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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 is Carboxy-methyl cellulose often used for?
Anomeric
45% - 52% - 90%
Water
Thickener in foods

2. Name the most common functional property of phospholipids in food systems.
Yes
Carrageenan
Emulsification
Lipase

3. What compounds oxidize to form brown color in fruits and vegetables?
No
Polyphenols
Fructose
Chitin

4. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
.05
Covalent (strongest) and Hydrophobic (Weakest)
V=IR and P=VI or I x I x are

5. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Sodium bicarbonate generates CO2
Pheophytia does not have magnesium in porphyrin ring.

6. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
Browning of freshly cut surfaces of fruits and vegetables.
Primary butyric acid also caproic acid.
Gliadins and Glutenins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

7. What ketohexose is most significant to food chemists?
Ammonia - Water - Carbon Dioxide
Thamautin
Fructose
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

8. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Thamautin
Pectin methyl esterase or galacturonase
Fatty Acid and Alcohol
pH 3-5

9. What is an isomer that is cheaper than Vitamin C?
It explodes
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.
Erythorbic Acid
Pheophytia does not have magnesium in porphyrin ring.

10. Name three non-nutritive sweeteners approved for use in USA?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pectin methyl esterase or galacturonase
Acsulfame-K - Saccharin - Cyclamate - Aspartame

11. Name two reasons why fats are hydrogenated.
Lipase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
2.5
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

12. Waxes are composed of what two basic chemical entities?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Gliadins and Glutenins
Tryptophan
Fatty Acid (Ester linked) to Fatty Alcohol

13. Alar is the trade name for what chemical compound?
Ammonia - Water - Carbon Dioxide
Fatty Acid (Ester linked) to Fatty Alcohol
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Daminozide

14. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Fat Oxidation
Fat Oxidation
.05

15. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Lysine - Arginine - and Histidine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin methyl esterase or galacturonase
Negative log of the hydrogen concentration (mol/l).

16. What is the winterization process for an oil?
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.
Sodium bicarbonate generates CO2
Thickener in foods
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

17. Name 3 factors influencing the consistency of commercial fats.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Browning of freshly cut surfaces of fruits and vegetables.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

18. How does ERH relate to water activity?
HPLC has higher pressure than FPLC
Anthocyanins
Bitter
ERH=100 x Aw

19. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Four
Prolamines
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Tryptophan

20. What does HLB stand for and What does a high and low HLB value indicate?
Fatty Acid (Ester linked) to Fatty Alcohol
Emulsification
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.
Cis

21. What are 3 mesomorphic structures associated with lipids in the liquid state?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Lamellar; Hexagonal I - II; Cubic
pH below positive charge; pH at no charge; pH above negative charge
Orange Juice

22. During freezing What are the two stages in the crystallization process?
.05
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Nucleation or crystal formation and crystal growth.
Fatty Acid and Alcohol

23. Name three nonpolar polar - and charged amino acids.
Sodium bicarbonate generates CO2
Emulsoids
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Water

24. In what food is butyric acid typically found?
Bright green
Milk
Monosodium Glutamate
Negative log of the hydrogen concentration (mol/l).

25. What is the Peroxide Value a measure of?
RNA transcribed to DNA
V=IR and P=VI or I x I x are
Fat Oxidation
Monosodium Glutamate

26. What does the acronym NPN stand for?
Daminozide
Initiation - Propagation - and Termination
Browning of freshly cut surfaces of fruits and vegetables.
Non-protein nitrogen

27. How is pH defined?
Ascorbic Acid and Citric Acid
Daminozide
Polyphenol Oxidase
Negative log of the hydrogen concentration (mol/l).

28. What is the major color compound in tomatoes?
Lycopenes
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of 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.
They act as catalysts - speeding the polymerization of acrylamide.

29. Contains the lowest content of water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Whole Milk
Sodium bicarbonate generates CO2
Monosodium Glutamate

30. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
NaCl (it dissociated to a 2M solution)
A concentrate of microfibrillar proteins of fish muscle.

31. Name three effects of protein denaturation.
1 - 3 - 7-trimethylxanthine
Lysine - Arginine - and Histidine
Sucrose
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

32. Name 5 proteins with good foaming properties.
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.
Fructose
ERH=100 x Aw
Monosodium Glutamate

33. Name the strongest biochemical bond and the weakest biochemical bond.
Sweet - Salty - Sour - and Bitter
Bitter
Covalent (strongest) and Hydrophobic (Weakest)
Onions ( or leeks)

34. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Oil in Water
Bitter
RNA transcribed to DNA

35. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Oil in Water
They act as catalysts - speeding the polymerization of acrylamide.
Capsaicin
20 carbons and 4 double bonds

36. 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.
Fatty Acid (Ester linked) to Fatty Alcohol
Pectins
Aspartic Acid and Phenylalanine

37. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
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
Lamellar; Hexagonal I - II; Cubic
Osmosis

38. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
A concentrate of microfibrillar proteins of fish muscle.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Yellow

39. What two enzymes degrade pectic substances?
Lipid oxidation
Pectin methylesterase & polygalacturonase
Two aldehydes
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

40. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
DNA transferred by cell to cell contact (bacterial sex).
Glycosides of anthocyanidins
Plasmids

41. Contains the lowest content of water
The speed of a molecule is proportional to the surrounding voltage gradient.
Whole Milk
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Blue pigment in flowers

42. What does the 'c' stand for in the equation E=mc2?
Polyphenols
Lycopenes
Speed of Light
.05 M HCL

43. 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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Water
Fatty Acid and Alcohol
Whole Milk

44. What pigment was first designated as anthocyanins?
Phenylketonuria
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Blue pigment in flowers

45. Name the three positively charged amino acids.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lysine - Arginine - and Histidine
Lipase

46. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Carrageenan
Parabens
Thickener in foods
Pectins

47. What are the fructose contents in commercial HFCS products.
Whole Milk
Blue pigment in flowers
Bright green
45% - 52% - 90%

48. At what pH is benzoic acid most effective?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Onions ( or leeks)
pH 3-5
Lysine - Arginine - and Histidine

49. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Olive Green
Daminozide
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Bitter

50. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
DNA transferred by cell to cell contact (bacterial sex).
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.