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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. Name the most common functional property of phospholipids in food systems.
Carrageenan
Emulsification
Yellow
Fatty Acid (Ester linked) to Fatty Alcohol

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

3. Name three non-nutritive sweeteners approved for use in USA?
1 - 3 - 7-trimethylxanthine
Orange Juice
Acsulfame-K - Saccharin - Cyclamate - Aspartame
V=IR and P=VI or I x I x are

4. What two common compounds are used together as an antioxidative system?
Thickener in foods
Ascorbic Acid and Citric Acid
Whole Milk
Orange Juice

5. What charge will a protein have when the pH of its solution is below at - and above its pKa?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Blue pigment in flowers
Cis
pH below positive charge; pH at no charge; pH above negative charge

6. What enzyme is most responsible for browning bananas?
Milk
Lipase
Polyphenol Oxidase
Thamautin

7. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
The speed of a molecule is proportional to the surrounding voltage gradient.
The speed of a molecule is proportional to the surrounding voltage gradient.
D: None of the above
Lipase

8. What is the structural difference between chlorophyll and pheophytia?
Sucrose
45% - 52% - 90%
NaCl (it dissociated to a 2M solution)
Pheophytia does not have magnesium in porphyrin ring.

9. Name 4 advantages of using enzymes in food processing.
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.
Sodium chloride reduces foam stability and sucrose improves foam stability.
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
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

10. Name the most common functional property of phospholipids in food systems.
Browning of freshly cut surfaces of fruits and vegetables.
Carrageenan
Emulsification
They act as catalysts - speeding the polymerization of acrylamide.

11. What is the Peroxide Value a measure of?
Ammonia - Water - Carbon Dioxide
Fat Oxidation
Emulsoids
No

12. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
ERH=100 x Aw
Pheophytia does not have magnesium in porphyrin ring.
Oil in Water

13. 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?
pH below positive charge; pH at no charge; pH above negative charge
Initiation - Propagation - Termination
.05 M HCL
Emulsoids

14. What does the iodine value measure and how is it measured?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenols
Covalent (strongest) and Hydrophobic (Weakest)

15. 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?
It explodes
Fatty Acid (Ester linked) to Fatty Alcohol
Sucrose
pH 3-5

16. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Parabens
Lipid oxidation
Anomeric

17. What is the acid present in fish oil?
Arachidonic 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.
Four
pH 3-5

18. Are sorbitol and mannitol sweet?
.05
Yes
Speed of Light
1 - 3 - 7-trimethylxanthine

19. Name two enzymes that are involved in softening fruits.
Whole Milk
Pectin Esterase - Polygalacturonase - Pectin Layase
Arachidonic Acid
Lipid oxidation

20. How does ERH relate to water activity?
Initiation - Propagation - and Termination
Emulsification
Bitter
ERH=100 x Aw

21. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Polyphenols
Pectins
Initiation - Propagation - and Termination
Sodium bicarbonate generates CO2

22. What does the acronym NPN stand for?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Sucrose
Non-protein nitrogen
Initiation - Propagation - and Termination

23. What does MSG stand for?
Monosodium Glutamate
Thickener in foods
45% - 52% - 90%
1 - 3 - 7-trimethylxanthine

24. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
RNA transcribed to DNA
Carrageenan

25. Name two main gluten proteins.
Lysine - Arginine - and Histidine
2.5
Gliadins and Glutenins
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

26. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Troponins and Tropomyosin
Onions ( or leeks)
pH below positive charge; pH at no charge; pH above negative charge

27. What is the geometric configuration of double bonds in most natural fatty acids?
Parabens
Four
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
Cis

28. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Acetoin
45% - 52% - 90%
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

29. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
20 carbons and 4 double bonds
Whole Milk
Carrageenan
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

30. Does kosmotrophil ion discourage water structure?
Primary butyric acid also caproic acid.
No
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
Polyphenoloxidase

31. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
Pectin Esterase - Polygalacturonase - Pectin Layase
Onions ( or leeks)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

32. How does ERH relate to water activity?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Onions ( or leeks)
ERH=100 x Aw
Initiation - Propagation - Termination

33. What is the fundamental driving of electrophoresis?
Daminozide
The speed of a molecule is proportional to the surrounding voltage gradient.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Negative log of the hydrogen concentration (mol/l).

34. What is Carboxy-methyl cellulose often used for?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Thickener in foods
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Sodium chloride reduces foam stability and sucrose improves foam stability.

35. Name 3 chemical agents capable of denaturing proteins.
Thamautin
Carmelization and Maillard
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Phenylketonuria

36. Name two enzymes that are involved in softening fruits.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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
Pectin Esterase - Polygalacturonase - Pectin Layase

37. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
14
Milk
Polyphenol Oxidase

38. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
pH below positive charge; pH at no charge; pH above negative charge
Lipid oxidation

39. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
No
Blue pigment in flowers
Tryptophan

40. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Blue pigment in flowers
Degradation of protein and production of acid from sugar at the same time.
Pheophytia does not have magnesium in porphyrin ring.
Oil in Water

41. Name one way foam stability can be assessed.
Phenophylin
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Thamautin

42. What is the name given to a mixture of equal parts of Darel Lisomers?
It explodes
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectin methyl esterase or galacturonase
Racemic Mixture

43. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
Orange Juice
Osmosis
D: None of the above

44. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Bright green
No
Fructose
Phenylketonuria

45. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Onions ( or leeks)
Milk
Pectin methyl esterase or galacturonase
Bright green

46. What toxic pigment is found in cottonseed endosperm?
Pectins
Gossypol (it is removed during the oil refining process)
Yes
Non-protein nitrogen

47. How many carbon atoms are there in the fatty acid myristic acid?
Prolamines
Polyphenol Oxidase
14
Emulsification

48. 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?
45% - 52% - 90%
Sucrose
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

49. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Arachidonic Acid
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectins

50. Alar is the trade name for what chemical compound?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Daminozide
Carmelization and Maillard
Carrageenan