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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 3 factors influencing the consistency of commercial fats.
Lamellar; Hexagonal I - II; Cubic
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Orange Juice
Fat Oxidation

2. 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.
Four
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

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

4. How many polypeptide chains make up an antibody?
Racemic Mixture
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.
Arachidonic Acid
Four

5. Name a naturally occurring protein sweetener.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
D: None of the above
Thamautin
Troponins and Tropomyosin

6. What is the chemical nomenclature for caffeine?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
They act as catalysts - speeding the polymerization of acrylamide.
1 - 3 - 7-trimethylxanthine
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

7. What are soluble polymers of anhydro-galacturonic acid and its esters called?
ERH=100 x Aw
Emulsification
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectins

8. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Thickener in foods
Gliadins and Glutenins
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.
Onions ( or leeks)

9. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Anomeric
.05 M HCL
Polyphenols

10. What happens to chlorophyll on heating?
Racemic Mixture
Pectin Esterase - Polygalacturonase - Pectin Layase
Pheophytin forms
Erythorbic Acid

11. In the enzyme Taq Polymerase What does Taq stand for?
ERH=100 x Aw
Thermus Aqauticus
Covalent (strongest) and Hydrophobic (Weakest)
HPLC has higher pressure than FPLC

12. In the enzyme Taq Polymerase What does Taq stand for?
Emulsoids
Polyphenol Oxidase
Blue pigment in flowers
Thermus Aqauticus

13. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Aspartic Acid and Phenylalanine
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

14. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Nucleation or crystal formation and crystal growth.
Fatty Acid and Alcohol

15. What does the acronym NPN stand for?
Non-protein nitrogen
Nucleation or crystal formation and crystal growth.
Browning of freshly cut surfaces of fruits and vegetables.
DNA transferred by cell to cell contact (bacterial sex).

16. What enzyme causes hyrolytic rancidity in milk?
Yellow
Fatty Acid and Alcohol
Lipase
Bright green

17. Name three nonpolar polar - and charged amino acids.
Orange Juice
Pheophytia does not have magnesium in porphyrin ring.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

18. Name three non-nutritive sweeteners approved for use in USA?
20 carbons and 4 double bonds
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Milk

19. What is the major color compound in tomatoes?
Fructose
Lycopenes
Pheophytia does not have magnesium in porphyrin ring.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

20. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Primary butyric acid also caproic acid.
Monosodium Glutamate

21. What enzyme is most responsible for browning bananas?
Initiation - Propagation - Termination
Polyphenol Oxidase
Monosodium Glutamate
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

22. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
1 - 3 - 7-trimethylxanthine
Arachidonic Acid

23. Name the three positively charged amino acids.
Nucleation or crystal formation and crystal growth.
pH below positive charge; pH at no charge; pH above negative charge
Glycosides of anthocyanidins
Lysine - Arginine - and Histidine

24. What is the enzyme responsible for browning in apples and lettuce?
Speed of Light
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Chitin
Polyphenol Oxidase

25. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
2.5
Speed of Light
Water

26. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Lamellar; Hexagonal I - II; Cubic
Thickener in foods
.05
Capsaicin

27. What ketohexose is most significant to food chemists?
Troponins and Tropomyosin
14
Sucrose
Fructose

28. What are 3 mesomorphic structures associated with lipids in the liquid state?
Polyphenol Oxidase
Bitter
Lamellar; Hexagonal I - II; Cubic
Non-protein nitrogen

29. What is the structural difference between chlorophyll and pheophytia?
Yellow
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Blue pigment in flowers
Pheophytia does not have magnesium in porphyrin ring.

30. Define molarity molality - and normality.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Polyphenoloxidase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

31. Name one way foam stability can be assessed.
45% - 52% - 90%
Gliadins and Glutenins
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.
Emulsoids

32. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

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33. What does Acid Degree Value measure and how is it measured?
Whole Milk
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Cis
Pectin methyl esterase or galacturonase

34. What does Reichert-Meissert Number measure?
Linoleic Acid
Pheophytin forms
Emulsification
Primary butyric acid also caproic acid.

35. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Thamautin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Anomeric
A concentrate of microfibrillar proteins of fish muscle.

36. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Carrageenan
Lysine - Arginine - and Histidine
Fat Oxidation
Pectins

37. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Pectin methyl esterase or galacturonase
Olive Green
Browning of freshly cut surfaces of fruits and vegetables.
Bright green

38. What are the three main steps in the autooxidation of lipids?
Parabens
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Polyphenoloxidase
Initiation - Propagation - Termination

39. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Pectin Esterase
Anomeric
1 - 3 - 7-trimethylxanthine

40. What does the 'c' stand for in the equation E=mc2?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phenylketonuria
Speed of Light
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

41. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
.05
NaCl (it dissociated to a 2M solution)
Pectin Esterase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

42. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Aspartic Acid and Phenylalanine
Glycosides of anthocyanidins
Phenophylin
It explodes

43. 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
Polyphenoloxidase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipid oxidation

44. 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?
Negative log of the hydrogen concentration (mol/l).
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Capsaicin
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.

45. Name 3 factors influencing the rate of lipid oxidation in foods.
Lipid oxidation
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Milk
Polyphenols

46. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Aspartic Acid and Phenylalanine
Monosodium Glutamate
Glycosides of anthocyanidins
Pectin methyl esterase or galacturonase

47. Which two amino acids is the aspartame derived from?
Lipase
Olive Green
Aspartic Acid and Phenylalanine
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

48. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Sodium bicarbonate generates CO2
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Bitter
Linoleic Acid

49. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Anomeric
Olive Green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

50. Name 3 chemical agents capable of denaturing proteins.
Primary butyric acid also caproic acid.
Primary butyric acid also caproic acid.
Chitin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents