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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. In the enzyme Taq Polymerase What does Taq stand for?
Water
Thermus Aqauticus
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Initiation - Propagation - and Termination

2. 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?
Pectins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
.05 M HCL
Chitin

3. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Racemic Mixture
Emulsoids
45% - 52% - 90%
They act as catalysts - speeding the polymerization of acrylamide.

4. What is surimi?
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.
Emulsoids
Gossypol (it is removed during the oil refining process)
A concentrate of microfibrillar proteins of fish muscle.

5. Define molarity molality - and normality.
Troponins and Tropomyosin
Polyphenol Oxidase
The speed of a molecule is proportional to the surrounding voltage gradient.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

6. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

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7. What is the geometric configuration of double bonds in most natural fatty acids?
Lamellar; Hexagonal I - II; Cubic
Cis
Racemic Mixture
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.

8. Name the most common functional property of phospholipids in food systems.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Emulsification
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.

9. What is the common name for 9 12 - cis-cis-octa dienoic 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.
Water
14
Linoleic Acid

10. Name 3 physical agents capable of denaturing proteins.
Polyphenol Oxidase
1 - 3 - 7-trimethylxanthine
Sucrose
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

11. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Pectin Esterase - Polygalacturonase - Pectin Layase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.

12. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
pH below positive charge; pH at no charge; pH above negative charge
Non-protein nitrogen
Yes

13. How is pH defined?
Polyphenol Oxidase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Plasmids
Negative log of the hydrogen concentration (mol/l).

14. How many carbon atoms are there in the fatty acid myristic acid?
Bitter
Fructose
The speed of a molecule is proportional to the surrounding voltage gradient.
14

15. Are sorbitol and mannitol sweet?
Water
20 carbons and 4 double bonds
Yes
Negative log of the hydrogen concentration (mol/l).

16. How does ERH relate to water activity?
ERH=100 x Aw
Pectin Esterase - Polygalacturonase - Pectin Layase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Gossypol (it is removed during the oil refining process)

17. Peptide bond formation results in the formation of what secondary compound?
Plasmids
Sodium bicarbonate generates CO2
Water
Yes

18. How many carbon atoms are there in the fatty acid myristic acid?
14
Daminozide
45% - 52% - 90%
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

19. Define molarity molality - and normality.
Polyphenols
Pheophytin forms
NaCl (it dissociated to a 2M solution)
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

20. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
Non-protein nitrogen
Nucleation or crystal formation and crystal growth.
Pheophytia does not have magnesium in porphyrin ring.

21. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Racemic Mixture
Capsaicin

22. What does the iodine value measure and how is it measured?
Non-protein nitrogen
Prolamines
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
pH 3-5

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

24. What is the enzyme that softens tomatoes?
Pectin Esterase
Tryptophan
ERH=100 x Aw
Sweet - Salty - Sour - and Bitter

25. What metabolic end product does the Voges-Proskauer test detect?
Pectin Esterase - Polygalacturonase - Pectin Layase
Browning of freshly cut surfaces of fruits and vegetables.
Acetoin
Ascorbic Acid and Citric Acid

26. How many polypeptide chains make up an antibody?
Polyphenol Oxidase
Fructose
They act as catalysts - speeding the polymerization of acrylamide.
Four

27. What two enzymes degrade pectic substances?
Carrageenan
Pectin methylesterase & polygalacturonase
NaCl (it dissociated to a 2M solution)
Chlocophyllide does not have a phytoltail

28. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Carrageenan
Polyphenoloxidase
Osmosis

29. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Nucleation or crystal formation and crystal growth.
Osmosis
Water
Capsaicin

30. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Thickener in foods
Bright green
Thermus Aqauticus
2.5

31. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
45% - 52% - 90%
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Phenylketonuria
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

32. Name 4 advantages of using enzymes in food processing.
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
Capsaicin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

33. What is the structural difference between chlorophyll and pheophytia?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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.
Initiation - Propagation - Termination

34. What does Acid Degree Value measure and how is it measured?
Yellow
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.
Chitin

35. What are the four basic flavors perceived by the tongue?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Polyphenoloxidase
DNA transferred by cell to cell contact (bacterial sex).
Sweet - Salty - Sour - and Bitter

36. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Pectin Esterase
Onions ( or leeks)
Erythorbic Acid
Carmelization and Maillard

37. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Anthocyanins
Initiation - Propagation - Termination
Browning of freshly cut surfaces of fruits and vegetables.

38. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

39. What are the three stages of oxidative rancidity?
Onions ( or leeks)
Capsaicin
Emulsoids
Initiation - Propagation - and Termination

40. What is Carboxy-methyl cellulose often used for?
Pheophytia does not have magnesium in porphyrin ring.
Racemic Mixture
They act as catalysts - speeding the polymerization of acrylamide.
Thickener in foods

41. What does HLB stand for and What does a high and low HLB value indicate?
Oil in Water
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.
Capsaicin
Onions ( or leeks)

42. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Sodium bicarbonate generates CO2
Polyphenol Oxidase
Phenylketonuria

43. How does ERH relate to water activity?
20 carbons and 4 double bonds
Erythorbic Acid
Anthocyanins
ERH=100 x Aw

44. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Cis
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Polyphenol Oxidase

45. What is the protein efficiency ratio (PER) of casein?
Whole Milk
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
2.5
Sodium bicarbonate generates CO2

46. Name one way foam stability can be assessed.
Lamellar; Hexagonal I - II; Cubic
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.
Olive Green
It explodes

47. What is the major color compound in tomatoes?
Linoleic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Water
Lycopenes

48. What pigment was first designated as anthocyanins?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Polyphenoloxidase
14
Blue pigment in flowers

49. What are proteins which are soluble in 50-80% ethanol known as?
20 carbons and 4 double bonds
They act as catalysts - speeding the polymerization of acrylamide.
Lycopenes
Prolamines

50. What is an isomer that is cheaper than Vitamin C?
Initiation - Propagation - Termination
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Erythorbic Acid
20 carbons and 4 double bonds