Food Chemistry Flashcards
1
Q
Would a more hydrophilic substance have a higher or lower HLB than a hydrophobic substance?
A
Higher
2
Q
Within what range of its pK is a buffering agent is effective?
A
Plus or minus 1 pH unit
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.
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
5
Q
Which sugar alcohol has the same sweetness as sucrose?
A
Xylitol
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
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
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)
9
Q
Which is more viscous: high DE or low DE corn syrup?
A
Low DE
10
Q
Which has a higher melting point: oleic or palmitic?
A
Palmitic
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)
12
Q
Which amino acids may form dehydroalanine?
A
Cysteine, cystine, serine, P-serine
13
Q
Where is banana oil obtained from?
A
Trick question? No oil in bananas?
14
Q
Where does isoamylase and pullinase attack on a starch molecule?
A
Breaks the alpha-1,6 bond between 2 glucose molecules
15
Q
When hydrogen peroxide is added, a positive catalase test shows the formation of what?
A
Oxygen
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
17
Q
What vitamin is a 6-carbon compound with a structure very similar to glucose?
A
Vitamin C (ascorbic acid)
18
Q
What type of secondary protein structure is most prevalent in β-lactoglobulin?
A
β-sheet
19
Q
What type of pectin will form gels if the pH is below 3.6?
A
High methoxyl pectin
20
Q
What type of pectin interacts with divalent cations to form gels?
A
Low methoxyl pectin
21
Q
What type of gum as three main fractions based upon increasing sulfate ester content, known as kappa, iota, and lambda?
A
Carrageenans
22
Q
What two sugars comprise lactose?
A
Glucose and galactose
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
24
Q
What term describes the spontaneous loss of fluid from a food gel?
A
Syneresis
25
What term describes the ability of a fat to exist in multiple crystal forms?
Polymorphorism
26
What results from the hydrolysis of a specific Phe105-Met106 bond in kappa casein?
Destabilization of the casein micelles (cheese curd formation)
27
What protein is responsible for transferring iron from the intestine to the blood stream?
Transferrin
28
What non-nutritive protein is a major component of connective tissue?
Collagen
29
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?
Pectin
30
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?
Circular Dichroism (CD)
31
What is winterizing?
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.
32
What is the water activity range for intermediate foods?
0.6 - 0.85
33
What is the trivial name for the saturated fatty acid with 24 carbons?
Lignociric acid
34
What is the third most abundant element in the Earth’s crust, used to make packaging materials? a) oxygen b) silica c) aluminum
c) aluminum
35
What is the term used to describe uncontrolled fat crystallization which gives chocolate an impaired texture and a gray surface appearance?
Fat Bloom
36
What is the term given to the disruption of a protein’s secondary, tertiary and quarternary structure without loss of the proteins primary structure?
Protein denaturation
37
What is the term for the methyl end of a fatty acid?
Omega
38
What is the term for the carboxyl end of a fatty acid?
Alpha position
39
What is the sweetest monosaccharide?
Fructose
40
What is the structural 5 carbon unit of carotenoids?
Isoprene or isoprenoid unit
41
What is the source of gum arabic?
Acacia tree
42
What is the source of alginates?
Brown seaweed extracts (Phaeophyceae)
43
What is the source of agar and carageenan?
Irish moss (Chondrus crispus) and other red algae/seaweed
44
What is the solid fat index?
Percent of solution that is crystalline at a specific temp
45
What is the significance of dehydroalanine in food?
Dehydroalanine may produce protein cross-links from its reaction with other amino acids decreasing that protein’s nutritive value.
46
What is the role of a surfactant in bakery products?
Modifies the texture of the food by interacting with the proteins and polysaccharides and helps stabilize the dough
47
What is the product of sugar reduction: a. acid, b. polyol, c. deoxysugar?
b. polyol
48
What is the primary ingredient in sand?
Silica (Silicon dioxide)
49
What is the natural carotenoid substance in tomatoes that acts as an antioxidant?
Lycopene
50
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?
Dextran - produced by Leuconostoc mesenteroides
51
What is the name for higher alcohols esterified with fatty acids?
Waxes
52
What is the name for a 6-carbon carbohydrate that exist is a five membered ring?
Furanose
53
What is the most widely distributed sugar in nature?
D-glucose
54
What is the most stable polymorphic form of triglycerides?
Beta (highest melting point)
55
What is the molarity of 0.5 moles of NaCl in 500 mL of water?
1.0 M
56
What is the microbial gum most commonly used in salad dressings?
Xanthan gum
57
What is the major linkage in starch?
Alpha 1-4
58
What is the major carotenoid pigment in corn?
Xanthophyll
59
What is the major apocarotenoid in annatto?
Bixin
60
What is the isoelectric point of caseins?
4.6
61
What is the form of pectic substances found in unripe fruit and some vegetables?
Protopectin - a methylated, very long polymer of galacturonic acid
62
What is the difference between high-methoxy pectin and low-methoxy pectin?
HMP>50% of carboxyl groups are in the methyl ester form; LMP has
63
What is the difference between a fat and an oil?
Fat is usually solid at room temperature whereas oil is liquid at room temperature, i.e., fats have higher melting points than oils.
64
What is the complex polymer, comprised of phenylpropane units, associated with cell walls of plants?
Lignin
65
What is the common name for 9,12,15-octadecatrienoic acid?
Linolenic acid
66
What is the common catalyst used for hydrogenation of unsaturated oils?
Nickel – other catalysts include: copper, platinum and boron
67
What is the basic building block for terpenoid biosynthesis called?
Isoprene or isoprene unit
68
What is racemization?
Exposure of amino acids to high pH causing a change from the L to the D configuration
69
What is Poising Capacity?
Apparent resistance to change in redox potential.
70
What is petroleum ether?
Mixture of short chain hydrocarbons; primarily pentane and hexane
71
What is pectic acid and where is it usually found?
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.
72
What is invert sugar?
Hydrolysis of sucrose to glucose and fructose
73
What is interesterification?
A process which involves an exchange of an acyl group among triglycerides
74
What is hysteresis?
Dehydrated food lose water holding capacity and they never rehydrate to their initial moisture levels
75
What is hydrolyzed during the enzymatic coagulation of milk?
Kappa-casein
76
What is common chemical intermediate in fat, protein, and carbohydrate metabolism?
Acetyl CoA
77
What is another name for the oliosaccharide that is called galactose 1-6 galactose or 1-2 fructose?
Stachyose
78
What is another name for phosphatidylcholine?
Lecithin
79
What is another name for Carob gum?
Locust bean gum, (also St. John’s Bread)
80
What is also formed when a dipeptide bond is made?
Water
81
What ingredient is used to inhibit haze formation during beer making?
Tannin
82
What happens to the melting point of a lipid/oil when its overall level of saturation is increased?
Melting point increases
83
What gelling agent is produced from the microorganism Alcaligenes faecalis var. myxogenes (a gram negative psychrotroph associated with refrigerated spoilage)?
Curdlan (Pureglucan)
84
What factors influence O-R Potential?
Composition of food, oxygen tension in atmosphere, and access that the atmosphere has to food
85
What enzyme is used as an indicator of proper blanching of vegetables?
Peroxidase
86
What enzyme is responsible for the cleavage of lactose from a disaccharide to 2 monosaccharides and what are the two monosaccharides?
β-galactosidase and galactose and glucose
87
What enzyme is commerically used to remove sugar from egg whites?
Glucose oxidase
88
What enzyme causes the browning reaction in freshly cut apples, pears, peaches, and bananas?
Polyphenyloxidase
89
What enzyme causes hydrolytic rancidity?
Lipase
90
What enzyme catalyzes the conversion of sucrose to glucose and fructose?
Invertase
91
What enzyme can accelerate lipid oxidation?
Lipoxygenase
92
What element is found in proteins but not in carbohydrates?
Nitrogen
93
What do the letters "DE" stand for pertaining to corn syrups?
Dextrose Equivalent
94
What constituent or property of a food does the iodine value measure?
Degree of unsaturation of fats or oils
95
What conditions favor cloud stability in products like tomato and orange juice? a) inactivation of polygalaturonase b) inactivation of PME c) addition of PME
b) inactivation of PME
96
What compound is responsible for the bitterness of orange juice?
Limonine
97
What compound is formed by decarboxylation of histidine?
Histamine
98
What components in milk would be responsible for the causing Maillard browning to occur?
Lactose (reducing sugar) and casein or whey (source of amine)
99
What component of oat bran constitutues the majority of its soluble protein?
Beta glucan
100
What chemical formed during frying of potato products and baking of bread is considered to be a potentially toxic?
Acrylamide
101
What chemical compound is determined as an indicator of Maillard Browning?
Hydroxy methyl furfural
102
What carotenoids contain oxygen?
Xanthophylls
103
What artificial sweetener is also a dipeptide?
Aspartame
104
What are two oligosaccharides that cause flatulence?
Stachyose and raffinose
105
What are three common substrates for the production of hydrogenated fats?
Platinum, Paladium, Nickel
106
What are the two main cell wall constituents of fruits, vegetables, and cereals?
Cellulose and hemicellulose
107
What are the two chemical components of triglycerides?
Glycerol and fatty acids
108
What are the three steps of oxidative rancidity?
Initiation, Propagation, and Termination
109
What are the products of superoxide ion O2- dismutation?
Three (3) O2 and H2O2
110
What are the products of starch hydrolysis having little to no sweetness (D. E. value
Maltodextrins
111
What are the primary products of autooxidation of unsaturated fats?
Hydroperoxides
112
What are the first and second most widely distributed food components?
Water, carbohydrates
113
What are pectinesterases and what do they do?
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
What are pectinates?
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
What amino acid generally is at the N-terminus of a peptide chain?
Methionine
116
Using the Osborne solubility classification for proteins, what term is used for cereal proteins that are soluble in 70% alcohol?
Prolamines
117
Under what conditions is the formation of lysinoalanine favored in foods?
Alkaline treatment of proteins
118
Under what conditions are zwitterions found?
At the isoelectric point
119
Trans fat occurs naturally in what substance?
Milk fat; adipose tissue from ruminant animals
120
This term describes the pH at which a protein becomes less soluble because it possesses an overall net neutral charge?
Isoelectric point
121
This straight chain, hydroxy fatty acid comprises up to 90% of the total acids in castor bean oil. What is it?
Ricinoleic acid
122
The two polysaccharides that comprise starch are
Amylose and amylopectin
123
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
aid in syneresis (D)
124
The lowest boiling component of a mixture of ethanol and water is 95% ethanol and 5% water. What is this called?
Azeotrope
125
The cis isomer of the 9 mono-eno of octadecanoic acid is called?
Oleic acid (the trans isomer is called elaidic acid)
126
Starch is a polymer of which of the following: a.) L-glucose b.) Lactose c.) D-glucose d.) Fructose
C.) D-glucose {anhydro-a-D-glucose units}
127
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?
hydrolases
128
Sorghum syrup is often mistakenly called this:
Molasses
129
Sorbitol is best described as a what? a) Dissacharide b) Sugar alcohol c) Organic acid
Sugar alcohol
130
Proteins are made up of about 22 amino acids linked together in chains by
Peptide bonds
131
PCB's are environmental contaminants that can contaminate foods. What does PCB stand for?
Polychlorinated biphenols
132
Name three ketone bodies?
Acetone, acetoacetate, beta-hydroxybutyrate
133
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.
Monolayer or Type 1
134
Name the type of rancidity which occurs by the hydrolysis of an ester bond to produce a free fatty acid?
Hydrolytic rancidity
135
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?
Cyclodextrin
136
Name the two ways to draw sugar monomers?
Fischer, Haworth, Newman
137
Name the pigment responsible for the desirable pink to orange coloring of the flesh of trout and salmon?
Astaxanthin
138
Name the group of polyphenolic antioxidants that occur naturally in fruits and vegetables and in beverages such as tea and wine.
Flavonoids
139
Name the fatty acid that contains 18 carbons and three double bonds?
Linolenic acid
140
Name the amino acids that make up aspartame?
Phenylalanine and aspartic acid
141
Name a food that has a pH greater than 7.0.
Egg white, olives, hominy, chocolate
142
Multiple forms of the same enzyme in a given tissue that arise from genetically determined differences in primary amino acid sequences are called?
Isozymes or isoenzymes
143
Minimum solubility of a protein is at: a) pHpI
b)pH=pI
144
Milk fat globules are surrounded by an interfacial layer called what?
milk fat globule membrane
145
Maltol and ethyl maltol are effective at sparing what common food ingredient?
Sugar
146
Magnesium ammonium phosphate crystals that look like glass and are sometimes found in canned tuna fish are called what?
Struvite
147
Lactase hydrolyzes lactose into what two components?
Glucose and galactose
148
Inulin is a polysaccharide found in some plants. What is the monosaccharide that makes up this polymer?
Fructose
149
In the international Union of Biochemistry system of enzyme nomenclature, the first number identifies what?
General reaction type
150
In surfactants, for what does the abbreviation “HLB” stand?
Hydrophile-lipophile balance
151
In enzymology, what is a turnover number?
Moles converted to product by one mole of enzyme in a given time period.
152
In cottonseed, what does gossypol chelate?
Iron
153
Hydrolysis of a fat by treatment with alkali is called what?
Saponification
154
Humulone and lupulone are two components of what plant added to beer?
Hops
155
How many times more acidic is something with a pH of 2 than a substance with a pH of 6?
10,000
156
How many molecules are in a mole?
6.022 x 10 23
157
How many isomers of a 6 carbon hexose exist?
16
158
How many isomers of a 5 carbon pentose exist?
four
159
How is soybean oil degummed?
Adding 2-3% water, agitating the mixture at about 50°C, and separating the hydrated phospholipids by settling or centrifugation.
160
How is invert sugar made?
The invertase enzyme hydrolyzes sucrose into glucose and fructose
161
How do apocarotenoids differ from carotenoids?
Contain 30 rather than 40 carbons
162
Glucose has 4 isometric carbons. How many stereoisomers does it have?
Sixteen (16)
163
From what amino acid is serotonin derived?
Tryptophan
164
For the D configuration of sugars, which side of the Fisher projection is the reference hydroxyl located?
Right
165
Enzymatic browning is caused by the oxidation of what type of compounds? Name the enzyme.
Phenolics; Poly phenol oxidase (PPO)
166
Degradation of amino acids to aldehydes, ammonia and carbon dioxide through reaction with dicarbonyls produced during Maillard Browning is called what?
Strecker degradation
167
Define water activity.
vapor pressure of water divided by that of pure water at the same temperature
168
Define a zero-order reaction.
It is a reaction which proceeds at a rate independent of the concentration of the reactants
169
Cyanogenetic glycosides are compounds that when treated with an acid or appropriate hydrolytic enzyme, yield what compound?
Hydrogen cyanide (HCN)
170
Compared to sucrose, what is the relative sweetness of saccharin?
Saccharin is 300 times sweeter than sucrose
171
Collagen molecules are rich in what amino acid derivative?
hydroxyproline
172
Certified food colorants can be divided into 2 types. What are they?
Dyes (water soluble) and Lakes (water and oil soluble)
173
Betalain pigments are obtained from what plant source?
Beets
174
Beta-amylase hydrolyzes what type of linkages?
alpha-1,4 glycosidic linkages
175
Benzopyrene or polycyclic hydrocarbons have been identified as carcinogens. What common picnic activity is thought to produce these undesirable compounds?
Charcoal burning or barbequeing
176
Benzene rings with attached methoxyl groups are called what?
Anisole
177
Benzene rings with attached hydroxyl groups are called what?
Phenolics
178
At what temperature range do most proteins denature?
50-60 C
179
At what temperature does a solution of 20% amylose and 80% water boil?
100C it is not a true solution
180
At what aw does oxidation of fats proceed most rapidly: a) 0.3 b) 0.2 c) 0.5 d) 0.8
b) – foods with an aw value of 0.1 or less oxidation proceeds very rapidly
181
Antioxidants like EDTA and citric acid function as antioxidants by reacting with what catalystis of oxidation?
Trace metals
182
Another name for triacylglycerides is?
Triglycerides
183
An exoenzyme that catalyzes hydrolysis of maltose units from the nonreducing end of starch is called?
Beta amylase
184
An example of a saturated fatty acid is the 16 carbon molecule called?
Palmitic acid
185
An enzyme that only catalyzes hydrolysis of alpha 1,6 linkages in starch is called what?
Pullunase (R enzyme) or isoamylase
186
An enzyme that breaks down pectin molecules and causes softening of fruit tissue (avocados, pears, tomatoes, and pineapple) is called?
Polygalacturonase; pectinase
187
All unsaturated fatty acids that contain an isolated cis double bond absorb light at approximately what length?
190 nm
188
Alitame is how many times sweeter than sucrose?
Two thousand (2000) times sweeter
189
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?
Glass transition
190
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. Colorless; B. Brown
191
What is the pH of a mixture of strong acids combining 100 ml of pH = 2 and 100 ml of pH = 3?
2.26 (Equal volumes of strong acid: Difference of 1 -- add 0.26; difference of 2 or more -- add 0.3)
192
What is the difference between a competitive enzyme inhibitor and a noncompetitive enzyme inhibitor?
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
What is O-R Potential? What does it measure?
Oxidation-Reduction Potential; The tendency of a reversible system to give or receive electrons
194
What is Flocculation?
The redeposition of small dissolved crystals or sol particles into larger crystals or sol particles in an oil-in-water emulsions
195
What do the initials BHT and BHA stand for and what is their use in foods?
Butylated hydroxytoluene, Butylated hydroxyanisole, Antioxidants
196
What are the two sulfur containing amino acids?
Cysteine and Methionine
197
What are the two stages of freezing?
Nucleation; Crystal growth & recrystallization
198
What are the two protein components of Gluten and what is their function?
Glutenin; function = elasticity, Gliadin; function = plasticity
199
What are the H3O+ and OH- concentrations in a solution with pH = 5?
[H3O+] = 10-5 moles/l; [OH-] = 10-9 moles/l
200
What are the five elements found in proteins?
Carbon, oxygen, nitrogen, hydrogen, sulfur
201
What are the 5 most abundant elements in the earth’s crust by weight?
Oxygen, Silicon, Aluminum, Iron, Calcium
202
What are the 3 primary gases in air?
Nitrogen (78%), Oxygen (21%), Argon (1%)
203
What are 3 folic acid rich foods?
Leafy green vegetables, citrus fruits and juices, beans lentils, fortified breakfast cereals
204
What acids would you check for TA in oranges, apples, yogurt, grapes?
Citric, malic, lactic, tartaric
205
What 5 parameters are critical for an extrusion process?
Barrel temperature, screw speed, moisture content, compression ratio
206
To aid in recycling, consumer plastics are given one of seven numbers. Give the number and type of plastic for 4 of these groups.
1 (polyethylene terepthalate), 2 (high density polyethylene), 3 (polyvinyl chloride), 4 (low-density polyethylene), 5 (polypropylene), 6 (polystyrene), 7 (other)
207
The redeposition of small dissolved crystals or sol particles into larger crystals or sol particles in a water-in-oil emulsion is called what?
Ostwald ripening
208
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
Beta > Beta prime > Alpha
209
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?
Cellophane, Nylon, Saran
210
Rank the following lipoproteins by size: HDL, VLDL, LDL, IDL, Chylomicrons.
Largest Chylomicrons > VLDL > IDL > LDL > HDL smallest
211
Name three types of enzyme inhibition?
Competitive, noncompetitive, uncompetitive, and suicide
212
Name three types of browning reactions in foods?
Maillard, carmelization, ascorbic acid browning, enzymatic browing
213
Name three products from the hydrolysis of starch by alpha amylase.
Oligosaccharides; Maltodextrins; Maltose; Glucose; Corn syrup
214
Name three gums not from plants?
Gellan, curdlan, xanthan
215
Name three compounds in dietary fiber:
Lignin, hemicellulose, pectin substances, cellulose, gums and musilages
216
Name the two substances that may be used for commercial caffeine extraction?
Methylene chloride, supercritical CO2 or H2O
217
Name the three types of conjugated lipids.
Phospholipids – contain a phosphoric acid molecule and a fat molecule; Cerebrosides – contain a carbohydrate and a fat molecule; Sulfolipids – contain a sulfate radical
218
Name the three basic amino acids?
Histidine, lysine, and arginine
219
Name the principle antimicrobial component of the following: thyme, oregano, cinnamon, cloves
thymol, carvacrol, cinnamic aldehyde, eugenol
220
Name the predominant organic acids in the following products: grapefruit, grapes, oranges, and vinegar
Grapefruit – citric acid; Grapes - tartaric acid; Oranges – Citric; Vinegar- acetic
221
Name 4 carotenoid pigments
B-carotene, capsorubin, canthaxanthin, lycopene, lutein, bixin, norbixin, and crocin
222
Name 3 factors that affect enzyme catalyzed reactions:
pH, temperature, [substrate], [enzyme], ionic strength, activators, inhibitors
223
Name 3 classes of flavonoids?
Anthocyanins, flavonals, flavones, catechins, flavanones
224
Name 3 blood plasma lipid classes
HDL, LDL, VLDL
225
Name 2 hydrocolloids that gel at high temperature:
Methyl cellulose, curdlan
226
List 5 of the major 6 classes of enzymes.
Oxidoreductase, Transferase, Hydrolase, Lyase, Isomerase, Ligase
227
List 3 limitations of using native starch in foods?
Cold water insoluble, Instability at low pH,Cohesive texture, Viscosity breakdown, Amylose, retrogradation, Amylopectin association
228
Give three reasons for adding starch to food.
Coating and glazing agent; thickening agent; colloidal stabilizer; moisture retention; gel forming; binding
229
Give the hydrogenation products of glucose, fructose, galactose, and xylose?
Sorbitol, manitol, glactitol, xylitol
230
Give the 3 main polymorphic forms of crystalline fat
Alpha, Beta prime, Beta
231
For the following saturated fatty acids give the systematic name or molecular formula: palmitic, stearic, acetic.
Palmitic, n-hexadecanoic, C16 H32 O2 Stearic, n-octadecanoic, C18 H36 O2 Acetic, C2 H4 O2
232
What are the components of a plant cell wall?
Pectin, cellulose, hemicellulose, lignin and protein
233
What are the two most abundant fatty acids in peanut oil?
Oleic acid and Linoleic acid
234
Chondrus crispus is the source for what polysaccharide hydrocolloid?
Carrageenan
235
Mixing leeched wood ashes with lard in the presence of heat will create what AND what is the chemical process called?
Soap AND saponification
236
What chemically modified cellulose will form a thermal gel at 55-60ºC but can return to solution at room temperature?
Methylcellulose (or hydroxypropylmethylcellulose)
237
What is Fehling's test used to determine?
Reducing sugars
238
What is the enzyme in saliva that breaks down some starches to maltose?
Ptyalin (or amylase)
239
What is the name of the pickled flower buds of Capparis spinosa, a Mediterranean shrub?
Capers
240
What spice is made from the dried stigmas of the crocus plant?
Safron
241
Where might one find the compound "linalool"?
Spices or herbs
242
Which two amino acids have the highest reactivity in Malliard reactions?
Arginine and lysine
243
What general type of compound is bixin?
Apocarotenoid
244
For what is the natural food color annatto used?
Cheese
245
From what tree is Gum Arabic obtained?
Acacia
246
What is the brand name used by Procter and Gamble for olestra?
Olean
247
Sake is a fermented alcoholic beverage made from what?
Rice
248
What are the six major anthocyanins?
Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, petunidin
249
Accumulation of unwanted material on solid surfaces resulting in decreased function is called what?
Fouling
250
What does the Karl Fischer test measure?
Water concentration
251
What is the soxhlet apparatus used for?
Fat determination
252
What does the Mojonnier Test measure?
Fat in Milk
253
What does the Babcock Test measure?
Fat concentration
254
What does the Kjeldahl measure?
Nitrogen concentration
255
Who worked at the Carlsberg Brewery Laboratory in Copenhagen, Denmark the late 1800s and developed a method to determine nitrogen concentration in organic substances?
Johan Kjeldahl
256
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?
Benedict's; aldehydes and alpha-hydroxy-ketones; brick-red precipitate
257
What term is used to describe the relationship between water activity and moisture of food at a given temperature and what is its shape?
Moisture sorption isotherm; Sigmoidal
258
Which of the following chemical bonds is involved in the secondary structure of proteins? Peptide, Glycosidic, Hydrogen, Van der Waals
Hydrogen
259
Luminometry is used to detect the presence of ATP based upon its enzymatically catalyzed reaction with what bioluminescent compound?
Luciferin
