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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. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Browning of freshly cut surfaces of fruits and vegetables.
A concentrate of microfibrillar proteins of fish muscle.
DNA transferred by cell to cell contact (bacterial sex).
Oil in Water

2. What is the main class of color compounds found in raspberries?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
pH 3-5
Anthocyanins
Arachidonic Acid

3. Name the strongest biochemical bond and the weakest biochemical bond.
Whole Milk
Covalent (strongest) and Hydrophobic (Weakest)
DNA transferred by cell to cell contact (bacterial sex).
Gossypol (it is removed during the oil refining process)

4. Name 4 advantages of using enzymes in food processing.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
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
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Fatty Acid and Alcohol

5. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
Lipid oxidation
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Degradation of protein and production of acid from sugar at the same time.

6. Name 5 proteins with good foaming properties.
An enzyme that converts hydrogen peroxide to water plus oxygen.
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.
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.
Initiation - Propagation - Termination

7. How do sodium chloride and sucrose affect foam stability?
It explodes
Fructose
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectins

8. 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
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
D: None of the above
Lipase
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.

9. 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
Bitter
Bright green
Parabens
Browning of freshly cut surfaces of fruits and vegetables.

10. 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?
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.
Tryptophan
Water
It explodes

11. What are the limiting amino acids in corn - potato - and green peas?
Linoleic Acid
Polyphenol Oxidase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Daminozide

12. What are two common reducing agents that break disulfide bonds in proteins?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Nucleation or crystal formation and crystal growth.
Initiation - Propagation - Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

13. When heated ammonium bicarbonate decomposes to form what end products?
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.
RNA transcribed to DNA
Ammonia - Water - Carbon Dioxide
Pectin methylesterase & polygalacturonase

14. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Thamautin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

15. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
45% - 52% - 90%
Onions ( or leeks)
Negative log of the hydrogen concentration (mol/l).

16. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lysine - Arginine - and Histidine
Plasmids
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

17. Name two reasons why fats are hydrogenated.
Pheophytia does not have magnesium in porphyrin ring.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Non-protein nitrogen
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

18. What ketohexose is most significant to food chemists?
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
Fructose
Olive Green
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.

19. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
2.5
They act as catalysts - speeding the polymerization of acrylamide.
Carmelization and Maillard
Two aldehydes

20. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Daminozide
Polyphenol Oxidase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

21. Name the two components that comprise the relaxing factor in muscle fibers.
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.
Troponins and Tropomyosin
Lysine - Arginine - and Histidine
Water

22. 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.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
pH 3-5
Initiation - Propagation - and Termination

23. What is Carboxy-methyl cellulose often used for?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Chitin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Thickener in foods

24. Does kosmotrophil ion discourage water structure?
Thickener in foods
No
Orange Juice
Sodium chloride reduces foam stability and sucrose improves foam stability.

25. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Initiation - Propagation - and Termination
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
NaCl (it dissociated to a 2M solution)

26. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Prolamines
Chlocophyllide does not have a phytoltail
Olive Green

27. What does the saponification value measure and how is it measured?
Nucleation or crystal formation and crystal growth.
Parabens
Oil in Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

28. What does the acronym NPN stand for?
Yellow
Non-protein nitrogen
Racemic Mixture
RNA transcribed to DNA

29. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Ascorbic Acid and Citric Acid
Emulsification
1 - 3 - 7-trimethylxanthine

30. How many carbon atoms are there in the fatty acid myristic acid?
14
Gossypol (it is removed during the oil refining process)
Orange Juice
Four

31. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
ERH=100 x Aw
Glycosides of anthocyanidins
Initiation - Propagation - and Termination
Onions ( or leeks)

32. When heated ammonium bicarbonate decomposes to form what end products?
Sweet - Salty - Sour - and Bitter
Ammonia - Water - Carbon Dioxide
Bitter
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

33. 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
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Oil in Water
Speed of Light

34. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Carmelization and Maillard
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Yellow

35. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Pheophytin forms
Orange Juice
Whole Milk
Capsaicin

36. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Orange Juice
Erythorbic Acid
V=IR and P=VI or I x I x are

37. What metabolic end product does the Voges-Proskauer test detect?
Anomeric
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.
Acetoin
2.5

38. Name 3 chemical agents capable of denaturing proteins.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Daminozide
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Polyphenols

39. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Ascorbic Acid and Citric Acid
Acsulfame-K - Saccharin - Cyclamate - Aspartame
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

40. What is the main class of color compounds found in raspberries?
They act as catalysts - speeding the polymerization of acrylamide.
No
Emulsification
Anthocyanins

41. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
Orange Juice
Daminozide
Racemic Mixture

42. What are the four basic flavors perceived by the tongue?
Oil in Water
Sweet - Salty - Sour - and Bitter
Sucrose
Speed of Light

43. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Polyphenol Oxidase
Aspartic Acid and Phenylalanine

44. Name three effects of protein denaturation.
Pheophytin forms
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
DNA transferred by cell to cell contact (bacterial sex).

45. What does the 'c' stand for in the equation E=mc2?
Pectin methyl esterase or galacturonase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Speed of Light
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

46. What is catalase?
Pectin methyl esterase or galacturonase
An enzyme that converts hydrogen peroxide to water plus oxygen.
Two aldehydes
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

47. Are sorbitol and mannitol sweet?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Sucrose
Aspartic Acid and Phenylalanine
Yes

48. At low water activity What is the main deteriorative concern?
Lysine - Arginine - and Histidine
Lamellar; Hexagonal I - II; Cubic
Lipid oxidation
Erythorbic Acid

49. Are sorbitol and mannitol sweet?
RNA transcribed to DNA
Yes
Gossypol (it is removed during the oil refining process)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

50. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
.05
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Fatty Acid and Alcohol
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)