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Food Chemistry Flashcards

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1
Q

Would a more hydrophilic substance have a higher or lower HLB than a hydrophobic substance?

A

Higher

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2
Q

Within what range of its pK is a buffering agent is effective?

A

Plus or minus 1 pH unit

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3
Q

Why do triglycerides normally soften slowly and don’t have sharp melting points?

A

Triglycerides can contain up to three different fatty acids and each fatty acid will have a different melting point.

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4
Q

Why do seed proteins like soy protein have a high isoelectric point?

A

Most of the glutamic and aspartic acid residues are amidated

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5
Q

Which sugar alcohol has the same sweetness as sucrose?

A

Xylitol

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6
Q

Which of the following solution would exhibit the lowest aw? Which the highest? a) 1 M NaCl b) 1 M glycerol c) 1 M glucose d) 1 M sucrose e) 1 M CaCl2

A

Lowest – 1 M sucrose, Highest – 1 M CaCl2

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7
Q

Which of the following gums should not be included in a formulation of a product, which does not require heating? Locust bean gum, Guar gum, Xanthan gum, or Gum Arabic

A

locust bean gum

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8
Q

Which of the following are emulsifying salts for use in processing cheese? sodium tartrate, sodium chloride, potassium chloride, all of the above

A

sodium tartrate (a)

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9
Q

Which is more viscous: high DE or low DE corn syrup?

A

Low DE

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10
Q

Which has a higher melting point: oleic or palmitic?

A

Palmitic

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11
Q

Which fatty acid would be expected to have the highest iodine value- linoleic, oleic, or linolenic?

A

Linolenic (18:3 - has more unsaturation) (oleic has 1 double bond, linoleic has 2 double bonds)

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12
Q

Which amino acids may form dehydroalanine?

A

Cysteine, cystine, serine, P-serine

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13
Q

Where is banana oil obtained from?

A

Trick question? No oil in bananas?

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14
Q

Where does isoamylase and pullinase attack on a starch molecule?

A

Breaks the alpha-1,6 bond between 2 glucose molecules

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15
Q

When hydrogen peroxide is added, a positive catalase test shows the formation of what?

A

Oxygen

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16
Q

When alpha-amylase attacks starch, what products are formed?

A

Alpha-amylase hydrolyzes alpha 1,4 glycosidic bonds producing glucose, maltose, and dextrins

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17
Q

What vitamin is a 6-carbon compound with a structure very similar to glucose?

A

Vitamin C (ascorbic acid)

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18
Q

What type of secondary protein structure is most prevalent in β-lactoglobulin?

A

β-sheet

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19
Q

What type of pectin will form gels if the pH is below 3.6?

A

High methoxyl pectin

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20
Q

What type of pectin interacts with divalent cations to form gels?

A

Low methoxyl pectin

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21
Q

What type of gum as three main fractions based upon increasing sulfate ester content, known as kappa, iota, and lambda?

A

Carrageenans

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22
Q

What two sugars comprise lactose?

A

Glucose and galactose

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23
Q

What term is given to strongly hydrophillic macromolecular materials that dissolve or disperse in water producing a thickening or viscosifying effect?

A

Hydrocolloids

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24
Q

What term describes the spontaneous loss of fluid from a food gel?

A

Syneresis

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25
Q

What term describes the ability of a fat to exist in multiple crystal forms?

A

Polymorphorism

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26
Q

What results from the hydrolysis of a specific Phe105-Met106 bond in kappa casein?

A

Destabilization of the casein micelles (cheese curd formation)

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27
Q

What protein is responsible for transferring iron from the intestine to the blood stream?

A

Transferrin

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28
Q

What non-nutritive protein is a major component of connective tissue?

A

Collagen

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29
Q

What molecule is a polymer of α-D-galacturonic acid that is produced commercially by extraction of citrus fruits and apples and is used to make jelly?

A

Pectin

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30
Q

What method, often used in protein analysis, aids a researcher in determining the relative percentages of alpha-helix and beta-sheets in a single protein?

A

Circular Dichroism (CD)

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31
Q

What is winterizing?

A

Refining step in which oils are chilled carefully to precipitate and remove fractions with high melting points that would interfere with the pourability of salad dressings or other products containing the oils.

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32
Q

What is the water activity range for intermediate foods?

A

0.6 - 0.85

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33
Q

What is the trivial name for the saturated fatty acid with 24 carbons?

A

Lignociric acid

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34
Q

What is the third most abundant element in the Earth’s crust, used to make packaging materials? a) oxygen b) silica c) aluminum

A

c) aluminum

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35
Q

What is the term used to describe uncontrolled fat crystallization which gives chocolate an impaired texture and a gray surface appearance?

A

Fat Bloom

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36
Q

What is the term given to the disruption of a protein’s secondary, tertiary and quarternary structure without loss of the proteins primary structure?

A

Protein denaturation

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37
Q

What is the term for the methyl end of a fatty acid?

A

Omega

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38
Q

What is the term for the carboxyl end of a fatty acid?

A

Alpha position

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39
Q

What is the sweetest monosaccharide?

A

Fructose

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40
Q

What is the structural 5 carbon unit of carotenoids?

A

Isoprene or isoprenoid unit

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41
Q

What is the source of gum arabic?

A

Acacia tree

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42
Q

What is the source of alginates?

A

Brown seaweed extracts (Phaeophyceae)

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43
Q

What is the source of agar and carageenan?

A

Irish moss (Chondrus crispus) and other red algae/seaweed

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44
Q

What is the solid fat index?

A

Percent of solution that is crystalline at a specific temp

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45
Q

What is the significance of dehydroalanine in food?

A

Dehydroalanine may produce protein cross-links from its reaction with other amino acids decreasing that protein’s nutritive value.

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46
Q

What is the role of a surfactant in bakery products?

A

Modifies the texture of the food by interacting with the proteins and polysaccharides and helps stabilize the dough

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47
Q

What is the product of sugar reduction: a. acid, b. polyol, c. deoxysugar?

A

b. polyol

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48
Q

What is the primary ingredient in sand?

A

Silica (Silicon dioxide)

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49
Q

What is the natural carotenoid substance in tomatoes that acts as an antioxidant?

A

Lycopene

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50
Q

What is the name of the gummy and slimy polymer that sometimes clogs the lines and pipes of sugar refineries and what organism produces this polymer?

A

Dextran - produced by Leuconostoc mesenteroides

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51
Q

What is the name for higher alcohols esterified with fatty acids?

A

Waxes

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52
Q

What is the name for a 6-carbon carbohydrate that exist is a five membered ring?

A

Furanose

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53
Q

What is the most widely distributed sugar in nature?

A

D-glucose

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54
Q

What is the most stable polymorphic form of triglycerides?

A

Beta (highest melting point)

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55
Q

What is the molarity of 0.5 moles of NaCl in 500 mL of water?

A

1.0 M

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56
Q

What is the microbial gum most commonly used in salad dressings?

A

Xanthan gum

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57
Q

What is the major linkage in starch?

A

Alpha 1-4

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58
Q

What is the major carotenoid pigment in corn?

A

Xanthophyll

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59
Q

What is the major apocarotenoid in annatto?

A

Bixin

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60
Q

What is the isoelectric point of caseins?

A

4.6

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61
Q

What is the form of pectic substances found in unripe fruit and some vegetables?

A

Protopectin - a methylated, very long polymer of galacturonic acid

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62
Q

What is the difference between high-methoxy pectin and low-methoxy pectin?

A

HMP>50% of carboxyl groups are in the methyl ester form; LMP has

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63
Q

What is the difference between a fat and an oil?

A

Fat is usually solid at room temperature whereas oil is liquid at room temperature, i.e., fats have higher melting points than oils.

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64
Q

What is the complex polymer, comprised of phenylpropane units, associated with cell walls of plants?

A

Lignin

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65
Q

What is the common name for 9,12,15-octadecatrienoic acid?

A

Linolenic acid

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66
Q

What is the common catalyst used for hydrogenation of unsaturated oils?

A

Nickel – other catalysts include: copper, platinum and boron

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67
Q

What is the basic building block for terpenoid biosynthesis called?

A

Isoprene or isoprene unit

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68
Q

What is racemization?

A

Exposure of amino acids to high pH causing a change from the L to the D configuration

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69
Q

What is Poising Capacity?

A

Apparent resistance to change in redox potential.

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70
Q

What is petroleum ether?

A

Mixture of short chain hydrocarbons; primarily pentane and hexane

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71
Q

What is pectic acid and where is it usually found?

A

Pectic acid is the smallest of the pectic substances and lacks methyl esters; found in overly ripe, very soft fruits and vegetables; no longer has gel-forming ability.

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72
Q

What is invert sugar?

A

Hydrolysis of sucrose to glucose and fructose

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73
Q

What is interesterification?

A

A process which involves an exchange of an acyl group among triglycerides

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74
Q

What is hysteresis?

A

Dehydrated food lose water holding capacity and they never rehydrate to their initial moisture levels

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75
Q

What is hydrolyzed during the enzymatic coagulation of milk?

A

Kappa-casein

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76
Q

What is common chemical intermediate in fat, protein, and carbohydrate metabolism?

A

Acetyl CoA

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77
Q

What is another name for the oliosaccharide that is called galactose 1-6 galactose or 1-2 fructose?

A

Stachyose

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78
Q

What is another name for phosphatidylcholine?

A

Lecithin

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79
Q

What is another name for Carob gum?

A

Locust bean gum, (also St. John’s Bread)

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80
Q

What is also formed when a dipeptide bond is made?

A

Water

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81
Q

What ingredient is used to inhibit haze formation during beer making?

A

Tannin

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82
Q

What happens to the melting point of a lipid/oil when its overall level of saturation is increased?

A

Melting point increases

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83
Q

What gelling agent is produced from the microorganism Alcaligenes faecalis var. myxogenes (a gram negative psychrotroph associated with refrigerated spoilage)?

A

Curdlan (Pureglucan)

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84
Q

What factors influence O-R Potential?

A

Composition of food, oxygen tension in atmosphere, and access that the atmosphere has to food

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85
Q

What enzyme is used as an indicator of proper blanching of vegetables?

A

Peroxidase

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86
Q

What enzyme is responsible for the cleavage of lactose from a disaccharide to 2 monosaccharides and what are the two monosaccharides?

A

β-galactosidase and galactose and glucose

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87
Q

What enzyme is commerically used to remove sugar from egg whites?

A

Glucose oxidase

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88
Q

What enzyme causes the browning reaction in freshly cut apples, pears, peaches, and bananas?

A

Polyphenyloxidase

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89
Q

What enzyme causes hydrolytic rancidity?

A

Lipase

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90
Q

What enzyme catalyzes the conversion of sucrose to glucose and fructose?

A

Invertase

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91
Q

What enzyme can accelerate lipid oxidation?

A

Lipoxygenase

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92
Q

What element is found in proteins but not in carbohydrates?

A

Nitrogen

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93
Q

What do the letters “DE” stand for pertaining to corn syrups?

A

Dextrose Equivalent

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94
Q

What constituent or property of a food does the iodine value measure?

A

Degree of unsaturation of fats or oils

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95
Q

What conditions favor cloud stability in products like tomato and orange juice? a) inactivation of polygalaturonase b) inactivation of PME c) addition of PME

A

b) inactivation of PME

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96
Q

What compound is responsible for the bitterness of orange juice?

A

Limonine

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97
Q

What compound is formed by decarboxylation of histidine?

A

Histamine

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98
Q

What components in milk would be responsible for the causing Maillard browning to occur?

A

Lactose (reducing sugar) and casein or whey (source of amine)

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99
Q

What component of oat bran constitutues the majority of its soluble protein?

A

Beta glucan

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100
Q

What chemical formed during frying of potato products and baking of bread is considered to be a potentially toxic?

A

Acrylamide

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101
Q

What chemical compound is determined as an indicator of Maillard Browning?

A

Hydroxy methyl furfural

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102
Q

What carotenoids contain oxygen?

A

Xanthophylls

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103
Q

What artificial sweetener is also a dipeptide?

A

Aspartame

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104
Q

What are two oligosaccharides that cause flatulence?

A

Stachyose and raffinose

105
Q

What are three common substrates for the production of hydrogenated fats?

A

Platinum, Paladium, Nickel

106
Q

What are the two main cell wall constituents of fruits, vegetables, and cereals?

A

Cellulose and hemicellulose

107
Q

What are the two chemical components of triglycerides?

A

Glycerol and fatty acids

108
Q

What are the three steps of oxidative rancidity?

A

Initiation, Propagation, and Termination

109
Q

What are the products of superoxide ion O2- dismutation?

A

Three (3) O2 and H2O2

110
Q

What are the products of starch hydrolysis having little to no sweetness (D. E. value

A

Maltodextrins

111
Q

What are the primary products of autooxidation of unsaturated fats?

A

Hydroperoxides

112
Q

What are the first and second most widely distributed food components?

A

Water, carbohydrates

113
Q

What are pectinesterases and what do they do?

A

Split off the methyl groups from protopectin and pectin; Removing the methyoxy groups causes loss of the gel-forming properties and a distinct softening in the structure of the fresh fruit

114
Q

What are pectinates?

A

Compounds resulting from the combination of pectinic acids or pectins with calcium or other ions to form salts and usually enhance gel-forming capability.

115
Q

What amino acid generally is at the N-terminus of a peptide chain?

A

Methionine

116
Q

Using the Osborne solubility classification for proteins, what term is used for cereal proteins that are soluble in 70% alcohol?

A

Prolamines

117
Q

Under what conditions is the formation of lysinoalanine favored in foods?

A

Alkaline treatment of proteins

118
Q

Under what conditions are zwitterions found?

A

At the isoelectric point

119
Q

Trans fat occurs naturally in what substance?

A

Milk fat; adipose tissue from ruminant animals

120
Q

This term describes the pH at which a protein becomes less soluble because it possesses an overall net neutral charge?

A

Isoelectric point

121
Q

This straight chain, hydroxy fatty acid comprises up to 90% of the total acids in castor bean oil. What is it?

A

Ricinoleic acid

122
Q

The two polysaccharides that comprise starch are

A

Amylose and amylopectin

123
Q

The main reason for cooking curds and whey in the manufacture of cheeses by adding milk clotting enzyme is to: kill psychotrophs; kill S. lactis and stop acid production; pasteurize the curds and whey; aid in syneresis

A

aid in syneresis (D)

124
Q

The lowest boiling component of a mixture of ethanol and water is 95% ethanol and 5% water. What is this called?

A

Azeotrope

125
Q

The cis isomer of the 9 mono-eno of octadecanoic acid is called?

A

Oleic acid (the trans isomer is called elaidic acid)

126
Q

Starch is a polymer of which of the following: a.) L-glucose b.) Lactose c.) D-glucose d.) Fructose

A

C.) D-glucose {anhydro-a-D-glucose units}

127
Q

Splitting the ester bonds in triglycerides can happen at high pH or due to enzymatic reaction. What class of enzymes is responsible for this reaction?

A

hydrolases

128
Q

Sorghum syrup is often mistakenly called this:

A

Molasses

129
Q

Sorbitol is best described as a what? a) Dissacharide b) Sugar alcohol c) Organic acid

A

Sugar alcohol

130
Q

Proteins are made up of about 22 amino acids linked together in chains by

A

Peptide bonds

131
Q

PCB’s are environmental contaminants that can contaminate foods. What does PCB stand for?

A

Polychlorinated biphenols

132
Q

Name three ketone bodies?

A

Acetone, acetoacetate, beta-hydroxybutyrate

133
Q

Name the type of water in a food system that is not a solvent, does not freeze, and is very tightly bound to the surface of a molecule.

A

Monolayer or Type 1

134
Q

Name the type of rancidity which occurs by the hydrolysis of an ester bond to produce a free fatty acid?

A

Hydrolytic rancidity

135
Q

Name the type of carbohydrate that is formed by the enzymatic cleavage of a starch molecule that results in the formation of a ring structure with a hydrophobic center and a hydrophilic outside edge?

A

Cyclodextrin

136
Q

Name the two ways to draw sugar monomers?

A

Fischer, Haworth, Newman

137
Q

Name the pigment responsible for the desirable pink to orange coloring of the flesh of trout and salmon?

A

Astaxanthin

138
Q

Name the group of polyphenolic antioxidants that occur naturally in fruits and vegetables and in beverages such as tea and wine.

A

Flavonoids

139
Q

Name the fatty acid that contains 18 carbons and three double bonds?

A

Linolenic acid

140
Q

Name the amino acids that make up aspartame?

A

Phenylalanine and aspartic acid

141
Q

Name a food that has a pH greater than 7.0.

A

Egg white, olives, hominy, chocolate

142
Q

Multiple forms of the same enzyme in a given tissue that arise from genetically determined differences in primary amino acid sequences are called?

A

Isozymes or isoenzymes

143
Q

Minimum solubility of a protein is at: a) pHpI

A

b)pH=pI

144
Q

Milk fat globules are surrounded by an interfacial layer called what?

A

milk fat globule membrane

145
Q

Maltol and ethyl maltol are effective at sparing what common food ingredient?

A

Sugar

146
Q

Magnesium ammonium phosphate crystals that look like glass and are sometimes found in canned tuna fish are called what?

A

Struvite

147
Q

Lactase hydrolyzes lactose into what two components?

A

Glucose and galactose

148
Q

Inulin is a polysaccharide found in some plants. What is the monosaccharide that makes up this polymer?

A

Fructose

149
Q

In the international Union of Biochemistry system of enzyme nomenclature, the first number identifies what?

A

General reaction type

150
Q

In surfactants, for what does the abbreviation “HLB” stand?

A

Hydrophile-lipophile balance

151
Q

In enzymology, what is a turnover number?

A

Moles converted to product by one mole of enzyme in a given time period.

152
Q

In cottonseed, what does gossypol chelate?

A

Iron

153
Q

Hydrolysis of a fat by treatment with alkali is called what?

A

Saponification

154
Q

Humulone and lupulone are two components of what plant added to beer?

A

Hops

155
Q

How many times more acidic is something with a pH of 2 than a substance with a pH of 6?

A

10,000

156
Q

How many molecules are in a mole?

A

6.022 x 10 23

157
Q

How many isomers of a 6 carbon hexose exist?

A

16

158
Q

How many isomers of a 5 carbon pentose exist?

A

four

159
Q

How is soybean oil degummed?

A

Adding 2-3% water, agitating the mixture at about 50°C, and separating the hydrated phospholipids by settling or centrifugation.

160
Q

How is invert sugar made?

A

The invertase enzyme hydrolyzes sucrose into glucose and fructose

161
Q

How do apocarotenoids differ from carotenoids?

A

Contain 30 rather than 40 carbons

162
Q

Glucose has 4 isometric carbons. How many stereoisomers does it have?

A

Sixteen (16)

163
Q

From what amino acid is serotonin derived?

A

Tryptophan

164
Q

For the D configuration of sugars, which side of the Fisher projection is the reference hydroxyl located?

A

Right

165
Q

Enzymatic browning is caused by the oxidation of what type of compounds? Name the enzyme.

A

Phenolics; Poly phenol oxidase (PPO)

166
Q

Degradation of amino acids to aldehydes, ammonia and carbon dioxide through reaction with dicarbonyls produced during Maillard Browning is called what?

A

Strecker degradation

167
Q

Define water activity.

A

vapor pressure of water divided by that of pure water at the same temperature

168
Q

Define a zero-order reaction.

A

It is a reaction which proceeds at a rate independent of the concentration of the reactants

169
Q

Cyanogenetic glycosides are compounds that when treated with an acid or appropriate hydrolytic enzyme, yield what compound?

A

Hydrogen cyanide (HCN)

170
Q

Compared to sucrose, what is the relative sweetness of saccharin?

A

Saccharin is 300 times sweeter than sucrose

171
Q

Collagen molecules are rich in what amino acid derivative?

A

hydroxyproline

172
Q

Certified food colorants can be divided into 2 types. What are they?

A

Dyes (water soluble) and Lakes (water and oil soluble)

173
Q

Betalain pigments are obtained from what plant source?

A

Beets

174
Q

Beta-amylase hydrolyzes what type of linkages?

A

alpha-1,4 glycosidic linkages

175
Q

Benzopyrene or polycyclic hydrocarbons have been identified as carcinogens. What common picnic activity is thought to produce these undesirable compounds?

A

Charcoal burning or barbequeing

176
Q

Benzene rings with attached methoxyl groups are called what?

A

Anisole

177
Q

Benzene rings with attached hydroxyl groups are called what?

A

Phenolics

178
Q

At what temperature range do most proteins denature?

A

50-60 C

179
Q

At what temperature does a solution of 20% amylose and 80% water boil?

A

100C it is not a true solution

180
Q

At what aw does oxidation of fats proceed most rapidly: a) 0.3 b) 0.2 c) 0.5 d) 0.8

A

b) – foods with an aw value of 0.1 or less oxidation proceeds very rapidly

181
Q

Antioxidants like EDTA and citric acid function as antioxidants by reacting with what catalystis of oxidation?

A

Trace metals

182
Q

Another name for triacylglycerides is?

A

Triglycerides

183
Q

An exoenzyme that catalyzes hydrolysis of maltose units from the nonreducing end of starch is called?

A

Beta amylase

184
Q

An example of a saturated fatty acid is the 16 carbon molecule called?

A

Palmitic acid

185
Q

An enzyme that only catalyzes hydrolysis of alpha 1,6 linkages in starch is called what?

A

Pullunase (R enzyme) or isoamylase

186
Q

An enzyme that breaks down pectin molecules and causes softening of fruit tissue (avocados, pears, tomatoes, and pineapple) is called?

A

Polygalacturonase; pectinase

187
Q

All unsaturated fatty acids that contain an isolated cis double bond absorb light at approximately what length?

A

190 nm

188
Q

Alitame is how many times sweeter than sucrose?

A

Two thousand (2000) times sweeter

189
Q

A physical change in an amorphous material promoted by the addition of heat and the uptake of low molecular weight substances called plasticizers is called what?

A

Glass transition

190
Q

What would you expect to happen to the following solutions if they were heated at the same temperature and for the same length of time? A. lysine and sucrose in water; B. lysine and glucose in water

A

A. Colorless; B. Brown

191
Q

What is the pH of a mixture of strong acids combining 100 ml of pH = 2 and 100 ml of pH = 3?

A

2.26 (Equal volumes of strong acid: Difference of 1 – add 0.26; difference of 2 or more – add 0.3)

192
Q

What is the difference between a competitive enzyme inhibitor and a noncompetitive enzyme inhibitor?

A

Competitive inhibitors usually resemble the substrate structurally and compete with substrate for binding to the active site of the enzyme. A noncompetitive inhibitor binds to the enzyme outside its active site independent of substrate

193
Q

What is O-R Potential? What does it measure?

A

Oxidation-Reduction Potential; The tendency of a reversible system to give or receive electrons

194
Q

What is Flocculation?

A

The redeposition of small dissolved crystals or sol particles into larger crystals or sol particles in an oil-in-water emulsions

195
Q

What do the initials BHT and BHA stand for and what is their use in foods?

A

Butylated hydroxytoluene, Butylated hydroxyanisole, Antioxidants

196
Q

What are the two sulfur containing amino acids?

A

Cysteine and Methionine

197
Q

What are the two stages of freezing?

A

Nucleation; Crystal growth & recrystallization

198
Q

What are the two protein components of Gluten and what is their function?

A

Glutenin; function = elasticity, Gliadin; function = plasticity

199
Q

What are the H3O+ and OH- concentrations in a solution with pH = 5?

A

[H3O+] = 10-5 moles/l; [OH-] = 10-9 moles/l

200
Q

What are the five elements found in proteins?

A

Carbon, oxygen, nitrogen, hydrogen, sulfur

201
Q

What are the 5 most abundant elements in the earth’s crust by weight?

A

Oxygen, Silicon, Aluminum, Iron, Calcium

202
Q

What are the 3 primary gases in air?

A

Nitrogen (78%), Oxygen (21%), Argon (1%)

203
Q

What are 3 folic acid rich foods?

A

Leafy green vegetables, citrus fruits and juices, beans lentils, fortified breakfast cereals

204
Q

What acids would you check for TA in oranges, apples, yogurt, grapes?

A

Citric, malic, lactic, tartaric

205
Q

What 5 parameters are critical for an extrusion process?

A

Barrel temperature, screw speed, moisture content, compression ratio

206
Q

To aid in recycling, consumer plastics are given one of seven numbers. Give the number and type of plastic for 4 of these groups.

A

1 (polyethylene terepthalate), 2 (high density polyethylene), 3 (polyvinyl chloride), 4 (low-density polyethylene), 5 (polypropylene), 6 (polystyrene), 7 (other)

207
Q

The redeposition of small dissolved crystals or sol particles into larger crystals or sol particles in a water-in-oil emulsion is called what?

A

Ostwald ripening

208
Q

The 3 main polymorphic forms of crystalline fat are alpha, beta prime and beta; put them in order of melting point from highest to lowest

A

Beta > Beta prime > Alpha

209
Q

Specific tradenames are often used in a generic sense to refer to products. What’s the trade name we almost always call the following: regenerated cellulose, polyamid, and polyvinylidene chloride?

A

Cellophane, Nylon, Saran

210
Q

Rank the following lipoproteins by size: HDL, VLDL, LDL, IDL, Chylomicrons.

A

Largest Chylomicrons > VLDL > IDL > LDL > HDL smallest

211
Q

Name three types of enzyme inhibition?

A

Competitive, noncompetitive, uncompetitive, and suicide

212
Q

Name three types of browning reactions in foods?

A

Maillard, carmelization, ascorbic acid browning, enzymatic browing

213
Q

Name three products from the hydrolysis of starch by alpha amylase.

A

Oligosaccharides; Maltodextrins; Maltose; Glucose; Corn syrup

214
Q

Name three gums not from plants?

A

Gellan, curdlan, xanthan

215
Q

Name three compounds in dietary fiber:

A

Lignin, hemicellulose, pectin substances, cellulose, gums and musilages

216
Q

Name the two substances that may be used for commercial caffeine extraction?

A

Methylene chloride, supercritical CO2 or H2O

217
Q

Name the three types of conjugated lipids.

A

Phospholipids – contain a phosphoric acid molecule and a fat molecule; Cerebrosides – contain a carbohydrate and a fat molecule; Sulfolipids – contain a sulfate radical

218
Q

Name the three basic amino acids?

A

Histidine, lysine, and arginine

219
Q

Name the principle antimicrobial component of the following: thyme, oregano, cinnamon, cloves

A

thymol, carvacrol, cinnamic aldehyde, eugenol

220
Q

Name the predominant organic acids in the following products: grapefruit, grapes, oranges, and vinegar

A

Grapefruit – citric acid; Grapes - tartaric acid; Oranges – Citric; Vinegar- acetic

221
Q

Name 4 carotenoid pigments

A

B-carotene, capsorubin, canthaxanthin, lycopene, lutein, bixin, norbixin, and crocin

222
Q

Name 3 factors that affect enzyme catalyzed reactions:

A

pH, temperature, [substrate], [enzyme], ionic strength, activators, inhibitors

223
Q

Name 3 classes of flavonoids?

A

Anthocyanins, flavonals, flavones, catechins, flavanones

224
Q

Name 3 blood plasma lipid classes

A

HDL, LDL, VLDL

225
Q

Name 2 hydrocolloids that gel at high temperature:

A

Methyl cellulose, curdlan

226
Q

List 5 of the major 6 classes of enzymes.

A

Oxidoreductase, Transferase, Hydrolase, Lyase, Isomerase, Ligase

227
Q

List 3 limitations of using native starch in foods?

A

Cold water insoluble, Instability at low pH,Cohesive texture, Viscosity breakdown, Amylose, retrogradation, Amylopectin association

228
Q

Give three reasons for adding starch to food.

A

Coating and glazing agent; thickening agent; colloidal stabilizer; moisture retention; gel forming; binding

229
Q

Give the hydrogenation products of glucose, fructose, galactose, and xylose?

A

Sorbitol, manitol, glactitol, xylitol

230
Q

Give the 3 main polymorphic forms of crystalline fat

A

Alpha, Beta prime, Beta

231
Q

For the following saturated fatty acids give the systematic name or molecular formula: palmitic, stearic, acetic.

A

Palmitic, n-hexadecanoic, C16 H32 O2 Stearic, n-octadecanoic, C18 H36 O2 Acetic, C2 H4 O2

232
Q

What are the components of a plant cell wall?

A

Pectin, cellulose, hemicellulose, lignin and protein

233
Q

What are the two most abundant fatty acids in peanut oil?

A

Oleic acid and Linoleic acid

234
Q

Chondrus crispus is the source for what polysaccharide hydrocolloid?

A

Carrageenan

235
Q

Mixing leeched wood ashes with lard in the presence of heat will create what AND what is the chemical process called?

A

Soap AND saponification

236
Q

What chemically modified cellulose will form a thermal gel at 55-60ºC but can return to solution at room temperature?

A

Methylcellulose (or hydroxypropylmethylcellulose)

237
Q

What is Fehling’s test used to determine?

A

Reducing sugars

238
Q

What is the enzyme in saliva that breaks down some starches to maltose?

A

Ptyalin (or amylase)

239
Q

What is the name of the pickled flower buds of Capparis spinosa, a Mediterranean shrub?

A

Capers

240
Q

What spice is made from the dried stigmas of the crocus plant?

A

Safron

241
Q

Where might one find the compound “linalool”?

A

Spices or herbs

242
Q

Which two amino acids have the highest reactivity in Malliard reactions?

A

Arginine and lysine

243
Q

What general type of compound is bixin?

A

Apocarotenoid

244
Q

For what is the natural food color annatto used?

A

Cheese

245
Q

From what tree is Gum Arabic obtained?

A

Acacia

246
Q

What is the brand name used by Procter and Gamble for olestra?

A

Olean

247
Q

Sake is a fermented alcoholic beverage made from what?

A

Rice

248
Q

What are the six major anthocyanins?

A

Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, petunidin

249
Q

Accumulation of unwanted material on solid surfaces resulting in decreased function is called what?

A

Fouling

250
Q

What does the Karl Fischer test measure?

A

Water concentration

251
Q

What is the soxhlet apparatus used for?

A

Fat determination

252
Q

What does the Mojonnier Test measure?

A

Fat in Milk

253
Q

What does the Babcock Test measure?

A

Fat concentration

254
Q

What does the Kjeldahl measure?

A

Nitrogen concentration

255
Q

Who worked at the Carlsberg Brewery Laboratory in Copenhagen, Denmark the late 1800s and developed a method to determine nitrogen concentration in organic substances?

A

Johan Kjeldahl

256
Q

What is the name the test for reducing sugars in foods? What organic groups does the test detect? What color change occurs with a positive test?

A

Benedict’s; aldehydes and alpha-hydroxy-ketones; brick-red precipitate

257
Q

What term is used to describe the relationship between water activity and moisture of food at a given temperature and what is its shape?

A

Moisture sorption isotherm; Sigmoidal

258
Q

Which of the following chemical bonds is involved in the secondary structure of proteins? Peptide, Glycosidic, Hydrogen, Van der Waals

A

Hydrogen

259
Q

Luminometry is used to detect the presence of ATP based upon its enzymatically catalyzed reaction with what bioluminescent compound?

A

Luciferin

► Food & Nutrition 4 (18 decks)

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