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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 happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Linoleic Acid
2.5
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
It explodes

2. Are sorbitol and mannitol sweet?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Initiation - Propagation - Termination
Yes
Pheophytin forms

3. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Glycosides of anthocyanidins
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Bright green

4. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Non-protein nitrogen
Anomeric
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Onions ( or leeks)

5. Name 3 chemical agents capable of denaturing proteins.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Carrageenan
Pheophytin forms

6. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
pH below positive charge; pH at no charge; pH above negative charge
Carmelization and Maillard
A concentrate of microfibrillar proteins of fish muscle.

7. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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
Oil in Water
Two aldehydes

8. Name 5 chelating agents used in the food industry.
Gossypol (it is removed during the oil refining process)
An enzyme that converts hydrogen peroxide to water plus oxygen.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

9. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Troponins and Tropomyosin
Blue pigment in flowers
Anomeric
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

10. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Lysine - Arginine - and Histidine
ERH=100 x Aw
Bright green
Linoleic Acid

11. What metabolic end product does the Voges-Proskauer test detect?
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
D: None of the above
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

12. What are the primary secondary - tertiary - and quaternary structures?
HPLC has higher pressure than FPLC
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
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.
Primary butyric acid also caproic acid.

13. What does MSG stand for?
Monosodium Glutamate
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Two aldehydes
Aspartic Acid and Phenylalanine

14. Which two amino acids is the aspartame derived from?
Nucleation or crystal formation and crystal growth.
Aspartic Acid and Phenylalanine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

15. What does HLB stand for and What does a high and low HLB value indicate?
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.
Lipase
.05
Carrageenan

16. Does kosmotrophil ion discourage water structure?
Chlocophyllide does not have a phytoltail
Troponins and Tropomyosin
D: None of the above
No

17. What are proteins which are soluble in 50-80% ethanol known as?
Phenylketonuria
Thamautin
Prolamines
Thamautin

18. 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
Whole Milk
ERH=100 x Aw
Browning of freshly cut surfaces of fruits and vegetables.
.05 M HCL

19. Name 3 chemical agents capable of denaturing proteins.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Fructose
No
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

20. 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
Pectin methyl esterase or galacturonase
Pectin Esterase - Polygalacturonase - Pectin Layase
Negative log of the hydrogen concentration (mol/l).

21. How does HPLC differ from FPLC?
A concentrate of microfibrillar proteins of fish muscle.
pH below positive charge; pH at no charge; pH above negative charge
HPLC has higher pressure than FPLC
DNA transferred by cell to cell contact (bacterial sex).

22. What does MSG stand for?
Blue pigment in flowers
Emulsoids
Monosodium Glutamate
Capsaicin

23. How do sodium chloride and sucrose affect foam stability?
Phenophylin
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectins
Sodium chloride reduces foam stability and sucrose improves foam stability.

24. What happens to chlorophyll on heating?
45% - 52% - 90%
Pheophytin forms
Bitter
Water

25. What are the limiting amino acids in corn - potato - and green peas?
Covalent (strongest) and Hydrophobic (Weakest)
Polyphenols
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Browning of freshly cut surfaces of fruits and vegetables.

26. Alar is the trade name for what chemical compound?
Plasmids
Initiation - Propagation - Termination
Monosodium Glutamate
Daminozide

27. Define molarity molality - and normality.
Phenylketonuria
Glycosides of anthocyanidins
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.

28. Name a commonly used household chemical leavening agent and the gas it generates.
Carrageenan
Sweet - Salty - Sour - and Bitter
Sodium bicarbonate generates CO2
Thickener in foods

29. Name three factors useful in controlling enzyme activity.
HPLC has higher pressure than FPLC
Emulsoids
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

30. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Two aldehydes
NaCl (it dissociated to a 2M solution)
Fatty Acid (Ester linked) to Fatty Alcohol

31. What is acid proteolysis?
Lysine - Arginine - and Histidine
Degradation of protein and production of acid from sugar at the same time.
Fatty Acid and Alcohol
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

32. 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.
Tryptophan
Pectin methyl esterase or galacturonase
Cis

33. What is the enzyme responsible for browning in apples and lettuce?
HPLC has higher pressure than FPLC
Polyphenol Oxidase
Orange Juice
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

34. What is the Peroxide Value a measure of?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Thickener in foods
Fat Oxidation
Arachidonic Acid

35. What happens to chlorophyll on heating?
Pheophytin forms
A concentrate of microfibrillar proteins of fish muscle.
Two aldehydes
Negative log of the hydrogen concentration (mol/l).

36. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Water
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
Carmelization and Maillard

37. What enzyme causes hyrolytic rancidity in milk?
Lipase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Fatty Acid (Ester linked) to Fatty Alcohol
pH below positive charge; pH at no charge; pH above negative charge

38. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
NaCl (it dissociated to a 2M solution)
Nucleation or crystal formation and crystal growth.
Milk

39. 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.
Initiation - Propagation - and Termination
.05
Plasmids

40. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Non-protein nitrogen
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Onions ( or leeks)

41. Name a naturally occurring protein sweetener.
Blue pigment in flowers
Thamautin
Linoleic Acid
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

42. At low water activity What is the main deteriorative concern?
Lipase
Pheophytia does not have magnesium in porphyrin ring.
Blue pigment in flowers
Lipid oxidation

43. What pigment was first designated as anthocyanins?
Capsaicin
Tryptophan
Blue pigment in flowers
NaCl (it dissociated to a 2M solution)

44. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Carrageenan
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Degradation of protein and production of acid from sugar at the same time.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

45. In what food is butyric acid typically found?
Milk
ERH=100 x Aw
Pheophytia does not have magnesium in porphyrin ring.
Ascorbic Acid and Citric Acid

46. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

47. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Emulsification
Anthocyanins
HPLC has higher pressure than FPLC

48. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Daminozide
Thickener in foods
Orange Juice

49. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Emulsoids
Sodium chloride reduces foam stability and sucrose improves foam stability.

50. What is acid proteolysis?
Primary butyric acid also caproic acid.
Degradation of protein and production of acid from sugar at the same time.
Primary butyric acid also caproic acid.
Daminozide