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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 does the 'c' stand for in the equation E=mc2?
Gossypol (it is removed during the oil refining process)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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.
Speed of Light

2. How does HPLC differ from FPLC?
ERH=100 x Aw
HPLC has higher pressure than FPLC
V=IR and P=VI or I x I x are
Non-protein nitrogen

3. What are two common reducing agents that break disulfide bonds in proteins?
Initiation - Propagation - and Termination
20 carbons and 4 double bonds
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

4. How many carbon atoms and how many double bonds are there in arachidonic acid?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
20 carbons and 4 double bonds
Chitin
.05

5. What two common compounds are used together as an antioxidative system?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Ascorbic Acid and Citric Acid
A concentrate of microfibrillar proteins of fish muscle.
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.

6. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Primary butyric acid also caproic acid.
.05

7. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Covalent (strongest) and Hydrophobic (Weakest)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Whole Milk

8. 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).
Onions ( or leeks)
Ammonia - Water - Carbon Dioxide
Linoleic Acid

9. What compounds oxidize to form brown color in fruits and vegetables?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Polyphenol Oxidase
Polyphenols
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

10. What are the only phenols approved for use in the microbiological preservation of foods?
They act as catalysts - speeding the polymerization of acrylamide.
Erythorbic Acid
Parabens
Non-protein nitrogen

11. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Whole Milk
Yellow
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

12. What does the saponification value measure and how is it measured?
Sodium bicarbonate generates CO2
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pheophytin forms
Plasmids

13. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Prolamines
Sucrose
The speed of a molecule is proportional to the surrounding voltage gradient.
Plasmids

14. Name a commonly used household chemical leavening agent and the gas it generates.
The speed of a molecule is proportional to the surrounding voltage gradient.
Bitter
Sodium bicarbonate generates CO2
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

15. How can a molecular weight of protein - DNA - and RNA be determined?
Orange Juice
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Fructose
Thermus Aqauticus

16. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
Polyphenoloxidase
Browning of freshly cut surfaces of fruits and vegetables.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Primary butyric acid also caproic acid.

17. Name two main gluten proteins.
Capsaicin
1 - 3 - 7-trimethylxanthine
Gliadins and Glutenins
Sodium chloride reduces foam stability and sucrose improves foam stability.

18. Waxes are composed of what two basic chemical entities?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Erythorbic 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.
Fatty Acid (Ester linked) to Fatty Alcohol

19. 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.
The speed of a molecule is proportional to the surrounding voltage gradient.
Daminozide
Fructose

20. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
ERH=100 x Aw
45% - 52% - 90%
Water

21. What is the fundamental driving of electrophoresis?
HPLC has higher pressure than FPLC
Parabens
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenoloxidase

22. In the enzyme Taq Polymerase What does Taq stand for?
Browning of freshly cut surfaces of fruits and vegetables.
Plasmids
Thermus Aqauticus
It explodes

23. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Acetoin

24. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Negative log of the hydrogen concentration (mol/l).
Thamautin
Fat Oxidation

25. What toxic pigment is found in cottonseed endosperm?
Thamautin
Prolamines
Fructose
Gossypol (it is removed during the oil refining process)

26. Name the most common functional property of phospholipids in food systems.
Emulsification
Non-protein nitrogen
Pheophytia does not have magnesium in porphyrin ring.
Anthocyanins

27. How does HPLC differ from FPLC?
Osmosis
D: None of the above
.05
HPLC has higher pressure than FPLC

28. What is acid proteolysis?
Fat Oxidation
Degradation of protein and production of acid from sugar at the same time.
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.
Whole Milk

29. What is the chemical nomenclature for caffeine?
Erythorbic Acid
1 - 3 - 7-trimethylxanthine
Browning of freshly cut surfaces of fruits and vegetables.
NaCl (it dissociated to a 2M solution)

30. What is the enzyme that softens tomatoes?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin Esterase
RNA transcribed to DNA

31. What is the Peroxide Value a measure of?
Cis
Fat Oxidation
Ammonia - Water - Carbon Dioxide
Osmosis

32. How many polypeptide chains make up an antibody?
Arachidonic Acid
Initiation - Propagation - and Termination
Polyphenols
Four

33. Name three factors useful in controlling enzyme activity.
Initiation - Propagation - Termination
Covalent (strongest) and Hydrophobic (Weakest)
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.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

34. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Fatty Acid and Alcohol
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

35. 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?
Pheophytin forms
Emulsoids
Bright green
.05 M HCL

36. Name 3 factors influencing the consistency of commercial fats.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
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.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

37. What does HLB stand for and What does a high and low HLB value indicate?
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.
Thickener in foods
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Parabens

38. Name three effects of protein denaturation.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Anomeric
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.

39. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Monosodium Glutamate
Degradation of protein and production of acid from sugar at the same time.
Oil in Water

40. What does Acid Degree Value measure and how is it measured?
20 carbons and 4 double bonds
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Polyphenol Oxidase
Thamautin

41. What are proteins which are soluble in 50-80% ethanol known as?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Tryptophan
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Prolamines

42. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase
Emulsification

43. What enzyme causes hyrolytic rancidity in milk?
Lipase
Water
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty Acid (Ester linked) to Fatty Alcohol

44. Name 5 chelating agents used in the food industry.
Bitter
Ascorbic Acid and Citric Acid
Four
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

45. At low water activity What is the main deteriorative concern?
Prolamines
Anomeric
Lipid oxidation
Pheophytin forms

46. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Negative log of the hydrogen concentration (mol/l).
Lycopenes

47. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
D: None of the above
Gliadins and Glutenins
Emulsoids

48. Name one way foam stability can be assessed.
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.
Sweet - Salty - Sour - and Bitter
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

49. At low water activity What is the main deteriorative concern?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Lipid oxidation
Water
Glycosides of anthocyanidins

50. Which two amino acids is the aspartame derived from?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Bitter
20 carbons and 4 double bonds
Aspartic Acid and Phenylalanine