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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. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin Esterase - Polygalacturonase - Pectin Layase
Water
Pectin methyl esterase or galacturonase
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

2. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
pH 3-5
RNA transcribed to DNA
Osmosis
Non-protein nitrogen

3. 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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Lipase
Troponins and Tropomyosin

4. What are the four basic flavors perceived by the tongue?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sweet - Salty - Sour - and Bitter
Pectins
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

5. What two common compounds are used together as an antioxidative system?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
2.5
Plasmids
Ascorbic Acid and Citric Acid

6. Name a naturally occurring protein sweetener.
Phenophylin
Whole Milk
.05 M HCL
Thamautin

7. What enzyme is most responsible for browning bananas?
.05
HPLC has higher pressure than FPLC
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Polyphenol Oxidase

8. During freezing What are the two stages in the crystallization process?
Osmosis
Four
Fructose
Nucleation or crystal formation and crystal growth.

9. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Glycosides of anthocyanidins
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.

10. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
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.
Racemic Mixture
.05 M HCL
Phenylketonuria

11. What is acid proteolysis?
Sweet - Salty - Sour - and Bitter
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
Degradation of protein and production of acid from sugar at the same time.
Glycosides of anthocyanidins

12. 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
Sodium chloride reduces foam stability and sucrose improves foam stability.
Nucleation or crystal formation and crystal growth.
D: None of the above
Linoleic Acid

13. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
45% - 52% - 90%
14
Osmosis

14. What are colloids that are stabilized by a layer of solvation called?
Negative log of the hydrogen concentration (mol/l).
Phenophylin
Daminozide
Emulsoids

15. Peptide bond formation results in the formation of what secondary compound?
It explodes
Gliadins and Glutenins
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Water

16. Will lipid oxidation be higher at a water activity of .05 or .5?
Lysine - Arginine - and Histidine
.05
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

17. What is an isomer that is cheaper than Vitamin C?
Pectin Esterase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Erythorbic Acid
Yellow

18. What is the main class of color compounds found in raspberries?
Plasmids
Pectin methylesterase & polygalacturonase
Anthocyanins
Bitter

19. What does the saponification value measure and how is it measured?
Sweet - Salty - Sour - and Bitter
Lysine - Arginine - and Histidine
Orange Juice
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

20. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
HPLC has higher pressure than FPLC
Pectins
Browning of freshly cut surfaces of fruits and vegetables.

21. What is acid proteolysis?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Degradation of protein and production of acid from sugar at the same time.
Sucrose
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

22. Name 5 proteins with good foaming properties.
Negative log of the hydrogen concentration (mol/l).
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.
Arachidonic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

23. Name 3 physical agents capable of denaturing proteins.
pH below positive charge; pH at no charge; pH above negative charge
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.
Nucleation or crystal formation and crystal growth.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

24. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Onions ( or leeks)
Sweet - Salty - Sour - and Bitter
Initiation - Propagation - Termination

25. At low water activity What is the main deteriorative concern?
Primary butyric acid also caproic acid.
Covalent (strongest) and Hydrophobic (Weakest)
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipid oxidation

26. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Racemic Mixture
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

27. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Monosodium Glutamate
Orange Juice
Prolamines
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

28. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
V=IR and P=VI or I x I x are
Bitter
Ammonia - Water - Carbon Dioxide

29. In the enzyme Taq Polymerase What does Taq stand for?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Orange Juice
Thermus Aqauticus
Sweet - Salty - Sour - and Bitter

30. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Water
Blue pigment in flowers
pH below positive charge; pH at no charge; pH above negative charge
They act as catalysts - speeding the polymerization of acrylamide.

31. Does kosmotrophil ion discourage water structure?
No
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Anomeric
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

32. What is the acid present in fish oil?
Bitter
Primary butyric acid also caproic acid.
Arachidonic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

33. What are two common reducing agents that break disulfide bonds in proteins?
Lysine - Arginine - and Histidine
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.
Plasmids

34. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Oil in Water
Pectins

35. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Lysine - Arginine - and Histidine
Olive Green
Phenylketonuria
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.

36. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
HPLC has higher pressure than FPLC
NaCl (it dissociated to a 2M solution)

37. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
DNA transferred by cell to cell contact (bacterial sex).
Degradation of protein and production of acid from sugar at the same time.

38. How many polypeptide chains make up an antibody?
Arachidonic Acid
Sucrose
Four
Erythorbic Acid

39. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Four
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Onions ( or leeks)

40. Name three effects of protein denaturation.
1 - 3 - 7-trimethylxanthine
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Cis
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

41. Name 4 advantages of using enzymes in food processing.
Fat Oxidation
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
V=IR and P=VI or I x I x are
Fatty Acid and Alcohol

42. What is the major color compound in tomatoes?
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.
Lycopenes
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
DNA transferred by cell to cell contact (bacterial sex).

43. Name 3 factors influencing the consistency of commercial fats.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Sweet - Salty - Sour - and Bitter
Pheophytia does not have magnesium in porphyrin ring.

44. What is the chemical nature of anthocyanins?
Whole Milk
An enzyme that converts hydrogen peroxide to water plus oxygen.
Glycosides of anthocyanidins
Water

45. Is a disaccharide
Primary butyric acid also caproic acid.
Speed of Light
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Sucrose

46. What is the structural difference between chlorophyll and pheophytia?
Arachidonic Acid
Daminozide
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
Pheophytia does not have magnesium in porphyrin ring.

47. What is the protein efficiency ratio (PER) of casein?
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
Fatty Acid (Ester linked) to Fatty Alcohol
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
2.5

48. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Thermus Aqauticus
Yellow
Cis
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

49. What is the Peroxide Value a measure of?
Fat Oxidation
Fatty Acid and Alcohol
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Polyphenol Oxidase

50. What does MSG stand for?
Browning of freshly cut surfaces of fruits and vegetables.
Monosodium Glutamate
Acetoin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)