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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 ketohexose is most significant to food chemists?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Thamautin
Fructose

2. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
1 - 3 - 7-trimethylxanthine
Lysine - Arginine - and Histidine
Thamautin

3. What are the three stages of oxidative rancidity?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Initiation - Propagation - and Termination
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectins

4. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Cis
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Prolamines

5. How many carbon atoms and how many double bonds are there in arachidonic acid?
Speed of Light
The speed of a molecule is proportional to the surrounding voltage gradient.
20 carbons and 4 double bonds
Lipase

6. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Blue pigment in flowers
Pectin methyl esterase or galacturonase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Two aldehydes

7. How many carbon atoms are there in the fatty acid myristic acid?
Fat Oxidation
Pectins
14
45% - 52% - 90%

8. 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.
Orange Juice
Olive Green
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

9. What two common compounds are used together as an antioxidative system?
Thermus Aqauticus
20 carbons and 4 double bonds
Ascorbic Acid and Citric Acid
Fructose

10. Contains the lowest content of water
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.
Whole Milk
Milk
.05 M HCL

11. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Aspartic Acid and Phenylalanine
Initiation - Propagation - and Termination
Thermus Aqauticus

12. What is the enzyme that softens tomatoes?
Plasmids
Pectin Esterase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
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.

13. 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.
Pheophytin forms
Sweet - Salty - Sour - and Bitter
Four

14. Name three factors useful in controlling enzyme activity.
Polyphenol Oxidase
Degradation of protein and production of acid from sugar at the same time.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Initiation - Propagation - and Termination

15. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Osmosis
pH 3-5
Bitter
Orange Juice

16. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Osmosis
Lamellar; Hexagonal I - II; Cubic
Water

17. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
Bright green
Acetoin
14

18. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Sucrose
Thickener in foods
Aspartic Acid and Phenylalanine

19. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Sweet - Salty - Sour - and Bitter
Pheophytia does not have magnesium in porphyrin ring.
DNA transferred by cell to cell contact (bacterial sex).
Bright green

20. What are proteins which are soluble in 50-80% ethanol known as?
Racemic Mixture
Prolamines
pH below positive charge; pH at no charge; pH above negative charge
A concentrate of microfibrillar proteins of fish muscle.

21. What are the primary secondary - tertiary - and quaternary structures?
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.
Plasmids
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
NaCl (it dissociated to a 2M solution)

22. What is the Peroxide Value a measure of?
Polyphenol Oxidase
Racemic Mixture
Non-protein nitrogen
Fat Oxidation

23. Define molarity molality - and normality.
Pheophytin forms
Bright green
Polyphenol Oxidase
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

24. What pigment was first designated as anthocyanins?
Blue pigment in flowers
It explodes
Bitter
Tryptophan

25. What does the acronym NPN stand for?
Olive Green
Emulsoids
Pectin methylesterase & polygalacturonase
Non-protein nitrogen

26. What does HLB stand for and What does a high and low HLB value indicate?
Pheophytin forms
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.
Glycosides of anthocyanidins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

27. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
45% - 52% - 90%
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

28. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
V=IR and P=VI or I x I x are
RNA transcribed to DNA
Four
Polyphenol Oxidase

29. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Speed of Light
Pectins
Water
Carrageenan

30. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Covalent (strongest) and Hydrophobic (Weakest)

31. How many polypeptide chains make up an antibody?
It explodes
Prolamines
Four
Browning of freshly cut surfaces of fruits and vegetables.

32. Name the two components that comprise the relaxing factor in muscle fibers.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Troponins and Tropomyosin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Gossypol (it is removed during the oil refining process)

33. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Polyphenol Oxidase
Phenylketonuria
Yes
RNA transcribed to DNA

34. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
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.
RNA transcribed to DNA
Olive Green
Carrageenan

35. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
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
Carrageenan
Two aldehydes

36. What is catalase?
Emulsification
RNA transcribed to DNA
Sodium bicarbonate generates CO2
An enzyme that converts hydrogen peroxide to water plus oxygen.

37. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
20 carbons and 4 double bonds
.05

38. What is Ohm's Law and What is Power Equation?
Nucleation or crystal formation and crystal growth.
Phenylketonuria
Lysine - Arginine - and Histidine
V=IR and P=VI or I x I x are

39. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Acetoin
Polyphenoloxidase
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.
Sweet - Salty - Sour - and Bitter

40. Name 5 chelating agents used in the food industry.
Chlocophyllide does not have a phytoltail
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Prolamines
Chlocophyllide does not have a phytoltail

41. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
Non-protein nitrogen
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
pH 3-5
Yellow

42. How does ERH relate to water activity?
ERH=100 x Aw
Chitin
No
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

43. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
A concentrate of microfibrillar proteins of fish muscle.
Oil in Water
Anomeric
They act as catalysts - speeding the polymerization of acrylamide.

44. Name three nonpolar polar - and charged amino acids.
Anthocyanins
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Polyphenols
Glycosides of anthocyanidins

45. What is the main class of color compounds found in raspberries?
Prolamines
Anthocyanins
An enzyme that converts hydrogen peroxide to water plus oxygen.
Gossypol (it is removed during the oil refining process)

46. At what pH is benzoic acid most effective?
Degradation of protein and production of acid from sugar at the same time.
Bitter
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH 3-5

47. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
Gliadins and Glutenins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

48. What enzyme is most responsible for browning bananas?
Sucrose
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Primary butyric acid also caproic acid.
Polyphenol Oxidase

49. When heated ammonium bicarbonate decomposes to form what end products?
A concentrate of microfibrillar proteins of fish muscle.
Water
Ammonia - Water - Carbon Dioxide
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

50. Name one way foam stability can be assessed.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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.
Nucleation or crystal formation and crystal growth.
Oil in Water