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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. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
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.
Initiation - Propagation - and Termination
NaCl (it dissociated to a 2M solution)

2. At what pH is benzoic acid most effective?
pH 3-5
Arachidonic Acid
Covalent (strongest) and Hydrophobic (Weakest)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

3. Name two non-enzymatic browning reactions.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Carmelization and Maillard
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Covalent (strongest) and Hydrophobic (Weakest)

4. What is the structural difference between chlorophyll and chlocophyllide?
pH below positive charge; pH at no charge; pH above negative charge
Thermus Aqauticus
Lipid oxidation
Chlocophyllide does not have a phytoltail

5. When heated ammonium bicarbonate decomposes to form what end products?
Sodium bicarbonate generates CO2
Ammonia - Water - Carbon Dioxide
Lipid oxidation
Ascorbic Acid and Citric Acid

6. What enzyme is most responsible for browning bananas?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
NaCl (it dissociated to a 2M solution)
Initiation - Propagation - Termination
Polyphenol Oxidase

7. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Pectin Esterase - Polygalacturonase - Pectin Layase
Pectin methylesterase & polygalacturonase
Pectin Esterase - Polygalacturonase - Pectin Layase

8. 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
D: None of the above
They act as catalysts - speeding the polymerization of acrylamide.
Milk
Browning of freshly cut surfaces of fruits and vegetables.

9. 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.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.
Lipase

10. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
It explodes
Ammonia - Water - Carbon Dioxide
45% - 52% - 90%
RNA transcribed to DNA

11. What does Reichert-Meissert Number measure?
Fructose
Racemic Mixture
Phenylketonuria
Primary butyric acid also caproic acid.

12. 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
Bright green
They act as catalysts - speeding the polymerization of acrylamide.
Racemic Mixture
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

13. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Blue pigment in flowers
.05 M HCL
DNA transferred by cell to cell contact (bacterial sex).
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

14. What is surimi?
Polyphenol Oxidase
Yellow
A concentrate of microfibrillar proteins of fish muscle.
Troponins and Tropomyosin

15. What charge will a protein have when the pH of its solution is below at - and above its pKa?
ERH=100 x Aw
pH below positive charge; pH at no charge; pH above negative charge
Pheophytia does not have magnesium in porphyrin ring.
Orange Juice

16. What is the name given to a mixture of equal parts of Darel Lisomers?
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
ERH=100 x Aw
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

17. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
Pectin methylesterase & polygalacturonase
Pectin Esterase
Osmosis

18. What two common compounds are used together as an antioxidative system?
Polyphenols
Ascorbic Acid and Citric Acid
Fructose
.05 M HCL

19. What are 3 mesomorphic structures associated with lipids in the liquid state?
Capsaicin
Lamellar; Hexagonal I - II; Cubic
D: None of the above
A concentrate of microfibrillar proteins of fish muscle.

20. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Gossypol (it is removed during the oil refining process)
A concentrate of microfibrillar proteins of fish muscle.
Initiation - Propagation - Termination

21. How many carbon atoms and how many double bonds are there in arachidonic acid?
Bitter
45% - 52% - 90%
Parabens
20 carbons and 4 double bonds

22. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
D: None of the above
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Gliadins and Glutenins
Non-protein nitrogen

23. At low water activity What is the main deteriorative concern?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Phenylketonuria
Lipid oxidation
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

24. What are the limiting amino acids in corn - potato - and green peas?
Carmelization and Maillard
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Prolamines
They act as catalysts - speeding the polymerization of acrylamide.

25. Contains the lowest content of water
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Fat Oxidation
Whole Milk
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

26. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Primary butyric acid also caproic acid.
Gliadins and Glutenins
Fatty Acid (Ester linked) to Fatty Alcohol

27. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Emulsoids
Polyphenols
Bitter
Olive Green

28. Name two main gluten proteins.
Gliadins and Glutenins
Lipid oxidation
Whole Milk
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

29. What does MSG stand for?
Anomeric
Monosodium Glutamate
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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

30. What metabolic end product does the Voges-Proskauer test detect?
Non-protein nitrogen
Pheophytia does not have magnesium in porphyrin ring.
Acetoin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

31. Is a disaccharide
Racemic Mixture
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Sucrose
Water

32. What are proteins which are soluble in 50-80% ethanol known as?
Capsaicin
Prolamines
D: None of the above
Lysine - Arginine - and Histidine

33. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Polyphenol Oxidase
Fatty Acid and Alcohol
NaCl (it dissociated to a 2M solution)

34. Name two reasons why fats are hydrogenated.
Lipid oxidation
Fat Oxidation
Chlocophyllide does not have a phytoltail
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

35. What does the iodine value measure and how is it measured?
Pectins
Gossypol (it is removed during the oil refining process)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenol Oxidase

36. What is the protein efficiency ratio (PER) of casein?
2.5
D: None of the above
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

37. 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
Anthocyanins
Aspartic Acid and Phenylalanine
Browning of freshly cut surfaces of fruits and vegetables.
Lysine - Arginine - and Histidine

38. What is Ohm's Law and What is Power Equation?
Browning of freshly cut surfaces of fruits and vegetables.
Capsaicin
V=IR and P=VI or I x I x are
NaCl (it dissociated to a 2M solution)

39. Name three factors useful in controlling enzyme activity.
Lycopenes
Troponins and Tropomyosin
An enzyme that converts hydrogen peroxide to water plus oxygen.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

40. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Nucleation or crystal formation and crystal growth.
Polyphenoloxidase
.05

41. What does the 'c' stand for in the equation E=mc2?
Thermus Aqauticus
Speed of Light
Parabens
Monosodium Glutamate

42. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
D: None of the above
Ascorbic Acid and Citric Acid
Chitin

43. What are the fructose contents in commercial HFCS products.
Initiation - Propagation - and Termination
Blue pigment in flowers
Emulsification
45% - 52% - 90%

44. Name 5 proteins with good foaming properties.
Daminozide
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
V=IR and P=VI or I x I x are
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.

45. Name three nonpolar polar - and charged amino acids.
HPLC has higher pressure than FPLC
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Erythorbic Acid
Phenylketonuria

46. What are the primary secondary - tertiary - and quaternary structures?
Pheophytin forms
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.
Nucleation or crystal formation and crystal growth.
ERH=100 x Aw

47. Are sorbitol and mannitol sweet?
Pectin methyl esterase or galacturonase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chitin
Yes

48. During freezing What are the two stages in the crystallization process?
Bitter
Anthocyanins
Nucleation or crystal formation and crystal growth.
Non-protein nitrogen

49. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Erythorbic Acid
Lamellar; Hexagonal I - II; Cubic
Onions ( or leeks)

50. What is the acid present in fish oil?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Thamautin
Four
Arachidonic Acid