Test your basic knowledge |

Food Chemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. Which two amino acids is the aspartame derived from?
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Aspartic Acid and Phenylalanine

2. What compounds oxidize to form brown color in fruits and vegetables?
D: None of the above
Chitin
Prolamines
Polyphenols

3. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Bright green
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Two aldehydes

4. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Cis
Onions ( or leeks)
Primary butyric acid also caproic acid.
The speed of a molecule is proportional to the surrounding voltage gradient.

5. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Osmosis
.05
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

6. What does the saponification value measure and how is it measured?
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.
Primary butyric acid also caproic acid.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Gossypol (it is removed during the oil refining process)

7. What is an isomer that is cheaper than Vitamin C?
Thickener in foods
Erythorbic Acid
Daminozide
Thickener in foods

8. What is the chemical nomenclature for caffeine?
Carrageenan
1 - 3 - 7-trimethylxanthine
They act as catalysts - speeding the polymerization of acrylamide.
Lipase

9. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Osmosis
Emulsoids
Bright green

10. How do sodium chloride and sucrose affect foam stability?
Carmelization and Maillard
1 - 3 - 7-trimethylxanthine
Monosodium Glutamate
Sodium chloride reduces foam stability and sucrose improves foam stability.

11. In what food is butyric acid typically found?
Carmelization and Maillard
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Milk
Browning of freshly cut surfaces of fruits and vegetables.

12. What enzyme is most responsible for browning bananas?
Browning of freshly cut surfaces of fruits and vegetables.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Polyphenol Oxidase
Fatty Acid and Alcohol

13. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
2.5
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

14. Name 5 chelating agents used in the food industry.
Anthocyanins
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Bright green
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

15. Name two non-enzymatic browning reactions.
Pectin Esterase - Polygalacturonase - Pectin Layase
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.
Carmelization and Maillard
ERH=100 x Aw

16. Name the three positively charged amino acids.
Lipid oxidation
Oil in Water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lysine - Arginine - and Histidine

17. Is a disaccharide
ERH=100 x Aw
Sucrose
Fatty Acid (Ester linked) to Fatty Alcohol
Whole Milk

18. 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
Initiation - Propagation - Termination
Primary butyric acid also caproic acid.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

19. 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
A concentrate of microfibrillar proteins of fish muscle.
They act as catalysts - speeding the polymerization of acrylamide.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

20. Contains the lowest content of water
Thamautin
Whole Milk
Sodium bicarbonate generates CO2
Gossypol (it is removed during the oil refining process)

21. What is an isomer that is cheaper than Vitamin C?
Degradation of protein and production of acid from sugar at the same time.
Erythorbic Acid
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.
Carmelization and Maillard

22. What metabolic end product does the Voges-Proskauer test detect?
A concentrate of microfibrillar proteins of fish muscle.
Acetoin
Sodium bicarbonate generates CO2
Water

23. When heated ammonium bicarbonate decomposes to form what end products?
Arachidonic Acid
Ammonia - Water - Carbon Dioxide
A concentrate of microfibrillar proteins of fish muscle.
Negative log of the hydrogen concentration (mol/l).

24. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Orange Juice
Polyphenoloxidase
Monosodium Glutamate
Acsulfame-K - Saccharin - Cyclamate - Aspartame

25. Name 3 factors influencing the consistency of commercial fats.
Capsaicin
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Carmelization and Maillard

26. Name the most common functional property of phospholipids in food systems.
Emulsification
Water
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.
Blue pigment in flowers

27. Name 4 advantages of using enzymes in food processing.
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
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.
Prolamines
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.

28. Name three non-nutritive sweeteners approved for use in USA?
Lipase
An enzyme that converts hydrogen peroxide to water plus oxygen.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
1 - 3 - 7-trimethylxanthine

29. What does the 'c' stand for in the equation E=mc2?
Olive Green
Nucleation or crystal formation and crystal growth.
Speed of Light
Primary butyric acid also caproic acid.

30. What are the primary secondary - tertiary - and quaternary structures?
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.
Tryptophan
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

31. What are the three stages of oxidative rancidity?
V=IR and P=VI or I x I x are
Emulsoids
Acetoin
Initiation - Propagation - and Termination

32. In the enzyme Taq Polymerase What does Taq stand for?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Thermus Aqauticus
Onions ( or leeks)
Erythorbic Acid

33. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

34. 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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
D: None of the above
Four

35. What does the saponification value measure and how is it measured?
Cis
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Carmelization and Maillard
Aspartic Acid and Phenylalanine

36. What are the three stages of oxidative rancidity?
Prolamines
The speed of a molecule is proportional to the surrounding voltage gradient.
Initiation - Propagation - and Termination
Phenophylin

37. What is the name given to a mixture of equal parts of Darel Lisomers?
Erythorbic Acid
Degradation of protein and production of acid from sugar at the same time.
Racemic Mixture
Osmosis

38. 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
Sweet - Salty - Sour - and Bitter
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
Fatty Acid and Alcohol

39. How does HPLC differ from FPLC?
Polyphenols
Covalent (strongest) and Hydrophobic (Weakest)
HPLC has higher pressure than FPLC
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

40. Name the strongest biochemical bond and the weakest biochemical bond.
Olive Green
Covalent (strongest) and Hydrophobic (Weakest)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

41. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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
Emulsoids

42. Name 3 chemical agents capable of denaturing proteins.
pH below positive charge; pH at no charge; pH above negative charge
Carmelization and Maillard
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
The speed of a molecule is proportional to the surrounding voltage gradient.

43. What are 3 mesomorphic structures associated with lipids in the liquid state?
pH below positive charge; pH at no charge; pH above negative charge
Lamellar; Hexagonal I - II; Cubic
Pectins
Tryptophan

44. What is the winterization process for an oil?
Monosodium Glutamate
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lipid oxidation
Covalent (strongest) and Hydrophobic (Weakest)

45. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Carrageenan
Emulsoids
Thamautin

46. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Tryptophan
2.5
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

47. What is the major color compound in tomatoes?
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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lycopenes
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

48. How does ERH relate to water activity?
Oil in Water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Browning of freshly cut surfaces of fruits and vegetables.
ERH=100 x Aw

49. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Two aldehydes
pH below positive charge; pH at no charge; pH above negative charge
Lamellar; Hexagonal I - II; Cubic
Glycosides of anthocyanidins

50. At what pH is benzoic acid most effective?
Bitter
pH 3-5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Fatty Acid (Ester linked) to Fatty Alcohol