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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. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Lycopenes
Linoleic Acid
Arachidonic Acid
Bitter

2. Does kosmotrophil ion discourage water structure?
Two aldehydes
Sodium bicarbonate generates CO2
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
No

3. What does the acronym NPN stand for?
Thamautin
Non-protein nitrogen
20 carbons and 4 double bonds
Thermus Aqauticus

4. Name one way foam stability can be assessed.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
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.
V=IR and P=VI or I x I x are
20 carbons and 4 double bonds

5. Name three factors useful in controlling enzyme activity.
Phenylketonuria
pH 3-5
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

6. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Carmelization and Maillard
Covalent (strongest) and Hydrophobic (Weakest)
Troponins and Tropomyosin
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

7. Name three factors useful in controlling enzyme activity.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
ERH=100 x Aw
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.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

8. What are the three stages of oxidative rancidity?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Initiation - Propagation - and Termination
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

9. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Linoleic Acid
Pheophytia does not have magnesium in porphyrin ring.
Chitin

10. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
45% - 52% - 90%
Fat Oxidation
Daminozide

11. What are the primary secondary - tertiary - and quaternary structures?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Parabens
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.
Monosodium Glutamate

12. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
2.5
Whole Milk
Carmelization and Maillard

13. What are colloids that are stabilized by a layer of solvation called?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Emulsoids
HPLC has higher pressure than FPLC
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. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Anthocyanins
Tryptophan
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
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.

15. How does ERH relate to water activity?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
ERH=100 x Aw
Chlocophyllide does not have a phytoltail
Thickener in foods

16. What is the chemical nomenclature for caffeine?
Orange Juice
1 - 3 - 7-trimethylxanthine
Daminozide
Non-protein nitrogen

17. Does kosmotrophil ion discourage water structure?
Primary butyric acid also caproic acid.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
No
Browning of freshly cut surfaces of fruits and vegetables.

18. Name a naturally occurring protein sweetener.
Thamautin
Anthocyanins
Degradation of protein and production of acid from sugar at the same time.
Chitin

19. Contains the lowest content of water
Whole Milk
Blue pigment in flowers
Osmosis
ERH=100 x Aw

20. What does Acid Degree Value measure and how is it measured?
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.
45% - 52% - 90%
Osmosis
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

21. Alar is the trade name for what chemical compound?
Osmosis
Daminozide
Parabens
Phenophylin

22. Name the most common functional property of phospholipids in food systems.
Emulsification
Fructose
Oil in Water
.05

23. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Polyphenols
Phenylketonuria
No
14

24. What is the main class of color compounds found in raspberries?
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.
Ascorbic Acid and Citric Acid
Tryptophan
Anthocyanins

25. How does HPLC differ from FPLC?
Plasmids
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.
HPLC has higher pressure than FPLC
Emulsification

26. What is Carboxy-methyl cellulose often used for?
14
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Thickener in foods
Degradation of protein and production of acid from sugar at the same time.

27. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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
Non-protein nitrogen
Pectin methylesterase & polygalacturonase
Milk

29. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Two aldehydes
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
Bitter

30. What are the only phenols approved for use in the microbiological preservation of foods?
Blue pigment in flowers
Ammonia - Water - Carbon Dioxide
Parabens
It explodes

31. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Pheophytia does not have magnesium in porphyrin ring.
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.
Lycopenes

32. What is the fundamental driving of electrophoresis?
Fatty Acid and Alcohol
The speed of a molecule is proportional to the surrounding voltage gradient.
Pectin methyl esterase or galacturonase
Troponins and Tropomyosin

33. Name 3 factors influencing the consistency of commercial fats.
Water
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
NaCl (it dissociated to a 2M solution)
Pectin Esterase - Polygalacturonase - Pectin Layase

34. What are two common reducing agents that break disulfide bonds in proteins?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

35. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Oil in Water
Onions ( or leeks)
Racemic Mixture

36. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Anthocyanins
Olive Green
Olive Green

37. What is surimi?
Bitter
A concentrate of microfibrillar proteins of fish muscle.
Fat Oxidation
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

38. 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.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pectin methylesterase & polygalacturonase
Pheophytia does not have magnesium in porphyrin ring.

39. What two enzymes degrade pectic substances?
Pectin Esterase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Pectin methylesterase & polygalacturonase
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

40. 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.
Lysine - Arginine - and Histidine
Pectin Esterase
Anthocyanins

41. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Prolamines
Sweet - Salty - Sour - and Bitter
HPLC has higher pressure than FPLC

42. What enzyme is most responsible for browning bananas?
NaCl (it dissociated to a 2M solution)
Onions ( or leeks)
Polyphenol Oxidase
Pectin methyl esterase or galacturonase

43. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
It explodes
Thickener in foods
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

44. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
A concentrate of microfibrillar proteins of fish muscle.
Pectin methyl esterase or galacturonase
Pectin methylesterase & polygalacturonase
Initiation - Propagation - Termination

45. At low water activity What is the main deteriorative concern?
Plasmids
Fatty Acid (Ester linked) to Fatty Alcohol
Water
Lipid oxidation

46. What are the fructose contents in commercial HFCS products.
Yellow
Polyphenol Oxidase
45% - 52% - 90%
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

47. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Ascorbic Acid and Citric Acid
D: None of the above
Onions ( or leeks)

48. What effect would the addition of sodium bicarbonate have to chocolate?
Aspartic Acid and Phenylalanine
The speed of a molecule is proportional to the surrounding voltage gradient.
Cis
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

49. What pigment was first designated as anthocyanins?
Phenylketonuria
V=IR and P=VI or I x I x are
Pectin methyl esterase or galacturonase
Blue pigment in flowers

50. 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?
.05 M HCL
Cis
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Speed of Light