Test your basic knowledge |

Food 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. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Initiation - Propagation - Termination
Parabens
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

2. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Fatty Acid and Alcohol
D: None of the above
Thermus Aqauticus
Anomeric

3. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
20 carbons and 4 double bonds
Gossypol (it is removed during the oil refining process)
Olive Green
Thamautin

4. What are the only phenols approved for use in the microbiological preservation of foods?
14
Daminozide
Parabens
It explodes

5. Name the strongest biochemical bond and the weakest biochemical bond.
Oil in Water
Sucrose
Covalent (strongest) and Hydrophobic (Weakest)
pH below positive charge; pH at no charge; pH above negative charge

6. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
pH below positive charge; pH at no charge; pH above negative charge
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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.

7. Name the most common functional property of phospholipids in food systems.
Emulsification
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Emulsoids
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

8. What is the fundamental driving of electrophoresis?
Osmosis
The speed of a molecule is proportional to the surrounding voltage gradient.
Covalent (strongest) and Hydrophobic (Weakest)
D: None of the above

9. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sweet - Salty - Sour - and Bitter
45% - 52% - 90%
Cis

10. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Anomeric
Lipid oxidation
Pectin methylesterase & polygalacturonase

11. Name one way foam stability can be assessed.
Ascorbic Acid and Citric Acid
Initiation - Propagation - Termination
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.
Fat Oxidation

12. 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)
Thickener in foods
Fatty Acid and Alcohol
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

13. 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.
Prolamines
Polyphenoloxidase
Pheophytia does not have magnesium in porphyrin ring.

14. What two types of compounds are joined with an ester bond to make a wax?
ERH=100 x Aw
Emulsification
Fatty Acid and Alcohol
They act as catalysts - speeding the polymerization of acrylamide.

15. What is the winterization process for an oil?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
It explodes
Four

16. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
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.

17. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Linoleic Acid
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fructose
Yellow

18. What is the chemical nomenclature for caffeine?
Yes
Speed of Light
1 - 3 - 7-trimethylxanthine
Initiation - Propagation - and Termination

19. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Pectin Esterase - Polygalacturonase - Pectin Layase
Acetoin
Bright green

20. Name the strongest biochemical bond and the weakest biochemical bond.
Pectins
Pectin Esterase - Polygalacturonase - Pectin Layase
Covalent (strongest) and Hydrophobic (Weakest)
Lipase

21. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Lycopenes
Carrageenan
Primary butyric acid also caproic acid.
Milk

22. Define molarity molality - and normality.
2.5
Degradation of protein and production of acid from sugar at the same time.
Thickener in foods
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

23. Is a disaccharide
Sucrose
Parabens
ERH=100 x Aw
Thickener in foods

24. Name a naturally occurring protein sweetener.
2.5
Thamautin
V=IR and P=VI or I x I x are
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

25. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Prolamines

26. 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?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
.05 M HCL

27. What ketohexose is most significant to food chemists?
Fructose
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Polyphenoloxidase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

28. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

29. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Pectins
.05 M HCL
Two aldehydes
Thamautin

30. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Capsaicin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Water

31. Is a disaccharide
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Anthocyanins
Sucrose

32. Name 3 factors influencing the consistency of commercial fats.
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
Plasmids
Parabens

33. What are the three stages of oxidative rancidity?
Capsaicin
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Initiation - Propagation - and Termination
Tryptophan

34. Name three non-nutritive sweeteners approved for use in USA?
Olive Green
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

35. How many carbon atoms and how many double bonds are there in arachidonic acid?
HPLC has higher pressure than FPLC
Parabens
20 carbons and 4 double bonds
Anthocyanins

36. What two enzymes degrade pectic substances?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Daminozide
Pectin methylesterase & polygalacturonase
.05

37. What is the common name for 9 12 - cis-cis-octa dienoic acid?
No
Osmosis
Non-protein nitrogen
Linoleic Acid

38. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Sweet - Salty - Sour - and Bitter
Ascorbic Acid and Citric Acid
Sodium chloride reduces foam stability and sucrose improves foam stability.

39. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Daminozide
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.
It explodes

40. Name two enzymes that are involved in softening fruits.
Pectins
Pectin Esterase - Polygalacturonase - Pectin Layase
Lysine - Arginine - and Histidine
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

41. What pigment was first designated as anthocyanins?
Gliadins and Glutenins
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Blue pigment in flowers
V=IR and P=VI or I x I x are

42. What enzyme is most responsible for browning bananas?
Emulsoids
Yellow
Polyphenol Oxidase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

43. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
NaCl (it dissociated to a 2M solution)

44. In what food is butyric acid typically found?
Browning of freshly cut surfaces of fruits and vegetables.
Milk
.05 M HCL
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

45. How many carbon atoms and how many double bonds are there in arachidonic acid?
Thickener in foods
20 carbons and 4 double bonds
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
HPLC has higher pressure than FPLC

46. How many polypeptide chains make up an antibody?
Chitin
Four
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Lamellar; Hexagonal I - II; Cubic

47. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Daminozide
HPLC has higher pressure than FPLC
Polyphenoloxidase
It explodes

48. What are the limiting amino acids in corn - potato - and green peas?
Acetoin
Water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Onions ( or leeks)

49. Name three nonpolar polar - and charged amino acids.
Anthocyanins
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Emulsification
Yes

50. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
Prolamines
It explodes
Polyphenol Oxidase