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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. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Degradation of protein and production of acid from sugar at the same time.
Aspartic Acid and Phenylalanine
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Polyphenol Oxidase

2. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Bright green
Bitter

3. What does HLB stand for and What does a high and low HLB value indicate?
Sweet - Salty - Sour - and Bitter
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.
Speed of Light
ERH=100 x Aw

4. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
No
Pheophytia does not have magnesium in porphyrin ring.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

5. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Sweet - Salty - Sour - and Bitter
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Browning of freshly cut surfaces of fruits and vegetables.

6. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
Lycopenes
Fatty Acid and Alcohol
Two aldehydes

7. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Oil in Water
Lysine - Arginine - and Histidine
Chitin

8. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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.
1 - 3 - 7-trimethylxanthine

9. Name three effects of protein denaturation.
Fatty Acid and Alcohol
Sucrose
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lipid oxidation

10. What enzyme is most responsible for browning bananas?
14
Nucleation or crystal formation and crystal growth.
Polyphenol Oxidase
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. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lamellar; Hexagonal I - II; Cubic
Orange Juice
Olive Green

12. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Speed of Light
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
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

13. Which two amino acids is the aspartame derived from?
Emulsification
Sucrose
Aspartic Acid and Phenylalanine
2.5

14. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
No
Emulsoids
Thamautin

15. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Polyphenoloxidase
Pectin Esterase - Polygalacturonase - Pectin Layase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

16. Name 3 physical agents capable of denaturing proteins.
Two aldehydes
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Acetoin
pH 3-5

17. What is a polymorphism?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
An enzyme that converts hydrogen peroxide to water plus oxygen.
A concentrate of microfibrillar proteins of fish muscle.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

18. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Bitter
NaCl (it dissociated to a 2M solution)
Racemic Mixture

19. What effect would the addition of sodium bicarbonate have to chocolate?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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

20. What two types of compounds are joined with an ester bond to make a wax?
Polyphenoloxidase
Fatty Acid and Alcohol
Browning of freshly cut surfaces of fruits and vegetables.
Chlocophyllide does not have a phytoltail

21. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Lipase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin methyl esterase or galacturonase
Carrageenan

22. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
.05
Capsaicin
DNA transferred by cell to cell contact (bacterial sex).
HPLC has higher pressure than FPLC

23. Define molarity molality - and normality.
Emulsoids
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
2.5
Acsulfame-K - Saccharin - Cyclamate - Aspartame

24. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
.05 M HCL
Covalent (strongest) and Hydrophobic (Weakest)
Onions ( or leeks)

25. How does ERH relate to water activity?
.05 M HCL
ERH=100 x Aw
Four
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

26. Name a naturally occurring protein sweetener.
Yellow
Thamautin
Browning of freshly cut surfaces of fruits and vegetables.
Lycopenes

27. In what food is butyric acid typically found?
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.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Carmelization and Maillard
Milk

28. What does MSG stand for?
Monosodium Glutamate
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Anomeric
D: None of the above

29. How does ERH relate to water activity?
Capsaicin
The speed of a molecule is proportional to the surrounding voltage gradient.
Bright green
ERH=100 x Aw

30. What are the limiting amino acids in corn - potato - and green peas?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
The speed of a molecule is proportional to the surrounding voltage gradient.
Pheophytin forms
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

31. What two common compounds are used together as an antioxidative system?
HPLC has higher pressure than FPLC
Degradation of protein and production of acid from sugar at the same time.
Covalent (strongest) and Hydrophobic (Weakest)
Ascorbic Acid and Citric Acid

32. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Daminozide
Thermus Aqauticus
Sodium chloride reduces foam stability and sucrose improves foam stability.
Linoleic Acid

33. What is the name given to a mixture of equal parts of Darel Lisomers?
Chitin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Racemic Mixture
V=IR and P=VI or I x I x are

34. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Gossypol (it is removed during the oil refining process)
Polyphenoloxidase

35. How many polypeptide chains make up an antibody?
Lycopenes
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Four
RNA transcribed to DNA

36. In genetics What is conjugation?
It explodes
Osmosis
DNA transferred by cell to cell contact (bacterial sex).
Cis

37. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
DNA transferred by cell to cell contact (bacterial sex).
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Yellow
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

38. How do sodium chloride and sucrose affect foam stability?
2.5
Pectin Esterase - Polygalacturonase - Pectin Layase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pheophytin forms

39. Name 3 factors influencing the rate of lipid oxidation in foods.
Bright green
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Thamautin
Glycosides of anthocyanidins

40. Are sorbitol and mannitol sweet?
Yes
Polyphenoloxidase
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
Pheophytin forms

41. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lipase
Degradation of protein and production of acid from sugar at the same time.
Emulsification

42. Define molarity molality - and normality.
Browning of freshly cut surfaces of fruits and vegetables.
Anthocyanins
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 carbons and 4 double bonds

43. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Emulsoids
Anomeric
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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. 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
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
D: None of the above
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectins

45. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lysine - Arginine - and Histidine

46. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Non-protein nitrogen
Cis
Aspartic Acid and Phenylalanine

47. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
NaCl (it dissociated to a 2M solution)
Primary butyric acid also caproic acid.
Fat Oxidation

48. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Sucrose
Polyphenol Oxidase
Chlocophyllide does not have a phytoltail

49. What are the fructose contents in commercial HFCS products.
Polyphenol Oxidase
45% - 52% - 90%
Pectin Esterase - Polygalacturonase - Pectin Layase
14

50. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Onions ( or leeks)
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.
Orange Juice