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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 two enzymes degrade pectic substances?
45% - 52% - 90%
20 carbons and 4 double bonds
Pectin methylesterase & polygalacturonase
Nucleation or crystal formation and crystal growth.

2. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
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.
2.5
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

3. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Racemic Mixture
Two aldehydes
Anomeric
Initiation - Propagation - Termination

4. Name the most common functional property of phospholipids in food systems.
Pectin Esterase - Polygalacturonase - Pectin Layase
Osmosis
Emulsification
14

5. At low water activity What is the main deteriorative concern?
Lipid oxidation
V=IR and P=VI or I x I x are
Phenylketonuria
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

6. 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.
Pectin Esterase - Polygalacturonase - Pectin Layase
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
Degradation of protein and production of acid from sugar at the same time.

7. 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
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.
Phenophylin
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
The speed of a molecule is proportional to the surrounding voltage gradient.

8. Name three non-nutritive sweeteners approved for use in USA?
Linoleic Acid
Bright green
Ascorbic Acid and Citric Acid
Acsulfame-K - Saccharin - Cyclamate - Aspartame

9. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Blue pigment in flowers
Ammonia - Water - Carbon Dioxide
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

10. What is the chemical nature of anthocyanins?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Glycosides of anthocyanidins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Blue pigment in flowers

11. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Daminozide
ERH=100 x Aw

12. Is a disaccharide
Sucrose
Orange Juice
D: None of the above
Pectins

13. Name 4 advantages of using enzymes in food processing.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
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
Non-protein nitrogen

14. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Initiation - Propagation - Termination
Orange Juice
Blue pigment in flowers

15. What pigment was first designated as anthocyanins?
pH below positive charge; pH at no charge; pH above negative charge
Yes
Browning of freshly cut surfaces of fruits and vegetables.
Blue pigment in flowers

16. 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)
Water
.05
Orange Juice

17. 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?
.05 M HCL
Emulsification
Capsaicin
Water

18. Name a naturally occurring protein sweetener.
Orange Juice
Pectin Esterase
Thamautin
Browning of freshly cut surfaces of fruits and vegetables.

19. What does the iodine value measure and how is it measured?
Phenophylin
Olive Green
Fructose
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

20. Name two enzymes that are involved in softening fruits.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin Esterase - Polygalacturonase - Pectin Layase
RNA transcribed to DNA
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

21. What are the four basic flavors perceived by the tongue?
Carrageenan
Lipid oxidation
45% - 52% - 90%
Sweet - Salty - Sour - and Bitter

22. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Pectin methylesterase & polygalacturonase
Capsaicin
Carmelization and Maillard
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

23. In the enzyme Taq Polymerase What does Taq stand for?
Cis
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
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thermus Aqauticus

24. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
HPLC has higher pressure than FPLC
Ammonia - Water - Carbon Dioxide
Thermus Aqauticus

25. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Chlocophyllide does not have a phytoltail
Tryptophan
Gliadins and Glutenins

26. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase
Two aldehydes
Water

27. What is surimi?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
A concentrate of microfibrillar proteins of fish muscle.
Degradation of protein and production of acid from sugar at the same time.
Pectins

28. How is pH defined?
Arachidonic Acid
Negative log of the hydrogen concentration (mol/l).
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pheophytia does not have magnesium in porphyrin ring.

29. What two types of compounds are joined with an ester bond to make a wax?
Sucrose
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Thickener in foods
Fatty Acid and Alcohol

30. 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
Water
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
Parabens

31. What are the primary secondary - tertiary - and quaternary structures?
Gliadins and Glutenins
Thermus Aqauticus
1 - 3 - 7-trimethylxanthine
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.

32. What is the chemical nature of anthocyanins?
45% - 52% - 90%
Glycosides of anthocyanidins
Milk
Phenophylin

33. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Daminozide
Carrageenan
Prolamines
Capsaicin

34. What two types of compounds are joined with an ester bond to make a wax?
Ascorbic Acid and Citric Acid
It explodes
Lamellar; Hexagonal I - II; Cubic
Fatty Acid and Alcohol

35. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Daminozide
Fatty Acid (Ester linked) to Fatty Alcohol
1 - 3 - 7-trimethylxanthine

36. In genetics What is conjugation?
Plasmids
HPLC has higher pressure than FPLC
Linoleic Acid
DNA transferred by cell to cell contact (bacterial sex).

37. How many carbon atoms and how many double bonds are there in arachidonic acid?
Carrageenan
Phenylketonuria
20 carbons and 4 double bonds
Negative log of the hydrogen concentration (mol/l).

38. How do sodium chloride and sucrose affect foam stability?
Pectin Esterase - Polygalacturonase - Pectin Layase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Phenylketonuria
Degradation of protein and production of acid from sugar at the same time.

39. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
1 - 3 - 7-trimethylxanthine
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

40. What is the structural difference between chlorophyll and pheophytia?
Carrageenan
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pheophytia does not have magnesium in porphyrin ring.
They act as catalysts - speeding the polymerization of acrylamide.

41. Name two main gluten proteins.
Linoleic Acid
.05
Gliadins and Glutenins
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

42. Contains the lowest content of water
Whole Milk
Troponins and Tropomyosin
Thermus Aqauticus
ERH=100 x Aw

43. What are the limiting amino acids in corn - potato - and green peas?
Fatty Acid (Ester linked) to Fatty Alcohol
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Nucleation or crystal formation and crystal growth.

44. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Acsulfame-K - Saccharin - Cyclamate - Aspartame
They act as catalysts - speeding the polymerization of acrylamide.
DNA transferred by cell to cell contact (bacterial sex).

45. What are the limiting amino acids in corn - potato - and green peas?
Polyphenoloxidase
20 carbons and 4 double bonds
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
An enzyme that converts hydrogen peroxide to water plus oxygen.

46. What is the chemical nomenclature for caffeine?
Aspartic Acid and Phenylalanine
1 - 3 - 7-trimethylxanthine
Four
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

47. Are sorbitol and mannitol sweet?
Emulsification
Yellow
Yes
Aspartic Acid and Phenylalanine

48. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Pectins
Plasmids
DNA transferred by cell to cell contact (bacterial sex).
Water

49. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Capsaicin

50. What is acid proteolysis?
Ammonia - Water - Carbon Dioxide
Four
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Degradation of protein and production of acid from sugar at the same time.