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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. Alar is the trade name for what chemical compound?
Initiation - Propagation - Termination
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
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
Daminozide

2. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Lipid oxidation
Orange Juice
NaCl (it dissociated to a 2M solution)
Degradation of protein and production of acid from sugar at the same time.

3. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Non-protein nitrogen
Oil in Water
Cis
Nucleation or crystal formation and crystal growth.

4. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Primary butyric acid also caproic acid.
Carmelization and Maillard
Polyphenols

5. Name two reasons why fats are hydrogenated.
Browning of freshly cut surfaces of fruits and vegetables.
Erythorbic Acid
Erythorbic Acid
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

6. What pigment was first designated as anthocyanins?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Blue pigment in flowers
Covalent (strongest) and Hydrophobic (Weakest)
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.

7. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
It explodes
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

8. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Water
Acsulfame-K - Saccharin - Cyclamate - Aspartame
D: None of the above

9. Name three non-nutritive sweeteners approved for use in USA?
Pectins
Non-protein nitrogen
NaCl (it dissociated to a 2M solution)
Acsulfame-K - Saccharin - Cyclamate - Aspartame

10. What is the major color compound in tomatoes?
Daminozide
Pectins
Lycopenes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

11. Are sorbitol and mannitol sweet?
Yellow
Yes
.05
Chlocophyllide does not have a phytoltail

12. Name three factors useful in controlling enzyme activity.
RNA transcribed to DNA
Fat Oxidation
Capsaicin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

13. What does Acid Degree Value measure and how is it measured?
Pectin methyl esterase or galacturonase
Emulsification
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

14. Alar is the trade name for what chemical compound?
Thickener in foods
Fat Oxidation
Daminozide
Pectin Esterase - Polygalacturonase - Pectin Layase

15. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Oil in Water
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
A concentrate of microfibrillar proteins of fish muscle.
Polyphenoloxidase

16. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
D: None of the above
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenoloxidase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

17. What is the enzyme that softens tomatoes?
NaCl (it dissociated to a 2M solution)
Pectin Esterase
Carrageenan
Fatty Acid and Alcohol

18. Name 3 factors influencing the consistency of commercial fats.
Arachidonic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Chlocophyllide does not have a phytoltail
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

19. What is a polymorphism?
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.
NaCl (it dissociated to a 2M solution)
Daminozide

20. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Yes
Chitin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Primary butyric acid also caproic acid.

21. Name the three positively charged amino acids.
Lycopenes
20 carbons and 4 double bonds
Carmelization and Maillard
Lysine - Arginine - and Histidine

22. What is the name of the degradation compound of chlorophyll?
Phenophylin
Browning of freshly cut surfaces of fruits and vegetables.
Speed of Light
Ascorbic Acid and Citric Acid

23. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Water
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Nucleation or crystal formation and crystal growth.

24. Name the strongest biochemical bond and the weakest biochemical bond.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Daminozide
Covalent (strongest) and Hydrophobic (Weakest)
ERH=100 x Aw

25. What is Carboxy-methyl cellulose often used for?
Pectin Esterase - Polygalacturonase - Pectin Layase
Thickener in foods
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Carmelization and Maillard

26. What is the geometric configuration of double bonds in most natural fatty acids?
NaCl (it dissociated to a 2M solution)
Cis
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

27. Name 5 chelating agents used in the food industry.
Whole Milk
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Carmelization and Maillard

28. What ketohexose is most significant to food chemists?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Fructose

29. What is the structural difference between chlorophyll and pheophytia?
HPLC has higher pressure than FPLC
Pheophytia does not have magnesium in porphyrin ring.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Plasmids

30. What is the enzyme that softens tomatoes?
Prolamines
pH 3-5
Milk
Pectin Esterase

31. How many carbon atoms are there in the fatty acid myristic acid?
14
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Water
Polyphenol Oxidase

32. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Yes
Two aldehydes
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

33. What are the fructose contents in commercial HFCS products.
Milk
Gossypol (it is removed during the oil refining process)
45% - 52% - 90%
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

34. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Monosodium Glutamate
Carrageenan
Phenophylin

35. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
45% - 52% - 90%
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.
Bitter
Chitin

36. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Anomeric
Blue pigment in flowers

37. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
14
Sucrose
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

38. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lipid oxidation
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

39. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Covalent (strongest) and Hydrophobic (Weakest)
Pectins
Capsaicin

40. 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.
Water
20 carbons and 4 double bonds
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

41. Name three nonpolar polar - and charged amino acids.
Pectin Esterase
Thamautin
Thamautin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

42. How does ERH relate to water activity?
45% - 52% - 90%
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Plasmids
ERH=100 x Aw

43. What is the structural difference between chlorophyll and chlocophyllide?
DNA transferred by cell to cell contact (bacterial sex).
Chlocophyllide does not have a phytoltail
Parabens
RNA transcribed to DNA

44. What is the Peroxide Value a measure of?
Fat Oxidation
Polyphenoloxidase
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
Gliadins and Glutenins

45. At low water activity What is the main deteriorative concern?
Lipid oxidation
Phenylketonuria
Water
Milk

46. What are the primary secondary - tertiary - and quaternary structures?
Pheophytin forms
pH below positive charge; pH at no charge; pH above negative charge
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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

47. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Non-protein nitrogen
Tryptophan
Thermus Aqauticus
NaCl (it dissociated to a 2M solution)

48. In the enzyme Taq Polymerase What does Taq stand for?
Troponins and Tropomyosin
NaCl (it dissociated to a 2M solution)
Thermus Aqauticus
Primary butyric acid also caproic acid.

49. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Covalent (strongest) and Hydrophobic (Weakest)
Phenophylin
Olive Green
Phenophylin

50. Are sorbitol and mannitol sweet?
Yes
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Sodium chloride reduces foam stability and sucrose improves foam stability.