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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
pH below positive charge; pH at no charge; pH above negative charge
Four
Racemic Mixture
Capsaicin

2. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
45% - 52% - 90%
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Initiation - Propagation - Termination

3. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Negative log of the hydrogen concentration (mol/l).
They act as catalysts - speeding the polymerization of acrylamide.

4. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
45% - 52% - 90%
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

5. Name three factors useful in controlling enzyme activity.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Erythorbic Acid
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Initiation - Propagation - and Termination

6. Name 3 chemical agents capable of denaturing proteins.
Yellow
Polyphenol Oxidase
Lipase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

7. What does the acronym NPN stand for?
Orange Juice
Onions ( or leeks)
Polyphenol Oxidase
Non-protein nitrogen

8. At what pH is benzoic acid most effective?
Acetoin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Daminozide
pH 3-5

9. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Degradation of protein and production of acid from sugar at the same time.
Capsaicin

10. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
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.
Sodium bicarbonate generates CO2

11. How can a molecular weight of protein - DNA - and RNA be determined?
Milk
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
pH below positive charge; pH at no charge; pH above negative charge

12. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Primary butyric acid also caproic acid.
Ammonia - Water - Carbon Dioxide
pH below positive charge; pH at no charge; pH above negative charge
Daminozide

13. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
V=IR and P=VI or I x I x are
NaCl (it dissociated to a 2M solution)
Arachidonic Acid

14. In what food is butyric acid typically found?
HPLC has higher pressure than FPLC
Milk
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Sweet - Salty - Sour - and Bitter

15. How many polypeptide chains make up an antibody?
Lysine - Arginine - and Histidine
Primary butyric acid also caproic acid.
Aspartic Acid and Phenylalanine
Four

16. What two common compounds are used together as an antioxidative system?
Anthocyanins
Covalent (strongest) and Hydrophobic (Weakest)
Carmelization and Maillard
Ascorbic Acid and Citric Acid

17. What enzyme is most responsible for browning bananas?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Polyphenol Oxidase
Racemic Mixture
Gliadins and Glutenins

18. What are colloids that are stabilized by a layer of solvation called?
Olive Green
Emulsoids
45% - 52% - 90%
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

19. Contains the lowest content of water
Water
Yellow
Whole Milk
Chitin

20. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Sweet - Salty - Sour - and Bitter
Ascorbic Acid and Citric Acid
Pectin methyl esterase or galacturonase

21. What is the structural difference between chlorophyll and chlocophyllide?
Milk
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Chlocophyllide does not have a phytoltail
They act as catalysts - speeding the polymerization of acrylamide.

22. What does the 'c' stand for in the equation E=mc2?
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.
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
Chlocophyllide does not have a phytoltail
Speed of Light

23. Define molarity molality - and normality.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Emulsification
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

24. 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?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Two aldehydes
Emulsification
It explodes

25. What metabolic end product does the Voges-Proskauer test detect?
Four
Sucrose
Two aldehydes
Acetoin

26. Name a naturally occurring protein sweetener.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Thamautin
Gossypol (it is removed during the oil refining process)
Lipase

27. What is Carboxy-methyl cellulose often used for?
Non-protein nitrogen
It explodes
Thickener in foods
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

28. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectin methyl esterase or galacturonase
Glycosides of anthocyanidins
They act as catalysts - speeding the polymerization of acrylamide.

29. Name two main gluten proteins.
It explodes
Anthocyanins
Gliadins and Glutenins
Yellow

30. How is pH defined?
Lipid oxidation
.05
Negative log of the hydrogen concentration (mol/l).
.05

31. What metabolic end product does the Voges-Proskauer test detect?
NaCl (it dissociated to a 2M solution)
Chitin
45% - 52% - 90%
Acetoin

32. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
HPLC has higher pressure than FPLC
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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
.05

33. Name 3 physical agents capable of denaturing proteins.
It explodes
Olive Green
Anomeric
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

34. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
It explodes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Phenylketonuria

35. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Speed of Light
Phenylketonuria
Four
Sodium chloride reduces foam stability and sucrose improves foam stability.

36. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Initiation - Propagation - Termination
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Tryptophan

37. Which two amino acids is the aspartame derived from?
Erythorbic Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Initiation - Propagation - Termination
Aspartic Acid and Phenylalanine

38. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Glycosides of anthocyanidins
RNA transcribed to DNA
Thermus Aqauticus

39. How can a molecular weight of protein - DNA - and RNA be determined?
Yellow
Cis
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Nucleation or crystal formation and crystal growth.

40. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Orange Juice
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectin Esterase

41. What is the main class of color compounds found in raspberries?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
No
Orange Juice
Anthocyanins

42. What two enzymes degrade pectic substances?
Chlocophyllide does not have a phytoltail
Primary butyric acid also caproic acid.
Pectin methylesterase & polygalacturonase
Tryptophan

43. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
No
Bitter
Lysine - Arginine - and Histidine
Polyphenols

44. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Pectin methylesterase & polygalacturonase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Water
Chitin

45. What does the saponification value measure and how is it measured?
Aspartic Acid and Phenylalanine
Negative log of the hydrogen concentration (mol/l).
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Polyphenol Oxidase

46. What is the enzyme responsible for browning in apples and lettuce?
Polyphenoloxidase
Polyphenol Oxidase
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.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

47. How many carbon atoms and how many double bonds are there in arachidonic acid?
Cis
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
Thickener in foods
20 carbons and 4 double bonds

48. What is the protein efficiency ratio (PER) of casein?
.05 M HCL
Racemic Mixture
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
2.5

49. Define molarity molality - and normality.
Parabens
Cis
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Lysine - Arginine - and Histidine

50. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Phenylketonuria
Four
Daminozide