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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. 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
Fatty Acid and Alcohol
No
1 - 3 - 7-trimethylxanthine

2. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Lycopenes
1 - 3 - 7-trimethylxanthine
Chlocophyllide does not have a phytoltail

3. What is the enzyme responsible for browning in apples and lettuce?
Nucleation or crystal formation and crystal growth.
Polyphenol Oxidase
Orange Juice
Fatty Acid and Alcohol

4. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Orange Juice
Onions ( or leeks)
Speed of Light
Bitter

5. What is the winterization process for an oil?
Aspartic Acid and Phenylalanine
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lycopenes
D: None of the above

6. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Water
Onions ( or leeks)
No
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

7. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
Polyphenoloxidase
Lipase
Gliadins and Glutenins

8. What does the iodine value measure and how is it measured?
Negative log of the hydrogen concentration (mol/l).
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Initiation - Propagation - Termination
Chitin

9. At what pH is benzoic acid most effective?
pH 3-5
Polyphenols
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
.05 M HCL

10. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Carrageenan
Sweet - Salty - Sour - and Bitter
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

11. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Pectin Esterase
Initiation - Propagation - and Termination
Olive Green
Phenylketonuria

12. When heated ammonium bicarbonate decomposes to form what end products?
Anthocyanins
Ammonia - Water - Carbon Dioxide
Anomeric
Olive Green

13. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Water
Covalent (strongest) and Hydrophobic (Weakest)
Erythorbic Acid

14. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Water
Yes
Capsaicin
Sodium chloride reduces foam stability and sucrose improves foam stability.

15. What is the fundamental driving of electrophoresis?
Olive Green
Plasmids
Nucleation or crystal formation and crystal growth.
The speed of a molecule is proportional to the surrounding voltage gradient.

16. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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
Anthocyanins
Water

17. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Lamellar; Hexagonal I - II; Cubic
Gliadins and Glutenins
Fat Oxidation

18. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Prolamines
Polyphenol Oxidase
Pheophytia does not have magnesium in porphyrin ring.

19. Alar is the trade name for what chemical compound?
Daminozide
Aspartic Acid and Phenylalanine
Gossypol (it is removed during the oil refining process)
Blue pigment in flowers

20. What two types of compounds are joined with an ester bond to make a wax?
Bright green
HPLC has higher pressure than FPLC
Fatty Acid and Alcohol
ERH=100 x Aw

21. Name a naturally occurring protein sweetener.
Sucrose
Thamautin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Capsaicin

22. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2.5
Phenophylin
Prolamines

23. What pigment was first designated as anthocyanins?
DNA transferred by cell to cell contact (bacterial sex).
Sodium chloride reduces foam stability and sucrose improves foam stability.
Blue pigment in flowers
Lysine - Arginine - and Histidine

24. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
pH below positive charge; pH at no charge; pH above negative charge
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.
ERH=100 x Aw
Phenylketonuria

25. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lamellar; Hexagonal I - II; Cubic
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

26. What is the protein efficiency ratio (PER) of casein?
Osmosis
Linoleic Acid
Polyphenoloxidase
2.5

27. 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
Lipase
Initiation - Propagation - Termination
V=IR and P=VI or I x I x are
Browning of freshly cut surfaces of fruits and vegetables.

28. 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)
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Osmosis

29. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Capsaicin
Capsaicin
Emulsification

30. What is the Peroxide Value a measure of?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Polyphenols
Fat Oxidation
Racemic Mixture

31. Name three factors useful in controlling enzyme activity.
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.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
45% - 52% - 90%
ERH=100 x Aw

32. What is a polymorphism?
Onions ( or leeks)
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.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
ERH=100 x Aw

33. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Linoleic Acid
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

34. What is the structural difference between chlorophyll and pheophytia?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pheophytia does not have magnesium in porphyrin ring.
Bitter
Non-protein nitrogen

35. Which two amino acids is the aspartame derived from?
45% - 52% - 90%
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Aspartic Acid and Phenylalanine
Speed of Light

36. Name 3 chemical agents capable of denaturing proteins.
Emulsoids
Browning of freshly cut surfaces of fruits and vegetables.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
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.

37. Name 5 chelating agents used in the food industry.
Pectin methyl esterase or galacturonase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
No
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

38. What is the acid present in fish oil?
Polyphenols
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Arachidonic Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

39. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
Ascorbic Acid and Citric Acid
Non-protein nitrogen
D: None of the above

40. At low water activity What is the main deteriorative concern?
Lipid oxidation
Covalent (strongest) and Hydrophobic (Weakest)
Monosodium Glutamate
Tryptophan

41. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pectin methyl esterase or galacturonase
.05 M HCL
Anomeric
Carrageenan

42. What does the 'c' stand for in the equation E=mc2?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Speed of Light
Blue pigment in flowers
pH 3-5

43. What are the three main steps in the autooxidation of lipids?
NaCl (it dissociated to a 2M solution)
Monosodium Glutamate
Pectin methylesterase & polygalacturonase
Initiation - Propagation - Termination

44. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
45% - 52% - 90%
Gossypol (it is removed during the oil refining process)
Thermus Aqauticus
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

45. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
RNA transcribed to DNA
20 carbons and 4 double bonds
It explodes

46. Name three nonpolar polar - and charged amino acids.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Anomeric
Pectins

47. Waxes are composed of what two basic chemical entities?
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.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Milk
Fatty Acid (Ester linked) to Fatty Alcohol

48. Name two main gluten proteins.
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.
Linoleic Acid
Acetoin
Gliadins and Glutenins

49. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Covalent (strongest) and Hydrophobic (Weakest)
Sodium chloride reduces foam stability and sucrose improves foam stability.
Fatty Acid and Alcohol

50. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
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.
Daminozide
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.