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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 kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Yes
45% - 52% - 90%
1 - 3 - 7-trimethylxanthine
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

2. What are the limiting amino acids in corn - potato - and green peas?
Lipid oxidation
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
20 carbons and 4 double bonds
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

3. What is the name of the degradation compound of chlorophyll?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytin forms
They act as catalysts - speeding the polymerization of acrylamide.
Phenophylin

4. Name 4 advantages of using enzymes in food processing.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Prolamines
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
V=IR and P=VI or I x I x are

5. What is catalase?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Chitin
.05
An enzyme that converts hydrogen peroxide to water plus oxygen.

6. What enzyme causes hyrolytic rancidity in milk?
Lipase
Olive Green
Osmosis
Linoleic Acid

7. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Sweet - Salty - Sour - and Bitter
Pectins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Racemic Mixture

8. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
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
Orange Juice
NaCl (it dissociated to a 2M solution)
pH below positive charge; pH at no charge; pH above negative charge

9. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Chlocophyllide does not have a phytoltail
Gossypol (it is removed during the oil refining process)
Nucleation or crystal formation and crystal growth.

10. What does the 'c' stand for in the equation E=mc2?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Oil in Water
Speed of Light
Arachidonic Acid

11. What are the fructose contents in commercial HFCS products.
Acetoin
Erythorbic Acid
Negative log of the hydrogen concentration (mol/l).
45% - 52% - 90%

12. Name two reasons why fats are hydrogenated.
Water
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Primary butyric acid also caproic acid.
They act as catalysts - speeding the polymerization of acrylamide.

13. Alar is the trade name for what chemical compound?
Daminozide
Thickener in foods
Two aldehydes
Blue pigment in flowers

14. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
1 - 3 - 7-trimethylxanthine
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
pH below positive charge; pH at no charge; pH above negative charge

15. Name a naturally occurring protein sweetener.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
NaCl (it dissociated to a 2M solution)
Thamautin
Plasmids

16. How many carbon atoms are there in the fatty acid myristic acid?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
2.5
14

17. Name the strongest biochemical bond and the weakest biochemical bond.
Osmosis
Covalent (strongest) and Hydrophobic (Weakest)
Pectin methylesterase & polygalacturonase
Emulsification

18. What is the main class of color compounds found in raspberries?
Ascorbic Acid and Citric Acid
Anthocyanins
Chlocophyllide does not have a phytoltail
Gossypol (it is removed during the oil refining process)

19. How many polypeptide chains make up an antibody?
Non-protein nitrogen
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
Four
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

20. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
D: None of the above
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin Esterase
Phenylketonuria

21. 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
Pheophytia does not have magnesium in porphyrin ring.
Pectin methylesterase & polygalacturonase
Parabens

22. What are the primary secondary - tertiary - and quaternary structures?
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.
Prolamines
Non-protein nitrogen
Blue pigment in flowers

23. Name two reasons why fats are hydrogenated.
Blue pigment in flowers
Prolamines
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
An enzyme that converts hydrogen peroxide to water plus oxygen.

24. At low water activity What is the main deteriorative concern?
Emulsoids
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Erythorbic Acid
Lipid oxidation

25. How does ERH relate to water activity?
ERH=100 x Aw
Erythorbic Acid
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Polyphenol Oxidase

26. Name 5 proteins with good foaming properties.
No
Whole Milk
Carmelization and Maillard
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.

27. 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
Primary butyric acid also caproic acid.
Browning of freshly cut surfaces of fruits and vegetables.
Glycosides of anthocyanidins
.05

28. 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 below positive charge; pH at no charge; pH above negative charge
Gliadins and Glutenins
It explodes
Pectin Esterase

29. What are proteins which are soluble in 50-80% ethanol known as?
D: None of the above
Yellow
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Prolamines

30. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Ammonia - Water - Carbon Dioxide
Polyphenol Oxidase
Onions ( or leeks)
A concentrate of microfibrillar proteins of fish muscle.

31. What is the enzyme responsible for browning in apples and lettuce?
Pheophytin forms
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Polyphenol Oxidase

32. In what food is butyric acid typically found?
HPLC has higher pressure than FPLC
Milk
Phenophylin
Sodium chloride reduces foam stability and sucrose improves foam stability.

33. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Whole Milk
Chitin
Oil in Water

34. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Lamellar; Hexagonal I - II; Cubic
Glycosides of anthocyanidins
Acsulfame-K - Saccharin - Cyclamate - Aspartame

35. In genetics What is conjugation?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lamellar; Hexagonal I - II; Cubic
DNA transferred by cell to cell contact (bacterial sex).
Thickener in foods

36. During freezing What are the two stages in the crystallization process?
Olive Green
Nucleation or crystal formation and crystal growth.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

37. What is catalase?
They act as catalysts - speeding the polymerization of acrylamide.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Yellow
Pectin Esterase - Polygalacturonase - Pectin Layase

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
Lipase
Erythorbic Acid
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Browning of freshly cut surfaces of fruits and vegetables.

39. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
pH 3-5
Pectin Esterase
No

40. At what pH is benzoic acid most effective?
Polyphenols
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.
pH 3-5
Thickener in foods

41. What is the name given to a mixture of equal parts of Darel Lisomers?
45% - 52% - 90%
ERH=100 x Aw
Racemic Mixture
Water

42. What is the structural difference between chlorophyll and pheophytia?
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
pH below positive charge; pH at no charge; pH above negative charge
Fatty Acid (Ester linked) to Fatty Alcohol
Pheophytia does not have magnesium in porphyrin ring.

43. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
.05 M HCL
It explodes
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

44. 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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Water
D: None of the above
A concentrate of microfibrillar proteins of fish muscle.

45. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Erythorbic Acid
Cis

46. In the enzyme Taq Polymerase What does Taq stand for?
pH below positive charge; pH at no charge; pH above negative charge
Thermus Aqauticus
Tryptophan
Lipase

47. What pigment was first designated as anthocyanins?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Blue pigment in flowers
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
1 - 3 - 7-trimethylxanthine

48. How many carbon atoms and how many double bonds are there in arachidonic acid?
Sodium chloride reduces foam stability and sucrose improves foam stability.
No
Linoleic Acid
20 carbons and 4 double bonds

49. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Orange Juice
NaCl (it dissociated to a 2M solution)
Water
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

50. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Carrageenan
Bright green
.05
Bitter