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. What compounds oxidize to form brown color in fruits and vegetables?
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
Polyphenols
Pectin Esterase
14

2. What is the name of the degradation compound of chlorophyll?
Phenophylin
Polyphenol Oxidase
Two aldehydes
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.

3. What are the primary secondary - tertiary - and quaternary structures?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
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.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Parabens

4. What toxic pigment is found in cottonseed endosperm?
Pectins
Gossypol (it is removed during the oil refining process)
20 carbons and 4 double bonds
Initiation - Propagation - and Termination

5. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
Orange Juice
Pectin methyl esterase or galacturonase
No

6. What happens to chlorophyll on heating?
Polyphenol Oxidase
Pheophytin forms
Anomeric
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

7. At what pH is benzoic acid most effective?
An enzyme that converts hydrogen peroxide to water plus oxygen.
DNA transferred by cell to cell contact (bacterial sex).
Bright green
pH 3-5

8. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Negative log of the hydrogen concentration (mol/l).
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.
14
Osmosis

9. Name 4 advantages of using enzymes in food processing.
They act as catalysts - speeding the polymerization of acrylamide.
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Primary butyric acid also caproic acid.

10. Contains the lowest content of water
Chitin
Ascorbic Acid and Citric Acid
Whole Milk
Linoleic Acid

11. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lysine - Arginine - and Histidine
NaCl (it dissociated to a 2M solution)

12. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
NaCl (it dissociated to a 2M solution)
Onions ( or leeks)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Pectin methylesterase & polygalacturonase

13. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Fat Oxidation
2.5
Yellow

14. What two types of compounds are joined with an ester bond to make a wax?
Sodium chloride reduces foam stability and sucrose improves foam stability.
They act as catalysts - speeding the polymerization of acrylamide.
Fatty Acid and Alcohol
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

15. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
It explodes
Polyphenoloxidase
Orange Juice

16. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Gliadins and Glutenins
Degradation of protein and production of acid from sugar at the same time.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

17. What is the Peroxide Value a measure of?
They act as catalysts - speeding the polymerization of acrylamide.
Prolamines
Fat Oxidation
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

18. What is the structural difference between chlorophyll and pheophytia?
Pheophytin forms
Pheophytia does not have magnesium in porphyrin ring.
Emulsification
Acsulfame-K - Saccharin - Cyclamate - Aspartame

19. What is the major color compound in tomatoes?
Pectin Esterase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Lycopenes
Degradation of protein and production of acid from sugar at the same time.

20. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
pH 3-5
Oil in Water
Emulsoids
20 carbons and 4 double bonds

21. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Pectin methyl esterase or galacturonase
Yellow
Anomeric
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

22. Name the two components that comprise the relaxing factor in muscle fibers.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
20 carbons and 4 double bonds
Chlocophyllide does not have a phytoltail
Troponins and Tropomyosin

23. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Nucleation or crystal formation and crystal growth.
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.
Thickener in foods
Linoleic Acid

24. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
D: None of the above
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
It explodes
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.

25. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Thermus Aqauticus
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Chitin
Bright green

26. Is a disaccharide
Arachidonic Acid
Sucrose
Polyphenoloxidase
Gliadins and Glutenins

27. Is a disaccharide
Carmelization and Maillard
Onions ( or leeks)
Anomeric
Sucrose

28. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Bright green
Carrageenan
Thamautin
Orange Juice

29. What does Acid Degree Value measure and how is it measured?
Daminozide
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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
An enzyme that converts hydrogen peroxide to water plus oxygen.

30. What does MSG stand for?
Monosodium Glutamate
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
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.
Water

31. How many carbon atoms and how many double bonds are there in arachidonic acid?
Plasmids
D: None of the above
20 carbons and 4 double bonds
Water

32. What is the structural difference between chlorophyll and pheophytia?
Anthocyanins
Pheophytia does not have magnesium in porphyrin ring.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

33. What does Reichert-Meissert Number measure?
Ammonia - Water - Carbon Dioxide
Bitter
Blue pigment in flowers
Primary butyric acid also caproic acid.

34. What is Ohm's Law and What is Power Equation?
Initiation - Propagation - and Termination
V=IR and P=VI or I x I x are
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fatty Acid and Alcohol

35. Peptide bond formation results in the formation of what secondary compound?
Water
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
20 carbons and 4 double bonds
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

36. What is the protein efficiency ratio (PER) of casein?
Thickener in foods
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2.5
Milk

37. What is the chemical nomenclature for caffeine?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
1 - 3 - 7-trimethylxanthine
Thamautin
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

38. What are 3 mesomorphic structures associated with lipids in the liquid state?
Degradation of protein and production of acid from sugar at the same time.
Initiation - Propagation - and Termination
Anthocyanins
Lamellar; Hexagonal I - II; Cubic

39. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Pectin methyl esterase or galacturonase
Osmosis
Two aldehydes
Gossypol (it is removed during the oil refining process)

40. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
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.
Daminozide
Capsaicin

41. What is the enzyme that softens tomatoes?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Arachidonic Acid
pH below positive charge; pH at no charge; pH above negative charge
Pectin Esterase

42. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fat Oxidation
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Non-protein nitrogen

43. What is the structural difference between chlorophyll and chlocophyllide?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Chlocophyllide does not have a phytoltail

44. 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?
1 - 3 - 7-trimethylxanthine
.05 M HCL
pH below positive charge; pH at no charge; pH above negative charge
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

45. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
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.
Osmosis
Phenophylin
V=IR and P=VI or I x I x are

46. How can a molecular weight of protein - DNA - and RNA be determined?
Monosodium Glutamate
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Water
Speed of Light

47. Name a commonly used household chemical leavening agent and the gas it generates.
Bitter
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Bright green
Sodium bicarbonate generates CO2

48. What two common compounds are used together as an antioxidative system?
Daminozide
Ascorbic Acid and Citric Acid
NaCl (it dissociated to a 2M solution)
Fructose

49. Name three nonpolar polar - and charged amino acids.
Browning of freshly cut surfaces of fruits and vegetables.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Carrageenan
A concentrate of microfibrillar proteins of fish muscle.

50. What does Reichert-Meissert Number measure?
Lysine - Arginine - and Histidine
Four
Lamellar; Hexagonal I - II; Cubic
Primary butyric acid also caproic acid.