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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. 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)
Negative log of the hydrogen concentration (mol/l).
Thermus Aqauticus
Thickener in foods

2. What are the three stages of oxidative rancidity?
A concentrate of microfibrillar proteins of fish muscle.
Linoleic Acid
.05
Initiation - Propagation - and Termination

3. What are the fructose contents in commercial HFCS products.
Pectin Esterase - Polygalacturonase - Pectin Layase
45% - 52% - 90%
NaCl (it dissociated to a 2M solution)
Fat Oxidation

4. Name the most common functional property of phospholipids in food systems.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Emulsification
Phenophylin
Phenylketonuria

5. What enzyme causes hyrolytic rancidity in milk?
Lipase
Linoleic Acid
It explodes
Prolamines

6. Will lipid oxidation be higher at a water activity of .05 or .5?
Sweet - Salty - Sour - and Bitter
Sodium bicarbonate generates CO2
Pheophytia does not have magnesium in porphyrin ring.
.05

7. Name two reasons why fats are hydrogenated.
Thickener in foods
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

8. At low water activity What is the main deteriorative concern?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lipid oxidation
Pectin methyl esterase or galacturonase
Sucrose

9. What does the 'c' stand for in the equation E=mc2?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Milk
Lamellar; Hexagonal I - II; Cubic
Speed of Light

10. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Nucleation or crystal formation and crystal growth.
Pheophytia does not have magnesium in porphyrin ring.
pH below positive charge; pH at no charge; pH above negative charge

11. Name three non-nutritive sweeteners approved for use in USA?
Chlocophyllide does not have a phytoltail
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Anomeric

12. How many polypeptide chains make up an antibody?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pectin methyl esterase or galacturonase
Four

13. What metabolic end product does the Voges-Proskauer test detect?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Olive Green
Acetoin
45% - 52% - 90%

14. Name two enzymes that are involved in softening fruits.
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenol Oxidase

15. Name a naturally occurring protein sweetener.
Daminozide
Tryptophan
Thamautin
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

16. Name the two components that comprise the relaxing factor in muscle fibers.
Phenophylin
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.
Troponins and Tropomyosin
Pectin methyl esterase or galacturonase

17. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
Chitin
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.
Lycopenes

18. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Speed of Light
Carrageenan
Fat Oxidation

19. Name three non-nutritive sweeteners approved for use in USA?
Nucleation or crystal formation and crystal growth.
RNA transcribed to DNA
.05
Acsulfame-K - Saccharin - Cyclamate - Aspartame

20. What is the Peroxide Value a measure of?
Fat Oxidation
HPLC has higher pressure than FPLC
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Lycopenes

21. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Pectin Esterase - Polygalacturonase - Pectin Layase
Carrageenan
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
2.5

22. Name 4 advantages of using enzymes in food processing.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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
Gliadins and Glutenins

23. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Pheophytin forms
Fructose
Primary butyric acid also caproic acid.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

24. What is the chemical nature of anthocyanins?
NaCl (it dissociated to a 2M solution)
DNA transferred by cell to cell contact (bacterial sex).
Glycosides of anthocyanidins
Water

25. Name 5 chelating agents used in the food industry.
Non-protein nitrogen
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Carrageenan
Anthocyanins

26. Alar is the trade name for what chemical compound?
Polyphenol Oxidase
Parabens
Daminozide
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

27. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
Pheophytin forms
Daminozide
Four

28. What ketohexose is most significant to food chemists?
Thickener in foods
Fructose
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Troponins and Tropomyosin

29. What does the iodine value measure and how is it measured?
Fat Oxidation
Polyphenols
Thickener in foods
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

30. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Tryptophan
Non-protein nitrogen
45% - 52% - 90%
Capsaicin

31. Which two amino acids is the aspartame derived from?
An enzyme that converts hydrogen peroxide to water plus oxygen.
RNA transcribed to DNA
Aspartic Acid and Phenylalanine
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

32. What toxic pigment is found in cottonseed endosperm?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Gossypol (it is removed during the oil refining process)
Polyphenol Oxidase
Pectin Esterase

33. What is the enzyme that softens tomatoes?
Thamautin
Thickener in foods
Daminozide
Pectin Esterase

34. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Acetoin
2.5
Arachidonic Acid

35. What enzyme is most responsible for browning bananas?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Polyphenol Oxidase
Erythorbic Acid

36. What pigment was first designated as anthocyanins?
Whole Milk
Blue pigment in flowers
Lipase
Polyphenols

37. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Primary butyric acid also caproic acid.
20 carbons and 4 double bonds
Plasmids
Orange Juice

38. Name three nonpolar polar - and charged amino acids.
Racemic Mixture
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Daminozide
The speed of a molecule is proportional to the surrounding voltage gradient.

39. What are the three main steps in the autooxidation of lipids?
Tryptophan
Initiation - Propagation - Termination
Bright green
Emulsoids

40. How does HPLC differ from FPLC?
Degradation of protein and production of acid from sugar at the same time.
14
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

41. Name 3 chemical agents capable of denaturing proteins.
Arachidonic Acid
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Speed of Light
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.

42. Name the most common functional property of phospholipids in food systems.
Primary butyric acid also caproic acid.
Initiation - Propagation - and Termination
Emulsification
Glycosides of anthocyanidins

43. What is the main class of color compounds found in raspberries?
Anthocyanins
Emulsoids
Initiation - Propagation - and Termination
.05 M HCL

44. Name 5 chelating agents used in the food industry.
Emulsification
45% - 52% - 90%
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

45. What is the fundamental driving of electrophoresis?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Thamautin
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
The speed of a molecule is proportional to the surrounding voltage gradient.

46. What is a polymorphism?
Yellow
Daminozide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Linoleic Acid

47. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Carmelization and Maillard
Cis
20 carbons and 4 double bonds

48. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
D: None of the above
Lycopenes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Capsaicin

49. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin Esterase - Polygalacturonase - Pectin Layase
NaCl (it dissociated to a 2M solution)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

50. What two types of compounds are joined with an ester bond to make a wax?
Ascorbic Acid and Citric Acid
Plasmids
Fatty Acid and Alcohol
An enzyme that converts hydrogen peroxide to water plus oxygen.