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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. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Lipase
Onions ( or leeks)
Bitter
Speed of Light

2. Name 5 chelating agents used in the food industry.
Polyphenols
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
An enzyme that converts hydrogen peroxide to water plus oxygen.
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

3. 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
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.
HPLC has higher pressure than FPLC
Browning of freshly cut surfaces of fruits and vegetables.

4. How do sodium chloride and sucrose affect foam stability?
Carrageenan
Thermus Aqauticus
Sodium chloride reduces foam stability and sucrose improves foam stability.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

5. Name a naturally occurring protein sweetener.
Pheophytin forms
Polyphenols
.05 M HCL
Thamautin

6. Will lipid oxidation be higher at a water activity of .05 or .5?
.05 M HCL
NaCl (it dissociated to a 2M solution)
Polyphenol Oxidase
.05

7. Which two amino acids is the aspartame derived from?
Racemic Mixture
Polyphenol Oxidase
Aspartic Acid and Phenylalanine
Pectin methylesterase & polygalacturonase

8. What does the acronym NPN stand for?
Non-protein nitrogen
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.
The speed of a molecule is proportional to the surrounding voltage gradient.
Ammonia - Water - Carbon Dioxide

9. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Aspartic Acid and Phenylalanine
Anomeric
Yellow

10. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin methyl esterase or galacturonase
HPLC has higher pressure than FPLC
No

11. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Ascorbic Acid and Citric Acid
Bitter
Sodium chloride reduces foam stability and sucrose improves foam stability.

12. What is the acid present in fish oil?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Arachidonic Acid
Whole Milk
Covalent (strongest) and Hydrophobic (Weakest)

13. Alar is the trade name for what chemical compound?
Carmelization and Maillard
Pectin Esterase - Polygalacturonase - Pectin Layase
HPLC has higher pressure than FPLC
Daminozide

14. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Monosodium Glutamate
Phenylketonuria
Degradation of protein and production of acid from sugar at the same time.

15. What is the chemical nomenclature for caffeine?
Racemic Mixture
1 - 3 - 7-trimethylxanthine
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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.

16. What is Ohm's Law and What is Power Equation?
Pectin methylesterase & polygalacturonase
No
V=IR and P=VI or I x I x are
.05

17. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Carrageenan
Emulsification
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

18. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Linoleic 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.
Thermus Aqauticus
They act as catalysts - speeding the polymerization of acrylamide.

19. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Olive Green
Daminozide
Parabens

20. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Sodium bicarbonate generates CO2
Thermus Aqauticus
Yes
Linoleic Acid

21. What two common compounds are used together as an antioxidative system?
Lysine - Arginine - and Histidine
Sucrose
Ascorbic Acid and Citric Acid
Oil in Water

22. What charge will a protein have when the pH of its solution is below at - and above its pKa?
20 carbons and 4 double bonds
It explodes
pH below positive charge; pH at no charge; pH above negative charge
Anthocyanins

23. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
Polyphenol Oxidase
Monosodium Glutamate
Phenylketonuria

24. What does MSG stand for?
Olive Green
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Fatty Acid (Ester linked) to Fatty Alcohol
Monosodium Glutamate

25. How is pH defined?
Thamautin
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Negative log of the hydrogen concentration (mol/l).

26. What ketohexose is most significant to food chemists?
Phenylketonuria
Fructose
Nucleation or crystal formation and crystal growth.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

27. What does HLB stand for and What does a high and low HLB value indicate?
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.
They act as catalysts - speeding the polymerization of acrylamide.
Browning of freshly cut surfaces of fruits and vegetables.
Thickener in foods

28. Name three effects of protein denaturation.
Emulsoids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

29. What is the major color compound in tomatoes?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
RNA transcribed to DNA
Browning of freshly cut surfaces of fruits and vegetables.
Lycopenes

30. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Pectin Esterase - Polygalacturonase - Pectin Layase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Cis
Polyphenoloxidase

31. What is the protein efficiency ratio (PER) of casein?
Bitter
2.5
Degradation of protein and production of acid from sugar at the same time.
pH 3-5

32. At low water activity What is the main deteriorative concern?
.05 M HCL
Linoleic Acid
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipid oxidation

33. What is Carboxy-methyl cellulose often used for?
Daminozide
Thickener in foods
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.

34. Name 5 proteins with good foaming properties.
Olive Green
Onions ( or leeks)
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.
Fat Oxidation

35. 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
Negative log of the hydrogen concentration (mol/l).
Daminozide
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pheophytia does not have magnesium in porphyrin ring.

36. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Capsaicin
Anomeric
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Chitin

37. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Yes
Browning of freshly cut surfaces of fruits and vegetables.
.05 M HCL
Osmosis

38. What are 3 mesomorphic structures associated with lipids in the liquid state?
Emulsification
Sodium bicarbonate generates CO2
Lamellar; Hexagonal I - II; Cubic
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

39. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Polyphenol Oxidase
pH 3-5
It explodes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

40. What compounds oxidize to form brown color in fruits and vegetables?
NaCl (it dissociated to a 2M solution)
Thermus Aqauticus
Polyphenols
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

41. Peptide bond formation results in the formation of what secondary compound?
Capsaicin
Water
Polyphenol Oxidase
.05 M HCL

42. Define molarity molality - and normality.
Ammonia - Water - Carbon Dioxide
Orange Juice
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

43. What is catalase?
pH 3-5
Pectin methylesterase & polygalacturonase
Bright green
An enzyme that converts hydrogen peroxide to water plus oxygen.

44. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Plasmids
pH below positive charge; pH at no charge; pH above negative charge

45. Define molarity molality - and normality.
Erythorbic 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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Parabens

46. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Daminozide
Polyphenol Oxidase
Acetoin

47. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
45% - 52% - 90%
Polyphenoloxidase
Blue pigment in flowers
RNA transcribed to DNA

48. In genetics What is conjugation?
Acetoin
Negative log of the hydrogen concentration (mol/l).
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
DNA transferred by cell to cell contact (bacterial sex).

49. What is catalase?
Two aldehydes
An enzyme that converts hydrogen peroxide to water plus oxygen.
Fat Oxidation
Daminozide

50. Name 4 advantages of using enzymes in food processing.
Lycopenes
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Polyphenols
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