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Food Chemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Olive Green
Cis
Parabens

2. What does HLB stand for and What does a high and low HLB value indicate?
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.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Browning of freshly cut surfaces of fruits and vegetables.

3. What is the structural difference between chlorophyll and chlocophyllide?
Emulsification
Thermus Aqauticus
Chlocophyllide does not have a phytoltail
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

4. What is an isomer that is cheaper than Vitamin C?
Cis
Olive Green
Aspartic Acid and Phenylalanine
Erythorbic Acid

5. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Yellow
Chitin
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Carmelization and Maillard

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

7. At low water activity What is the main deteriorative concern?
Troponins and Tropomyosin
They act as catalysts - speeding the polymerization of acrylamide.
Lipid oxidation
Thermus Aqauticus

8. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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
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.

9. What pigment was first designated as anthocyanins?
Initiation - Propagation - Termination
Polyphenols
Blue pigment in flowers
Primary butyric acid also caproic acid.

10. What ketohexose is most significant to food chemists?
Fructose
The speed of a molecule is proportional to the surrounding voltage gradient.
Speed of Light
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

11. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Fatty Acid (Ester linked) to Fatty Alcohol
Sucrose
pH below positive charge; pH at no charge; pH above negative charge

12. What does the acronym NPN stand for?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Non-protein nitrogen
Ammonia - Water - Carbon Dioxide
Emulsoids

13. Name two enzymes that are involved in softening fruits.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pectin Esterase - Polygalacturonase - Pectin Layase
Fatty Acid and Alcohol
Gliadins and Glutenins

14. What ketohexose is most significant to food chemists?
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.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Daminozide
Fructose

15. Name 3 chemical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Olive Green
Acetoin
Monosodium Glutamate

16. What enzyme is most responsible for browning bananas?
Bright green
Polyphenol Oxidase
Chitin
.05 M HCL

17. What are the primary secondary - tertiary - and quaternary structures?
Glycosides of anthocyanidins
Fatty Acid and Alcohol
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.
Gossypol (it is removed during the oil refining process)

18. What are 3 mesomorphic structures associated with lipids in the liquid state?
Thamautin
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lamellar; Hexagonal I - II; Cubic
Whole Milk

19. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Ammonia - Water - Carbon Dioxide
Milk
pH 3-5
Yellow

20. What is the main class of color compounds found in raspberries?
Yes
Anthocyanins
Initiation - Propagation - and Termination
HPLC has higher pressure than FPLC

21. What does the iodine value measure and how is it measured?
Browning of freshly cut surfaces of fruits and vegetables.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Whole Milk
Daminozide

22. At what pH is benzoic acid most effective?
Whole Milk
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Thickener in foods
pH 3-5

23. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Lycopenes
Ascorbic Acid and Citric Acid
Pectin Esterase - Polygalacturonase - Pectin Layase

24. Name two enzymes that are involved in softening fruits.
Daminozide
An enzyme that converts hydrogen peroxide to water plus oxygen.
Pectin Esterase - Polygalacturonase - Pectin Layase
Tryptophan

25. Name one way foam stability can be assessed.
Degradation of protein and production of acid from sugar at the same time.
Polyphenoloxidase
Polyphenols
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.

26. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Tryptophan
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.
DNA transferred by cell to cell contact (bacterial sex).

27. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Pheophytia does not have magnesium in porphyrin ring.
Parabens
Pectins
NaCl (it dissociated to a 2M solution)

28. What does the acronym NPN stand for?
Ammonia - Water - Carbon Dioxide
Browning of freshly cut surfaces of fruits and vegetables.
Bitter
Non-protein nitrogen

29. Is a disaccharide
Thermus Aqauticus
Sucrose
Emulsoids
Monosodium Glutamate

30. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
2.5
Parabens
Ammonia - Water - Carbon Dioxide

31. Which two amino acids is the aspartame derived from?
Whole Milk
V=IR and P=VI or I x I x are
A concentrate of microfibrillar proteins of fish muscle.
Aspartic Acid and Phenylalanine

32. What are 3 mesomorphic structures associated with lipids in the liquid state?
Oil in Water
Initiation - Propagation - and Termination
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lamellar; Hexagonal I - II; Cubic

33. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Acetoin
Onions ( or leeks)
Daminozide
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

34. Are sorbitol and mannitol sweet?
Nucleation or crystal formation and crystal growth.
Sweet - Salty - Sour - and Bitter
Yes
D: None of the above

35. Name three non-nutritive sweeteners approved for use in USA?
DNA transferred by cell to cell contact (bacterial sex).
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.
Acsulfame-K - Saccharin - Cyclamate - Aspartame

36. Waxes are composed of what two basic chemical entities?
Primary butyric acid also caproic acid.
Milk
1 - 3 - 7-trimethylxanthine
Fatty Acid (Ester linked) to Fatty Alcohol

37. What enzyme causes hyrolytic rancidity in milk?
Sodium bicarbonate generates CO2
Sodium bicarbonate generates CO2
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lipase

38. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
14
Thickener in foods
Two aldehydes
45% - 52% - 90%

39. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Gliadins and Glutenins
Yes
ERH=100 x Aw

40. What are the limiting amino acids in corn - potato - and green peas?
Pectin methylesterase & polygalacturonase
Thamautin
Two aldehydes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

41. Name 4 advantages of using enzymes in food processing.
Erythorbic Acid
Acetoin
Osmosis
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

42. Name 3 chemical agents capable of denaturing proteins.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Emulsification
Initiation - Propagation - Termination

43. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Two aldehydes
Cis
Onions ( or leeks)
Fat Oxidation

44. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Phenophylin
Plasmids
Bitter
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

45. What is a polymorphism?
Lycopenes
Gossypol (it is removed during the oil refining process)
ERH=100 x Aw
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

46. What does the iodine value measure and how is it measured?
Degradation of protein and production of acid from sugar at the same time.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenol Oxidase

47. How does ERH relate to water activity?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Tryptophan
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
ERH=100 x Aw

48. What does HLB stand for and What does a high and low HLB value indicate?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Racemic Mixture
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.
Plasmids

49. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Pheophytia does not have magnesium in porphyrin ring.
pH below positive charge; pH at no charge; pH above negative charge
Two aldehydes

50. How do sodium chloride and sucrose affect foam stability?
Pectin methyl esterase or galacturonase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Oil in Water