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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. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fructose
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

2. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Blue pigment in flowers
NaCl (it dissociated to a 2M solution)
Pheophytia does not have magnesium in porphyrin ring.
Pheophytin forms

3. At what pH is benzoic acid most effective?
pH 3-5
An enzyme that converts hydrogen peroxide to water plus oxygen.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Primary butyric acid also caproic acid.

4. Alar is the trade name for what chemical compound?
Olive Green
Daminozide
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
Speed of Light

5. Is a disaccharide
Sucrose
Phenophylin
Fructose
Onions ( or leeks)

6. What two common compounds are used together as an antioxidative system?
Fatty Acid and Alcohol
Pectin methylesterase & polygalacturonase
Nucleation or crystal formation and crystal growth.
Ascorbic Acid and Citric Acid

7. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Negative log of the hydrogen concentration (mol/l).
Fatty Acid and Alcohol
pH 3-5
Two aldehydes

8. How many carbon atoms are there in the fatty acid myristic acid?
Emulsoids
Emulsification
14
Capsaicin

9. What is the geometric configuration of double bonds in most natural fatty acids?
pH 3-5
Cis
Troponins and Tropomyosin
Olive Green

10. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
RNA transcribed to DNA
DNA transferred by cell to cell contact (bacterial sex).
Carmelization and Maillard

11. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Yellow
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
They act as catalysts - speeding the polymerization of acrylamide.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

12. What two enzymes degrade pectic substances?
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
45% - 52% - 90%
Pectin methylesterase & polygalacturonase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

13. What does the saponification value measure and how is it measured?
Polyphenols
Fat Oxidation
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
An enzyme that converts hydrogen peroxide to water plus oxygen.

14. Will lipid oxidation be higher at a water activity of .05 or .5?
Whole Milk
.05
Onions ( or leeks)
Capsaicin

15. How can a molecular weight of protein - DNA - and RNA be determined?
14
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
No

16. Name 5 chelating agents used in the food industry.
Initiation - Propagation - and Termination
Glycosides of anthocyanidins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Gliadins and Glutenins

17. What does the acronym NPN stand for?
NaCl (it dissociated to a 2M solution)
Non-protein nitrogen
Pectin methylesterase & polygalacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.

18. Name three factors useful in controlling enzyme activity.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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)

19. What is the fundamental driving of electrophoresis?
Acetoin
Initiation - Propagation - and Termination
The speed of a molecule is proportional to the surrounding voltage gradient.
Thermus Aqauticus

20. How does HPLC differ from FPLC?
Polyphenol Oxidase
HPLC has higher pressure than FPLC
DNA transferred by cell to cell contact (bacterial sex).
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

21. Alar is the trade name for what chemical compound?
No
Daminozide
Nucleation or crystal formation and crystal growth.
Phenophylin

22. What are colloids that are stabilized by a layer of solvation called?
Chitin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Phenophylin
Emulsoids

23. 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?
Acetoin
.05 M HCL
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.
Orange Juice

24. Name two non-enzymatic browning reactions.
Carmelization and Maillard
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.
Speed of Light
NaCl (it dissociated to a 2M solution)

25. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
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.
Primary butyric acid also caproic acid.
Carrageenan
.05 M HCL

26. What two types of compounds are joined with an ester bond to make a wax?
Anthocyanins
Racemic Mixture
Fatty Acid and Alcohol
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

27. What is the fundamental driving of electrophoresis?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
The speed of a molecule is proportional to the surrounding voltage gradient.
Ammonia - Water - Carbon Dioxide
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

28. What is the acid present in fish oil?
Tryptophan
Arachidonic Acid
They act as catalysts - speeding the polymerization of acrylamide.
Degradation of protein and production of acid from sugar at the same time.

29. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Cis
Osmosis
Yes

30. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
Pectins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
2.5

31. What toxic pigment is found in cottonseed endosperm?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
.05 M HCL
Degradation of protein and production of acid from sugar at the same time.
Gossypol (it is removed during the oil refining process)

32. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Racemic Mixture
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Osmosis

33. What two types of compounds are joined with an ester bond to make a wax?
Fat Oxidation
Initiation - Propagation - and Termination
Acetoin
Fatty Acid and Alcohol

34. What is the name given to a mixture of equal parts of Darel Lisomers?
Daminozide
Arachidonic Acid
Emulsification
Racemic Mixture

35. What is the protein efficiency ratio (PER) of casein?
Nucleation or crystal formation and crystal growth.
2.5
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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

36. In what food is butyric acid typically found?
Daminozide
Milk
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Bright green

37. What is the protein efficiency ratio (PER) of casein?
Tryptophan
Emulsification
2.5
Sodium bicarbonate generates CO2

38. What are 3 mesomorphic structures associated with lipids in the liquid state?
pH 3-5
Phenylketonuria
Lamellar; Hexagonal I - II; Cubic
Initiation - Propagation - and Termination

39. Does kosmotrophil ion discourage water structure?
No
20 carbons and 4 double bonds
Phenophylin
Browning of freshly cut surfaces of fruits and vegetables.

40. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Polyphenol Oxidase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
An enzyme that converts hydrogen peroxide to water plus oxygen.

41. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Thamautin
Browning of freshly cut surfaces of fruits and vegetables.
Anomeric
Olive Green

42. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
Glycosides of anthocyanidins
ERH=100 x Aw
Emulsoids

43. Name three nonpolar polar - and charged amino acids.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Speed of Light
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
pH below positive charge; pH at no charge; pH above negative charge

44. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
Two aldehydes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bitter
HPLC has higher pressure than FPLC

45. What are the three main steps in the autooxidation of lipids?
Pheophytin forms
Initiation - Propagation - Termination
Fat Oxidation
Gliadins and Glutenins

46. What is a polymorphism?
Daminozide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thamautin
Racemic Mixture

47. What is the acid present in fish oil?
Olive Green
Fat Oxidation
Arachidonic Acid
Plasmids

48. How do sodium chloride and sucrose affect foam stability?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
RNA transcribed to DNA
D: None of the above
Sodium chloride reduces foam stability and sucrose improves foam stability.

49. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Onions ( or leeks)
Polyphenoloxidase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Initiation - Propagation - and Termination

50. What is Ohm's Law and What is Power Equation?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
It explodes
V=IR and P=VI or I x I x are
Emulsoids