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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. At what pH is benzoic acid most effective?
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 3-5
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
They act as catalysts - speeding the polymerization of acrylamide.
2. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Capsaicin
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase
Water
3. What metabolic end product does the Voges-Proskauer test detect?
Emulsoids
Acetoin
Phenophylin
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.
4. 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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
ERH=100 x Aw
5. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
Lysine - Arginine - and Histidine
Thermus Aqauticus
A concentrate of microfibrillar proteins of fish muscle.
6. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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.
.05
Sodium bicarbonate generates CO2
7. Name the most common functional property of phospholipids in food systems.
Bright green
Emulsification
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
8. Give one word for a carbon atom involved in hemiacetal or acetal formation.
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
Anomeric
.05 M HCL
Polyphenol Oxidase
9. Name two main gluten proteins.
Lipase
DNA transferred by cell to cell contact (bacterial sex).
Gliadins and Glutenins
Yes
10. Name 3 factors influencing the rate of lipid oxidation in foods.
Emulsoids
Racemic Mixture
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
11. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Browning of freshly cut surfaces of fruits and vegetables.
Orange Juice
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.
12. What is the enzyme responsible for browning in apples and lettuce?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Cis
Polyphenol Oxidase
Lamellar; Hexagonal I - II; Cubic
13. Name three nonpolar polar - and charged amino acids.
Lysine - Arginine - and Histidine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Nucleation or crystal formation and crystal growth.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
14. 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.
Four
No
Whole Milk
15. Define molarity molality - and normality.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Racemic Mixture
Milk
DNA transferred by cell to cell contact (bacterial sex).
16. 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?
Carmelization and Maillard
Carrageenan
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Sweet - Salty - Sour - and Bitter
17. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Initiation - Propagation - and Termination
HPLC has higher pressure than FPLC
18. In what food is butyric acid typically found?
Lipase
Milk
Glycosides of anthocyanidins
Troponins and Tropomyosin
19. How can a molecular weight of protein - DNA - and RNA be determined?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Primary butyric acid also caproic acid.
.05
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
20. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Daminozide
Pheophytia does not have magnesium in porphyrin ring.
14
21. What is surimi?
Capsaicin
A concentrate of microfibrillar proteins of fish muscle.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Initiation - Propagation - Termination
22. 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.
Pectin methylesterase & polygalacturonase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Thamautin
23. What is the main class of color compounds found in raspberries?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Degradation of protein and production of acid from sugar at the same time.
RNA transcribed to DNA
Anthocyanins
24. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Monosodium Glutamate
Lamellar; Hexagonal I - II; Cubic
Lycopenes
25. What is the main class of color compounds found in raspberries?
Anthocyanins
Capsaicin
Bright green
It explodes
26. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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.
V=IR and P=VI or I x I x are
27. How can a molecular weight of protein - DNA - and RNA be determined?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
HPLC has higher pressure than FPLC
28. What are the three main steps in the autooxidation of lipids?
Carrageenan
Initiation - Propagation - Termination
20 carbons and 4 double bonds
Anomeric
29. 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)
Negative log of the hydrogen concentration (mol/l).
Onions ( or leeks)
NaCl (it dissociated to a 2M solution)
30. What is the name given to a mixture of equal parts of Darel Lisomers?
Carrageenan
Racemic Mixture
pH 3-5
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.
31. Name the two components that comprise the relaxing factor in muscle fibers.
A concentrate of microfibrillar proteins of fish muscle.
Cis
Troponins and Tropomyosin
Polyphenols
32. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Polyphenoloxidase
Thickener in foods
Lycopenes
33. What pigment was first designated as anthocyanins?
Pectin methylesterase & polygalacturonase
Blue pigment in flowers
Water
Linoleic Acid
34. Define molarity molality - and normality.
Pectin methyl esterase or galacturonase
Phenylketonuria
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.
35. During freezing What are the two stages in the crystallization process?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
45% - 52% - 90%
Nucleation or crystal formation and crystal growth.
36. How does ERH relate to water activity?
Aspartic Acid and Phenylalanine
Phenylketonuria
ERH=100 x Aw
Bitter
37. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Two aldehydes
DNA transferred by cell to cell contact (bacterial sex).
Bright green
38. What ketohexose is most significant to food chemists?
pH below positive charge; pH at no charge; pH above negative charge
Negative log of the hydrogen concentration (mol/l).
Fructose
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
39. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
ERH=100 x Aw
Browning of freshly cut surfaces of fruits and vegetables.
Thickener in foods
40. Name three non-nutritive sweeteners approved for use in USA?
DNA transferred by cell to cell contact (bacterial sex).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
14
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
41. Name three nonpolar polar - and charged amino acids.
Cis
Phenophylin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Monosodium Glutamate
42. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
They act as catalysts - speeding the polymerization of acrylamide.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Orange Juice
Carmelization and Maillard
43. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
No
Tryptophan
Water
44. Alar is the trade name for what chemical compound?
Daminozide
Thermus Aqauticus
Thamautin
Chlocophyllide does not have a phytoltail
45. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Yellow
Oil in Water
Tryptophan
Emulsification
46. Waxes are composed of what two basic chemical entities?
Fructose
Fatty Acid (Ester linked) to Fatty Alcohol
Carrageenan
NaCl (it dissociated to a 2M solution)
47. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
45% - 52% - 90%
Lipid oxidation
Onions ( or leeks)
48. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Orange Juice
Monosodium Glutamate
Bitter
Pectin methyl esterase or galacturonase
49. Peptide bond formation results in the formation of what secondary compound?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Water
Polyphenol Oxidase
Thamautin
50. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Carrageenan
Daminozide
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Lipid oxidation