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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. What are the primary secondary - tertiary - and quaternary structures?
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
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.
Lipid oxidation
Gossypol (it is removed during the oil refining process)

2. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
A concentrate of microfibrillar proteins of fish muscle.
Water
D: None of the above
RNA transcribed to DNA

3. Which two amino acids is the aspartame derived from?
Speed of Light
Aspartic Acid and Phenylalanine
Troponins and Tropomyosin
An enzyme that converts hydrogen peroxide to water plus oxygen.

4. Are sorbitol and mannitol sweet?
Carmelization and Maillard
Yes
Oil in Water
Whole Milk

5. 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?
Pectin methylesterase & polygalacturonase
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
It explodes
Carmelization and Maillard

6. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Nucleation or crystal formation and crystal growth.
D: None of the above
.05

7. Alar is the trade name for what chemical compound?
Water
Bitter
Chitin
Daminozide

8. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Sodium bicarbonate generates CO2
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Non-protein nitrogen

9. What does HLB stand for and What does a high and low HLB value indicate?
Sucrose
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.
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
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

10. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Pectin methyl esterase or galacturonase
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.
It explodes
Carrageenan

11. Name two non-enzymatic browning reactions.
.05 M HCL
Bright green
Carmelization and Maillard
ERH=100 x Aw

12. What is an isomer that is cheaper than Vitamin C?
pH below positive charge; pH at no charge; pH above negative charge
Pectin Esterase - Polygalacturonase - Pectin Layase
Erythorbic Acid
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.

13. What is the name given to a mixture of equal parts of Darel Lisomers?
Thamautin
NaCl (it dissociated to a 2M solution)
Anthocyanins
Racemic Mixture

14. Does kosmotrophil ion discourage water structure?
No
Ammonia - Water - Carbon Dioxide
Emulsification
A concentrate of microfibrillar proteins of fish muscle.

15. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Sucrose
Capsaicin
Chitin
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.

16. What is the major color compound in tomatoes?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
RNA transcribed to DNA
Lycopenes
Cis

17. Contains the lowest content of water
RNA transcribed to DNA
Whole Milk
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Carmelization and Maillard

18. What are the fructose contents in commercial HFCS products.
Chlocophyllide does not have a phytoltail
.05
45% - 52% - 90%
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

19. What is the chemical nature of anthocyanins?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Glycosides of anthocyanidins
.05

20. Does kosmotrophil ion discourage water structure?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
No
Racemic Mixture

21. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Lipid oxidation
An enzyme that converts hydrogen peroxide to water plus oxygen.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

22. Name 3 factors influencing the rate of lipid oxidation in foods.
Polyphenol Oxidase
Negative log of the hydrogen concentration (mol/l).
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

23. How do sodium chloride and sucrose affect foam stability?
Ascorbic Acid and Citric Acid
Sodium chloride reduces foam stability and sucrose improves foam stability.
Parabens
Pheophytia does not have magnesium in porphyrin ring.

24. 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?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Yellow
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

25. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Polyphenols
Tryptophan
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

26. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
Thamautin
Pectin methylesterase & polygalacturonase
Thickener in foods

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

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28. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
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.
Anthocyanins
They act as catalysts - speeding the polymerization of acrylamide.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

29. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Two aldehydes
Water
20 carbons and 4 double bonds
Osmosis

30. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Two aldehydes
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Bitter
Water

31. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Glycosides of anthocyanidins
Sodium bicarbonate generates CO2
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Plasmids

32. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Anomeric
Osmosis
Polyphenols

33. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Polyphenol Oxidase
ERH=100 x Aw
Initiation - Propagation - Termination
Pectins

34. What is the enzyme that softens tomatoes?
Aspartic Acid and Phenylalanine
Acetoin
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin Esterase

35. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Cis
Carrageenan
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

36. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
2.5
Pectins
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
They act as catalysts - speeding the polymerization of acrylamide.

37. What is the Peroxide Value a measure of?
Thickener in foods
Browning of freshly cut surfaces of fruits and vegetables.
Milk
Fat Oxidation

38. Name a commonly used household chemical leavening agent and the gas it generates.
Orange Juice
Sodium bicarbonate generates CO2
Nucleation or crystal formation and crystal growth.
Emulsoids

39. What compounds oxidize to form brown color in fruits and vegetables?
It explodes
Pectin Esterase
Polyphenols
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

40. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
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.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Water
They act as catalysts - speeding the polymerization of acrylamide.

41. What is the major color compound in tomatoes?
Glycosides of anthocyanidins
Lycopenes
1 - 3 - 7-trimethylxanthine
Pectin methyl esterase or galacturonase

42. 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.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

43. What two enzymes degrade pectic substances?
Sucrose
ERH=100 x Aw
Arachidonic Acid
Pectin methylesterase & polygalacturonase

44. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Non-protein nitrogen
Pectins
Fatty Acid (Ester linked) to Fatty Alcohol
Covalent (strongest) and Hydrophobic (Weakest)

45. 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?
Anthocyanins
Orange Juice
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
RNA transcribed to DNA

46. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Osmosis
Acetoin
RNA transcribed to DNA
Fructose

47. 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.
2.5
Browning of freshly cut surfaces of fruits and vegetables.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

48. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Gossypol (it is removed during the oil refining process)
Yellow
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

49. What are colloids that are stabilized by a layer of solvation called?
Initiation - Propagation - Termination
Carmelization and Maillard
Emulsoids
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.

50. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
Glycosides of anthocyanidins
Anthocyanins
Speed of Light