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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. What does the saponification value measure and how is it measured?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fat Oxidation
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fatty Acid and Alcohol
2. What two common compounds are used together as an antioxidative system?
Fat Oxidation
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Sucrose
Ascorbic Acid and Citric Acid
3. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
2.5
Water
Lipid oxidation
4. What effect would the addition of sodium bicarbonate have to chocolate?
Linoleic Acid
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
1 - 3 - 7-trimethylxanthine
Lamellar; Hexagonal I - II; Cubic
5. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
D: None of the above
Lamellar; Hexagonal I - II; Cubic
Polyphenol Oxidase
Carmelization and Maillard
6. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Daminozide
Linoleic Acid
Fatty Acid and Alcohol
Monosodium Glutamate
7. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenols
Parabens
RNA transcribed to DNA
8. What are soluble polymers of anhydro-galacturonic acid and its esters called?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Arachidonic Acid
Pectins
9. What is the enzyme responsible for browning in apples and lettuce?
Milk
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Polyphenol Oxidase
The speed of a molecule is proportional to the surrounding voltage gradient.
10. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Lipase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Yellow
Sodium bicarbonate generates CO2
11. How is pH defined?
Blue pigment in flowers
Negative log of the hydrogen concentration (mol/l).
Troponins and Tropomyosin
Speed of Light
12. What is the enzyme that softens tomatoes?
ERH=100 x Aw
Pectin Esterase
Onions ( or leeks)
They act as catalysts - speeding the polymerization of acrylamide.
13. What two enzymes degrade pectic substances?
Polyphenol Oxidase
Pectin methylesterase & polygalacturonase
Sucrose
Blue pigment in flowers
14. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Acetoin
2.5
Phenylketonuria
Polyphenols
15. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Polyphenols
NaCl (it dissociated to a 2M solution)
Pectin Esterase - Polygalacturonase - Pectin Layase
Water
16. Name one way foam stability can be assessed.
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.
Linoleic Acid
2.5
20 carbons and 4 double bonds
17. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
1 - 3 - 7-trimethylxanthine
Aspartic Acid and Phenylalanine
Arachidonic Acid
18. What toxic pigment is found in cottonseed endosperm?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Oil in Water
Gossypol (it is removed during the oil refining process)
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
19. How does ERH relate to water activity?
.05 M HCL
Thamautin
RNA transcribed to DNA
ERH=100 x Aw
20. At what pH is benzoic acid most effective?
pH 3-5
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Anthocyanins
Pectin Esterase
21. Name a commonly used household chemical leavening agent and the gas it generates.
NaCl (it dissociated to a 2M solution)
Sodium bicarbonate generates CO2
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Daminozide
22. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Two aldehydes
Arachidonic Acid
Gossypol (it is removed during the oil refining process)
23. Is a disaccharide
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Phenophylin
Sucrose
Whole Milk
24. What is a polymorphism?
Carmelization and Maillard
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
20 carbons and 4 double bonds
Onions ( or leeks)
25. What is the geometric configuration of double bonds in most natural fatty acids?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Cis
Acetoin
Polyphenoloxidase
26. What compounds oxidize to form brown color in fruits and vegetables?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Polyphenols
Negative log of the hydrogen concentration (mol/l).
Anthocyanins
27. How many carbon atoms are there in the fatty acid myristic acid?
14
V=IR and P=VI or I x I x are
Chlocophyllide does not have a phytoltail
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. What enzyme is most responsible for browning bananas?
pH below positive charge; pH at no charge; pH above negative charge
Emulsoids
Polyphenol Oxidase
Capsaicin
29. How can a molecular weight of protein - DNA - and RNA be determined?
Onions ( or leeks)
Sucrose
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Cis
30. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Four
Orange Juice
31. What two enzymes degrade pectic substances?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Erythorbic Acid
Pectin methylesterase & polygalacturonase
No
32. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Fatty Acid (Ester linked) to Fatty Alcohol
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pectin Esterase
33. What are two common reducing agents that break disulfide bonds in proteins?
Initiation - Propagation - and Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pheophytia does not have magnesium in porphyrin ring.
34. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Emulsification
Speed of Light
They act as catalysts - speeding the polymerization of acrylamide.
2.5
35. What is catalase?
Linoleic Acid
An enzyme that converts hydrogen peroxide to water plus oxygen.
Monosodium Glutamate
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
36. What two types of compounds are joined with an ester bond to make a wax?
Emulsification
Two aldehydes
Fatty Acid and Alcohol
Anomeric
37. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Non-protein nitrogen
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Daminozide
38. Will lipid oxidation be higher at a water activity of .05 or .5?
1 - 3 - 7-trimethylxanthine
.05
14
They act as catalysts - speeding the polymerization of acrylamide.
39. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Daminozide
Emulsification
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.
40. When heated ammonium bicarbonate decomposes to form what end products?
Sodium bicarbonate generates CO2
Polyphenoloxidase
Polyphenols
Ammonia - Water - Carbon Dioxide
41. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
Lamellar; Hexagonal I - II; Cubic
Bright green
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
42. Name two non-enzymatic browning reactions.
Pectin Esterase
Pectin methylesterase & polygalacturonase
Emulsification
Carmelization and Maillard
43. During freezing What are the two stages in the crystallization process?
Blue pigment in flowers
Aspartic Acid and Phenylalanine
Nucleation or crystal formation and crystal growth.
Anomeric
44. Name two enzymes that are involved in softening fruits.
Lysine - Arginine - and Histidine
Fatty Acid and Alcohol
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectin Esterase - Polygalacturonase - Pectin Layase
45. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
pH 3-5
Emulsoids
Daminozide
46. Name 5 chelating agents used in the food industry.
Monosodium Glutamate
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
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
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
47. Name three nonpolar polar - and charged amino acids.
2.5
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Gliadins and Glutenins
48. What does MSG stand for?
Monosodium Glutamate
Bitter
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.
49. Name the two components that comprise the relaxing factor in muscle fibers.
They act as catalysts - speeding the polymerization of acrylamide.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Troponins and Tropomyosin
Whole Milk
50. Waxes are composed of what two basic chemical entities?
Thickener in foods
Fatty Acid (Ester linked) to Fatty Alcohol
Whole Milk
Bitter