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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 enzyme is most responsible for browning bananas?
Yellow
.05 M HCL
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase

2. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Fatty Acid (Ester linked) to Fatty Alcohol
Two aldehydes
Monosodium Glutamate

3. Name 3 chemical agents capable of denaturing proteins.
No
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Primary butyric acid also caproic acid.
Anomeric

4. What compounds oxidize to form brown color in fruits and vegetables?
Degradation of protein and production of acid from sugar at the same time.
Polyphenols
Parabens
Chlocophyllide does not have a phytoltail

5. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
It explodes
They act as catalysts - speeding the polymerization of acrylamide.
Chitin

6. Contains the lowest content of water
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Whole Milk
pH below positive charge; pH at no charge; pH above negative charge
Erythorbic Acid

7. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Acetoin
Plasmids
pH below positive charge; pH at no charge; pH above negative charge
Tryptophan

8. Name the most common functional property of phospholipids in food systems.
Initiation - Propagation - and Termination
Troponins and Tropomyosin
Non-protein nitrogen
Emulsification

9. Does kosmotrophil ion discourage water structure?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
No
Gliadins and Glutenins
Carrageenan

10. Name 5 proteins with good foaming properties.
Browning of freshly cut surfaces of fruits and vegetables.
They act as catalysts - speeding the polymerization of acrylamide.
Water
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.

11. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
ERH=100 x Aw
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
Ammonia - Water - Carbon Dioxide

12. Alar is the trade name for what chemical compound?
D: None of the above
Daminozide
Pectins
pH below positive charge; pH at no charge; pH above negative charge

13. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
A concentrate of microfibrillar proteins of fish muscle.
Degradation of protein and production of acid from sugar at the same time.
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

14. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
.05 M HCL

15. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
20 carbons and 4 double bonds
Browning of freshly cut surfaces of fruits and vegetables.
Capsaicin
The speed of a molecule is proportional to the surrounding voltage gradient.

16. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Onions ( or leeks)
ERH=100 x Aw
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

17. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Lamellar; Hexagonal I - II; Cubic
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Carmelization and Maillard

18. Name 5 chelating agents used in the food industry.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Fatty Acid and Alcohol
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

19. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Thermus Aqauticus
Speed of Light
Two aldehydes

20. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Yes
.05 M HCL
Olive Green
Osmosis

21. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Tryptophan
Osmosis
Fatty Acid (Ester linked) to Fatty Alcohol
Bright green

22. What are the three stages of oxidative rancidity?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Yes
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Initiation - Propagation - and Termination

23. 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.
Yellow
pH below positive charge; pH at no charge; pH above negative charge
Tryptophan

24. 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
They act as catalysts - speeding the polymerization of acrylamide.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
D: None of the above

25. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Ammonia - Water - Carbon Dioxide
Aspartic Acid and Phenylalanine
Daminozide

26. What does the iodine value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Phenophylin
Chlocophyllide does not have a phytoltail

27. Name one way foam stability can be assessed.
Gliadins and Glutenins
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.
Linoleic Acid
Initiation - Propagation - Termination

28. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Tryptophan
NaCl (it dissociated to a 2M solution)
Emulsification
.05 M HCL

29. Will lipid oxidation be higher at a water activity of .05 or .5?
Sweet - Salty - Sour - and Bitter
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
.05
Negative log of the hydrogen concentration (mol/l).

30. When heated ammonium bicarbonate decomposes to form what end products?
Chitin
20 carbons and 4 double bonds
Ammonia - Water - Carbon Dioxide
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

31. What is the acid present in fish oil?
Pectin methylesterase & polygalacturonase
Anthocyanins
Arachidonic Acid
Parabens

32. Name 3 factors influencing the rate of lipid oxidation in foods.
Anomeric
Chlocophyllide does not have a phytoltail
The speed of a molecule is proportional to the surrounding voltage gradient.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

33. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Yellow
Browning of freshly cut surfaces of fruits and vegetables.
HPLC has higher pressure than FPLC

34. 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?
Osmosis
Pectin methyl esterase or galacturonase
Emulsoids
.05 M HCL

35. 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
Browning of freshly cut surfaces of fruits and vegetables.
Chlocophyllide does not have a phytoltail
D: None of the above
Fatty Acid (Ester linked) to Fatty Alcohol

36. Name 5 chelating agents used in the food industry.
Pectins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Thamautin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

37. What are the fructose contents in commercial HFCS products.
Anomeric
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
45% - 52% - 90%

38. Name two reasons why fats are hydrogenated.
Pectin methylesterase & polygalacturonase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectin methylesterase & polygalacturonase

39. What is surimi?
20 carbons and 4 double bonds
14
A concentrate of microfibrillar proteins of fish muscle.
Gliadins and Glutenins

40. How does HPLC differ from FPLC?
Lamellar; Hexagonal I - II; Cubic
Gliadins and Glutenins
HPLC has higher pressure than FPLC
Olive Green

41. 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
14
Monosodium Glutamate
ERH=100 x Aw
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

42. What happens to chlorophyll on heating?
45% - 52% - 90%
2.5
Pheophytin forms
Fatty Acid and Alcohol

43. Alar is the trade name for what chemical compound?
Daminozide
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Primary butyric acid also caproic acid.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

44. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Pectin methylesterase & polygalacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.

45. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Onions ( or leeks)
Pectin methyl esterase or galacturonase
Olive Green

46. What two enzymes degrade pectic substances?
Chitin
Yellow
Pectin methylesterase & polygalacturonase
Lamellar; Hexagonal I - II; Cubic

47. Is a disaccharide
45% - 52% - 90%
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sucrose
Degradation of protein and production of acid from sugar at the same time.

48. How many carbon atoms are there in the fatty acid myristic acid?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Sucrose
14
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

49. What are 3 mesomorphic structures associated with lipids in the liquid state?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lamellar; Hexagonal I - II; Cubic
Monosodium Glutamate
Browning of freshly cut surfaces of fruits and vegetables.

50. Name 3 factors influencing the consistency of commercial fats.
Cis
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Phenophylin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.