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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 is catalase?
Milk
Lipid oxidation
An enzyme that converts hydrogen peroxide to water plus oxygen.
Fat Oxidation
2. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chlocophyllide does not have a phytoltail
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Linoleic Acid
3. How does HPLC differ from FPLC?
Gossypol (it is removed during the oil refining process)
Chlocophyllide does not have a phytoltail
HPLC has higher pressure than FPLC
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
4. How many carbon atoms and how many double bonds are there in arachidonic acid?
.05 M HCL
20 carbons and 4 double bonds
ERH=100 x Aw
Negative log of the hydrogen concentration (mol/l).
5. In what food is butyric acid typically found?
Pectins
Daminozide
Milk
Prolamines
6. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Lysine - Arginine - and Histidine
Bright green
Plasmids
Covalent (strongest) and Hydrophobic (Weakest)
7. What compounds oxidize to form brown color in fruits and vegetables?
The speed of a molecule is proportional to the surrounding voltage gradient.
Erythorbic Acid
1 - 3 - 7-trimethylxanthine
Polyphenols
8. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Osmosis
Bitter
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
9. Is a disaccharide
Sucrose
Fatty Acid (Ester linked) to Fatty Alcohol
Polyphenol Oxidase
Cis
10. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
Olive Green
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
Polyphenoloxidase
11. What ketohexose is most significant to food chemists?
Fructose
Oil in Water
Aspartic Acid and Phenylalanine
Polyphenol Oxidase
12. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Initiation - Propagation - Termination
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Two aldehydes
Pectin methylesterase & polygalacturonase
13. What does HLB stand for and What does a high and low HLB value indicate?
Thermus Aqauticus
Polyphenol Oxidase
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.
Emulsoids
14. What does the 'c' stand for in the equation E=mc2?
Pectins
2.5
Speed of Light
Chlocophyllide does not have a phytoltail
15. How can a molecular weight of protein - DNA - and RNA be determined?
NaCl (it dissociated to a 2M solution)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
ERH=100 x Aw
It explodes
16. What is the fundamental driving of electrophoresis?
Thickener in foods
They act as catalysts - speeding the polymerization of acrylamide.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
The speed of a molecule is proportional to the surrounding voltage gradient.
17. What is the enzyme that softens tomatoes?
Pheophytia does not have magnesium in porphyrin ring.
Pectin Esterase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
18. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Olive Green
Lysine - Arginine - and Histidine
Sodium chloride reduces foam stability and sucrose improves foam stability.
19. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Phenophylin
Acetoin
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
RNA transcribed to DNA
20. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
No
Lamellar; Hexagonal I - II; Cubic
Initiation - Propagation - and Termination
21. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Carrageenan
ERH=100 x Aw
Ascorbic Acid and Citric Acid
22. 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
Capsaicin
Lysine - Arginine - and Histidine
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Anomeric
23. What effect would the addition of sodium bicarbonate have to chocolate?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Lamellar; Hexagonal I - II; Cubic
Water
24. Name 5 chelating agents used in the food industry.
Non-protein nitrogen
pH 3-5
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Water
25. Give one word for a carbon atom involved in hemiacetal or acetal formation.
The speed of a molecule is proportional to the surrounding voltage gradient.
Anomeric
Lysine - Arginine - and Histidine
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
26. 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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sweet - Salty - Sour - and Bitter
Oil in Water
27. 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?
It explodes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
28. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Lipid oxidation
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
Capsaicin
Plasmids
29. What is a polymorphism?
Covalent (strongest) and Hydrophobic (Weakest)
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Polyphenols
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
30. What is the acid present in fish oil?
Initiation - Propagation - Termination
Lysine - Arginine - and Histidine
Parabens
Arachidonic Acid
31. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Yellow
Nucleation or crystal formation and crystal growth.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Tryptophan
32. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Covalent (strongest) and Hydrophobic (Weakest)
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Erythorbic Acid
33. Name two non-enzymatic browning reactions.
Lycopenes
Water
Troponins and Tropomyosin
Carmelization and Maillard
34. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Sucrose
RNA transcribed to DNA
Bright green
Polyphenoloxidase
35. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
45% - 52% - 90%
Thamautin
Onions ( or leeks)
Lamellar; Hexagonal I - II; Cubic
36. Waxes are composed of what two basic chemical entities?
Pectins
Fatty Acid (Ester linked) to Fatty Alcohol
Ascorbic Acid and Citric Acid
Lycopenes
37. Alar is the trade name for what chemical compound?
No
Blue pigment in flowers
They act as catalysts - speeding the polymerization of acrylamide.
Daminozide
38. What are 3 mesomorphic structures associated with lipids in the liquid state?
Whole Milk
Initiation - Propagation - and Termination
Lamellar; Hexagonal I - II; Cubic
Carmelization and Maillard
39. What is the enzyme responsible for browning in apples and lettuce?
HPLC has higher pressure than FPLC
Fructose
A concentrate of microfibrillar proteins of fish muscle.
Polyphenol Oxidase
40. Name two main gluten proteins.
No
Anthocyanins
Aspartic Acid and Phenylalanine
Gliadins and Glutenins
41. What are the limiting amino acids in corn - potato - and green peas?
Cis
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
pH below positive charge; pH at no charge; pH above negative charge
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
42. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Blue pigment in flowers
Two aldehydes
43. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
Yes
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Ammonia - Water - Carbon Dioxide
44. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Carrageenan
Water
.05 M HCL
Anthocyanins
45. Does kosmotrophil ion discourage water structure?
Plasmids
Daminozide
No
Arachidonic Acid
46. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
D: None of the above
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
ERH=100 x Aw
Phenophylin
47. What is the name of the degradation compound of chlorophyll?
Phenophylin
Chitin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Osmosis
48. Name two reasons why fats are hydrogenated.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lamellar; Hexagonal I - II; Cubic
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fat Oxidation
49. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
50. How is pH defined?
Plasmids
Lamellar; Hexagonal I - II; Cubic
An enzyme that converts hydrogen peroxide to water plus oxygen.
Negative log of the hydrogen concentration (mol/l).