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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. What are the fructose contents in commercial HFCS products.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
45% - 52% - 90%
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Chlocophyllide does not have a phytoltail

2. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Four
Pheophytin forms
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Chitin

3. How can a molecular weight of protein - DNA - and RNA be determined?
Fatty Acid (Ester linked) to Fatty Alcohol
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Bitter

4. What enzyme is most responsible for browning bananas?
Two aldehydes
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
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Polyphenol Oxidase

5. Contains the lowest content of water
Four
Whole Milk
Sucrose
Anthocyanins

6. What is an isomer that is cheaper than Vitamin C?
Thermus Aqauticus
Phenophylin
Erythorbic Acid
Thermus Aqauticus

7. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Lamellar; Hexagonal I - II; Cubic
Fructose
1 - 3 - 7-trimethylxanthine

8. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
D: None of the above
Lycopenes
A concentrate of microfibrillar proteins of fish muscle.

9. Name a naturally occurring protein sweetener.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Anthocyanins
Chlocophyllide does not have a phytoltail
Thamautin

10. Name three effects of protein denaturation.
45% - 52% - 90%
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Whole Milk
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

11. Name two enzymes that are involved in softening fruits.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Tryptophan
Pectin Esterase - Polygalacturonase - Pectin Layase
Fatty Acid (Ester linked) to Fatty Alcohol

12. Name 5 chelating agents used in the food industry.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Anomeric
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Onions ( or leeks)

13. What does the iodine value measure and how is it measured?
Degradation of protein and production of acid from sugar at the same time.
DNA transferred by cell to cell contact (bacterial sex).
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Ammonia - Water - Carbon Dioxide

14. How many carbon atoms are there in the fatty acid myristic acid?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
14
Troponins and Tropomyosin
1 - 3 - 7-trimethylxanthine

15. How do sodium chloride and sucrose affect foam stability?
Pheophytia does not have magnesium in porphyrin ring.
Sodium chloride reduces foam stability and sucrose improves foam stability.
D: None of the above
An enzyme that converts hydrogen peroxide to water plus oxygen.

16. What two common compounds are used together as an antioxidative system?
Lycopenes
Troponins and Tropomyosin
HPLC has higher pressure than FPLC
Ascorbic Acid and Citric Acid

17. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
They act as catalysts - speeding the polymerization of acrylamide.
Initiation - Propagation - Termination
Fatty Acid and Alcohol

18. What is the fundamental driving of electrophoresis?
Covalent (strongest) and Hydrophobic (Weakest)
1 - 3 - 7-trimethylxanthine
Sweet - Salty - Sour - and Bitter
The speed of a molecule is proportional to the surrounding voltage gradient.

19. 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?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
.05 M HCL
Glycosides of anthocyanidins
Sodium bicarbonate generates CO2

20. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
V=IR and P=VI or I x I x are
Emulsification
Pectin Esterase

21. What is the geometric configuration of double bonds in most natural fatty acids?
Thickener in foods
Cis
pH 3-5
Pectin methyl esterase or galacturonase

22. What is the enzyme that softens tomatoes?
Polyphenol Oxidase
Pectin Esterase
Ascorbic Acid and Citric Acid
Whole Milk

23. What metabolic end product does the Voges-Proskauer test detect?
Fatty Acid (Ester linked) to Fatty Alcohol
20 carbons and 4 double bonds
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Acetoin

24. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
DNA transferred by cell to cell contact (bacterial sex).

25. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Pectin methylesterase & polygalacturonase
Oil in Water
Nucleation or crystal formation and crystal growth.
Water

26. At low water activity What is the main deteriorative concern?
Aspartic Acid and Phenylalanine
Onions ( or leeks)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lipid oxidation

27. What are the limiting amino acids in corn - potato - and green peas?
Thermus Aqauticus
Polyphenol Oxidase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

28. Does kosmotrophil ion discourage water structure?
Oil in Water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
No
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

29. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Troponins and Tropomyosin
Aspartic Acid and Phenylalanine
Onions ( or leeks)
Linoleic Acid

30. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Polyphenols
Two aldehydes
Blue pigment in flowers

31. What is Ohm's Law and What is Power Equation?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Covalent (strongest) and Hydrophobic (Weakest)
Yes
V=IR and P=VI or I x I x are

32. 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?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Capsaicin
Pectin Esterase - Polygalacturonase - Pectin Layase
.05 M HCL

33. What does the acronym NPN stand for?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Water
Daminozide
Non-protein nitrogen

34. Give one word for a carbon atom involved in hemiacetal or acetal formation.
1 - 3 - 7-trimethylxanthine
Anomeric
Capsaicin
Troponins and Tropomyosin

35. How many polypeptide chains make up an antibody?
Water
Four
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenoloxidase

36. What happens to chlorophyll on heating?
Yellow
Pheophytin forms
V=IR and P=VI or I x I x are
Thickener in foods

37. 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
pH below positive charge; pH at no charge; pH above negative charge
Non-protein nitrogen
HPLC has higher pressure than FPLC

38. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
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.
Cis
Pheophytia does not have magnesium in porphyrin ring.

39. What is the main class of color compounds found in raspberries?
Capsaicin
It explodes
ERH=100 x Aw
Anthocyanins

40. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Pectin methylesterase & polygalacturonase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
D: None of the above

41. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
It explodes
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

42. Peptide bond formation results in the formation of what secondary compound?
Four
Glycosides of anthocyanidins
Water
Nucleation or crystal formation and crystal growth.

43. What is a polymorphism?
Monosodium Glutamate
Chitin
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).

44. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Monosodium Glutamate
Linoleic Acid
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

45. What are the three main steps in the autooxidation of lipids?
Non-protein nitrogen
Initiation - Propagation - Termination
Monosodium Glutamate
Browning of freshly cut surfaces of fruits and vegetables.

46. What ketohexose is most significant to food chemists?
Fructose
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Two aldehydes
Speed of Light

47. 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.
Pectin Esterase
pH below positive charge; pH at no charge; pH above negative charge
45% - 52% - 90%

48. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Plasmids
Carrageenan
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin methyl esterase or galacturonase

49. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Pheophytia does not have magnesium in porphyrin ring.
Yellow
Water

50. 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
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Polyphenol Oxidase
Polyphenols
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)