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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. In what food is butyric acid typically found?
Fructose
Milk
Carrageenan
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.

2. Name a naturally occurring protein sweetener.
Initiation - Propagation - Termination
Thamautin
Polyphenols
An enzyme that converts hydrogen peroxide to water plus oxygen.

3. Does kosmotrophil ion discourage water structure?
Non-protein nitrogen
Ammonia - Water - Carbon Dioxide
Oil in Water
No

4. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
45% - 52% - 90%
Polyphenols
An enzyme that converts hydrogen peroxide to water plus oxygen.

5. What is acid proteolysis?
Erythorbic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Degradation of protein and production of acid from sugar at the same time.
Pheophytin forms

6. What is surimi?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
A concentrate of microfibrillar proteins of fish muscle.
Olive Green
Negative log of the hydrogen concentration (mol/l).

7. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
V=IR and P=VI or I x I x are
Chitin
Pectins

8. What does MSG stand for?
Monosodium Glutamate
Thickener in foods
Chlocophyllide does not have a phytoltail
Glycosides of anthocyanidins

9. What ketohexose is most significant to food chemists?
Two aldehydes
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lamellar; Hexagonal I - II; Cubic
Fructose

10. Name three factors useful in controlling enzyme activity.
Nucleation or crystal formation and crystal growth.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
The speed of a molecule is proportional to the surrounding voltage gradient.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

11. What are colloids that are stabilized by a layer of solvation called?
Water
Emulsoids
Erythorbic Acid
Gliadins and Glutenins

12. Are sorbitol and mannitol sweet?
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
14
Yes

13. What does Acid Degree Value measure and how is it measured?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Phenophylin
HPLC has higher pressure than FPLC
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

14. Does kosmotrophil ion discourage water structure?
No
An enzyme that converts hydrogen peroxide to water plus oxygen.
Anthocyanins
ERH=100 x Aw

15. What is the geometric configuration of double bonds in most natural fatty acids?
Phenophylin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Linoleic Acid
Cis

16. What does HLB stand for and What does a high and low HLB value indicate?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Osmosis
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. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Capsaicin
Pectin methylesterase & polygalacturonase

18. What is the structural difference between chlorophyll and pheophytia?
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
No
Erythorbic Acid
Pheophytia does not have magnesium in porphyrin ring.

19. What is the main class of color compounds found in raspberries?
Gliadins and Glutenins
Anthocyanins
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Carrageenan

20. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Non-protein nitrogen
Initiation - Propagation - and Termination

21. What is surimi?
Phenylketonuria
Thickener in foods
A concentrate of microfibrillar proteins of fish muscle.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

22. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Whole Milk
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.
Anthocyanins

23. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Chlocophyllide does not have a phytoltail
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.

24. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
20 carbons and 4 double bonds
Lamellar; Hexagonal I - II; Cubic
Gliadins and Glutenins
Oil in Water

25. At what pH is benzoic acid most effective?
Linoleic Acid
Milk
pH 3-5
ERH=100 x Aw

26. Name a naturally occurring protein sweetener.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Monosodium Glutamate
Thamautin
Chitin

27. What pigment was first designated as anthocyanins?
ERH=100 x Aw
Blue pigment in flowers
Olive Green
Daminozide

28. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Covalent (strongest) and Hydrophobic (Weakest)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Thickener in foods
Speed of Light

29. What is a polymorphism?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenols
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

30. 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
Primary butyric acid also caproic acid.
D: None of the above
Aspartic Acid and Phenylalanine
Four

31. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Lamellar; Hexagonal I - II; Cubic
Water
Gliadins and Glutenins
Arachidonic Acid

32. At what pH is benzoic acid most effective?
Pectin methyl esterase or galacturonase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
pH 3-5
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.

33. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Yellow
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
Thermus Aqauticus
Polyphenol Oxidase

34. What is the protein efficiency ratio (PER) of casein?
An enzyme that converts hydrogen peroxide to water plus oxygen.
It explodes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2.5

35. Name 5 chelating agents used in the food industry.
Chlocophyllide does not have a phytoltail
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Thickener in foods

36. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Polyphenoloxidase
Acetoin
Bright green
Whole Milk

37. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Primary butyric acid also caproic acid.
NaCl (it dissociated to a 2M solution)
Pectins
14

38. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Two aldehydes
14
It explodes

39. What is an isomer that is cheaper than Vitamin C?
Plasmids
Acetoin
Arachidonic Acid
Erythorbic Acid

40. What effect would the addition of sodium bicarbonate have to chocolate?
Linoleic Acid
Sodium chloride reduces foam stability and sucrose improves foam stability.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Oil in Water

41. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Anthocyanins
Fat Oxidation
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Bitter

42. Name the strongest biochemical bond and the weakest biochemical bond.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
RNA transcribed to DNA
Racemic Mixture
Covalent (strongest) and Hydrophobic (Weakest)

43. What are the primary secondary - tertiary - and quaternary structures?
Yellow
Fructose
Pectins
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.

44. Name one way foam stability can be assessed.
Sweet - Salty - Sour - and Bitter
Water
Emulsification
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. What happens to chlorophyll on heating?
Pheophytin forms
A concentrate of microfibrillar proteins of fish muscle.
Fatty Acid (Ester linked) to Fatty Alcohol
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

46. Name the strongest biochemical bond and the weakest biochemical bond.
HPLC has higher pressure than FPLC
Negative log of the hydrogen concentration (mol/l).
Covalent (strongest) and Hydrophobic (Weakest)
Lipid oxidation

47. Name 3 physical agents capable of denaturing proteins.
Fatty Acid and Alcohol
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Erythorbic Acid
Fatty Acid and Alcohol

48. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
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.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Milk

49. What is the major color compound in tomatoes?
Lycopenes
Monosodium Glutamate
Lipid oxidation
Nucleation or crystal formation and crystal growth.

50. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Lysine - Arginine - and Histidine
.05 M HCL
Erythorbic Acid