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Food Chemistry

Instructions:

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 is Ohm's Law and What is Power Equation?
Gossypol (it is removed during the oil refining process)
Glycosides of anthocyanidins
Polyphenol Oxidase
V=IR and P=VI or I x I x are

2. How many carbon atoms are there in the fatty acid myristic acid?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
14
Pectin methylesterase & polygalacturonase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

3. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Osmosis
Carmelization and Maillard
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

4. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Polyphenol Oxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Fatty Acid (Ester linked) to Fatty Alcohol
Tryptophan

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

6. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
.05
Phenylketonuria
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.

7. 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 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.
Non-protein nitrogen
Water
Phenylketonuria

8. What does Acid Degree Value measure and how is it measured?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
V=IR and P=VI or I x I x are
Pheophytia does not have magnesium in porphyrin ring.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

9. How is pH defined?
20 carbons and 4 double bonds
Negative log of the hydrogen concentration (mol/l).
Daminozide
Chitin

10. Name the strongest biochemical bond and the weakest biochemical bond.
DNA transferred by cell to cell contact (bacterial sex).
Polyphenols
Covalent (strongest) and Hydrophobic (Weakest)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

11. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Initiation - Propagation - and Termination
Aspartic Acid and Phenylalanine
Prolamines

12. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Thickener in foods
Erythorbic Acid
Yellow

13. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Polyphenoloxidase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

14. Waxes are composed of what two basic chemical entities?
Polyphenols
Sodium chloride reduces foam stability and sucrose improves foam stability.
Fatty Acid (Ester linked) to Fatty Alcohol
RNA transcribed to DNA

15. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
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.
Daminozide
Thamautin

16. Name two non-enzymatic browning reactions.
A concentrate of microfibrillar proteins of fish muscle.
Pectin methyl esterase or galacturonase
Carmelization and Maillard
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

17. What is the fundamental driving of electrophoresis?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Polyphenoloxidase
Osmosis
The speed of a molecule is proportional to the surrounding voltage gradient.

18. Will lipid oxidation be higher at a water activity of .05 or .5?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Two aldehydes
.05

19. Name the three positively charged amino acids.
Olive Green
Thickener in foods
Lysine - Arginine - and Histidine
Onions ( or leeks)

20. Name the most common functional property of phospholipids in food systems.
Emulsification
RNA transcribed to DNA
.05 M HCL
Phenylketonuria

21. Name 5 proteins with good foaming properties.
Whole Milk
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Acetoin
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.

22. What pigment was first designated as anthocyanins?
Orange Juice
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Blue pigment in flowers
Monosodium Glutamate

23. What two enzymes degrade pectic substances?
Lycopenes
Gliadins and Glutenins
Pectin methylesterase & polygalacturonase
They act as catalysts - speeding the polymerization of acrylamide.

24. What is catalase?
Emulsification
A concentrate of microfibrillar proteins of fish muscle.
Parabens
An enzyme that converts hydrogen peroxide to water plus oxygen.

25. What happens to chlorophyll on heating?
Ascorbic Acid and Citric Acid
Blue pigment in flowers
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pheophytin forms

26. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
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.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
V=IR and P=VI or I x I x are
Capsaicin

27. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Plasmids
Blue pigment in flowers
RNA transcribed to DNA

28. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
V=IR and P=VI or I x I x are

29. What is the major color compound in tomatoes?
Blue pigment in flowers
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

30. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Osmosis
Ascorbic Acid and Citric Acid
NaCl (it dissociated to a 2M solution)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

31. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Carrageenan
pH below positive charge; pH at no charge; pH above negative charge
.05
Phenylketonuria

32. Name a commonly used household chemical leavening agent and the gas it generates.
Carmelization and Maillard
Sodium bicarbonate generates CO2
Osmosis
Non-protein nitrogen

33. Name the two components that comprise the relaxing factor in muscle fibers.
The speed of a molecule is proportional to the surrounding voltage gradient.
HPLC has higher pressure than FPLC
Troponins and Tropomyosin
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

34. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Degradation of protein and production of acid from sugar at the same time.
Capsaicin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

35. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Polyphenoloxidase
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Acsulfame-K - Saccharin - Cyclamate - Aspartame

36. What are the four basic flavors perceived by the tongue?
Fatty Acid (Ester linked) to Fatty Alcohol
pH below positive charge; pH at no charge; pH above negative charge
Sweet - Salty - Sour - and Bitter
pH below positive charge; pH at no charge; pH above negative charge

37. 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?
.05 M HCL
pH below positive charge; pH at no charge; pH above negative charge
Lamellar; Hexagonal I - II; Cubic
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

38. 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
Two aldehydes
Browning of freshly cut surfaces of fruits and vegetables.
Pheophytin forms
Emulsification

39. 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.
Four
Fat Oxidation
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

40. What compounds oxidize to form brown color in fruits and vegetables?
Emulsoids
Sodium bicarbonate generates CO2
NaCl (it dissociated to a 2M solution)
Polyphenols

41. What is a polymorphism?
45% - 52% - 90%
1 - 3 - 7-trimethylxanthine
Water
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

42. What is an isomer that is cheaper than Vitamin C?
Emulsoids
Erythorbic Acid
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
No

43. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Sucrose
Negative log of the hydrogen concentration (mol/l).
Pectins

44. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Initiation - Propagation - and Termination
Racemic Mixture
Bright green

45. What is the name of the degradation compound of chlorophyll?
Carrageenan
Polyphenol Oxidase
Water
Phenophylin

46. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Lipid oxidation
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Anomeric

47. Peptide bond formation results in the formation of what secondary compound?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytin forms
D: None of the above
Water

48. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
DNA transferred by cell to cell contact (bacterial sex).
Sodium chloride reduces foam stability and sucrose improves foam stability.
Sodium bicarbonate generates CO2
Plasmids

49. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pheophytin forms
Parabens
Two aldehydes
Anomeric

50. How does HPLC differ from FPLC?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.
Yes
HPLC has higher pressure than FPLC