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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. Name three non-nutritive sweeteners approved for use in USA?
Tryptophan
Fatty Acid and Alcohol
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Yes
2. What is the geometric configuration of double bonds in most natural fatty acids?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lysine - Arginine - and Histidine
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Cis
3. What are colloids that are stabilized by a layer of solvation called?
Linoleic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Emulsoids
Pectin methyl esterase or galacturonase
4. Name 3 chemical agents capable of denaturing proteins.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Troponins and Tropomyosin
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
5. When heated ammonium bicarbonate decomposes to form what end products?
Yes
Nucleation or crystal formation and crystal growth.
Thamautin
Ammonia - Water - Carbon Dioxide
6. What is the main class of color compounds found in raspberries?
Four
Sodium bicarbonate generates CO2
Glycosides of anthocyanidins
Anthocyanins
7. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
DNA transferred by cell to cell contact (bacterial sex).
Emulsification
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
8. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
pH 3-5
Two aldehydes
Whole Milk
9. How many carbon atoms and how many double bonds are there in arachidonic acid?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
20 carbons and 4 double bonds
.05 M HCL
Whole Milk
10. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Prolamines
pH 3-5
Tryptophan
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
11. Name one way foam stability can be assessed.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin methylesterase & polygalacturonase
Cis
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.
12. What are 3 mesomorphic structures associated with lipids in the liquid state?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin methylesterase & polygalacturonase
13. Are sorbitol and mannitol sweet?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Yes
Chitin
Pectin Esterase - Polygalacturonase - Pectin Layase
14. What two common compounds are used together as an antioxidative system?
Initiation - Propagation - Termination
Ascorbic Acid and Citric Acid
Lipid oxidation
Sweet - Salty - Sour - and Bitter
15. Name two non-enzymatic browning reactions.
Ascorbic Acid and Citric Acid
Tryptophan
Pheophytin forms
Carmelization and Maillard
16. When heated ammonium bicarbonate decomposes to form what end products?
Yes
Bright green
Pectins
Ammonia - Water - Carbon Dioxide
17. What are the fructose contents in commercial HFCS products.
Degradation of protein and production of acid from sugar at the same time.
pH 3-5
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
45% - 52% - 90%
18. Contains the lowest content of water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Pectin methyl esterase or galacturonase
Whole Milk
1 - 3 - 7-trimethylxanthine
19. What metabolic end product does the Voges-Proskauer test detect?
45% - 52% - 90%
Acetoin
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
20. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
Orange Juice
Lipid oxidation
Yes
21. How many carbon atoms are there in the fatty acid myristic acid?
14
Arachidonic Acid
Polyphenols
Osmosis
22. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Bitter
Parabens
Yellow
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
23. Name a naturally occurring protein sweetener.
Thamautin
Lycopenes
Pheophytia does not have magnesium in porphyrin ring.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
24. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lipase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
20 carbons and 4 double bonds
25. What ketohexose is most significant to food chemists?
2.5
Fructose
Polyphenols
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
26. In genetics What is conjugation?
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
DNA transferred by cell to cell contact (bacterial sex).
Fatty Acid and Alcohol
Monosodium Glutamate
27. What pigment was first designated as anthocyanins?
.05 M HCL
Carmelization and Maillard
Blue pigment in flowers
Nucleation or crystal formation and crystal growth.
28. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
DNA transferred by cell to cell contact (bacterial sex).
RNA transcribed to DNA
Negative log of the hydrogen concentration (mol/l).
29. What two types of compounds are joined with an ester bond to make a wax?
No
Thickener in foods
Fatty Acid and Alcohol
Lipid oxidation
30. What is surimi?
Pectin methylesterase & polygalacturonase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
A concentrate of microfibrillar proteins of fish muscle.
pH 3-5
31. What two common compounds are used together as an antioxidative system?
Degradation of protein and production of acid from sugar at the same time.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Ascorbic Acid and Citric Acid
Chitin
32. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Phenophylin
Glycosides of anthocyanidins
Speed of Light
33. Name a commonly used household chemical leavening agent and the gas it generates.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectins
Sodium bicarbonate generates CO2
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
34. What are soluble polymers of anhydro-galacturonic acid and its esters called?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Racemic Mixture
Pectins
Negative log of the hydrogen concentration (mol/l).
35. 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?
Fatty Acid and Alcohol
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
A concentrate of microfibrillar proteins of fish muscle.
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.
36. What are the fructose contents in commercial HFCS products.
Polyphenols
Erythorbic Acid
Whole Milk
45% - 52% - 90%
37. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fatty Acid and Alcohol
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
38. 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
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.
Initiation - Propagation - and Termination
Capsaicin
39. What does the saponification value measure and how is it measured?
Phenophylin
Speed of Light
Four
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
40. How does HPLC differ from FPLC?
Blue pigment in flowers
HPLC has higher pressure than FPLC
Fructose
Two aldehydes
41. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
pH 3-5
Glycosides of anthocyanidins
Non-protein nitrogen
42. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Pectin Esterase - Polygalacturonase - Pectin Layase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Bright green
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
43. What are the limiting amino acids in corn - potato - and green peas?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
44. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Pectin Esterase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Onions ( or leeks)
Ammonia - Water - Carbon Dioxide
45. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Water
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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.
46. Waxes are composed of what two basic chemical entities?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lipid oxidation
Chitin
Fatty Acid (Ester linked) to Fatty Alcohol
47. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Browning of freshly cut surfaces of fruits and vegetables.
Speed of Light
Troponins and Tropomyosin
pH below positive charge; pH at no charge; pH above negative charge
48. Name the two components that comprise the relaxing factor in muscle fibers.
Speed of Light
Troponins and Tropomyosin
Olive Green
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
49. What is the enzyme responsible for browning in apples and lettuce?
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
Initiation - Propagation - and Termination
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.
50. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Yellow
Browning of freshly cut surfaces of fruits and vegetables.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Osmosis