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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name the two components that comprise the relaxing factor in muscle fibers.
Pectin methyl esterase or galacturonase
D: None of the above
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.
Troponins and Tropomyosin

2. Name three nonpolar polar - and charged amino acids.
1 - 3 - 7-trimethylxanthine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

3. What metabolic end product does the Voges-Proskauer test detect?
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.
Acetoin
Aspartic Acid and Phenylalanine
Fat Oxidation

4. 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?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Degradation of protein and production of acid from sugar at the same time.
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.
Pectin methylesterase & polygalacturonase

5. How does ERH relate to water activity?
Pectins
Polyphenoloxidase
ERH=100 x Aw
Polyphenoloxidase

6. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Emulsification
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

7. What is the enzyme responsible for browning in apples and lettuce?
Polyphenoloxidase
Polyphenol Oxidase
Bitter
Initiation - Propagation - Termination

8. What charge will a protein have when the pH of its solution is below at - and above its pKa?
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.
Pheophytin forms
pH below positive charge; pH at no charge; pH above negative charge
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

9. Name two main gluten proteins.
Polyphenol Oxidase
Gliadins and Glutenins
Lycopenes
Yes

10. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Cis
Pectin Esterase
Olive Green
14

11. What effect would the addition of sodium bicarbonate have to chocolate?
Polyphenol Oxidase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Degradation of protein and production of acid from sugar at the same time.

12. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Degradation of protein and production of acid from sugar at the same time.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH below positive charge; pH at no charge; pH above negative charge

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?
.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.
Whole Milk
Pectin methylesterase & polygalacturonase

14. Name two enzymes that are involved in softening fruits.
Arachidonic Acid
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin Esterase - Polygalacturonase - Pectin Layase

15. Name one way foam stability can be assessed.
D: None of the above
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.
V=IR and P=VI or I x I x are
Covalent (strongest) and Hydrophobic (Weakest)

16. What happens to chlorophyll on heating?
Initiation - Propagation - and Termination
Pheophytin forms
Linoleic Acid
Browning of freshly cut surfaces of fruits and vegetables.

17. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Bright green
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.
V=IR and P=VI or I x I x are
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

18. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Chlocophyllide does not have a phytoltail
Bitter
Emulsification

19. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
The speed of a molecule is proportional to the surrounding voltage gradient.
Pectin Esterase
Emulsoids

20. What is the fundamental driving of electrophoresis?
.05 M HCL
The speed of a molecule is proportional to the surrounding voltage gradient.
ERH=100 x Aw
pH 3-5

21. Name 3 chemical agents capable of denaturing proteins.
Pectins
Daminozide
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Sodium bicarbonate generates CO2

22. In genetics What is conjugation?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Bright green
DNA transferred by cell to cell contact (bacterial sex).
Oil in Water

23. What is the acid present in fish oil?
Arachidonic Acid
Parabens
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

24. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Thermus Aqauticus
Milk
pH below positive charge; pH at no charge; pH above negative charge

25. What is the structural difference between chlorophyll and pheophytia?
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.
20 carbons and 4 double bonds
Pheophytia does not have magnesium in porphyrin ring.

26. At low water activity What is the main deteriorative concern?
Chitin
Blue pigment in flowers
Lipid oxidation
Onions ( or leeks)

27. What is the main class of color compounds found in raspberries?
Capsaicin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Anthocyanins

28. 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.
Initiation - Propagation - and Termination
Linoleic Acid
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

29. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
.05

30. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
They act as catalysts - speeding the polymerization of acrylamide.
D: None of the above
45% - 52% - 90%

31. 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.
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
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.
A concentrate of microfibrillar proteins of fish muscle.

32. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Speed of Light
Pheophytin forms
It explodes
Phenylketonuria

33. What is the geometric configuration of double bonds in most natural fatty acids?
Lamellar; Hexagonal I - II; Cubic
Cis
Lysine - Arginine - and Histidine
Olive Green

34. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Osmosis
Carrageenan

35. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
V=IR and P=VI or I x I x are
Non-protein nitrogen
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.

36. What does Acid Degree Value measure and how is it measured?
Orange Juice
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
pH 3-5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

37. What two common compounds are used together as an antioxidative system?
Orange Juice
Bright green
Prolamines
Ascorbic Acid and Citric Acid

38. What toxic pigment is found in cottonseed endosperm?
Chitin
Aspartic Acid and Phenylalanine
Gossypol (it is removed during the oil refining process)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

39. What does the acronym NPN stand for?
Prolamines
14
Anomeric
Non-protein nitrogen

40. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Initiation - Propagation - Termination
Bitter
Gossypol (it is removed during the oil refining process)
Yes

41. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
.05
D: None of the above
Degradation of protein and production of acid from sugar at the same time.

42. What are the three stages of oxidative rancidity?
.05
Lamellar; Hexagonal I - II; Cubic
Initiation - Propagation - and Termination
Phenylketonuria

43. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
NaCl (it dissociated to a 2M solution)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

44. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Thickener in foods
Whole Milk
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

45. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Carmelization and Maillard
pH below positive charge; pH at no charge; pH above negative charge
The speed of a molecule is proportional to the surrounding voltage gradient.

46. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Thermus Aqauticus
14
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

47. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Glycosides of anthocyanidins
Thamautin
Daminozide
Pectins

48. What is surimi?
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.
Non-protein nitrogen
A concentrate of microfibrillar proteins of fish muscle.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

49. Name a commonly used household chemical leavening agent and the gas it generates.
Olive Green
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Sodium bicarbonate generates CO2
Nucleation or crystal formation and crystal growth.

50. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Yellow