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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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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. How can a molecular weight of protein - DNA - and RNA be determined?
Polyphenols
Plasmids
Arachidonic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

2. What is the name given to a mixture of equal parts of Darel Lisomers?
Polyphenol Oxidase
20 carbons and 4 double bonds
Onions ( or leeks)
Racemic Mixture

3. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Initiation - Propagation - Termination
Four
Yes

4. Name three effects of protein denaturation.
2.5
RNA transcribed to DNA
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Fatty Acid (Ester linked) to Fatty Alcohol

5. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
Lycopenes
Fatty Acid and Alcohol
Two aldehydes

6. What are the primary secondary - tertiary - and quaternary structures?
Lycopenes
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
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.
45% - 52% - 90%

7. What does Reichert-Meissert Number measure?
Orange Juice
Primary butyric acid also caproic acid.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Emulsoids

8. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Bright green
Cis
They act as catalysts - speeding the polymerization of acrylamide.
D: None of the above

9. What metabolic end product does the Voges-Proskauer test detect?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Olive Green
Acetoin
2.5

10. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Erythorbic Acid
14
.05 M HCL

11. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Oil in Water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Racemic Mixture
Bitter

12. At what pH is benzoic acid most effective?
pH 3-5
Daminozide
Lycopenes
Gliadins and Glutenins

13. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Polyphenols
Chitin
Pectins
Onions ( or leeks)

14. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Initiation - Propagation - and Termination
Fatty Acid and Alcohol
Orange Juice
Gossypol (it is removed during the oil refining process)

15. Define molarity molality - and normality.
Initiation - Propagation - and Termination
Emulsoids
Sweet - Salty - Sour - and Bitter
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

16. 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?
20 carbons and 4 double bonds
Cis
.05 M HCL
Linoleic Acid

17. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
NaCl (it dissociated to a 2M solution)
Prolamines
Primary butyric acid also caproic acid.
Plasmids

18. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Cis
Gossypol (it is removed during the oil refining process)
Initiation - Propagation - Termination
Polyphenoloxidase

19. What ketohexose is most significant to food chemists?
Racemic Mixture
pH 3-5
No
Fructose

20. What is the protein efficiency ratio (PER) of casein?
Emulsification
2.5
Fatty Acid (Ester linked) to Fatty Alcohol
Emulsoids

21. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Cis
Phenylketonuria
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

22. Peptide bond formation results in the formation of what secondary compound?
Carmelization and Maillard
Water
Pectin Esterase
20 carbons and 4 double bonds

23. What two types of compounds are joined with an ester bond to make a wax?
Phenylketonuria
V=IR and P=VI or I x I x are
Fatty Acid and Alcohol
Fat Oxidation

24. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Two aldehydes
Browning of freshly cut surfaces of fruits and vegetables.
Oil in Water
Bright green

25. Name the most common functional property of phospholipids in food systems.
Emulsification
Plasmids
Sodium chloride reduces foam stability and sucrose improves foam stability.
Carmelization and Maillard

26. Define molarity molality - and normality.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Pectin Esterase - Polygalacturonase - Pectin Layase
Pectin methyl esterase or galacturonase
Ammonia - Water - Carbon Dioxide

27. What are the four basic flavors perceived by the tongue?
Pectins
ERH=100 x Aw
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Sweet - Salty - Sour - and Bitter

28. What is an isomer that is cheaper than Vitamin C?
Cis
Erythorbic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

29. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Phenophylin
Troponins and Tropomyosin
Linoleic Acid

30. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Browning of freshly cut surfaces of fruits and vegetables.
Pectins
Degradation of protein and production of acid from sugar at the same time.

31. What is the structural difference between chlorophyll and pheophytia?
Thamautin
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenol Oxidase
Pheophytia does not have magnesium in porphyrin ring.

32. What are 3 mesomorphic structures associated with lipids in the liquid state?
Browning of freshly cut surfaces of fruits and vegetables.
Aspartic Acid and Phenylalanine
Lamellar; Hexagonal I - II; Cubic
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

33. Is a disaccharide
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Sucrose
Yellow
Pectin methyl esterase or galacturonase

34. Name one way foam stability can be assessed.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Gossypol (it is removed during the oil refining process)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
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.

35. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Emulsoids
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Yellow
pH below positive charge; pH at no charge; pH above negative charge

36. Name 3 factors influencing the consistency of commercial fats.
Emulsoids
HPLC has higher pressure than FPLC
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

37. Which two amino acids is the aspartame derived from?
Anomeric
Fatty Acid and Alcohol
Aspartic Acid and Phenylalanine
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.

38. Name the strongest biochemical bond and the weakest biochemical bond.
Water
Aspartic Acid and Phenylalanine
Covalent (strongest) and Hydrophobic (Weakest)
Four

39. Name two non-enzymatic browning reactions.
Lipid oxidation
ERH=100 x Aw
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
Carmelization and Maillard

40. What does the iodine value measure and how is it measured?
NaCl (it dissociated to a 2M solution)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Oil in Water
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.

41. What are the three main steps in the autooxidation of lipids?
Plasmids
pH 3-5
Erythorbic Acid
Initiation - Propagation - Termination

42. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Whole Milk
Negative log of the hydrogen concentration (mol/l).

43. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Blue pigment in flowers
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Onions ( or leeks)

44. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectins
Yellow

45. What are the primary secondary - tertiary - and quaternary structures?
20 carbons and 4 double bonds
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.
Osmosis
Monosodium Glutamate

46. Alar is the trade name for what chemical compound?
Daminozide
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.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

47. What is the protein efficiency ratio (PER) of casein?
Sweet - Salty - Sour - and Bitter
45% - 52% - 90%
2.5
It explodes

48. Alar is the trade name for what chemical compound?
Onions ( or leeks)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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.
Daminozide

49. What does MSG stand for?
Initiation - Propagation - Termination
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Monosodium Glutamate
Blue pigment in flowers

50. Name two non-enzymatic browning reactions.
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
Pheophytia does not have magnesium in porphyrin ring.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Carmelization and Maillard