskauer test detect?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acetoin
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
45% - 52% - 90%

26. How many carbon atoms are there in the fatty acid myristic acid?
14
Osmosis
Daminozide
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

27. What is the geometric configuration of double bonds in most natural fatty acids?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lycopenes
Cis
Negative log of the hydrogen concentration (mol/l).

28. During freezing What are the two stages in the crystallization process?
A concentrate of microfibrillar proteins of fish muscle.
Water
Nucleation or crystal formation and crystal growth.
HPLC has higher pressure than FPLC

29. How many polypeptide chains make up an antibody?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Four
Yes
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

30. Name a naturally occurring protein sweetener.
Thamautin
Sodium chloride reduces foam stability and sucrose improves foam stability.
Anomeric
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

31. How does HPLC differ from FPLC?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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).
Two aldehydes

32. What are colloids that are stabilized by a layer of solvation called?
No
Emulsoids
Lamellar; Hexagonal I - II; Cubic
Thickener in foods

33. Name the most common functional property of phospholipids in food systems.
Fructose
Erythorbic Acid
Emulsification
Fructose

34. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Racemic Mixture
Orange Juice
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

35. What does the iodine value measure and how is it measured?
45% - 52% - 90%
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
ERH=100 x Aw
HPLC has higher pressure than FPLC

36. What are two common reducing agents that break disulfide bonds in proteins?
14
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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.
Oil in Water

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
Bright green
V=IR and P=VI or I x I x are
It explodes

38. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
D: None of the above
Carrageenan
Initiation - Propagation - and Termination
V=IR and P=VI or I x I x are

39. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
RNA transcribed to DNA
DNA transferred by cell to cell contact (bacterial sex).
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

40. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
2.5
pH 3-5
Bright green

41. 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
45% - 52% - 90%

42. Will lipid oxidation be higher at a water activity of .05 or .5?
45% - 52% - 90%
Acetoin
.05
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

43. What is the acid present in fish oil?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Phenophylin
Arachidonic Acid

44. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
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.
Initiation - Propagation - and Termination
Lamellar; Hexagonal I - II; Cubic

45. Name 3 factors influencing the consistency of commercial fats.
They act as catalysts - speeding the polymerization of acrylamide.
Fructose
RNA transcribed to DNA
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

46. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
1 - 3 - 7-trimethylxanthine
Chlocophyllide does not have a phytoltail

47. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lipase
Yellow
Water

48. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Browning of freshly cut surfaces of fruits and vegetables.
Onions ( or leeks)
Troponins and Tropomyosin
Chitin

49. 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.
Pectin methylesterase & polygalacturonase
pH below positive charge; pH at no charge; pH above negative charge
Emulsoids

50. What is the fundamental driving of electrophoresis?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
No
Anomeric
The speed of a molecule is proportional to the surrounding voltage gradient.