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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 are the three stages of oxidative rancidity?
V=IR and P=VI or I x I x are
Racemic Mixture
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Initiation - Propagation - and Termination

2. What does Reichert-Meissert Number measure?
Degradation of protein and production of acid from sugar at the same time.
Bitter
Primary butyric acid also caproic acid.
Acetoin

3. 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
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Troponins and Tropomyosin
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Phenylketonuria

4. Name a commonly used household chemical leavening agent and the gas it generates.
Linoleic Acid
Sodium bicarbonate generates CO2
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Pheophytia does not have magnesium in porphyrin ring.

5. Name two non-enzymatic browning reactions.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Bitter
Bitter
Carmelization and Maillard

6. What toxic pigment is found in cottonseed endosperm?
pH 3-5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Gossypol (it is removed during the oil refining process)
Pectin methylesterase & polygalacturonase

7. What is the geometric configuration of double bonds in most natural fatty acids?
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
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Cis
20 carbons and 4 double bonds

8. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Speed of Light
V=IR and P=VI or I x I x are
Bitter

9. What is an isomer that is cheaper than Vitamin C?
Gossypol (it is removed during the oil refining process)
Bright green
Initiation - Propagation - and Termination
Erythorbic Acid

10. Name 4 advantages of using enzymes in food processing.
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
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

11. What are the three main steps in the autooxidation of lipids?
Gliadins and Glutenins
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin methyl esterase or galacturonase
Initiation - Propagation - Termination

12. Name a naturally occurring protein sweetener.
Racemic Mixture
DNA transferred by cell to cell contact (bacterial sex).
Thamautin
Speed of Light

13. How is pH defined?
Nucleation or crystal formation and crystal growth.
Negative log of the hydrogen concentration (mol/l).
Bright green
pH below positive charge; pH at no charge; pH above negative charge

14. In genetics What is conjugation?
Lysine - Arginine - and Histidine
DNA transferred by cell to cell contact (bacterial sex).
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

15. What happens to chlorophyll on heating?
Fatty Acid and Alcohol
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Pheophytin forms
Onions ( or leeks)

16. What is the enzyme that softens tomatoes?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Pectin Esterase
14
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

17. 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?
Non-protein nitrogen
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
.05 M HCL

18. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Yellow
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Onions ( or leeks)

19. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Aspartic Acid and Phenylalanine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Oil in Water
.05 M HCL

20. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Thamautin
Chlocophyllide does not have a phytoltail
Acetoin

21. 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.
Fructose
Primary butyric acid also caproic acid.
RNA transcribed to DNA

22. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Bitter
20 carbons and 4 double bonds
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

23. What are the limiting amino acids in corn - potato - and green peas?
Daminozide
Negative log of the hydrogen concentration (mol/l).
Acetoin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

24. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Chitin
Olive Green
Pectins
Daminozide

25. Are sorbitol and mannitol sweet?
Primary butyric acid also caproic acid.
Daminozide
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Yes

26. What are the fructose contents in commercial HFCS products.
.05 M HCL
Yes
45% - 52% - 90%
Ammonia - Water - Carbon Dioxide

27. Peptide bond formation results in the formation of what secondary compound?
Water
Milk
.05 M HCL
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

28. Is a disaccharide
Pheophytin forms
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Oil in Water
Sucrose

29. In the enzyme Taq Polymerase What does Taq stand for?
Primary butyric acid also caproic acid.
Erythorbic Acid
Thermus Aqauticus
ERH=100 x Aw

30. In what food is butyric acid typically found?
Milk
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Arachidonic Acid

31. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Fructose
Two aldehydes
Water

32. Name one way foam stability can be assessed.
Anthocyanins
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.
Degradation of protein and production of acid from sugar at the same time.
Polyphenol Oxidase

33. 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?
pH 3-5
Chitin
It explodes
Thermus Aqauticus

34. What are the primary secondary - tertiary - and quaternary structures?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
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.
Erythorbic Acid
DNA transferred by cell to cell contact (bacterial sex).

35. Peptide bond formation results in the formation of what secondary compound?
Sodium bicarbonate generates CO2
Linoleic Acid
Water
Bitter

36. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Sodium bicarbonate generates CO2
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
V=IR and P=VI or I x I x are
Two aldehydes

37. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Gliadins and Glutenins
Aspartic Acid and Phenylalanine

38. Name the most common functional property of phospholipids in food systems.
NaCl (it dissociated to a 2M solution)
Olive Green
Emulsification
Bitter

39. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Gossypol (it is removed during the oil refining process)
The speed of a molecule is proportional to the surrounding voltage gradient.
Two aldehydes
Yes

40. Name three effects of protein denaturation.
Onions ( or leeks)
Covalent (strongest) and Hydrophobic (Weakest)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Initiation - Propagation - Termination

41. What is a polymorphism?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
DNA transferred by cell to cell contact (bacterial sex).
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

42. At low water activity What is the main deteriorative concern?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Lipid oxidation
RNA transcribed to DNA
Two aldehydes

43. What does the acronym NPN stand for?
Thamautin
1 - 3 - 7-trimethylxanthine
Two aldehydes
Non-protein nitrogen

44. What ketohexose is most significant to food chemists?
Negative log of the hydrogen concentration (mol/l).
Fructose
HPLC has higher pressure than FPLC
NaCl (it dissociated to a 2M solution)

45. What is the structural difference between chlorophyll and chlocophyllide?
Ammonia - Water - Carbon Dioxide
Water
Chlocophyllide does not have a phytoltail
2.5

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

47. What does the iodine value measure and how is it measured?
The speed of a molecule is proportional to the surrounding voltage gradient.
Milk
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

48. Define molarity molality - and normality.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
NaCl (it dissociated to a 2M solution)

49. Name three nonpolar polar - and charged amino acids.
.05
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Phenylketonuria
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

50. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
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.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Negative log of the hydrogen concentration (mol/l).