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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. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
pH 3-5
Polyphenol Oxidase
Thermus Aqauticus
Two aldehydes

2. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Browning of freshly cut surfaces of fruits and vegetables.
Speed of Light
Racemic Mixture
Plasmids

3. What does the iodine value measure and how is it measured?
Speed of Light
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Aspartic Acid and Phenylalanine
Osmosis

4. What does the iodine value measure and how is it measured?
Linoleic Acid
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Pectin Esterase - Polygalacturonase - Pectin Layase
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.

5. What are two common reducing agents that break disulfide bonds in proteins?
.05 M HCL
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
.05 M HCL

6. What is acid proteolysis?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Nucleation or crystal formation and crystal growth.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Degradation of protein and production of acid from sugar at the same time.

7. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
D: None of the above
Water
Parabens

8. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
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.
Thickener in foods

9. What is the enzyme responsible for browning in apples and lettuce?
RNA transcribed to DNA
Osmosis
Polyphenol Oxidase
Thickener in foods

10. What ketohexose is most significant to food chemists?
Fructose
Tryptophan
pH below positive charge; pH at no charge; pH above negative charge
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

11. How can a molecular weight of protein - DNA - and RNA be determined?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lysine - Arginine - and Histidine
Pectin methyl esterase or galacturonase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

12. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Emulsoids
Degradation of protein and production of acid from sugar at the same time.
pH below positive charge; pH at no charge; pH above negative charge
Speed of Light

13. 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?
Degradation of protein and production of acid from sugar at the same time.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
.05 M HCL
Phenophylin

14. Will lipid oxidation be higher at a water activity of .05 or .5?
NaCl (it dissociated to a 2M solution)
Prolamines
.05
Whole Milk

15. What are the limiting amino acids in corn - potato - and green peas?
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.
A concentrate of microfibrillar proteins of fish muscle.
Yellow
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

16. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Oil in Water
Orange Juice
Four
Capsaicin

17. Does kosmotrophil ion discourage water structure?
No
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
RNA transcribed to DNA
Orange Juice

18. What is the Peroxide Value a measure of?
Bright green
Fat Oxidation
Pectin methylesterase & polygalacturonase
2.5

19. What two enzymes degrade pectic substances?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Capsaicin
Pectin methylesterase & polygalacturonase
Sodium chloride reduces foam stability and sucrose improves foam stability.

20. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Racemic Mixture
Water

21. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Polyphenol Oxidase
Thermus Aqauticus
Chitin
It explodes

22. What are the three main steps in the autooxidation of lipids?
Polyphenoloxidase
Initiation - Propagation - Termination
.05 M HCL
Acetoin

23. What are the fructose contents in commercial HFCS products.
Two aldehydes
Initiation - Propagation - and Termination
NaCl (it dissociated to a 2M solution)
45% - 52% - 90%

24. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
45% - 52% - 90%
NaCl (it dissociated to a 2M solution)
Polyphenoloxidase
Anomeric

25. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Phenophylin
Pectin Esterase
Parabens

26. What is the major color compound in tomatoes?
RNA transcribed to DNA
Lycopenes
V=IR and P=VI or I x I x are
pH below positive charge; pH at no charge; pH above negative charge

27. Peptide bond formation results in the formation of what secondary compound?
Gliadins and Glutenins
Daminozide
Water
NaCl (it dissociated to a 2M solution)

28. During freezing What are the two stages in the crystallization process?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Nucleation or crystal formation and crystal growth.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Arachidonic Acid

29. What are the three main steps in the autooxidation of lipids?
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
Initiation - Propagation - Termination
Prolamines

30. Name the most common functional property of phospholipids in food systems.
Emulsification
DNA transferred by cell to cell contact (bacterial sex).
Cis
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

31. Alar is the trade name for what chemical compound?
Daminozide
Arachidonic Acid
Ascorbic Acid and Citric Acid
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.

32. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
14
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
HPLC has higher pressure than FPLC

33. What are the four basic flavors perceived by the tongue?
Phenophylin
Sweet - Salty - Sour - and Bitter
14
Emulsification

34. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
RNA transcribed to DNA
Pectins
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

35. Name 3 chemical agents capable of denaturing proteins.
Polyphenoloxidase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Thermus Aqauticus
Initiation - Propagation - and Termination

36. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Primary butyric acid also caproic acid.
Bitter
Glycosides of anthocyanidins

37. Alar is the trade name for what chemical compound?
1 - 3 - 7-trimethylxanthine
Fructose
Daminozide
Initiation - Propagation - Termination

38. What are the primary secondary - tertiary - and quaternary structures?
Daminozide
pH 3-5
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.
A concentrate of microfibrillar proteins of fish muscle.

39. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Osmosis
Gliadins and Glutenins
A concentrate of microfibrillar proteins of fish muscle.
Bright green

40. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Bright green
Linoleic Acid
NaCl (it dissociated to a 2M solution)
Emulsoids

41. Define molarity molality - and normality.
Daminozide
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
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Water

42. In the enzyme Taq Polymerase What does Taq stand for?
Anthocyanins
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Thermus Aqauticus
Four

43. What does the 'c' stand for in the equation E=mc2?
Thickener in foods
Linoleic Acid
Speed of Light
Browning of freshly cut surfaces of fruits and vegetables.

44. What is acid proteolysis?
Yes
Fructose
It explodes
Degradation of protein and production of acid from sugar at the same time.

45. 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?
.05 M HCL
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
45% - 52% - 90%

46. What are proteins which are soluble in 50-80% ethanol known as?
Non-protein nitrogen
Prolamines
Lipase
Lysine - Arginine - and Histidine

47. What is the name given to a mixture of equal parts of Darel Lisomers?
Pectins
Nucleation or crystal formation and crystal growth.
Racemic Mixture
HPLC has higher pressure than FPLC

48. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
Water
Sodium bicarbonate generates CO2
14

49. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Polyphenol Oxidase
Negative log of the hydrogen concentration (mol/l).
Lipase

50. Does kosmotrophil ion discourage water structure?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipid oxidation
No
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.