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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 structural difference between chlorophyll and chlocophyllide?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
1 - 3 - 7-trimethylxanthine
Degradation of protein and production of acid from sugar at the same time.
Chlocophyllide does not have a phytoltail

2. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Bright green
No
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

3. Name the three positively charged amino acids.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectin Esterase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lysine - Arginine - and Histidine

4. Name the two components that comprise the relaxing factor in muscle fibers.
Polyphenoloxidase
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
NaCl (it dissociated to a 2M solution)
Troponins and Tropomyosin

5. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Pectin methylesterase & polygalacturonase
Degradation of protein and production of acid from sugar at the same time.
Non-protein nitrogen
Phenylketonuria

6. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Racemic Mixture
The speed of a molecule is proportional to the surrounding voltage gradient.
Capsaicin
Fatty Acid (Ester linked) to Fatty Alcohol

7. Name three factors useful in controlling enzyme activity.
Polyphenol Oxidase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
14
pH 3-5

8. 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.
Lipase
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
Sodium bicarbonate generates CO2

9. What happens to chlorophyll on heating?
Polyphenol Oxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Pheophytin forms

10. Contains the lowest content of water
Two aldehydes
Acetoin
Whole Milk
Lipid oxidation

11. What toxic pigment is found in cottonseed endosperm?
HPLC has higher pressure than FPLC
Troponins and Tropomyosin
Osmosis
Gossypol (it is removed during the oil refining process)

12. 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?
Emulsoids
Daminozide
Covalent (strongest) and Hydrophobic (Weakest)
It explodes

13. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
20 carbons and 4 double bonds
They act as catalysts - speeding the polymerization of acrylamide.
Gossypol (it is removed during the oil refining process)
Emulsification

14. How is pH defined?
pH 3-5
HPLC has higher pressure than FPLC
An enzyme that converts hydrogen peroxide to water plus oxygen.
Negative log of the hydrogen concentration (mol/l).

15. What is catalase?
Thickener in foods
Oil in Water
An enzyme that converts hydrogen peroxide to water plus oxygen.
They act as catalysts - speeding the polymerization of acrylamide.

16. What does HLB stand for and What does a high and low HLB value indicate?
Troponins and Tropomyosin
Ascorbic Acid and Citric Acid
Carmelization and Maillard
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.

17. Name two enzymes that are involved in softening fruits.
Bright green
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
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Pectin Esterase - Polygalacturonase - Pectin Layase

18. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Chitin
Orange Juice
Carrageenan
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.

19. What is the main class of color compounds found in raspberries?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
They act as catalysts - speeding the polymerization of acrylamide.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Anthocyanins

20. How does ERH relate to water activity?
Arachidonic Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Browning of freshly cut surfaces of fruits and vegetables.
ERH=100 x Aw

21. Name 5 proteins with good foaming properties.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thermus Aqauticus
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.
No

22. Name one way foam stability can be assessed.
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.
Parabens
It explodes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

23. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Sucrose
Orange Juice
Phenylketonuria

24. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Initiation - Propagation - Termination
Olive Green
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Pectin Esterase

25. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
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
Orange Juice
Glycosides of anthocyanidins
Chlocophyllide does not have a phytoltail

26. Name one way foam stability can be assessed.
Erythorbic Acid
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.
Primary butyric acid also caproic acid.
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.

27. When heated ammonium bicarbonate decomposes to form what end products?
Browning of freshly cut surfaces of fruits and vegetables.
Ammonia - Water - Carbon Dioxide
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.

28. What does HLB stand for and What does a high and low HLB value indicate?
Chlocophyllide does not have a phytoltail
Milk
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.
V=IR and P=VI or I x I x are

29. Alar is the trade name for what chemical compound?
Lipid oxidation
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Daminozide
Lycopenes

30. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Troponins and Tropomyosin
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Nucleation or crystal formation and crystal growth.

31. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Lipase
Speed of Light
Whole Milk
Osmosis

32. What two enzymes degrade pectic substances?
Polyphenol Oxidase
Pectin methylesterase & polygalacturonase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
pH 3-5

33. Name three nonpolar polar - and charged amino acids.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Sucrose
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pectins

34. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Acetoin
Linoleic Acid
Pectin Esterase - Polygalacturonase - Pectin Layase
Nucleation or crystal formation and crystal growth.

35. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Oil in Water
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Tryptophan

36. Alar is the trade name for what chemical compound?
Fatty Acid (Ester linked) to Fatty Alcohol
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
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.
Daminozide

37. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Milk
Phenylketonuria
ERH=100 x Aw
Onions ( or leeks)

38. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
D: None of the above
Lamellar; Hexagonal I - II; Cubic
Orange Juice

39. Name two non-enzymatic browning reactions.
Polyphenol Oxidase
Carmelization and Maillard
Lipid oxidation
Parabens

40. What are the three stages of oxidative rancidity?
Thermus Aqauticus
Carmelization and Maillard
Initiation - Propagation - and Termination
Sweet - Salty - Sour - and Bitter

41. What is the geometric configuration of double bonds in most natural fatty acids?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Cis
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)

42. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin Esterase
Polyphenoloxidase

43. 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?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pheophytin forms
Daminozide
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

44. What does the 'c' stand for in the equation E=mc2?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Speed of Light
They act as catalysts - speeding the polymerization of acrylamide.

45. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
45% - 52% - 90%
Initiation - Propagation - Termination
Parabens
Tryptophan

46. What are the fructose contents in commercial HFCS products.
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.
Fatty Acid and Alcohol
45% - 52% - 90%
Negative log of the hydrogen concentration (mol/l).

47. What ketohexose is most significant to food chemists?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Carrageenan
Fructose
Erythorbic Acid

48. Does kosmotrophil ion discourage water structure?
No
A concentrate of microfibrillar proteins of fish muscle.
Fructose
DNA transferred by cell to cell contact (bacterial sex).

49. What is the fundamental driving of electrophoresis?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
The speed of a molecule is proportional to the surrounding voltage gradient.
Oil in Water

50. Name three non-nutritive sweeteners approved for use in USA?
RNA transcribed to DNA
Acsulfame-K - Saccharin - Cyclamate - Aspartame
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Olive Green