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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Racemic Mixture
Glycosides of anthocyanidins
Speed of Light

2. 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
Negative log of the hydrogen concentration (mol/l).
Browning of freshly cut surfaces of fruits and vegetables.
Fructose
Phenylketonuria

3. What metabolic end product does the Voges-Proskauer test detect?
Pectin Esterase
Sweet - Salty - Sour - and Bitter
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Acetoin

4. 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.
V=IR and P=VI or I x I x are
Pheophytin forms
pH below positive charge; pH at no charge; pH above negative charge

5. How many polypeptide chains make up an antibody?
Browning of freshly cut surfaces of fruits and vegetables.
45% - 52% - 90%
Pheophytia does not have magnesium in porphyrin ring.
Four

6. What happens to chlorophyll on heating?
Bright green
Pheophytin forms
1 - 3 - 7-trimethylxanthine
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

7. What does Acid Degree Value measure and how is it measured?
Plasmids
Blue pigment in flowers
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Arachidonic Acid

8. Peptide bond formation results in the formation of what secondary compound?
Thickener in foods
Parabens
Pectin methylesterase & polygalacturonase
Water

9. Name one way foam stability can be assessed.
Phenylketonuria
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.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

10. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
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.
Water
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

11. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
NaCl (it dissociated to a 2M solution)
1 - 3 - 7-trimethylxanthine
Primary butyric acid also caproic acid.
Lipid oxidation

12. Contains the lowest content of water
Fructose
Whole Milk
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
Polyphenoloxidase

13. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Fructose
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.
Glycosides of anthocyanidins
Linoleic Acid

14. What is the enzyme that softens tomatoes?
It explodes
Sodium chloride reduces foam stability and sucrose improves foam stability.
Pectin Esterase
Orange Juice

15. What is the structural difference between chlorophyll and chlocophyllide?
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.
Chlocophyllide does not have a phytoltail
Nucleation or crystal formation and crystal growth.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

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?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Thamautin
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

17. What ketohexose is most significant to food chemists?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Degradation of protein and production of acid from sugar at the same time.
Fructose
Anthocyanins

18. What is the major color compound in tomatoes?
Lycopenes
Fat Oxidation
Thickener in foods
Anthocyanins

19. Name three nonpolar polar - and charged amino acids.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Plasmids
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
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.

20. What does the acronym NPN stand for?
Ammonia - Water - Carbon Dioxide
V=IR and P=VI or I x I x are
Non-protein nitrogen
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

21. 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
Emulsoids
Sodium bicarbonate generates CO2
Browning of freshly cut surfaces of fruits and vegetables.
Bitter

22. What two types of compounds are joined with an ester bond to make a wax?
Osmosis
They act as catalysts - speeding the polymerization of acrylamide.
Pectin methylesterase & polygalacturonase
Fatty Acid and Alcohol

23. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
It explodes

24. Name 3 chemical agents capable of denaturing proteins.
Four
Monosodium Glutamate
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Milk

25. Will lipid oxidation be higher at a water activity of .05 or .5?
Fatty Acid and Alcohol
.05
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin methylesterase & polygalacturonase

26. Name the three positively charged amino acids.
20 carbons and 4 double bonds
Degradation of protein and production of acid from sugar at the same time.
Lysine - Arginine - and Histidine
Covalent (strongest) and Hydrophobic (Weakest)

27. Name the two components that comprise the relaxing factor in muscle fibers.
Anthocyanins
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
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.
Troponins and Tropomyosin

28. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Pheophytia does not have magnesium in porphyrin ring.
Glycosides of anthocyanidins
Daminozide

29. At low water activity What is the main deteriorative concern?
Thickener in foods
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Fructose
Lipid oxidation

30. What are the fructose contents in commercial HFCS products.
Lysine - Arginine - and Histidine
45% - 52% - 90%
Parabens
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

31. What is acid proteolysis?
Yes
Degradation of protein and production of acid from sugar at the same time.
Pectin methylesterase & polygalacturonase
Chitin

32. How does ERH relate to water activity?
Thamautin
ERH=100 x Aw
Milk
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.

33. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Troponins and Tropomyosin
It explodes
Lysine - Arginine - and Histidine

34. What are two common reducing agents that break disulfide bonds in proteins?
Polyphenoloxidase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Acsulfame-K - Saccharin - Cyclamate - Aspartame
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

35. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Polyphenol Oxidase
14
Milk

36. What is catalase?
ERH=100 x Aw
Carmelization and Maillard
Milk
An enzyme that converts hydrogen peroxide to water plus oxygen.

37. 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.
pH below positive charge; pH at no charge; pH above negative charge
Polyphenol Oxidase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

38. Name the strongest biochemical bond and the weakest biochemical bond.
Anomeric
Sodium bicarbonate generates CO2
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Covalent (strongest) and Hydrophobic (Weakest)

39. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Anomeric
Plasmids
Blue pigment in flowers

40. What does HLB stand for and What does a high and low HLB value indicate?
Fatty Acid (Ester linked) to Fatty Alcohol
Monosodium Glutamate
Prolamines
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.

41. Contains the lowest content of water
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Whole Milk
An enzyme that converts hydrogen peroxide to water plus oxygen.
Sodium bicarbonate generates CO2

42. What are proteins which are soluble in 50-80% ethanol known as?
Degradation of protein and production of acid from sugar at the same time.
Prolamines
Troponins and Tropomyosin
Lipase

43. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
A concentrate of microfibrillar proteins of fish muscle.
Orange Juice
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.

44. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
20 carbons and 4 double bonds
Daminozide
RNA transcribed to DNA
Negative log of the hydrogen concentration (mol/l).

45. What is the chemical nomenclature for caffeine?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
1 - 3 - 7-trimethylxanthine
Capsaicin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

46. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Capsaicin
Monosodium Glutamate
A concentrate of microfibrillar proteins of fish muscle.

47. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Four
Glycosides of anthocyanidins
Thermus Aqauticus

48. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
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.
Erythorbic Acid
Nucleation or crystal formation and crystal growth.

49. What is the chemical nature of anthocyanins?
Polyphenoloxidase
Glycosides of anthocyanidins
Milk
Emulsoids

50. What does MSG stand for?
Monosodium Glutamate
A concentrate of microfibrillar proteins of fish muscle.
They act as catalysts - speeding the polymerization of acrylamide.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)