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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 causes hyrolytic rancidity in milk?
Fatty Acid and Alcohol
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lipase
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

2. What is the chemical nature of anthocyanins?
Thermus Aqauticus
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Glycosides of anthocyanidins
1 - 3 - 7-trimethylxanthine

3. What is the name given to a mixture of equal parts of Darel Lisomers?
Anthocyanins
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Racemic Mixture
Chitin

4. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Pectin methyl esterase or galacturonase
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Capsaicin
Pheophytia does not have magnesium in porphyrin ring.

5. What is the acid present in fish oil?
Covalent (strongest) and Hydrophobic (Weakest)
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
Arachidonic Acid
Emulsoids

6. Name one way foam stability can be assessed.
DNA transferred by cell to cell contact (bacterial sex).
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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. How do sodium chloride and sucrose affect foam stability?
Pectin Esterase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lycopenes
Thermus Aqauticus

8. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Anthocyanins
Lipase
Cis

9. What is the winterization process for an oil?
Anthocyanins
Troponins and Tropomyosin
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

10. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Linoleic Acid
Anthocyanins

11. What is Ohm's Law and What is Power Equation?
Carmelization and Maillard
2.5
Fructose
V=IR and P=VI or I x I x are

12. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Degradation of protein and production of acid from sugar at the same time.
Pectins
Polyphenols

13. What does the iodine value measure and how is it measured?
Emulsification
Anthocyanins
Cis
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

14. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Whole Milk
Olive Green
Bitter

15. What is the main class of color compounds found in raspberries?
Fatty Acid (Ester linked) to Fatty Alcohol
Browning of freshly cut surfaces of fruits and vegetables.
Anthocyanins
Acetoin

16. What are the only phenols approved for use in the microbiological preservation of foods?
Daminozide
Parabens
Initiation - Propagation - Termination
Initiation - Propagation - Termination

17. What does HLB stand for and What does a high and low HLB value indicate?
Bright green
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.
Acetoin
Ascorbic Acid and Citric Acid

18. What is Ohm's Law and What is Power Equation?
HPLC has higher pressure than FPLC
Gliadins and Glutenins
V=IR and P=VI or I x I x are
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

19. What are colloids that are stabilized by a layer of solvation called?
Fatty Acid and Alcohol
Emulsoids
Erythorbic Acid
Anthocyanins

20. What two common compounds are used together as an antioxidative system?
Acetoin
Ascorbic Acid and Citric Acid
Monosodium Glutamate
Thermus Aqauticus

21. What ketohexose is most significant to food chemists?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
The speed of a molecule is proportional to the surrounding voltage gradient.
Fructose

22. What is an isomer that is cheaper than Vitamin C?
Thamautin
Erythorbic Acid
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Pheophytin forms

23. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
No
Osmosis
Emulsification

24. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Whole Milk
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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
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.

25. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
D: None of the above
Pectin Esterase
Milk

26. Name two reasons why fats are hydrogenated.
It explodes
Speed of Light
They act as catalysts - speeding the polymerization of acrylamide.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

27. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Arachidonic Acid
RNA transcribed to DNA
Blue pigment in flowers
Pectin methyl esterase or galacturonase

28. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
14
.05
Initiation - Propagation - Termination

29. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Milk
Anomeric
Pectin methylesterase & polygalacturonase

30. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
45% - 52% - 90%
Primary butyric acid also caproic acid.
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. How many polypeptide chains make up an antibody?
Non-protein nitrogen
45% - 52% - 90%
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.
Four

32. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Milk
Pectins
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

33. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Troponins and Tropomyosin
Troponins and Tropomyosin
Osmosis
The speed of a molecule is proportional to the surrounding voltage gradient.

34. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
It explodes
Pectins
Fatty Acid and Alcohol

35. Name three effects of protein denaturation.
Lipase
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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.

36. At low water activity What is the main deteriorative concern?
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.
pH 3-5
D: None of the above
Lipid oxidation

37. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
pH 3-5
Phenophylin
HPLC has higher pressure than FPLC

38. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Gossypol (it is removed during the oil refining process)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.
Polyphenols

39. Name two main gluten proteins.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
1 - 3 - 7-trimethylxanthine
Thamautin
Gliadins and Glutenins

40. How do sodium chloride and sucrose affect foam stability?
pH below positive charge; pH at no charge; pH above negative charge
Bright green
Sodium chloride reduces foam stability and sucrose improves foam stability.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

41. Name 3 chemical agents capable of denaturing proteins.
Gossypol (it is removed during the oil refining process)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Primary butyric acid also caproic acid.
2.5

42. 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
Browning of freshly cut surfaces of fruits and vegetables.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Phenophylin
Arachidonic Acid

43. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
45% - 52% - 90%
They act as catalysts - speeding the polymerization of acrylamide.
RNA transcribed to DNA
Bitter

44. At low water activity What is the main deteriorative concern?
Orange Juice
Lipid oxidation
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

45. How does HPLC differ from FPLC?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Chitin
HPLC has higher pressure than FPLC
Phenophylin

46. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Fat Oxidation
Olive Green
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
45% - 52% - 90%

47. In genetics What is conjugation?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
DNA transferred by cell to cell contact (bacterial sex).
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.
Ammonia - Water - Carbon Dioxide

48. Peptide bond formation results in the formation of what secondary compound?
Chitin
Water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

49. What is the protein efficiency ratio (PER) of casein?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Nucleation or crystal formation and crystal growth.
20 carbons and 4 double bonds
2.5

50. What are the fructose contents in commercial HFCS products.
20 carbons and 4 double bonds
45% - 52% - 90%
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.