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Food Chemistry

Instructions:

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. How many carbon atoms are there in the fatty acid myristic acid?
14
An enzyme that converts hydrogen peroxide to water plus oxygen.
Gliadins and Glutenins
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

2. What does the acronym NPN stand for?
Fatty Acid and Alcohol
Non-protein nitrogen
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lamellar; Hexagonal I - II; Cubic

3. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Four
Ascorbic Acid and Citric Acid
Onions ( or leeks)
The speed of a molecule is proportional to the surrounding voltage gradient.

4. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Speed of Light
Pectin Esterase - Polygalacturonase - Pectin Layase
Chitin
Pectin methylesterase & polygalacturonase

5. What enzyme is most responsible for browning bananas?
Yes
Chitin
Chlocophyllide does not have a phytoltail
Polyphenol Oxidase

6. What is the major color compound in tomatoes?
Cis
Lycopenes
Fructose
Lamellar; Hexagonal I - II; Cubic

7. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
pH below positive charge; pH at no charge; pH above negative charge

8. How many polypeptide chains make up an antibody?
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
Thickener in foods
Capsaicin
Four

9. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Carrageenan
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

10. In what food is butyric acid typically found?
Prolamines
Milk
Carmelization and Maillard
NaCl (it dissociated to a 2M solution)

11. What is catalase?
20 carbons and 4 double bonds
Arachidonic Acid
Pectin Esterase - Polygalacturonase - Pectin Layase
An enzyme that converts hydrogen peroxide to water plus oxygen.

12. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Lipase
Daminozide
45% - 52% - 90%

13. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Pectin Esterase - Polygalacturonase - Pectin Layase
Oil in Water
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

14. What two common compounds are used together as an antioxidative system?
Thickener in foods
Covalent (strongest) and Hydrophobic (Weakest)
Racemic Mixture
Ascorbic Acid and Citric Acid

15. Which two amino acids is the aspartame derived from?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
HPLC has higher pressure than FPLC
Primary butyric acid also caproic acid.
Aspartic Acid and Phenylalanine

16. What is the Peroxide Value a measure of?
Gossypol (it is removed during the oil refining process)
The speed of a molecule is proportional to the surrounding voltage gradient.
Acetoin
Fat Oxidation

17. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
They act as catalysts - speeding the polymerization of acrylamide.
Nucleation or crystal formation and crystal growth.
Whole Milk

18. What is Carboxy-methyl cellulose often used for?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fructose
Thickener in foods
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

19. What does MSG stand for?
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
Acetoin
Monosodium Glutamate
Daminozide

20. What is the acid present in fish oil?
Arachidonic Acid
Fructose
Pheophytia does not have magnesium in porphyrin ring.
Phenylketonuria

21. What are the limiting amino acids in corn - potato - and green peas?
Phenophylin
Chitin
The speed of a molecule is proportional to the surrounding voltage gradient.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

22. In genetics What is conjugation?
HPLC has higher pressure than FPLC
20 carbons and 4 double bonds
Water
DNA transferred by cell to cell contact (bacterial sex).

23. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Non-protein nitrogen
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
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

24. What does Acid Degree Value measure and how is it measured?
Thermus Aqauticus
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fructose
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

25. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Lysine - Arginine - and Histidine
Tryptophan
Pectin Esterase
Aspartic Acid and Phenylalanine

26. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Osmosis
pH below positive charge; pH at no charge; pH above negative charge
Lamellar; Hexagonal I - II; Cubic

27. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Emulsoids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
The speed of a molecule is proportional to the surrounding voltage gradient.

28. Name 5 proteins with good foaming properties.
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.
Yellow
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

29. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Thickener in foods
14
Tryptophan
Sucrose

30. Name one way foam stability can be assessed.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
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
It explodes
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.

31. What are the four basic flavors perceived by the tongue?
Polyphenol Oxidase
Covalent (strongest) and Hydrophobic (Weakest)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sweet - Salty - Sour - and Bitter

32. What pigment was first designated as anthocyanins?
They act as catalysts - speeding the polymerization of acrylamide.
Blue pigment in flowers
Daminozide
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

33. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Initiation - Propagation - and Termination
Ascorbic Acid and Citric Acid
Nucleation or crystal formation and crystal growth.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

34. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

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35. What are two common reducing agents that break disulfide bonds in proteins?
Sodium chloride reduces foam stability and sucrose improves foam stability.
DNA transferred by cell to cell contact (bacterial sex).
It explodes
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

36. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectins

37. What is the chemical nomenclature for caffeine?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
1 - 3 - 7-trimethylxanthine
Initiation - Propagation - and Termination
Pheophytia does not have magnesium in porphyrin ring.

38. What are the three stages of oxidative rancidity?
pH 3-5
Water
D: None of the above
Initiation - Propagation - and Termination

39. How does ERH relate to water activity?
Anthocyanins
Nucleation or crystal formation and crystal growth.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
ERH=100 x Aw

40. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Initiation - Propagation - and Termination
Yellow
Bitter
Pectin methylesterase & polygalacturonase

41. Name the three positively charged amino acids.
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
Lysine - Arginine - and Histidine
Polyphenol Oxidase
Whole Milk

42. In genetics What is conjugation?
.05
DNA transferred by cell to cell contact (bacterial sex).
Yellow
Cis

43. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
1 - 3 - 7-trimethylxanthine
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

44. How many carbon atoms are there in the fatty acid myristic acid?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Lamellar; Hexagonal I - II; Cubic
Chlocophyllide does not have a phytoltail
14

45. 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.
Ascorbic Acid and Citric Acid
Sweet - Salty - Sour - and Bitter
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

46. Name one way foam stability can be assessed.
Lysine - Arginine - and Histidine
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.
Polyphenol Oxidase
RNA transcribed to DNA

47. What are the three main steps in the autooxidation of lipids?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Initiation - Propagation - Termination
45% - 52% - 90%
Osmosis

48. What is the major color compound in tomatoes?
Lycopenes
RNA transcribed to DNA
DNA transferred by cell to cell contact (bacterial sex).
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

49. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Fructose
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.

50. Will lipid oxidation be higher at a water activity of .05 or .5?
Polyphenol Oxidase
Blue pigment in flowers
.05
Water