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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. What effect would the addition of sodium bicarbonate have to chocolate?
Gossypol (it is removed during the oil refining process)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Covalent (strongest) and Hydrophobic (Weakest)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

2. What is the fundamental driving of electrophoresis?
Gliadins and Glutenins
.05 M HCL
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
The speed of a molecule is proportional to the surrounding voltage gradient.

3. What does the iodine value measure and how is it measured?
Cis
Erythorbic Acid
14
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

4. What is acid proteolysis?
Bright green
Degradation of protein and production of acid from sugar at the same time.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
45% - 52% - 90%

5. What are the limiting amino acids in corn - potato - and green peas?
NaCl (it dissociated to a 2M solution)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
An enzyme that converts hydrogen peroxide to water plus oxygen.
pH below positive charge; pH at no charge; pH above negative charge

6. How many carbon atoms and how many double bonds are there in arachidonic acid?
Capsaicin
ERH=100 x Aw
20 carbons and 4 double bonds
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

7. What is an isomer that is cheaper than Vitamin C?
Gliadins and Glutenins
Erythorbic Acid
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Bitter

8. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Daminozide
Water
pH below positive charge; pH at no charge; pH above negative charge
Anomeric

9. Name 3 factors influencing the rate of lipid oxidation in foods.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Tryptophan
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Non-protein nitrogen

10. What does the saponification value measure and how is it measured?
Covalent (strongest) and Hydrophobic (Weakest)
Gliadins and Glutenins
Oil in Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

11. Name 3 factors influencing the consistency of commercial fats.
Arachidonic Acid
Initiation - Propagation - Termination
DNA transferred by cell to cell contact (bacterial sex).
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

12. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Sodium bicarbonate generates CO2
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Phenylketonuria
Capsaicin

13. What is catalase?
Lysine - Arginine - and Histidine
Anthocyanins
An enzyme that converts hydrogen peroxide to water plus oxygen.
Orange Juice

14. 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
Thickener in foods
Carmelization and Maillard
Browning of freshly cut surfaces of fruits and vegetables.
Ammonia - Water - Carbon Dioxide

15. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
HPLC has higher pressure than FPLC
They act as catalysts - speeding the polymerization of acrylamide.
Sucrose

16. What toxic pigment is found in cottonseed endosperm?
Anomeric
Two aldehydes
Gossypol (it is removed during the oil refining process)
Lipase

17. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
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.
Oil in Water
pH below positive charge; pH at no charge; pH above negative charge
HPLC has higher pressure than FPLC

18. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
A concentrate of microfibrillar proteins of fish muscle.
Parabens

19. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Phenophylin
pH below positive charge; pH at no charge; pH above negative charge
Anomeric
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

20. Define molarity molality - and normality.
Pheophytia does not have magnesium in porphyrin ring.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Sodium bicarbonate generates CO2
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

21. What is the name given to a mixture of equal parts of Darel Lisomers?
Polyphenols
pH below positive charge; pH at no charge; pH above negative charge
Racemic Mixture
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

22. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Parabens
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
Gliadins and Glutenins

23. What is the name of the degradation compound of chlorophyll?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Polyphenol Oxidase
Phenophylin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

24. 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?
Pectins
.05 M HCL
ERH=100 x Aw
Prolamines

25. Name two non-enzymatic browning reactions.
Polyphenols
Racemic Mixture
Carmelization and Maillard
Plasmids

26. 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
Phenophylin
Carrageenan
Lipase

27. 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.
Anthocyanins
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Chlocophyllide does not have a phytoltail

28. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Gossypol (it is removed during the oil refining process)
Carrageenan
Oil in Water

29. How is pH defined?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Primary butyric acid also caproic acid.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Negative log of the hydrogen concentration (mol/l).

30. What does the acronym NPN stand for?
Non-protein nitrogen
Thamautin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

31. 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
Fatty Acid and Alcohol
A concentrate of microfibrillar proteins of fish muscle.

32. Will lipid oxidation be higher at a water activity of .05 or .5?
Phenylketonuria
Emulsoids
.05
1 - 3 - 7-trimethylxanthine

33. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Troponins and Tropomyosin
pH below positive charge; pH at no charge; pH above negative charge
They act as catalysts - speeding the polymerization of acrylamide.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

34. Name three nonpolar polar - and charged amino acids.
Nucleation or crystal formation and crystal growth.
Daminozide
2.5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

35. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
No
Thamautin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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.

36. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Orange Juice
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Four

37. What is Carboxy-methyl cellulose often used for?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
D: None of the above
Thickener in foods
Tryptophan

38. What is the enzyme responsible for browning in apples and lettuce?
Emulsoids
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.
pH 3-5
Polyphenol Oxidase

39. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
V=IR and P=VI or I x I x are
Phenophylin
Pectin Esterase - Polygalacturonase - Pectin Layase

40. What are proteins which are soluble in 50-80% ethanol known as?
Yellow
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.
Whole Milk
Prolamines

41. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectins
Orange Juice
pH below positive charge; pH at no charge; pH above negative charge

42. What is surimi?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Daminozide
A concentrate of microfibrillar proteins of fish muscle.
Thickener in foods

43. Name 4 advantages of using enzymes in food processing.
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
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
Racemic Mixture
Polyphenoloxidase

44. What are two common reducing agents that break disulfide bonds in proteins?
Daminozide
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Arachidonic Acid
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

45. 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)
45% - 52% - 90%
2.5
Aspartic Acid and Phenylalanine

46. What enzyme causes hyrolytic rancidity in milk?
Carmelization and Maillard
Lipase
Fatty Acid (Ester linked) to Fatty Alcohol
Capsaicin

47. Alar is the trade name for what chemical compound?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Negative log of the hydrogen concentration (mol/l).
Fatty Acid and Alcohol
Daminozide

48. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Ascorbic Acid and Citric Acid
Pectin methyl esterase or galacturonase
Osmosis
Polyphenol Oxidase

49. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
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
Anomeric

50. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
No
Thamautin
Pectins