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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. Is a disaccharide
Sucrose
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Water

2. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
14
Anthocyanins

3. In genetics What is conjugation?
.05
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
DNA transferred by cell to cell contact (bacterial sex).
Orange Juice

4. What ketohexose is most significant to food chemists?
Fructose
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectins
Erythorbic Acid

5. What is Carboxy-methyl cellulose often used for?
Pectin methylesterase & polygalacturonase
Fructose
Polyphenols
Thickener in foods

6. What is the chemical nature of anthocyanins?
Gliadins and Glutenins
Bright green
Lycopenes
Glycosides of anthocyanidins

7. What is the protein efficiency ratio (PER) of casein?
2.5
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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
Osmosis

8. Define molarity molality - and normality.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Two aldehydes
Fat Oxidation
Fatty Acid (Ester linked) to Fatty Alcohol

9. 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?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Aspartic Acid and Phenylalanine
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Primary butyric acid also caproic acid.

10. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Carrageenan
Polyphenoloxidase
D: None of the above
Bitter

11. Alar is the trade name for what chemical compound?
Daminozide
Carmelization and Maillard
Speed of Light
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

12. Define molarity molality - and normality.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Pheophytin forms
Pectin Esterase

13. Name 5 chelating agents used in the food industry.
Daminozide
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

14. 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?
.05 M HCL
Two aldehydes
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Primary butyric acid also caproic acid.

15. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
Troponins and Tropomyosin
Primary butyric acid also caproic acid.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

16. What two types of compounds are joined with an ester bond to make a wax?
Speed of Light
Initiation - Propagation - and Termination
Fatty Acid and Alcohol
Anthocyanins

17. Name two main gluten proteins.
.05
Thickener in foods
Gliadins and Glutenins
Capsaicin

18. What is the major color compound in tomatoes?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Chlocophyllide does not have a phytoltail
Troponins and Tropomyosin
Lycopenes

19. What metabolic end product does the Voges-Proskauer test detect?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Gliadins and Glutenins
Olive Green
Acetoin

20. What enzyme causes hyrolytic rancidity in milk?
Lipase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
D: None of the above
1 - 3 - 7-trimethylxanthine

21. What is the name given to a mixture of equal parts of Darel Lisomers?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
20 carbons and 4 double bonds
Lysine - Arginine - and Histidine
Racemic Mixture

22. What is the major color compound in tomatoes?
Lycopenes
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
Pectin methylesterase & polygalacturonase
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

23. What does the iodine value measure and how is it measured?
Pectins
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Sweet - Salty - Sour - and Bitter
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

24. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Water
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

25. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
D: None of the above
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Degradation of protein and production of acid from sugar at the same time.
Yes

26. When heated ammonium bicarbonate decomposes to form what end products?
20 carbons and 4 double bonds
Ammonia - Water - Carbon Dioxide
Oil in Water
Polyphenol Oxidase

27. Name three nonpolar polar - and charged amino acids.
Racemic Mixture
Yes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

28. How is pH defined?
Two aldehydes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Negative log of the hydrogen concentration (mol/l).
Sodium bicarbonate generates CO2

29. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lycopenes
Carrageenan
Pectin Esterase

30. 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
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Chitin
Gossypol (it is removed during the oil refining process)

31. What is the fundamental driving of electrophoresis?
NaCl (it dissociated to a 2M solution)
Fatty Acid (Ester linked) to Fatty Alcohol
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
The speed of a molecule is proportional to the surrounding voltage gradient.

32. Name two enzymes that are involved in softening fruits.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectin Esterase - Polygalacturonase - Pectin Layase
Whole Milk
Covalent (strongest) and Hydrophobic (Weakest)

33. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Fatty Acid and Alcohol
Sodium bicarbonate generates CO2

34. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phenophylin
Gossypol (it is removed during the oil refining process)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Anthocyanins

35. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Erythorbic Acid
Yes
Degradation of protein and production of acid from sugar at the same time.

36. 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
Sucrose
No
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.
Browning of freshly cut surfaces of fruits and vegetables.

37. What is the chemical nomenclature for caffeine?
Racemic Mixture
Thamautin
1 - 3 - 7-trimethylxanthine
Acetoin

38. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lipid oxidation
Four
Covalent (strongest) and Hydrophobic (Weakest)

39. Name the two components that comprise the relaxing factor in muscle fibers.
No
Phenylketonuria
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Troponins and Tropomyosin

40. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
Bitter
RNA transcribed to DNA
Acsulfame-K - Saccharin - Cyclamate - Aspartame

41. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Capsaicin
Pectin methyl esterase or galacturonase
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Phenophylin

42. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Non-protein nitrogen
Aspartic Acid and Phenylalanine
Cis
Oil in Water

43. Name the three positively charged amino acids.
Phenophylin
1 - 3 - 7-trimethylxanthine
Lysine - Arginine - and Histidine
Anthocyanins

44. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lysine - Arginine - and Histidine
NaCl (it dissociated to a 2M solution)
Gliadins and Glutenins

45. What are 3 mesomorphic structures associated with lipids in the liquid state?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
A concentrate of microfibrillar proteins of fish muscle.
Lamellar; Hexagonal I - II; Cubic
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

46. What are the three main steps in the autooxidation of lipids?
1 - 3 - 7-trimethylxanthine
Aspartic Acid and Phenylalanine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Initiation - Propagation - Termination

47. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
Monosodium Glutamate
D: None of the above
Pheophytia does not have magnesium in porphyrin ring.
Daminozide

48. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Erythorbic Acid
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

49. What happens to chlorophyll on heating?
Gliadins and Glutenins
Sweet - Salty - Sour - and Bitter
Pheophytin forms
Lycopenes

50. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Carmelization and Maillard
Olive Green
Monosodium Glutamate
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.