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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 does the saponification value measure and how is it measured?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
pH below positive charge; pH at no charge; pH above negative charge
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Thermus Aqauticus

2. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
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.
Browning of freshly cut surfaces of fruits and vegetables.
Lamellar; Hexagonal I - II; Cubic

3. 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?
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
.05 M HCL
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

4. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
DNA transferred by cell to cell contact (bacterial sex).
DNA transferred by cell to cell contact (bacterial sex).
Bitter
Pheophytia does not have magnesium in porphyrin ring.

5. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Yes
Pectins
Phenylketonuria
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

6. What does MSG stand for?
The speed of a molecule is proportional to the surrounding voltage gradient.
Monosodium Glutamate
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Cis

7. 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?
Water
Gossypol (it is removed during the oil refining process)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
.05 M HCL

8. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
NaCl (it dissociated to a 2M solution)
Olive Green
Initiation - Propagation - Termination

9. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Browning of freshly cut surfaces of fruits and vegetables.
Pectin methyl esterase or galacturonase
Oil in Water
They act as catalysts - speeding the polymerization of acrylamide.

10. At low water activity What is the main deteriorative concern?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Oil in Water
Aspartic Acid and Phenylalanine
Lipid oxidation

11. What is the acid present in fish oil?
Aspartic Acid and Phenylalanine
Emulsification
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Arachidonic Acid

12. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Cis
Anomeric
Thickener in foods
An enzyme that converts hydrogen peroxide to water plus oxygen.

13. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Yellow
Glycosides of anthocyanidins
Thamautin

14. What are the three stages of oxidative rancidity?
Carrageenan
Initiation - Propagation - and Termination
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

15. What is an isomer that is cheaper than Vitamin C?
Nucleation or crystal formation and crystal growth.
Emulsification
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Erythorbic Acid

16. How many polypeptide chains make up an antibody?
Four
V=IR and P=VI or I x I x are
Pectin Esterase - Polygalacturonase - Pectin Layase
Initiation - Propagation - and Termination

17. What is a polymorphism?
Fatty Acid and Alcohol
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Olive Green
Lipid oxidation

18. How many carbon atoms and how many double bonds are there in arachidonic acid?
Acetoin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Erythorbic Acid
20 carbons and 4 double bonds

19. Waxes are composed of what two basic chemical entities?
Yellow
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Fatty Acid (Ester linked) to Fatty Alcohol
Negative log of the hydrogen concentration (mol/l).

20. Does kosmotrophil ion discourage water structure?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lamellar; Hexagonal I - II; Cubic
Polyphenoloxidase
No

21. What is the winterization process for an oil?
Racemic Mixture
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
.05 M HCL
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

22. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
The speed of a molecule is proportional to the surrounding voltage gradient.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Capsaicin

23. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Thermus Aqauticus
DNA transferred by cell to cell contact (bacterial sex).
Monosodium Glutamate

24. What ketohexose is most significant to food chemists?
Thermus Aqauticus
Non-protein nitrogen
Fructose
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

25. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Prolamines
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Polyphenoloxidase
Yes

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
Acetoin
Arachidonic Acid
Cis

27. Name the strongest biochemical bond and the weakest biochemical bond.
Lipase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Covalent (strongest) and Hydrophobic (Weakest)
Acsulfame-K - Saccharin - Cyclamate - Aspartame

28. What is the Peroxide Value a measure of?
Polyphenoloxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Fat Oxidation
Monosodium Glutamate

29. Contains the lowest content of water
Whole Milk
The speed of a molecule is proportional to the surrounding voltage gradient.
Pheophytin forms
Daminozide

30. Alar is the trade name for what chemical compound?
Daminozide
Pectin Esterase - Polygalacturonase - Pectin Layase
RNA transcribed to DNA
Lamellar; Hexagonal I - II; Cubic

31. What effect would the addition of sodium bicarbonate have to chocolate?
They act as catalysts - speeding the polymerization of acrylamide.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
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.

32. Name two enzymes that are involved in softening fruits.
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.
Pectin Esterase - Polygalacturonase - Pectin Layase
Phenylketonuria
Troponins and Tropomyosin

33. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Anthocyanins
Osmosis
Nucleation or crystal formation and crystal growth.
Lipase

34. Alar is the trade name for what chemical compound?
Daminozide
Thamautin
Chitin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

35. 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
Chlocophyllide does not have a phytoltail
Aspartic Acid and Phenylalanine
An enzyme that converts hydrogen peroxide to water plus oxygen.

36. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Polyphenoloxidase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Acsulfame-K - Saccharin - Cyclamate - Aspartame

37. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Tryptophan
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Capsaicin

38. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Initiation - Propagation - Termination
Plasmids
Pheophytia does not have magnesium in porphyrin ring.

39. Alar is the trade name for what chemical compound?
Bright green
Oil in Water
Pectins
Daminozide

40. What is the structural difference between chlorophyll and chlocophyllide?
HPLC has higher pressure than FPLC
Chlocophyllide does not have a phytoltail
.05 M HCL
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

41. What enzyme causes hyrolytic rancidity in milk?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fat Oxidation

42. At low water activity What is the main deteriorative concern?
Lipid oxidation
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Linoleic Acid
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

43. Name a naturally occurring protein sweetener.
Prolamines
Blue pigment in flowers
RNA transcribed to DNA
Thamautin

44. What is the enzyme that softens tomatoes?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
DNA transferred by cell to cell contact (bacterial sex).
Pectin Esterase
Lysine - Arginine - and Histidine

45. In what food is butyric acid typically found?
Milk
Chitin
Lysine - Arginine - and Histidine
Lysine - Arginine - and Histidine

46. What does Reichert-Meissert Number measure?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Yes
Pectin methyl esterase or galacturonase
Primary butyric acid also caproic acid.

47. What does the acronym NPN stand for?
Yes
Non-protein nitrogen
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

48. What are the only phenols approved for use in the microbiological preservation of foods?
It explodes
Parabens
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

49. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Oil in Water
Glycosides of anthocyanidins

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