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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. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
It explodes
Oil in Water
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

2. Alar is the trade name for what chemical compound?
20 carbons and 4 double bonds
14
Plasmids
Daminozide

3. Name 5 proteins with good foaming properties.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
ERH=100 x Aw
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.
A concentrate of microfibrillar proteins of fish muscle.

4. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Emulsification
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.
Tryptophan
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

5. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Fructose
The speed of a molecule is proportional to the surrounding voltage gradient.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
14

6. Name one way foam stability can be assessed.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Browning of freshly cut surfaces of fruits and vegetables.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
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.

7. 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)
Orange Juice
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Anthocyanins

8. What enzyme is most responsible for browning bananas?
Emulsoids
Lipase
Polyphenol Oxidase
Lipid oxidation

9. When heated ammonium bicarbonate decomposes to form what end products?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Nucleation or crystal formation and crystal growth.
Bitter
Ammonia - Water - Carbon Dioxide

10. Is a disaccharide
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sucrose
An enzyme that converts hydrogen peroxide to water plus oxygen.

11. What happens to chlorophyll on heating?
pH below positive charge; pH at no charge; pH above negative charge
Capsaicin
Troponins and Tropomyosin
Pheophytin forms

12. What is the chemical nomenclature for caffeine?
Anthocyanins
Speed of Light
1 - 3 - 7-trimethylxanthine
Polyphenol Oxidase

13. What is a polymorphism?
Pectin methyl esterase or galacturonase
Polyphenol Oxidase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Monosodium Glutamate

14. Define molarity molality - and normality.
Sucrose
Initiation - Propagation - and Termination
14
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. How does HPLC differ from FPLC?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Non-protein nitrogen
HPLC has higher pressure than FPLC
D: None of the above

16. What is the major color compound in tomatoes?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Four
Thamautin
Lycopenes

17. What is the fundamental driving of electrophoresis?
Anomeric
Pheophytin forms
The speed of a molecule is proportional to the surrounding voltage gradient.
Milk

18. What does MSG stand for?
Pectin Esterase
Initiation - Propagation - and Termination
Monosodium Glutamate
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

19. What is the protein efficiency ratio (PER) of casein?
2.5
Primary butyric acid also caproic acid.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
NaCl (it dissociated to a 2M solution)

20. Name 4 advantages of using enzymes in food processing.
Monosodium Glutamate
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
Lipid oxidation
Parabens

21. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Lipase
Daminozide
Fatty Acid and Alcohol
Water

22. 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.
Thamautin
Two aldehydes
2.5

23. What is the acid present in fish oil?
Arachidonic Acid
Gossypol (it is removed during the oil refining process)
Troponins and Tropomyosin
Erythorbic Acid

24. Name two non-enzymatic browning reactions.
.05
Speed of Light
Carmelization and Maillard
Sucrose

25. What is the protein efficiency ratio (PER) of casein?
Thamautin
Cis
2.5
Carrageenan

26. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Pectins
D: None of the above
Carrageenan
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

27. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
ERH=100 x Aw
V=IR and P=VI or I x I x are
Initiation - Propagation - Termination

28. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Lipid oxidation
Four
Two aldehydes
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.

29. What ketohexose is most significant to food chemists?
Emulsoids
Fructose
It explodes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

30. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
D: None of the above
Prolamines
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

31. What are the limiting amino acids in corn - potato - and green peas?
Initiation - Propagation - Termination
Bitter
Glycosides of anthocyanidins
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

32. How can a molecular weight of protein - DNA - and RNA be determined?
Aspartic Acid and Phenylalanine
Nucleation or crystal formation and crystal growth.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Tryptophan

33. Name the three positively charged amino acids.
Pheophytia does not have magnesium in porphyrin ring.
Pectin methylesterase & polygalacturonase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lysine - Arginine - and Histidine

34. What happens to chlorophyll on heating?
A concentrate of microfibrillar proteins of fish muscle.
Bright green
Pheophytin forms
Fat Oxidation

35. Name 3 physical agents capable of denaturing proteins.
Nucleation or crystal formation and crystal growth.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

36. Name three factors useful in controlling enzyme activity.
Racemic Mixture
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

37. What is the chemical nomenclature for caffeine?
Speed of Light
Phenophylin
V=IR and P=VI or I x I x are
1 - 3 - 7-trimethylxanthine

38. Alar is the trade name for what chemical compound?
HPLC has higher pressure than FPLC
Pectin Esterase
Daminozide
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

39. What are the fructose contents in commercial HFCS products.
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
Phenophylin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
45% - 52% - 90%

40. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Thickener in foods
Linoleic Acid
Daminozide
Glycosides of anthocyanidins

41. What is an isomer that is cheaper than Vitamin C?
Milk
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenols
Erythorbic Acid

42. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
V=IR and P=VI or I x I x are
Four
Onions ( or leeks)
Polyphenol Oxidase

43. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Sweet - Salty - Sour - and Bitter
Capsaicin
Thickener in foods
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

44. Name a naturally occurring protein sweetener.
Thamautin
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.
Phenophylin
Pectin methylesterase & polygalacturonase

45. 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?
They act as catalysts - speeding the polymerization of acrylamide.
D: None of the above
20 carbons and 4 double bonds
.05 M HCL

46. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Polyphenoloxidase
Phenophylin
Daminozide

47. What are the four basic flavors perceived by the tongue?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Pectin methyl esterase or galacturonase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Sweet - Salty - Sour - and Bitter

48. Name one way foam stability can be assessed.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Sodium bicarbonate generates CO2
Gliadins and Glutenins
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.

49. Are sorbitol and mannitol sweet?
Cis
Fructose
Yes
Ammonia - Water - Carbon Dioxide

50. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Orange Juice
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bitter