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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. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Osmosis
DNA transferred by cell to cell contact (bacterial sex).
Yes

2. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Sodium bicarbonate generates CO2
Parabens
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

3. When heated ammonium bicarbonate decomposes to form what end products?
Yes
Ammonia - Water - Carbon Dioxide
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Emulsification

4. What does HLB stand for and What does a high and low HLB value indicate?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Fatty Acid (Ester linked) to Fatty Alcohol
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.
Pectin Esterase

5. What is the Peroxide Value a measure of?
Fat Oxidation
Two aldehydes
Polyphenol Oxidase
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

6. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenol Oxidase
Polyphenols
pH below positive charge; pH at no charge; pH above negative charge
Plasmids

7. How many carbon atoms and how many double bonds are there in arachidonic acid?
Initiation - Propagation - Termination
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Aspartic Acid and Phenylalanine
20 carbons and 4 double bonds

8. What is the acid present in fish oil?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Arachidonic Acid
Fatty Acid (Ester linked) to Fatty Alcohol

9. 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.
They act as catalysts - speeding the polymerization of acrylamide.
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

10. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin methyl esterase or galacturonase
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

11. What are proteins which are soluble in 50-80% ethanol known as?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Prolamines
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Monosodium Glutamate

12. What is Carboxy-methyl cellulose often used for?
Blue pigment in flowers
Four
Thickener in foods
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

13. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
pH below positive charge; pH at no charge; pH above negative charge
Pectin methyl esterase or galacturonase
Lipid oxidation
Tryptophan

14. How is pH defined?
Tryptophan
Negative log of the hydrogen concentration (mol/l).
Whole Milk
RNA transcribed to DNA

15. What are the three main steps in the autooxidation of lipids?
14
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Initiation - Propagation - Termination

16. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
V=IR and P=VI or I x I x are
Whole Milk
RNA transcribed to DNA
Fatty Acid (Ester linked) to Fatty Alcohol

17. Name one way foam stability can be assessed.
Polyphenols
Aspartic Acid and Phenylalanine
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.
Gliadins and Glutenins

18. Name two reasons why fats are hydrogenated.
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.
Covalent (strongest) and Hydrophobic (Weakest)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

19. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
14
Carrageenan
It explodes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

20. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Polyphenol Oxidase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Non-protein nitrogen

21. Name three effects of protein denaturation.
Ascorbic Acid and Citric Acid
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
Sucrose
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

22. Name 3 factors influencing the rate of lipid oxidation in foods.
Primary butyric acid also caproic acid.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
They act as catalysts - speeding the polymerization of acrylamide.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

23. Peptide bond formation results in the formation of what secondary compound?
Pectins
Polyphenoloxidase
Olive Green
Water

24. What are the fructose contents in commercial HFCS products.
20 carbons and 4 double bonds
Cis
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
45% - 52% - 90%

25. What is Ohm's Law and What is Power Equation?
An enzyme that converts hydrogen peroxide to water plus oxygen.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
V=IR and P=VI or I x I x are
Initiation - Propagation - and Termination

26. What is the name of the degradation compound of chlorophyll?
pH 3-5
Olive Green
ERH=100 x Aw
Phenophylin

27. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Sodium bicarbonate generates CO2
Sodium chloride reduces foam stability and sucrose improves foam stability.
No

28. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Browning of freshly cut surfaces of fruits and vegetables.

29. Name a naturally occurring protein sweetener.
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
Thamautin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
14

30. What enzyme is most responsible for browning bananas?
Speed of Light
Plasmids
Polyphenol Oxidase
Phenophylin

31. What is a polymorphism?
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.
Water
Emulsoids

32. What two enzymes degrade pectic substances?
Fructose
Lamellar; Hexagonal I - II; Cubic
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
Pectin methylesterase & polygalacturonase

33. What is the winterization process for an oil?
RNA transcribed to DNA
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Thermus Aqauticus

34. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fatty Acid and Alcohol

35. Name 3 chemical agents capable of denaturing proteins.
Pheophytia does not have magnesium in porphyrin ring.
Covalent (strongest) and Hydrophobic (Weakest)
Lipase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

36. What happens to chlorophyll on heating?
Pheophytin forms
Bitter
Aspartic Acid and Phenylalanine
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

37. What effect would the addition of sodium bicarbonate have to chocolate?
Emulsoids
Racemic Mixture
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

38. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Carmelization and Maillard
The speed of a molecule is proportional to the surrounding voltage gradient.
No

39. What are soluble polymers of anhydro-galacturonic acid and its esters called?
It explodes
Acetoin
Pectins
Thamautin

40. Name a naturally occurring protein sweetener.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Thamautin
Polyphenoloxidase
A concentrate of microfibrillar proteins of fish muscle.

41. What is the chemical nomenclature for caffeine?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Lamellar; Hexagonal I - II; Cubic
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
1 - 3 - 7-trimethylxanthine

42. Alar is the trade name for what chemical compound?
Negative log of the hydrogen concentration (mol/l).
Daminozide
Tryptophan
Carrageenan

43. At what pH is benzoic acid most effective?
Browning of freshly cut surfaces of fruits and vegetables.
Pectin Esterase - Polygalacturonase - Pectin Layase
pH 3-5
Sodium chloride reduces foam stability and sucrose improves foam stability.

44. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Water
Acsulfame-K - Saccharin - Cyclamate - Aspartame
No

45. Give one word for a carbon atom involved in hemiacetal or acetal formation.
20 carbons and 4 double bonds
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Polyphenol Oxidase
Anomeric

46. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Polyphenol Oxidase
Arachidonic Acid
Anomeric

47. What does MSG stand for?
Monosodium Glutamate
Initiation - Propagation - Termination
Erythorbic Acid
Phenophylin

48. During freezing What are the two stages in the crystallization process?
Polyphenol Oxidase
Nucleation or crystal formation and crystal growth.
Sucrose
Two aldehydes

49. What is catalase?
Arachidonic Acid
An enzyme that converts hydrogen peroxide to water plus oxygen.
Pectin Esterase - Polygalacturonase - Pectin Layase
Water

50. What effect would the addition of sodium bicarbonate have to chocolate?
Blue pigment in flowers
Fatty Acid (Ester linked) to Fatty Alcohol
Gossypol (it is removed during the oil refining process)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).