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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
14
Non-protein nitrogen
Cis
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

2. What enzyme is most responsible for browning bananas?
Pheophytin forms
Osmosis
D: None of the above
Polyphenol Oxidase

3. What is the fundamental driving of electrophoresis?
Browning of freshly cut surfaces of fruits and vegetables.
The speed of a molecule is proportional to the surrounding voltage gradient.
Daminozide
Pheophytin forms

4. 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.
Yes
Primary butyric acid also caproic acid.
Lysine - Arginine - and Histidine

5. Name two main gluten proteins.
Gliadins and Glutenins
Polyphenol Oxidase
Thickener in foods
An enzyme that converts hydrogen peroxide to water plus oxygen.

6. What is the fundamental driving of electrophoresis?
Sucrose
The speed of a molecule is proportional to the surrounding voltage gradient.
No
Two aldehydes

7. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
Polyphenol Oxidase
Sucrose
Non-protein nitrogen
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

8. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Phenophylin
Nucleation or crystal formation and crystal growth.
Pectin methylesterase & polygalacturonase

9. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
A concentrate of microfibrillar proteins of fish muscle.
They act as catalysts - speeding the polymerization of acrylamide.
Gossypol (it is removed during the oil refining process)
Orange Juice

10. What are the limiting amino acids in corn - potato - and green peas?
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
Prolamines
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

11. What ketohexose is most significant to food chemists?
Racemic Mixture
Fructose
ERH=100 x Aw
Orange Juice

12. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Phenylketonuria
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Lipase

13. What is the common name for 9 12 - cis-cis-octa dienoic acid?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Linoleic Acid
Gossypol (it is removed during the oil refining process)
Racemic Mixture

14. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Carmelization and Maillard
Plasmids
Lysine - Arginine - and Histidine

15. What happens to chlorophyll on heating?
Olive Green
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Pheophytin forms
Lysine - Arginine - and Histidine

16. What does the acronym NPN stand for?
Chitin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Non-protein nitrogen
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

17. What does MSG stand for?
Parabens
Daminozide
Monosodium Glutamate
2.5

18. What are colloids that are stabilized by a layer of solvation called?
Anthocyanins
Emulsoids
Gossypol (it is removed during the oil refining process)
NaCl (it dissociated to a 2M solution)

19. Name 3 factors influencing the consistency of commercial fats.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
20 carbons and 4 double bonds
Daminozide

20. What are 3 mesomorphic structures associated with lipids in the liquid state?
Parabens
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.
Blue pigment in flowers
Lamellar; Hexagonal I - II; Cubic

21. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Initiation - Propagation - Termination
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
Sucrose
NaCl (it dissociated to a 2M solution)

22. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Acetoin
Fat Oxidation
Carrageenan
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

23. At low water activity What is the main deteriorative concern?
Lipid oxidation
Parabens
Sucrose
Browning of freshly cut surfaces of fruits and vegetables.

24. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
It explodes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

25. Name 3 factors influencing the rate of lipid oxidation in foods.
Initiation - Propagation - Termination
Bright green
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

26. Peptide bond formation results in the formation of what secondary compound?
Lysine - Arginine - and Histidine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Water
pH 3-5

27. What enzyme causes hyrolytic rancidity in milk?
Lipase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
They act as catalysts - speeding the polymerization of acrylamide.
NaCl (it dissociated to a 2M solution)

28. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
They act as catalysts - speeding the polymerization of acrylamide.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

29. What pigment was first designated as anthocyanins?
Troponins and Tropomyosin
Blue pigment in flowers
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Monosodium Glutamate

30. Name the three positively charged amino acids.
20 carbons and 4 double bonds
Browning of freshly cut surfaces of fruits and vegetables.
Lysine - Arginine - and Histidine
Oil in Water

31. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Non-protein nitrogen
Pectin Esterase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

32. What are soluble polymers of anhydro-galacturonic acid and its esters called?
A concentrate of microfibrillar proteins of fish muscle.
Water
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
Pectins

33. Name a naturally occurring protein sweetener.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Thamautin
Gossypol (it is removed during the oil refining process)
Capsaicin

34. Contains the lowest content of water
pH below positive charge; pH at no charge; pH above negative charge
Ascorbic Acid and Citric Acid
Ammonia - Water - Carbon Dioxide
Whole Milk

35. How can a molecular weight of protein - DNA - and RNA be determined?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Parabens
14
Sodium chloride reduces foam stability and sucrose improves foam stability.

36. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Degradation of protein and production of acid from sugar at the same time.
Gossypol (it is removed during the oil refining process)
Fat Oxidation

37. Name one way foam stability can be assessed.
Glycosides of anthocyanidins
Ascorbic Acid and Citric Acid
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.

38. What happens to chlorophyll on heating?
Pheophytin forms
.05
Degradation of protein and production of acid from sugar at the same time.
Polyphenol Oxidase

39. What is surimi?
Water
DNA transferred by cell to cell contact (bacterial sex).
A concentrate of microfibrillar proteins of fish muscle.
Prolamines

40. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
Gliadins and Glutenins
Water
Lipid oxidation

41. Does kosmotrophil ion discourage water structure?
Two aldehydes
No
Plasmids
A concentrate of microfibrillar proteins of fish muscle.

42. Name a naturally occurring protein sweetener.
Thamautin
pH 3-5
Fructose
Initiation - Propagation - and Termination

43. What is surimi?
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.
A concentrate of microfibrillar proteins of fish muscle.
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

44. How do sodium chloride and sucrose affect foam stability?
Two aldehydes
Pheophytia does not have magnesium in porphyrin ring.
It explodes
Sodium chloride reduces foam stability and sucrose improves foam stability.

45. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
No
Initiation - Propagation - and Termination
Bright green

46. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Four
Fructose
Linoleic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

47. How do sodium chloride and sucrose affect foam stability?
Pectins
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
The speed of a molecule is proportional to the surrounding voltage gradient.
Sodium chloride reduces foam stability and sucrose improves foam stability.

48. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Non-protein nitrogen
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Phenylketonuria
Lycopenes

49. What two types of compounds are joined with an ester bond to make a wax?
Pectin Esterase
Fatty Acid and Alcohol
Monosodium Glutamate
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

50. When heated ammonium bicarbonate decomposes to form what end products?
Thamautin
Polyphenol Oxidase
Fatty Acid (Ester linked) to Fatty Alcohol
Ammonia - Water - Carbon Dioxide