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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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1. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
45% - 52% - 90%
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
2.5

2. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Polyphenoloxidase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Chitin

3. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
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.
Plasmids
Chlocophyllide does not have a phytoltail
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

4. Name two enzymes that are involved in softening fruits.
Bright green
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin Esterase - Polygalacturonase - Pectin Layase

5. 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
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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.
Browning of freshly cut surfaces of fruits and vegetables.
Pectin Esterase - Polygalacturonase - Pectin Layase

6. What is the enzyme responsible for browning in apples and lettuce?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Polyphenol Oxidase
Osmosis
Pectin methyl esterase or galacturonase

7. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pheophytin forms
pH below positive charge; pH at no charge; pH above negative charge
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
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.

8. Alar is the trade name for what chemical compound?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Speed of Light
Daminozide

9. What is the Peroxide Value a measure of?
Fat Oxidation
Thermus Aqauticus
Linoleic Acid
Pheophytia does not have magnesium in porphyrin ring.

10. What is the enzyme that softens tomatoes?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Carrageenan
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin Esterase

11. When heated ammonium bicarbonate decomposes to form what end products?
HPLC has higher pressure than FPLC
Blue pigment in flowers
Primary butyric acid also caproic acid.
Ammonia - Water - Carbon Dioxide

12. What is the name given to a mixture of equal parts of Darel Lisomers?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Degradation of protein and production of acid from sugar at the same time.
Racemic Mixture
Sodium chloride reduces foam stability and sucrose improves foam stability.

13. Waxes are composed of what two basic chemical entities?
Fat Oxidation
Pheophytin forms
Fatty Acid (Ester linked) to Fatty Alcohol
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. Alar is the trade name for what chemical compound?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fatty Acid (Ester linked) to Fatty Alcohol
Daminozide
ERH=100 x Aw

15. In genetics What is conjugation?
Pectin Esterase
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Sweet - Salty - Sour - and Bitter
DNA transferred by cell to cell contact (bacterial sex).

16. What does Reichert-Meissert Number measure?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Primary butyric acid also caproic acid.
No
Fat Oxidation

17. Name the most common functional property of phospholipids in food systems.
The speed of a molecule is proportional to the surrounding voltage gradient.
Emulsification
Anthocyanins
Osmosis

18. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
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.
Pectin methyl esterase or galacturonase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
No

19. What is Ohm's Law and What is Power Equation?
Anthocyanins
V=IR and P=VI or I x I x are
45% - 52% - 90%
D: None of the above

20. What is the Peroxide Value a measure of?
Fat Oxidation
Primary butyric acid also caproic acid.
Tryptophan
Phenylketonuria

21. What effect would the addition of sodium bicarbonate have to chocolate?
Gossypol (it is removed during the oil refining process)
Two aldehydes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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

22. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Initiation - Propagation - Termination
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
They act as catalysts - speeding the polymerization of acrylamide.
Osmosis

23. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Oil in Water
Primary butyric acid also caproic acid.
Aspartic Acid and Phenylalanine
Anomeric

24. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Four
Orange Juice
Osmosis
Tryptophan

25. How is pH defined?
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
Acetoin
An enzyme that converts hydrogen peroxide to water plus oxygen.
Negative log of the hydrogen concentration (mol/l).

26. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Fatty Acid (Ester linked) to Fatty Alcohol
D: None of the above
Thickener in foods

27. Name 5 chelating agents used in the food industry.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lipid oxidation
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

28. What is the structural difference between chlorophyll and chlocophyllide?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chlocophyllide does not have a phytoltail

29. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Pectin Esterase - Polygalacturonase - Pectin Layase
Phenylketonuria
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

30. What is Ohm's Law and What is Power Equation?
Tryptophan
Sweet - Salty - Sour - and Bitter
Two aldehydes
V=IR and P=VI or I x I x are

31. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
It explodes
Carrageenan
Fructose

32. What are two common reducing agents that break disulfide bonds in proteins?
Polyphenols
Yes
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Aspartic Acid and Phenylalanine

33. How many carbon atoms are there in the fatty acid myristic acid?
Anthocyanins
NaCl (it dissociated to a 2M solution)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
14

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
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
No
Olive Green

35. Alar is the trade name for what chemical compound?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Yellow
Lipid oxidation
Daminozide

36. 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
Primary butyric acid also caproic acid.
Phenylketonuria
Nucleation or crystal formation and crystal growth.

37. Waxes are composed of what two basic chemical entities?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fatty Acid (Ester linked) to Fatty Alcohol
Gossypol (it is removed during the oil refining process)
1 - 3 - 7-trimethylxanthine

38. How can a molecular weight of protein - DNA - and RNA be determined?
Initiation - Propagation - and Termination
Thamautin
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Sodium bicarbonate generates CO2

39. What metabolic end product does the Voges-Proskauer test detect?
Sweet - Salty - Sour - and Bitter
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
14
Acetoin

40. At low water activity What is the main deteriorative concern?
Daminozide
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Lipid oxidation
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

41. Name three non-nutritive sweeteners approved for use in USA?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Pectin methyl esterase or galacturonase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

42. What is the winterization process for an oil?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
It explodes
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Non-protein nitrogen

43. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
Daminozide
Fructose
Gliadins and Glutenins

44. Name the strongest biochemical bond and the weakest biochemical bond.
Lysine - Arginine - and Histidine
Covalent (strongest) and Hydrophobic (Weakest)
Thermus Aqauticus
Racemic Mixture

45. Name one way foam stability can be assessed.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
It explodes
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.
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.

46. What is the structural difference between chlorophyll and chlocophyllide?
Thickener in foods
Chlocophyllide does not have a phytoltail
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Tryptophan

47. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Whole Milk
Yellow
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Racemic Mixture

48. What are proteins which are soluble in 50-80% ethanol known as?
Aspartic Acid and Phenylalanine
Gliadins and Glutenins
Initiation - Propagation - Termination
Prolamines

49. What ketohexose is most significant to food chemists?
Fructose
Pectin methyl esterase or galacturonase
Erythorbic Acid
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

50. 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?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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
Fat Oxidation
It explodes