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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. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lipase
DNA transferred by cell to cell contact (bacterial sex).
Lamellar; Hexagonal I - II; Cubic

2. Waxes are composed of what two basic chemical entities?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Polyphenols
Fatty Acid (Ester linked) to Fatty Alcohol
Blue pigment in flowers

3. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Fructose
Ascorbic Acid and Citric Acid
Oil in Water
Yellow

4. What two common compounds are used together as an antioxidative system?
Fatty Acid (Ester linked) to Fatty Alcohol
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Ascorbic Acid and Citric Acid
Bright green

5. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
14
Ascorbic Acid and Citric Acid
V=IR and P=VI or I x I x are

6. What is the geometric configuration of double bonds in most natural fatty acids?
Fatty Acid (Ester linked) to Fatty Alcohol
Cis
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
It explodes

7. How many carbon atoms are there in the fatty acid myristic acid?
Lipid oxidation
ERH=100 x Aw
Daminozide
14

8. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Aspartic Acid and Phenylalanine
They act as catalysts - speeding the polymerization of acrylamide.
Oil in Water
Milk

9. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
14
Aspartic Acid and Phenylalanine
Parabens

10. At low water activity What is the main deteriorative concern?
Lipid oxidation
Emulsification
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
.05 M HCL

11. What happens to chlorophyll on heating?
pH 3-5
Thamautin
Pheophytin forms
Lipase

12. Name a naturally occurring protein sweetener.
Water
Thamautin
Linoleic Acid
Arachidonic Acid

13. 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
Bitter
Pectins
HPLC has higher pressure than FPLC

14. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It explodes
RNA transcribed to DNA

15. What is the major color compound in tomatoes?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Lycopenes
Orange Juice
Prolamines

16. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in 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
Polyphenol Oxidase
HPLC has higher pressure than FPLC

17. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Orange Juice
Tryptophan
Sodium bicarbonate generates CO2

18. What does the 'c' stand for in the equation E=mc2?
Degradation of protein and production of acid from sugar at the same time.
Covalent (strongest) and Hydrophobic (Weakest)
Gliadins and Glutenins
Speed of Light

19. In the enzyme Taq Polymerase What does Taq stand for?
It explodes
Sweet - Salty - Sour - and Bitter
Lipid oxidation
Thermus Aqauticus

20. What compounds oxidize to form brown color in fruits and vegetables?
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
HPLC has higher pressure than FPLC
Polyphenols
Plasmids

21. What does the 'c' stand for in the equation E=mc2?
Two aldehydes
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Speed of Light
45% - 52% - 90%

22. Alar is the trade name for what chemical compound?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Gossypol (it is removed during the oil refining process)
Daminozide
Linoleic Acid

23. What is the major color compound in tomatoes?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lycopenes
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.
ERH=100 x Aw

24. How many carbon atoms are there in the fatty acid myristic acid?
Pheophytia does not have magnesium in porphyrin ring.
Fructose
Degradation of protein and production of acid from sugar at the same time.
14

25. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Initiation - Propagation - Termination
Orange Juice
ERH=100 x Aw

26. What is the name of the degradation compound of chlorophyll?
1 - 3 - 7-trimethylxanthine
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Phenophylin
45% - 52% - 90%

27. Define molarity molality - and normality.
Acetoin
Bright green
Water
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

28. What is the enzyme that softens tomatoes?
Plasmids
Pectin Esterase
Lamellar; Hexagonal I - II; Cubic
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

29. Name three non-nutritive sweeteners approved for use in USA?
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
20 carbons and 4 double bonds
Gliadins and Glutenins

30. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Gossypol (it is removed during the oil refining process)
Yes
Pectin methylesterase & polygalacturonase

31. 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
Daminozide
V=IR and P=VI or I x I x are
Monosodium Glutamate

32. What does the saponification value measure and how is it measured?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Primary butyric acid also caproic acid.
Thickener in foods

33. What does the iodine value measure and how is it measured?
Browning of freshly cut surfaces of fruits and vegetables.
Prolamines
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
.05

34. Name three non-nutritive sweeteners approved for use in USA?
2.5
Acetoin
Thickener in foods
Acsulfame-K - Saccharin - Cyclamate - Aspartame

35. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Parabens
No

36. How many polypeptide chains make up an antibody?
Four
Water
Lycopenes
Phenophylin

37. Name 3 physical agents capable of denaturing proteins.
Sweet - Salty - Sour - and Bitter
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Pectin methyl esterase or galacturonase
Fat Oxidation

38. At what pH is benzoic acid most effective?
Pheophytin forms
Linoleic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
pH 3-5

39. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Pheophytia does not have magnesium in porphyrin ring.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
NaCl (it dissociated to a 2M solution)
Orange Juice

40. Name the three positively charged amino acids.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Daminozide
Lysine - Arginine - and Histidine
Polyphenol Oxidase

41. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Anthocyanins

42. What are the three main steps in the autooxidation of lipids?
Polyphenols
Prolamines
No
Initiation - Propagation - Termination

43. Name three factors useful in controlling enzyme activity.
.05
Sodium chloride reduces foam stability and sucrose improves foam stability.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

44. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
ERH=100 x Aw
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenols

45. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Browning of freshly cut surfaces of fruits and vegetables.
They act as catalysts - speeding the polymerization of acrylamide.
Linoleic Acid
Tryptophan

46. What does MSG stand for?
Monosodium Glutamate
.05
Fatty Acid and Alcohol
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

47. What are the three main steps in the autooxidation of lipids?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty Acid and Alcohol
Initiation - Propagation - Termination
Nucleation or crystal formation and crystal growth.

48. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Parabens
Onions ( or leeks)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

49. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
pH 3-5
Lysine - Arginine - and Histidine
Sodium chloride reduces foam stability and sucrose improves foam stability.

50. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Glycosides of anthocyanidins
Capsaicin
Chlocophyllide does not have a phytoltail
2.5