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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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1. Name 3 factors influencing the rate of lipid oxidation in foods.
Onions ( or leeks)
Oil in Water
A concentrate of microfibrillar proteins of fish muscle.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

2. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Fatty Acid (Ester linked) to Fatty Alcohol
Gliadins and Glutenins

3. What is the fundamental driving of electrophoresis?
1 - 3 - 7-trimethylxanthine
Fatty Acid and Alcohol
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.
The speed of a molecule is proportional to the surrounding voltage gradient.

4. During freezing What are the two stages in the crystallization process?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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
Nucleation or crystal formation and crystal growth.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

5. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Troponins and Tropomyosin
Water
Fatty Acid (Ester linked) to Fatty Alcohol

6. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Phenylketonuria
Daminozide

7. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

8. Name 3 factors influencing the consistency of commercial fats.
NaCl (it dissociated to a 2M solution)
Gossypol (it is removed during the oil refining process)
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.

9. What are the fructose contents in commercial HFCS products.
Prolamines
45% - 52% - 90%
Linoleic Acid
Bright green

10. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Phenylketonuria
RNA transcribed to DNA
Polyphenols
2.5

11. What is a polymorphism?
Thickener in foods
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
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

12. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Troponins and Tropomyosin
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.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

13. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Browning of freshly cut surfaces of fruits and vegetables.
14
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

14. How many polypeptide chains make up an antibody?
Sucrose
Fatty Acid and Alcohol
Four
Erythorbic Acid

15. Alar is the trade name for what chemical compound?
Speed of Light
Pectin methylesterase & polygalacturonase
Daminozide
Lipase

16. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Fructose
Polyphenoloxidase
Thickener in foods
Primary butyric acid also caproic acid.

17. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
.05 M HCL
Daminozide
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

18. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Milk
Daminozide
HPLC has higher pressure than FPLC

19. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Linoleic Acid
Phenophylin
Speed of Light

20. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
14
Pectin methylesterase & polygalacturonase
Bright green
V=IR and P=VI or I x I x are

21. How many carbon atoms are there in the fatty acid myristic acid?
14
Speed of Light
Polyphenol Oxidase
D: None of the above

22. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Ascorbic Acid and Citric Acid
Thickener in foods
Fructose
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

23. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Plasmids
NaCl (it dissociated to a 2M solution)
Fatty Acid (Ester linked) to Fatty Alcohol
Monosodium Glutamate

24. What are the fructose contents in commercial HFCS products.
Aspartic Acid and Phenylalanine
45% - 52% - 90%
Non-protein nitrogen
Emulsoids

25. What are proteins which are soluble in 50-80% ethanol known as?
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.
Prolamines
Osmosis
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

26. What is the structural difference between chlorophyll and chlocophyllide?
Carrageenan
Monosodium Glutamate
Yes
Chlocophyllide does not have a phytoltail

27. Name one way foam stability can be assessed.
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.
Chitin
Onions ( or leeks)
45% - 52% - 90%

28. Name two enzymes that are involved in softening fruits.
Initiation - Propagation - and Termination
Linoleic Acid
Pheophytin forms
Pectin Esterase - Polygalacturonase - Pectin Layase

29. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Thermus Aqauticus
Polyphenols
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

30. What toxic pigment is found in cottonseed endosperm?
Speed of Light
Degradation of protein and production of acid from sugar at the same time.
Troponins and Tropomyosin
Gossypol (it is removed during the oil refining process)

31. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Degradation of protein and production of acid from sugar at the same time.
Carrageenan
The speed of a molecule is proportional to the surrounding voltage gradient.
RNA transcribed to DNA

32. Name one way foam stability can be assessed.
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.
They act as catalysts - speeding the polymerization of acrylamide.
Anthocyanins
Sweet - Salty - Sour - and Bitter

33. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Pheophytia does not have magnesium in porphyrin ring.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Olive Green
D: None of the above

34. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Polyphenol Oxidase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Non-protein nitrogen
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

35. How many carbon atoms are there in the fatty acid myristic acid?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
14
Browning of freshly cut surfaces of fruits and vegetables.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

36. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Orange Juice
NaCl (it dissociated to a 2M solution)
Pheophytia does not have magnesium in porphyrin ring.

37. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Polyphenol Oxidase
A concentrate of microfibrillar proteins of fish muscle.
RNA transcribed to DNA
Polyphenols

38. What metabolic end product does the Voges-Proskauer test detect?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Acetoin
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
1 - 3 - 7-trimethylxanthine

39. What is the protein efficiency ratio (PER) of casein?
2.5
Initiation - Propagation - and Termination
Milk
Anomeric

40. 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
Thickener in foods
Tryptophan
Browning of freshly cut surfaces of fruits and vegetables.
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.

41. How does HPLC differ from FPLC?
Cis
Pheophytin forms
HPLC has higher pressure than FPLC
Primary butyric acid also caproic acid.

42. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Prolamines
D: None of the above
They act as catalysts - speeding the polymerization of acrylamide.
Negative log of the hydrogen concentration (mol/l).

43. Waxes are composed of what two basic chemical entities?
Fat Oxidation
Fatty Acid (Ester linked) to Fatty Alcohol
Pectin Esterase
Prolamines

44. Alar is the trade name for what chemical compound?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Thermus Aqauticus
Daminozide
20 carbons and 4 double bonds

45. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Yes
Carrageenan
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Bitter

46. What is the geometric configuration of double bonds in most natural fatty acids?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Tryptophan
Orange Juice
Cis

47. Does kosmotrophil ion discourage water structure?
Daminozide
Olive Green
No
Fructose

48. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Ammonia - Water - Carbon Dioxide
Sodium bicarbonate generates CO2
It explodes

49. Name two enzymes that are involved in softening fruits.
Initiation - Propagation - and Termination
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
Bright green

50. What does the iodine value measure and how is it measured?
20 carbons and 4 double bonds
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Covalent (strongest) and Hydrophobic (Weakest)
A concentrate of microfibrillar proteins of fish muscle.