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Food Chemistry

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Answer 50 questions in 15 minutes.
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1. Name 3 factors influencing the rate of lipid oxidation in foods.
Chitin
Two aldehydes
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

2. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Browning of freshly cut surfaces of fruits and vegetables.
Anomeric
No
Two aldehydes

3. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Carrageenan

4. What does the saponification value measure and how is it measured?
Negative log of the hydrogen concentration (mol/l).
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
They act as catalysts - speeding the polymerization of acrylamide.
Anthocyanins

5. What is the chemical nomenclature for caffeine?
Acetoin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Anthocyanins
1 - 3 - 7-trimethylxanthine

6. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
No
Capsaicin
Daminozide

7. What is Carboxy-methyl cellulose often used for?
Thickener in foods
Erythorbic Acid
Lamellar; Hexagonal I - II; Cubic
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

8. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
ERH=100 x Aw
RNA transcribed to DNA

9. Contains the lowest content of water
Whole Milk
Emulsification
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

10. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Monosodium Glutamate
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
pH below positive charge; pH at no charge; pH above negative charge

11. What is the geometric configuration of double bonds in most natural fatty acids?
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
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Pectin Esterase - Polygalacturonase - Pectin Layase
Cis

12. What are the only phenols approved for use in the microbiological preservation of foods?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Parabens
Oil in Water
Polyphenol Oxidase

13. Name 4 advantages of using enzymes in food processing.
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
Carmelization and Maillard
1 - 3 - 7-trimethylxanthine

14. What is the main class of color compounds found in raspberries?
Anthocyanins
Olive Green
Browning of freshly cut surfaces of fruits and vegetables.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

15. What two types of compounds are joined with an ester bond to make a wax?
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
.05 M HCL
Fatty Acid and Alcohol
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

16. How can a molecular weight of protein - DNA - and RNA be determined?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
An enzyme that converts hydrogen peroxide to water plus oxygen.
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.
Gossypol (it is removed during the oil refining process)

17. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
A concentrate of microfibrillar proteins of fish muscle.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Pheophytin forms
Primary butyric acid also caproic acid.

18. What is acid proteolysis?
Acetoin
Primary butyric acid also caproic acid.
Degradation of protein and production of acid from sugar at the same time.
pH below positive charge; pH at no charge; pH above negative charge

19. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
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.
Phenylketonuria
Daminozide
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

20. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
No
Fatty Acid and Alcohol
Plasmids

21. What does the iodine value measure and how is it measured?
No
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Sweet - Salty - Sour - and Bitter
Aspartic Acid and Phenylalanine

22. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Negative log of the hydrogen concentration (mol/l).
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Capsaicin

23. What does the 'c' stand for in the equation E=mc2?
Glycosides of anthocyanidins
Thermus Aqauticus
Speed of Light
Prolamines

24. 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
Nucleation or crystal formation and crystal growth.
Primary butyric acid also caproic acid.
Browning of freshly cut surfaces of fruits and vegetables.
.05 M HCL

25. At low water activity What is the main deteriorative concern?
Parabens
Plasmids
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lipid oxidation

26. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Milk
Cis
Parabens

27. What is surimi?
The speed of a molecule is proportional to the surrounding voltage gradient.
Phenophylin
DNA transferred by cell to cell contact (bacterial sex).
A concentrate of microfibrillar proteins of fish muscle.

28. Name three nonpolar polar - and charged amino acids.
Ascorbic Acid and Citric Acid
Fat Oxidation
2.5
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

29. Name the most common functional property of phospholipids in food systems.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
ERH=100 x Aw
Chitin
Emulsification

30. What is Ohm's Law and What is Power Equation?
Sweet - Salty - Sour - and Bitter
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
V=IR and P=VI or I x I x are

31. What are colloids that are stabilized by a layer of solvation called?
2.5
V=IR and P=VI or I x I x are
.05
Emulsoids

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

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33. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Lipase
Oil in Water
20 carbons and 4 double bonds

34. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
NaCl (it dissociated to a 2M solution)
Lipid oxidation
Pheophytia does not have magnesium in porphyrin ring.

35. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Thermus Aqauticus
Plasmids
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Thamautin

36. What two common compounds are used together as an antioxidative system?
Anthocyanins
Fat Oxidation
Ascorbic Acid and Citric Acid
Gliadins and Glutenins

37. What is an isomer that is cheaper than Vitamin C?
Negative log of the hydrogen concentration (mol/l).
Erythorbic Acid
RNA transcribed to DNA
Orange Juice

38. What is the structural difference between chlorophyll and chlocophyllide?
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
Initiation - Propagation - Termination
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

39. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Thickener in foods
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.
Arachidonic Acid

40. 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)
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.
Racemic Mixture
Lipid oxidation

41. What does the acronym NPN stand for?
Ascorbic Acid and Citric Acid
1 - 3 - 7-trimethylxanthine
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Non-protein nitrogen

42. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectin Esterase
Water
Prolamines

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

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44. What are two common reducing agents that break disulfide bonds in proteins?
Parabens
No
Thamautin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

45. Is a disaccharide
Bitter
Anomeric
Yes
Sucrose

46. Which two amino acids is the aspartame derived from?
Negative log of the hydrogen concentration (mol/l).
Aspartic Acid and Phenylalanine
Onions ( or leeks)
Olive Green

47. How many carbon atoms and how many double bonds are there in arachidonic acid?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
pH below positive charge; pH at no charge; pH above negative charge
20 carbons and 4 double bonds
DNA transferred by cell to cell contact (bacterial sex).

48. What does the acronym NPN stand for?
Phenylketonuria
Osmosis
Pectin Esterase - Polygalacturonase - Pectin Layase
Non-protein nitrogen

49. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
Chitin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Water

50. What is the geometric configuration of double bonds in most natural fatty acids?
Arachidonic Acid
Cis
Emulsoids
Glycosides of anthocyanidins