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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 is the geometric configuration of double bonds in most natural fatty acids?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Sweet - Salty - Sour - and Bitter
Phenophylin
Cis

2. What two common compounds are used together as an antioxidative system?
14
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Ascorbic Acid and Citric Acid

3. Name one way foam stability can be assessed.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
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.
Aspartic Acid and Phenylalanine
Racemic Mixture

4. How many polypeptide chains make up an antibody?
NaCl (it dissociated to a 2M solution)
Four
Pectin methyl esterase or galacturonase
V=IR and P=VI or I x I x are

5. What is acid proteolysis?
Daminozide
Ammonia - Water - Carbon Dioxide
Water
Degradation of protein and production of acid from sugar at the same time.

6. Define molarity molality - and normality.
Pectin Esterase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
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

7. What is the enzyme responsible for browning in apples and lettuce?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Polyphenol Oxidase
Thickener in foods
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

8. What happens to chlorophyll on heating?
Pheophytin forms
Carmelization and Maillard
1 - 3 - 7-trimethylxanthine
45% - 52% - 90%

9. Name the most common functional property of phospholipids in food systems.
Pectin methyl esterase or galacturonase
Emulsification
Fat Oxidation
An enzyme that converts hydrogen peroxide to water plus oxygen.

10. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Daminozide
Sodium bicarbonate generates CO2
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.
Onions ( or leeks)

11. Waxes are composed of what two basic chemical entities?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Fatty Acid (Ester linked) to Fatty Alcohol
Polyphenols
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

12. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Initiation - Propagation - Termination
Sucrose
Onions ( or leeks)
Chitin

13. What does the iodine value measure and how is it measured?
Pectins
Polyphenol Oxidase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Thermus Aqauticus

14. What is the structural difference between chlorophyll and chlocophyllide?
Prolamines
Lysine - Arginine - and Histidine
Phenophylin
Chlocophyllide does not have a phytoltail

15. Name 5 proteins with good foaming properties.
Plasmids
Four
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.
Erythorbic Acid

16. Name 5 chelating agents used in the food industry.
Lipase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Gliadins and Glutenins
Carrageenan

17. What ketohexose is most significant to food chemists?
Fructose
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Orange Juice

18. Name 4 advantages of using enzymes in food processing.
Nucleation or crystal formation and crystal growth.
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
Polyphenol Oxidase
Lycopenes

19. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Pectins
Yellow
Polyphenol Oxidase
Aspartic Acid and Phenylalanine

20. What are the three main steps in the autooxidation of lipids?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Initiation - Propagation - Termination

21. What is the enzyme that softens tomatoes?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Emulsoids
Pectin Esterase
Osmosis

22. At what pH is benzoic acid most effective?
pH 3-5
Polyphenol Oxidase
Bitter
14

23. Name 3 factors influencing the consistency of commercial fats.
Arachidonic Acid
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

24. Name 3 factors influencing the consistency of commercial fats.
RNA transcribed to DNA
Polyphenoloxidase
pH below positive charge; pH at no charge; pH above negative charge
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

25. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Osmosis
Fatty Acid and Alcohol
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

26. Name 5 chelating agents used in the food industry.
Daminozide
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.
Pectin methylesterase & polygalacturonase

27. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Pheophytia does not have magnesium in porphyrin ring.
A concentrate of microfibrillar proteins of fish muscle.
Tryptophan
Pectin Esterase - Polygalacturonase - Pectin Layase

28. Name one way foam stability can be assessed.
pH 3-5
Pectin Esterase
Pectins
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.

29. When heated ammonium bicarbonate decomposes to form what end products?
Olive Green
Ammonia - Water - Carbon Dioxide
Daminozide
Four

30. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Pheophytia does not have magnesium in porphyrin ring.
Nucleation or crystal formation and crystal growth.
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

31. What is the Peroxide Value a measure of?
Lipase
Polyphenol Oxidase
Fat Oxidation
An enzyme that converts hydrogen peroxide to water plus oxygen.

32. In the enzyme Taq Polymerase What does Taq stand for?
Yellow
Arachidonic Acid
Anthocyanins
Thermus Aqauticus

33. What effect would the addition of sodium bicarbonate have to chocolate?
Gliadins and Glutenins
pH below positive charge; pH at no charge; pH above negative charge
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

34. 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
Four
Yes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

35. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Lysine - Arginine - and Histidine
Bitter
Pectin methylesterase & polygalacturonase
pH 3-5

36. What does the iodine value measure and how is it measured?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Milk
Racemic Mixture

37. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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.
Emulsoids
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

38. What is acid proteolysis?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Carmelization and Maillard
Thermus Aqauticus
Degradation of protein and production of acid from sugar at the same time.

39. What does HLB stand for and What does a high and low HLB value indicate?
Ammonia - Water - Carbon Dioxide
Phenylketonuria
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

40. Name three non-nutritive sweeteners approved for use in USA?
pH 3-5
Thermus Aqauticus
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

41. 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.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
DNA transferred by cell to cell contact (bacterial sex).
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

42. 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?
It explodes
Capsaicin
Initiation - Propagation - Termination
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

43. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Pectin methylesterase & polygalacturonase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

44. Name two non-enzymatic browning reactions.
Orange Juice
Pectins
Carmelization and Maillard
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

45. What is the chemical nomenclature for caffeine?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Onions ( or leeks)
1 - 3 - 7-trimethylxanthine
Non-protein nitrogen

46. What is the structural difference between chlorophyll and chlocophyllide?
Chitin
Degradation of protein and production of acid from sugar at the same time.
Chlocophyllide does not have a phytoltail
Lipase

47. What are the fructose contents in commercial HFCS products.
Olive Green
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
45% - 52% - 90%
Fatty Acid and Alcohol

48. Is a disaccharide
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Sucrose
Polyphenol Oxidase
Phenylketonuria

49. Name the three positively charged amino acids.
Polyphenol Oxidase
Phenophylin
Lysine - Arginine - and Histidine
Acsulfame-K - Saccharin - Cyclamate - Aspartame

50. Does kosmotrophil ion discourage water structure?
No
Carmelization and Maillard
pH 3-5
Plasmids