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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 the chemical nature of anthocyanins?
Non-protein nitrogen
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Glycosides of anthocyanidins

2. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
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.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Daminozide

3. What are the four basic flavors perceived by the tongue?
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.
DNA transferred by cell to cell contact (bacterial sex).
Sweet - Salty - Sour - and Bitter
Acetoin

4. What two common compounds are used together as an antioxidative system?
Water
Pectins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Ascorbic Acid and Citric Acid

5. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Linoleic Acid
Fatty Acid (Ester linked) to Fatty Alcohol
Pectin methyl esterase or galacturonase
Plasmids

6. What metabolic end product does the Voges-Proskauer test detect?
Nucleation or crystal formation and crystal growth.
Degradation of protein and production of acid from sugar at the same time.
D: None of the above
Acetoin

7. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Oil in Water
2.5
Troponins and Tropomyosin

8. Name two non-enzymatic browning reactions.
Lycopenes
Carmelization and Maillard
Pectin methylesterase & polygalacturonase
Degradation of protein and production of acid from sugar at the same time.

9. What does HLB stand for and What does a high and low HLB value indicate?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Four
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.
Phenylketonuria

10. 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.
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)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

11. What is surimi?
Emulsification
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
A concentrate of microfibrillar proteins of fish muscle.
Pheophytia does not have magnesium in porphyrin ring.

12. How many polypeptide chains make up an antibody?
pH 3-5
Four
Milk
Ammonia - Water - Carbon Dioxide

13. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Gossypol (it is removed during the oil refining process)
It explodes
Lysine - Arginine - and Histidine

14. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Negative log of the hydrogen concentration (mol/l).
Bright green
Yes
Arachidonic Acid

15. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Thickener in foods
Lipid oxidation
Bitter
Prolamines

16. 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?
Pectin methyl esterase or galacturonase
Aspartic Acid and Phenylalanine
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Sucrose

17. Name the strongest biochemical bond and the weakest biochemical bond.
Water
Racemic Mixture
Oil in Water
Covalent (strongest) and Hydrophobic (Weakest)

18. What is the winterization process for an oil?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Capsaicin
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Fatty Acid (Ester linked) to Fatty Alcohol

19. 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
Milk
Primary butyric acid also caproic acid.
Pectin Esterase - Polygalacturonase - Pectin Layase

20. Name one way foam stability can be assessed.
Pectin Esterase - Polygalacturonase - Pectin Layase
Non-protein nitrogen
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.
Yellow

21. When heated ammonium bicarbonate decomposes to form what end products?
.05 M HCL
Troponins and Tropomyosin
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Ammonia - Water - Carbon Dioxide

22. 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?
It explodes
.05 M HCL
HPLC has higher pressure than FPLC
Plasmids

23. Name two main gluten proteins.
Gliadins and Glutenins
14
NaCl (it dissociated to a 2M solution)
They act as catalysts - speeding the polymerization of acrylamide.

24. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Yellow
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bright green

25. What are the four basic flavors perceived by the tongue?
Yellow
Sweet - Salty - Sour - and Bitter
Pectin Esterase
Acetoin

26. Contains the lowest content of water
Whole Milk
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Osmosis
Milk

27. What is the geometric configuration of double bonds in most natural fatty acids?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Cis
Initiation - Propagation - and Termination
Capsaicin

28. What ketohexose is most significant to food chemists?
Yes
Anomeric
Fructose
Daminozide

29. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Acetoin
Two aldehydes
Blue pigment in flowers
Speed of Light

30. What is acid proteolysis?
Pectin Esterase - Polygalacturonase - Pectin Layase
Monosodium Glutamate
Degradation of protein and production of acid from sugar at the same time.
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

31. What does the iodine value measure and how is it measured?
Fatty Acid (Ester linked) to Fatty Alcohol
Gossypol (it is removed during the oil refining process)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
V=IR and P=VI or I x I x are

32. What charge will a protein have when the pH of its solution is below at - and above its pKa?
RNA transcribed to DNA
pH below positive charge; pH at no charge; pH above negative charge
An enzyme that converts hydrogen peroxide to water plus oxygen.
Milk

33. What enzyme causes hyrolytic rancidity in milk?
Lipase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Initiation - Propagation - Termination
Plasmids

34. Will lipid oxidation be higher at a water activity of .05 or .5?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
.05
Bitter

35. Name one way foam stability can be assessed.
Pectin methylesterase & polygalacturonase
Covalent (strongest) and Hydrophobic (Weakest)
Glycosides of anthocyanidins
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.

36. What is an isomer that is cheaper than Vitamin C?
Milk
Erythorbic Acid
Thermus Aqauticus
Emulsoids

37. What is the structural difference between chlorophyll and pheophytia?
Degradation of protein and production of acid from sugar at the same time.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pheophytia does not have magnesium in porphyrin ring.

38. What does MSG stand for?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Polyphenols
Monosodium Glutamate
Fructose

39. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Thickener in foods
Two aldehydes
Olive Green

40. What is the main class of color compounds found in raspberries?
.05
Anthocyanins
NaCl (it dissociated to a 2M solution)
Gliadins and Glutenins

41. Name two non-enzymatic browning reactions.
Carrageenan
Carmelization and Maillard
Emulsoids
Racemic Mixture

42. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Parabens
DNA transferred by cell to cell contact (bacterial sex).

43. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Whole Milk
RNA transcribed to DNA
Phenophylin

44. What is the winterization process for an oil?
Thamautin
Emulsification
D: None of the above
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

45. How does ERH relate to water activity?
Sweet - Salty - Sour - and Bitter
ERH=100 x Aw
Negative log of the hydrogen concentration (mol/l).
2.5

46. How many carbon atoms are there in the fatty acid myristic acid?
Polyphenol Oxidase
V=IR and P=VI or I x I x are
14
Tryptophan

47. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
RNA transcribed to DNA
Onions ( or leeks)
Fatty Acid and Alcohol
Lamellar; Hexagonal I - II; Cubic

48. Name the two components that comprise the relaxing factor in muscle fibers.
Water
Troponins and Tropomyosin
Water
Fructose

49. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pectin methylesterase & polygalacturonase
Pheophytin forms
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Anomeric

50. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Acetoin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
45% - 52% - 90%