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Test your basic knowledge |
Food Chemistry
Start Test
Study First
Subjects
:
engineering
,
chemistry
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
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. Alar is the trade name for what chemical compound?
RNA transcribed to DNA
Sweet - Salty - Sour - and Bitter
2.5
Daminozide
2. What ketohexose is most significant to food chemists?
Yes
Fructose
Emulsoids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
3. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
14
Blue pigment in flowers
4. What enzyme causes hyrolytic rancidity in milk?
NaCl (it dissociated to a 2M solution)
RNA transcribed to DNA
Lipase
V=IR and P=VI or I x I x are
5. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Emulsoids
Daminozide
Oil in Water
6. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Covalent (strongest) and Hydrophobic (Weakest)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Monosodium Glutamate
7. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Capsaicin
Orange Juice
Gossypol (it is removed during the oil refining process)
.05 M HCL
8. Name two reasons why fats are hydrogenated.
Carmelization and Maillard
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the 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).
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
9. At what pH is benzoic acid most effective?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
pH 3-5
Anthocyanins
Blue pigment in flowers
10. How can a molecular weight of protein - DNA - and RNA be determined?
Blue pigment in flowers
Yellow
Osmosis
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
11. How does HPLC differ from FPLC?
Monosodium Glutamate
HPLC has higher pressure than FPLC
Emulsification
Fatty Acid and Alcohol
12. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Fatty Acid (Ester linked) to Fatty Alcohol
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Carrageenan
13. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Pectin methyl esterase or galacturonase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Bitter
14. What is the name given to a mixture of equal parts of Darel Lisomers?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Racemic Mixture
Sodium bicarbonate generates CO2
Oil in Water
15. Name the most common functional property of phospholipids in food systems.
Blue pigment in flowers
The speed of a molecule is proportional to the surrounding voltage gradient.
Pectins
Emulsification
16. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Pectins
Arachidonic Acid
Plasmids
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
17. What is the acid present in fish oil?
Arachidonic Acid
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Erythorbic Acid
Whole Milk
18. What is the fundamental driving of electrophoresis?
2.5
The speed of a molecule is proportional to the surrounding voltage gradient.
Aspartic Acid and Phenylalanine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
19. What happens to chlorophyll on heating?
Pheophytin forms
Erythorbic Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Whole Milk
20. How does HPLC differ from FPLC?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
45% - 52% - 90%
HPLC has higher pressure than FPLC
21. Is a disaccharide
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sucrose
Primary butyric acid also caproic acid.
22. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Daminozide
Glycosides of anthocyanidins
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Water
23. 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
Lysine - Arginine - and Histidine
Browning of freshly cut surfaces of fruits and vegetables.
Lamellar; Hexagonal I - II; Cubic
Pectin Esterase - Polygalacturonase - Pectin Layase
24. What is the chemical nomenclature for caffeine?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lipid oxidation
1 - 3 - 7-trimethylxanthine
Pectin Esterase - Polygalacturonase - Pectin Layase
25. Name 4 advantages of using enzymes in food processing.
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
Cis
HPLC has higher pressure than FPLC
Emulsification
26. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Olive Green
Osmosis
Bright green
14
27. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Parabens
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pectin Esterase - Polygalacturonase - Pectin Layase
Bright green
28. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Polyphenoloxidase
Ammonia - Water - Carbon Dioxide
45% - 52% - 90%
29. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Emulsification
Sucrose
Pheophytia does not have magnesium in porphyrin ring.
30. In what food is butyric acid typically found?
RNA transcribed to DNA
Sucrose
Carrageenan
Milk
31. Which two amino acids is the aspartame derived from?
Prolamines
Aspartic Acid and Phenylalanine
2.5
Fat Oxidation
32. Waxes are composed of what two basic chemical entities?
Sucrose
Oil in Water
Fatty Acid (Ester linked) to Fatty Alcohol
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
33. Name a naturally occurring protein sweetener.
DNA transferred by cell to cell contact (bacterial sex).
Acetoin
Thamautin
Capsaicin
34. What is Ohm's Law and What is Power Equation?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Negative log of the hydrogen concentration (mol/l).
V=IR and P=VI or I x I x are
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
35. Name three factors useful in controlling enzyme activity.
Emulsification
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fat Oxidation
Ascorbic Acid and Citric Acid
36. Alar is the trade name for what chemical compound?
Daminozide
Arachidonic Acid
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
37. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Bright green
Anomeric
Troponins and Tropomyosin
Pheophytin forms
38. 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.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Fructose
39. How do sodium chloride and sucrose affect foam stability?
Linoleic Acid
Aspartic Acid and Phenylalanine
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectin Esterase - Polygalacturonase - Pectin Layase
40. What toxic pigment is found in cottonseed endosperm?
Gossypol (it is removed during the oil refining process)
Thamautin
Anthocyanins
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
41. What does MSG stand for?
Pectin methyl esterase or galacturonase
Ascorbic Acid and Citric Acid
Monosodium Glutamate
Pectin methylesterase & polygalacturonase
42. Name a naturally occurring protein sweetener.
Pheophytin forms
Onions ( or leeks)
Thamautin
No
43. What effect would the addition of sodium bicarbonate have to chocolate?
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
The speed of a molecule is proportional to the surrounding voltage gradient.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Fructose
44. Alar is the trade name for what chemical compound?
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Daminozide
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
45. What is the chemical nature of anthocyanins?
Initiation - Propagation - Termination
Glycosides of anthocyanidins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
46. What metabolic end product does the Voges-Proskauer test detect?
Cis
Fructose
Acetoin
Orange Juice
47. When heated ammonium bicarbonate decomposes to form what end products?
Thickener in foods
Ammonia - Water - Carbon Dioxide
Gossypol (it is removed during the oil refining process)
HPLC has higher pressure than FPLC
48. What are colloids that are stabilized by a layer of solvation called?
Water
Emulsoids
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
49. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Capsaicin
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
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
50. 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?
Browning of freshly cut surfaces of fruits and vegetables.
.05 M HCL
Water
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)