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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. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Sweet - Salty - Sour - and Bitter
Sodium chloride reduces foam stability and sucrose improves foam stability.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

2. What two enzymes degrade pectic substances?
Aspartic Acid and Phenylalanine
Monosodium Glutamate
V=IR and P=VI or I x I x are
Pectin methylesterase & polygalacturonase

3. What is surimi?
Sucrose
A concentrate of microfibrillar proteins of fish muscle.
Two aldehydes
Yes

4. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
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.
Polyphenoloxidase
Thermus Aqauticus

5. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
An enzyme that converts hydrogen peroxide to water plus oxygen.
Degradation of protein and production of acid from sugar at the same time.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

6. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
14
Orange Juice
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.

7. What does the saponification value measure and how is it measured?
Fatty Acid (Ester linked) to Fatty Alcohol
Lipid oxidation
Monosodium Glutamate
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

8. What is the enzyme that softens tomatoes?
Bright green
Sucrose
Gossypol (it is removed during the oil refining process)
Pectin Esterase

9. What does Reichert-Meissert Number measure?
Acetoin
Ammonia - Water - Carbon Dioxide
Primary butyric acid also caproic acid.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

10. Name three factors useful in controlling enzyme activity.
Sucrose
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
HPLC has higher pressure than FPLC
Oil in Water

11. How many carbon atoms are there in the fatty acid myristic acid?
14
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
.05 M HCL
Thermus Aqauticus

12. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Phenophylin
pH 3-5
Acsulfame-K - Saccharin - Cyclamate - Aspartame

13. What is the Peroxide Value a measure of?
Thickener in foods
Plasmids
Olive Green
Fat Oxidation

14. 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?
Speed of Light
V=IR and P=VI or I x I x are
.05 M HCL
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

15. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lipase
Polyphenol Oxidase

16. What does the saponification value measure and how is it measured?
Chitin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

17. What ketohexose is most significant to food chemists?
2.5
Daminozide
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

18. What are the only phenols approved for use in the microbiological preservation of foods?
Anthocyanins
Parabens
pH 3-5
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

19. At low water activity What is the main deteriorative concern?
Tryptophan
Blue pigment in flowers
Lipid oxidation
Sodium chloride reduces foam stability and sucrose improves foam stability.

20. In genetics What is conjugation?
Initiation - Propagation - Termination
DNA transferred by cell to cell contact (bacterial sex).
Two aldehydes
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

21. What is catalase?
D: None of the above
Milk
An enzyme that converts hydrogen peroxide to water plus oxygen.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

22. 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
D: None of the above
Daminozide
Chitin
Capsaicin

23. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Lipid oxidation
Capsaicin
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
Anomeric

24. What is the main class of color compounds found in raspberries?
Gliadins and Glutenins
Troponins and Tropomyosin
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Anthocyanins

25. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Linoleic Acid

26. 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?
Aspartic Acid and Phenylalanine
Monosodium Glutamate
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Negative log of the hydrogen concentration (mol/l).

27. Name one way foam stability can be assessed.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic 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.
Yellow

28. What two types of compounds are joined with an ester bond to make a wax?
NaCl (it dissociated to a 2M solution)
Fatty Acid and Alcohol
20 carbons and 4 double bonds
Milk

29. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
14
Lysine - Arginine - and Histidine
Bitter
NaCl (it dissociated to a 2M solution)

30. Waxes are composed of what two basic chemical entities?
Ascorbic Acid and Citric Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fatty Acid (Ester linked) to Fatty Alcohol
HPLC has higher pressure than FPLC

31. What is the fundamental driving of electrophoresis?
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.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fatty Acid (Ester linked) to Fatty Alcohol
The speed of a molecule is proportional to the surrounding voltage gradient.

32. Name two non-enzymatic browning reactions.
Lipase
NaCl (it dissociated to a 2M solution)
Carmelization and Maillard
D: None of the above

33. Name two reasons why fats are hydrogenated.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
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
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

34. What are two common reducing agents that break disulfide bonds in proteins?
Thickener in foods
2.5
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Yes

35. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Bitter
Onions ( or leeks)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

36. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Bitter
Anomeric
Pectin Esterase - Polygalacturonase - Pectin Layase

37. Name three effects of protein denaturation.
Primary butyric acid also caproic acid.
Orange Juice
Fat Oxidation
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

38. Name three nonpolar polar - and charged amino acids.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

39. What are the three stages of oxidative rancidity?
Gliadins and Glutenins
Initiation - Propagation - and Termination
Tryptophan
Degradation of protein and production of acid from sugar at the same time.

40. Does kosmotrophil ion discourage water structure?
No
Onions ( or leeks)
They act as catalysts - speeding the polymerization of acrylamide.
Pectin Esterase

41. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Pheophytia does not have magnesium in porphyrin ring.
Capsaicin
It explodes
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

42. What is the winterization process for an oil?
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
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Onions ( or leeks)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

43. What happens to chlorophyll on heating?
Glycosides of anthocyanidins
Pheophytin forms
Carmelization and Maillard
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

44. 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.
Gliadins and Glutenins
Prolamines
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

45. What is Carboxy-methyl cellulose often used for?
Lysine - Arginine - and Histidine
Thickener in foods
Phenylketonuria
Lamellar; Hexagonal I - II; Cubic

46. How many polypeptide chains make up an antibody?
Emulsoids
Four
Thamautin
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

47. During freezing What are the two stages in the crystallization process?
Fructose
Nucleation or crystal formation and crystal growth.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Primary butyric acid also caproic acid.

48. What does HLB stand for and What does a high and low HLB value indicate?
Four
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.
Carrageenan
Covalent (strongest) and Hydrophobic (Weakest)

49. Name the strongest biochemical bond and the weakest biochemical bond.
Lysine - Arginine - and Histidine
HPLC has higher pressure than FPLC
Oil in Water
Covalent (strongest) and Hydrophobic (Weakest)

50. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Primary butyric acid also caproic acid.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Ascorbic Acid and Citric Acid