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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 a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
Parabens
Degradation of protein and production of acid from sugar at the same time.
Lamellar; Hexagonal I - II; Cubic
2. Name 3 factors influencing the consistency of commercial fats.
Polyphenoloxidase
1 - 3 - 7-trimethylxanthine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Blue pigment in flowers
3. What are the only phenols approved for use in the microbiological preservation of foods?
Covalent (strongest) and Hydrophobic (Weakest)
Parabens
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Polyphenoloxidase
4. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Pectin methyl esterase or galacturonase
NaCl (it dissociated to a 2M solution)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Sodium chloride reduces foam stability and sucrose improves foam stability.
5. What happens to chlorophyll on heating?
Yes
Pheophytin forms
Sucrose
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.
6. What is the enzyme that softens tomatoes?
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
Pectin Esterase
Yes
Negative log of the hydrogen concentration (mol/l).
7. What enzyme is most responsible for browning bananas?
Initiation - Propagation - Termination
Polyphenol Oxidase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Erythorbic Acid
8. 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
Ammonia - Water - Carbon Dioxide
Pectin Esterase - Polygalacturonase - Pectin Layase
Browning of freshly cut surfaces of fruits and vegetables.
Bitter
9. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Gliadins and Glutenins
10. What does the 'c' stand for in the equation E=mc2?
Emulsification
Ascorbic Acid and Citric Acid
HPLC has higher pressure than FPLC
Speed of Light
11. If you take 20 ml of .1 M NaOH to titrate 40 mL of an HCL solution to the penolphthalein end point What is the molarity of the HCL solution?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
.05 M HCL
Pectin Esterase - Polygalacturonase - Pectin Layase
Gliadins and Glutenins
12. What are the three stages of oxidative rancidity?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
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
Carrageenan
Initiation - Propagation - and Termination
13. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Covalent (strongest) and Hydrophobic (Weakest)
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
The speed of a molecule is proportional to the surrounding voltage gradient.
14. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Sodium bicarbonate generates CO2
Capsaicin
Monosodium Glutamate
RNA transcribed to DNA
15. Name 3 chemical agents capable of denaturing proteins.
Bitter
Capsaicin
Pheophytin forms
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
16. Name the strongest biochemical bond and the weakest biochemical bond.
Polyphenoloxidase
V=IR and P=VI or I x I x are
Covalent (strongest) and Hydrophobic (Weakest)
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
17. Name a naturally occurring protein sweetener.
Ammonia - Water - Carbon Dioxide
Thamautin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Blue pigment in flowers
18. Name two enzymes that are involved in softening fruits.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pectin Esterase - Polygalacturonase - Pectin Layase
Aspartic Acid and Phenylalanine
Polyphenol Oxidase
19. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Covalent (strongest) and Hydrophobic (Weakest)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
20. What is Carboxy-methyl cellulose often used for?
Prolamines
pH below positive charge; pH at no charge; pH above negative charge
Parabens
Thickener in foods
21. What does HLB stand for and What does a high and low HLB value indicate?
Troponins and Tropomyosin
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.
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.
Whole Milk
22. What are the primary secondary - tertiary - and quaternary structures?
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.
Fructose
A concentrate of microfibrillar proteins of fish muscle.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
23. What happens to chlorophyll on heating?
Erythorbic Acid
Pheophytin forms
Initiation - Propagation - Termination
Glycosides of anthocyanidins
24. 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?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Polyphenols
Chlocophyllide does not have a phytoltail
Oil in Water
25. What is the major color compound in tomatoes?
Gossypol (it is removed during the oil refining process)
Monosodium Glutamate
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lycopenes
26. What is Ohm's Law and What is Power Equation?
Negative log of the hydrogen concentration (mol/l).
Capsaicin
V=IR and P=VI or I x I x are
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
27. At what pH is benzoic acid most effective?
Orange Juice
Polyphenol Oxidase
Linoleic Acid
pH 3-5
28. Name three non-nutritive sweeteners approved for use in USA?
Bitter
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Water
Phenylketonuria
29. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Four
Fat Oxidation
30. Are sorbitol and mannitol sweet?
Lipid oxidation
Yes
Covalent (strongest) and Hydrophobic (Weakest)
It explodes
31. In what food is butyric acid typically found?
Cis
Carrageenan
Milk
Initiation - Propagation - Termination
32. What toxic pigment is found in cottonseed endosperm?
Anthocyanins
Erythorbic Acid
Gossypol (it is removed during the oil refining process)
.05 M HCL
33. What is the enzyme responsible for browning in apples and lettuce?
Initiation - Propagation - Termination
Polyphenol Oxidase
Monosodium Glutamate
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
34. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Yellow
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pectin methyl esterase or galacturonase
Fatty Acid (Ester linked) to Fatty Alcohol
35. What is the main class of color compounds found in raspberries?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Oil in Water
Sucrose
Anthocyanins
36. 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
NaCl (it dissociated to a 2M solution)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
37. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Gossypol (it is removed during the oil refining process)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Glycosides of anthocyanidins
38. 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?
Sweet - Salty - Sour - and Bitter
Bitter
It explodes
Thickener in foods
39. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Gliadins and Glutenins
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
40. Define molarity molality - and normality.
Pectin Esterase - Polygalacturonase - Pectin Layase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Sodium chloride reduces foam stability and sucrose improves foam stability.
41. Name the three positively charged amino acids.
Tryptophan
Yes
Lysine - Arginine - and Histidine
pH below positive charge; pH at no charge; pH above negative charge
42. What is the major color compound in tomatoes?
Lycopenes
Polyphenol Oxidase
ERH=100 x Aw
Polyphenoloxidase
43. How can a molecular weight of protein - DNA - and RNA be determined?
Covalent (strongest) and Hydrophobic (Weakest)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Gossypol (it is removed during the oil refining process)
Racemic Mixture
44. How many carbon atoms and how many double bonds are there in arachidonic acid?
Ammonia - Water - Carbon Dioxide
Fructose
20 carbons and 4 double bonds
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
45. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Daminozide
Acetoin
Carrageenan
46. Does kosmotrophil ion discourage water structure?
Blue pigment in flowers
Sodium bicarbonate generates CO2
Initiation - Propagation - Termination
No
47. Name 5 chelating agents used in the food industry.
Gliadins and Glutenins
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
48. What is the Peroxide Value a measure of?
Whole Milk
Fat Oxidation
Blue pigment in flowers
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
49. What does the iodine value measure and how is it measured?
Ascorbic Acid and Citric Acid
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Erythorbic Acid
Polyphenol Oxidase
50. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Osmosis
Arachidonic Acid
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Yes