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2) Food Chemistry I > Midterm Review > Flashcards

Midterm Review Flashcards

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1
Q

What is the difference in terms of structure between liquid and solid waxes? Give examples of both.

A

Liquid wax: short-chain (ex: jojoba oil)

Solid wax: long-chain

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2
Q

In phospholipids, what is the structure called when X=OH?

A

Phosphatidic acid

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3
Q

In phospholipids, what is the structure called when X=O-CH2-CH2-NH2?

A

Phosphatidylethanolamine

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4
Q

In phospholipids, what is the structure called when X=O-CH2-CH2-N+(CH2)3

A

Phosphatidylcholine

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5
Q

In phospholipids, what is the structure called when X=O-CH2-CH(NH2)-COOH

A

Phosphatidylserine

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6
Q

In phospholipids, what is the structure called when X=sugar

A

Phosphatidylinositol

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7
Q

What are the three classes of phospholipids?

A
  • Lecithins (Phosphatidylcholines)
  • Cephalins (Phosphatidylethanolamines)
  • Phosphatidyl inositols
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8
Q

How do short-chain fatty acids and long-chain fatty acids differ in terms of their contributions to flavour?

A

Short-chain FA: contribute to flavour

Long-chain FA: have no flavour per se BUT they will give a soapy flavour in the presence of salts

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9
Q

The presence of ________ can lower the smoke point of edible oils when used for frying.

A

free fatty acids

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10
Q

What does this structure correspond to?
CH3-(CH2)n-CH2-OH
How many carbons do they need to have at least?

A
  • Alcohols

- At least 6 carbons

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11
Q

Short-chain ______ are often major contributors to flavour.

A

alcohols

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12
Q

How many carbons does a fundamental isoprene unit contain?

A

5 carbons

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13
Q

What are terpenes components of?

A

Components of the fragrant oils obtained from leaves, flowers and fruits

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14
Q

What are the main constituents of essential oils?

A

Monoterpenes, with sesquiterpenes

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15
Q 
How many isoprene units and carbons do these terpene classes contain: 
A) Monoterpenes
B) Sesquiterpenes
C) Diterpenes
D) Sesterterpenes
E) Triterpenes
A 
A) 2, 10
B) 3, 15
C) 4, 20
D) 5, 25
E) 6, 30
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16
Q

What is the main mechanism for oils becoming plastic fats?

A

cis -> trans conversion during hydrogenation

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17
Q

Differentiate unconjugated and conjugated double bonds.

A

Unconjugated: separated by methylene group (natural state of most fatty acids)
Conjugated: double bonds are next to each other, not interrupted by a methylene (CH2) group (not naturally found)

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18
Q

What does a mixed bonding system lead to? Where is that positioned?

A
  • Leads to formation of an ACTIVE METHYLENE group

- Positioned between a conjugated and unconjugated double bonds

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19
Q

The omega nomenclature is based on two assumptions. What are they?

A
  • All natural fatty acids are in the cis form

- The double bonds will be always be UNCONJUGATED

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20
Q

Arachidonic acid, C__, with __ unconjugated double bonds, the first double bond in position _, the next at _, _, and _, respectively

A
  • C20
  • 4 unconjugated double bonds
  • 6, 9, 12, 15
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21
Q

What group does Erucic acid belong to?

A

Omega-9

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22
Q

What group does arachidonic acid belong to?

A

Omega-6

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23
Q

There are no simple, analytical methods for separating, isolating and identifying individual _________.

A

triglycerides

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24
Q

In plant seeds, what kind of lipids are used as a source of energy for germination?

A

Triglycerides

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25
Q

What lipid is responsible in part for the desirable flavour of aged cheese?

A

Short-chain fatty acids

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26
Q

How many carbons does the lauric acid group contain?

A

12

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27
Q

What are the sources of the lauric acid group?

A
  • Oil palm (tropical oils)

- Palm kernal oil, coconut and babasu

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28
Q

How does palm kernal oil differ from palm oil?

A
  • Palm kernal oil (extracted from palm oilseeds)

- Palm oil (from palm fruit), which is much more highly unsaturated and is not part of the lauric acid group

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29
Q

Are lauric acids solid or liquid at room temperature?

A
  • Although largely saturated

- They are oils owing to the high proportion of C12 fatty acids in their triglycerides

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30
Q

What kind of fatty acids are resistant to oxidative rancidity? Which group is an example of this?

A
  • Low degree of unsaturation

- Lauric acid

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31
Q

Most oils in this group tend to be categorized as industrial “drying oils”. Which group does this passage refer to?

A

Linolenic acid

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32
Q

Why are linolenic acids sometimes referred as “drying oils”?

A

Because of their ability to polymerize into a hard film if applied as a thin layer on surfaces (paint)

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33
Q

The polymerization capability is present in all _____________ oils, but those containing high levels of _____________ are more reactive

A

unsaturated oils, linolenic acid

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34
Q

What are common examples of the linolenic acid group?

A

Soybean, linseed, castor, hempseed and perilla oils

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35
Q

Processed soybean oil, if stored after extraction without modification, suffers from a problem commonly termed _______.

A

Reversion

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36
Q

What is reversion?

A

Relatively rapid transition from a bland, tasteless oil shortly after processing to a grassy, hay-like and then fishy flavour

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37
Q

How is reversion overcome? What fats are converted to what?

A

By hydrogenation to convert a substantial portion of linolenic to oleic and linoleic acids

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38
Q

Animal fat depot group has a higher ratio of what compared to the oleic-linoleic acid group?

A

Di-saturated (gs2u) and tri-saturated (gs3) glycerides

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39
Q

Some fish oil fatty acids can be highly unsaturated. Up to how many double bonds do they contain?

A

Up to 6 double bonds

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40
Q

What are two examples of the erucic acid group?

A

Rapeseed oil and mustard oil

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41
Q

How was rapeseed oil used originally?

A

Used extensively as a marine motor oil

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42
Q

What allows the separation of cis from trans isomers?

A

Silver ion chromatography

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43
Q

What kind of lipid is biodiesel?

A

Methyl esters

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44
Q

Which fatty acid group is useful in cosmetics?

A

Lauric acids

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45
Q

What is the fatty acid breakdown of olive oil?

A
  • Oleic (75%) - M
  • Palmitic (10%) - S
  • Linoleic (10%) - U
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46
Q

What is the first step of the processing of oilseeds?

A
  • Crush the oilseed

- Give the crush a heat treatment

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47
Q

What does the heat treatment of a crush do?

A

Aids in knocking out the enzymes lipase and lipoxygenase, which can cause a deteriorative reaction

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48
Q

What deteriorative reactions do lipases cause? How? What are they present in?

A
  • Lipolysis
  • Hydrolysis of the ester linkage between glycerol and a fatty acid in the TG
  • Enzyme present in every living system
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49
Q

What deteriorative reactions do lipoxygenase cause? How?

A
  • Autoxidation

- Oxidation of polyunsaturated fatty acid chains that have a cis,cis-1,4-pentadiene group (e.g. linoleic and linolenic)

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50
Q

In the case of fats and oils from animal and fish sources, what is the most common method of processing?

A

Rendering

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51
Q

What are the four steps most oils go through following extraction?

A

1) Settling/degumming
2) Refining
3) Bleaching
4) Deodorizing

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52
Q

What is the use of settling/degumming? What does it get rid of?

A
  • Carbs, proteins and phospholipids hydrate and associate themselves with the aqueous phase
  • Over time, aqueous phase separates from the oil, carrying with it the cellular debris, carbs and phospholipids
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53
Q

In the settling/degumming phase of soybean oil, what is recovered from the aqueous layer? Why?

A
  • The phospholipids since soybeans contain 5-8% phospholipids (mainly lecithin)
  • They have commercial value as emulsifiers
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54
Q

What does refining remove?

A

Removes the free fatty acids from the oil

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55
Q

What does bleaching remove?

A

Designed to remove the coloured material from the oil (carotenoids, chlorophyll, and pheophytin)

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56
Q

What does deodorization remove?

A

Removes the volatile compounds that give the oil off-flavours

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57
Q

In olive oil, what compounds are not removed for the best quality? Which steps are not used?

A
  • Flavour and colour compounds

- Only pressed; bleaching and deodorization are not used

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58
Q

Define selectivity. It is a property of what?

A
  • Preferentially hydrogenating more highly unsaturated fatty acids
  • Property of the catalyst
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59
Q

What is proprietary?

A

Knowledge of conditions and selectivity characteristics provides control

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60
Q

What causes lard to be “grainy”?

A

In lard, the GS2U component is largely made up of oleopalmitostearin, which has a propensity to form large crystals.

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61
Q

How can the structure of lipids in human milk be reproduced artificially?

A

Enzymatic interesterification reaction using sn-1,3 specific lipase as a catalyst.

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62
Q

Why can fat have plasticity or spreadability?

A

Because a fat is made up of a liquid in a crystalline matrix

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63
Q

The crystalline matrix of fat forms a 3-D network that holds the system together by what force? How does it explain plasticity?

A
  • Van der Waals forces

- Because they are weak forces, they can be broken and readily re-formed again

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64
Q

When a fat can be deformed readily, it is said to be in what range?

A

Plastic range

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65
Q

How is the solid fat content commonly determined?

A
  • Dilatometry

- Nuclear magnetic resonance (NMR) measurements

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66
Q

What is plotted in dilatometry?

A

The specific volume is plotted as a function of temperature

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67
Q

What do the 3 curves in the specific volume over temperature graph represent?

A

A) Thermal expansion of the solid fat
B) Expansion due to a change in state
C) Thermal expansion of the liquid only

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68
Q

How does the pulsed NMR SFC measurement work?

A
  • Sample of fat is placed in a magnetic field

- Radiofrequency (RF) pulse is applied perpendicular to the field to “tip” the spins

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69
Q

What is the signal accompanying the relaxation process of the 1H magnetic spins after they are disturbed by the RF pulse?

A

FID (free induction decay)

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70
Q

Which spins of the 1H nucleic relax more rapidly? Compared to what?

A

Spins in the solid state relax more rapidly than those in the liquid phase

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71
Q

What is polymorphism? What exhibits it?

A
  • The occurrence of several different crystal forms for a single compound
  • Triglycerides
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72
Q

What are the most common polymorphic forms in order of relative stability?

A

Alpha (a), beta prime (B’), and beta (B)

73
Q

How do alpha, beta-prime, and beta polymorphs differ in terms of the cooling of liquid fat?

A

Alpha: rapid cooling of liquid fat
Beta-Prime: slow cooling of liquid fat
Beta: very slow cooling of liquid fat

74
Q

What are the four methods for conversion from Beta to Beta-prime?

A
  • Interestification
  • Hydrogenation
  • Winterization (destearinization)
  • Addition of cottonseed oil and/or tallow flakes (beta‐prime)
75
Q

Does the volume increase or decrease as the temperature increase?

A

Volume increases

76
Q

How do the triglyceride polymorphs compare in terms of their long spacing?

A

Alpha: longest long spacing
Beta-Prime: intermediate
Beta: shortest long spacing

77
Q

How do the triglyceride polymorphs compare in terms of their packing?

A

Alpha: more loosely packed
Beta-Prime: more closely packed
Beta: most closely packed

78
Q

What do the microscopic analyses of the triglyceride polymorphs reveal?

A

Alpha: platelet (5u)
Beta-Prime: fine needle (1 u)
Beta: long needle (25-50 u)

79
Q

What does the infrared spectroscopic analyses of the triglyceride polymorphs reveal?

A

Alpha: singlet at 720cm^-1
Beta-Prime: doublet at 719 and 727 cm^-1
Beta: singlet at 717 cm^-1

80
Q

How do the triglyceride polymorphs differ in terms of stability and melting point?

A

Alpha: most unstable, lowest melting point
Beta-Prime: unstable, intermediate melting point
Beta: most stable, highest melting point

81
Q

What does the color analyses of the triglyceride polymorphs reveal?

A

Alpha: translucent
Beta-Prime: in-between
Beta: opaque

82
Q

Why is the specific volume of alpha high?

A

Since it does not pack well

83
Q

What are high temperature base catalysts used in interesterification?

A

KOH and NaOH

84
Q

What are low-temperature catalysts used in interesterification?

A

Sodium methoxide (NaOCH3)

85
Q

What does the base catalyst do in interesterification?

A

Initial removal of an a‐proton by the base catalyst leads to the charge‐delocalized enulate anion.

86
Q

In the interesterification of lard, what do conditions that favor intramolecular interchange result in?

A

Crystal-modified lard (CML)

87
Q

In the interesterification of lard, conditions that favor random distribution can be controlled to yield what?

A

Partially modified lard (PML)

88
Q

In the interesterification of lard, conditions favoring directed interesterification can be used to control what content? Of what lard?

A

GS3 content of direct interesterified lard (DIL)

89
Q

Compare the solid fat index of directed, natural and randomized lard.

A
  • Directed has the highest amount of solid fat (more plasticity)
  • Randomized, similar to natural, higher though
  • Natural: very low solid fat
90
Q

How do you determine how many double bonds are lost during hydrogenation (catalyst activity)?

A

Defined as decrease in iodine number per unit of time during a hydrogenation under a specific set of conditions

91
Q

What is the iodine number?

A

Defined as the number of grams of iodine absorbed by 100 grams of fat.

92
Q

What are the five steps in the hydrogenation of oils?

A

1) Transfer and/or diffusion
2) Adsorption
3) Hydrogenation/Isomerization
4) Desorption
5) Transfer

93
Q

Which steps are critical for controlling the degree of isomerization and selectivity of reactions in hydrogenation?

A
  • Transfer/Diffusion

- Adsorption

94
Q

How can selectivity be expressed?

A
  • Ratio Klo/Ko

- The rate of hydrogenation of linoleate relative to that of oleate

95
Q

What are the two types of catalysts for hydrogenation?

A
  • Nickel catalyst

- Copper-Chromium catalyst

96
Q

How does the AOCS determine catalyst activity?
Time required to hydrogenate soybean oil to an iodine value of __ from ___ at ___oF, __ psig, ____%
catalyst concentration compared to the time required using AOCS standard catalyst under the same conditions.

A

Time required to hydrogenate soybean oil to an iodine value of 80 from 120 at 350oF, 20 psig, 0.05%
catalyst concentration compared to the time required using AOCS standard catalyst under the same conditions.

97
Q

What are the independent variables that affect hydrogenation?

A
  • Pressure
  • Temperature
  • Agitation
  • Catalyst concentration
98
Q

What are the dependent variables that affect hydrogenation?

A
  • trans fatty acids
  • Selectivity ratio
  • Hydrogenation rate
99
Q

If the pressure increases in hydrogenation, how is the selectivity ratio, the trans content, and the reaction rate affected?

A

Selectivity Ratio: Decrease
Trans content: Decrease
Reaction Rate: Increase

100
Q

If the agitation increases in hydrogenation, how is the selectivity ratio, the trans content, and the reaction rate affected?

A

Selectivity Ratio: Decrease
Trans content: Decrease
Reaction Rate: Increase

101
Q

What is the saponification value?

A
  • The number of milligrams (mg) of potassium hydroxide (KOH) required to neutralize the fatty acids resulting from the complete hydrolysis of 1 g of the sample.
  • mg of KOH required to saponify 1 gram of fat
102
Q

How many mg of KOH does it require to saponify 1 mol of TG? How do you calculate the SV?

A
  • 168 000 mg

- SN = 168000/MW(TG)

103
Q

In shortenings, how does the proportion of palmitic acid change? Which position?

A

The proportion of palmitic acid in the 2-position is reduced from about 64% to 24% on random interesterification.

104
Q

Which fats have greater shortening abilities? How are they prepared?

A
  • Fats with higher levels of unsaturated fatty acids

- Often prepared by hydrogenation of vegetable oils

105
Q

Which fat is a natural shortening? What does its quality depend on?

A
  • Lard

- Quality depends on the dominant crystal form and its solid fat content

106
Q

How do beta-prime crystals incorporate air?

A

Large amount of small air bubbles; creamier, uniform and glossy shortenings

107
Q

What is tempering?

A

Holding a fat at a temperature and for an amount of time that permits transformation to the desired polymorphic form.

108
Q

What must be removed during tempering? Why?

A

The heat of transformation must be removed to avoid melting and a later conversion into large beta crystals.

109
Q

What determines characteristic cocoa butter texture?

A

POS

110
Q

What happens when POS (palmitic, oleic, stearic) is converted from beta-prime to beta?

A

Chocolate “bloom” - white spots and dull surface appearance

111
Q

What is the key to the self-propagating nature of the autoxidation reactions?

A

Peroxy radical has a preference for terminating its radical state by abstracting a hydrogen from another fatty acid

112
Q

What is the precursor molecule for compounds that are responsible for off-flavours?

A

Hydroperoxides

113
Q

What are the primary oxidation products? (2)

A
  • Hydroperoxides (R-O-O-H)

- Peroxides (R-O-O-R)

114
Q

When does the monomolecular hydroperoxide breakdown predominate? When does the bimolecular predominate?

A

Monomolecular: when hydroperoxide concentration is LOW
Bimolecualr: when hydorperoxide concentration is HIGH

115
Q

How does the alkoxy radical decompose? (3)

A
  • Aldehyde generation
  • Alcohol generation (direct)
  • Formation of a ketone
116
Q

What does the peroxy radical prefer to do?

A

Prefer to abstract a hydrogen from a fatty acid (propagation radicals)

117
Q

What is the definition of the peroxide value?

A

milli-equivalents (mEq) of peroxide oxygen per 1000 grams of fat.

118
Q

What is the induction period?

A
  • Slow initial accumulation of hydroperoxides

- Predominantly the monomolecular reaction

119
Q

Why does PV fall off later on?

A

Due to the fact that the decomposition of hydroperoxides is outpacing their formation

120
Q

What does malonaldehyde react with in the TBA test? What does it produce?

A
  • Reacts with 2 molecules of TBA

- Produces a red complex, which can be readily assessed spectrophotometrically

121
Q

Why are molecules with double bonds more susceptible to abstraction of a hydrogen?

A
  • Because the LIFETIME of the free radical formed is extended significantly
  • Electrons from the double bonds can resonate and stabilize the free radical structure
122
Q

Positional cis/trans isomers occur as ________ form and decompose.

A

Peroxy radicals

123
Q

Which oil is found naturally in the unconjugated form, but is readily converted into a mixed bonding system?

A

Linolenic acid

124
Q

Where is the most unstable hydrogen in an oil?

A

The hydrogen from the methylene carbon

125
Q

What is reversion?

A
  • Rapid onset of rancidity without an apparent rise in the peroxide value
  • An accelerated oxidation reaction, which does not allow hydroperoxides to linger
126
Q

What is the major function of true antioxidants?

A

Have the property of being able to interrupt the PROPAGATION step of the autoxidation process

127
Q

What do antioxidants typically give their free radical to?

A

Generally a peroxy radical

128
Q

What do antioxidants lengthen?

A

They lengthen the induction period

129
Q

What is the antioxidant legal limit? What is it based on?

A
  • Under 0.02% (200 ppm)

- Based on the fat content of the product

130
Q

Metal ions shorten the ____________ and increase the overall __________

A

induction period, rate of the reaction

131
Q

Does metal ion catalysis favour the second or third oxidation state reaction? What does it form?

A

Favours the second oxidation state; forms an alkoxy

132
Q

What does the third oxidation state of a metal ion form?

A

A peroxy

133
Q

What does the chelation of metal ions cause?

A
  • Causes STERIC HINDRANCE

- Eliminates the catalytic role metal ions would otherwise play

134
Q

Where is lipoxygenase relatively abundant? What is it responsible for?

A
  • In plant tissues

- Responsible for the development of characteristic flavours

135
Q

What do enzymes catalyze in the lipid of plant tissues?

A
  • Catalyzes the formation of hydroperoxides

- Instigates the free radical mechanism

136
Q

What does the bleaching of pigments (chlorophyll, beta-carotene) occur as a result?

A

Result of autoxidation initiated by lipoxygenase

137
Q

How does the nature of triplet and singlet oxygen compare?

A

Triplet: diradical
Singlet: no radical

138
Q

How does the reaction of triplet and singlet oxygen compare?

A

Triplet: radical
Singlet: electron-rich

139
Q

Photosynthesizers absorb light in the ____ - ____ range

A

380-900

140
Q

The singlet state is produced first by the _______________, but it has a _____ lifetime, decaying to _______________ to the ground state and by _________________ to the triplet state

A

light absorbed
short
fluorescence
intersystem crossing

141
Q

Lipoxygenase exhibits substrate specificity for what?

A

cis-cis-penta-1,4-diene unit

142
Q

What is the role of preventative antioxidants?

A

Minimizes the formation of initiating radicals

143
Q

Name some preventative antioxidants.

A
  • Superoxide dismutase

- Catalase

144
Q

What is the role of radical scavenging antioxidants?

A

Breaks the free radical chain reactions by donating hydrogen to free radicals (Vitamin C, Tocopherol)

145
Q

___________ are opposite to synergists.

A

Pro-oxidants

146
Q

Give examples of metal chelators.

A
  • EDTA (very efficient)
  • Citric acid
  • Phosphoric acid
147
Q

What does the Benzidine test indicate?

A

If you have a yellow measurement, you have aldehydes in your oil

148
Q

What does the TBA test indicate?

A

If you have an intense red colour, you have aldehydes in your oil (extensive oxidation)

149
Q

What does the AOM method determine? What does it mean?

A
  • Oxygen is bubbled at a controlled rate
  • You can determine if the oil is prone to reversion within minutes
  • Active Oxygen Method
150
Q

Do efficient antioxidants have low or oxidation potentials?

A

High

151
Q

Do efficient antioxidants have low or high reduction potentials?

A

Low

152
Q

Name 3 factors that affect your choice of antioxidant.

A
  • Safety
  • Off-odor
  • Stability to pH and food processing
153
Q

In milk fat, long chain fatty acids are preferred in which positions?

A
  • sn-1

- sn-2

154
Q

In milk fat, short-chain fatty acids are preferred in which positions?

A

sn-3

155
Q

What kind of TG are preferentially synthesized in milk fats?

A

TG with one short and two long-chain FA

156
Q

TG are contained within ___________ that are surrounded by a _________

A
  • fat globules

- membrane

157
Q

_________ are synthesized by the microflora of the cow, and present health benefits

A

Conjugated linoleic acid (CLAs)

158
Q

What are the components of the membrane that surround the fat globules in milk fats?

A
  • Protein (41%)
  • Phospholipids and glycolipids (30%)
  • Cholesterol (2%)
  • Neutral glycerides (14%)
  • Water (13%)
159
Q

How much cholesterol does milk, shrimp, and eggs contain?

A
  • Milk: 27 mg
  • Shrimp: 125 mg
  • Eggs: 275 mg
160
Q

What does the membrane that surrounds the fat globules in milk contain?

A
  • Double layer of lipoproteins

- Enzymes, including lipase

161
Q

What is the function of the membrane of the fat globule

A

Prevents lipolysis

162
Q

What is the consequence of the disruption of the membrane of fat globules? In which situation could this happen?

A
  • Homogenization of milk
  • Allows lipase to bind to the fat globules and to hydrolyze TG at a high rate
  • Milk becomes unpalatable
163
Q

What must be done prior to homogenization? Why?

A

Lipases must be inactivated by pasteurization to avoid them hydrolyzing the TG

164
Q

What is lactose degraded to during ripening? How?

A

Degraded to lactic acid by homofermentation

165
Q

What is a prerequisite for good aroma in cheese? What are the exceptions?

A
  • As little lipolysis as possible

- Exceptions: stinky cheeses (ex: roquefort)

166
Q

What is the % of total monounsaturated lipids in red meat? Which fatty acids are the most present?

A
  • Total: 50%

- Oleic (18:1) > Palmitoleic (16:1)

167
Q

What is the function of cholesterol in red meat? How much is found in 100 grams?

A
  • Integral component of cellular membranes

- 70-90mg/100 grams

168
Q

What is the main polyunsaturated fatty acids found in skeletal muscles of red meat? What is the main source of saturated? What is the main source of unsaturated?

A
  • Polyunsaturated: Linoleic acid
  • Monounsaturated: Oleic acid
  • Saturated: Palmitic and stearic acid (2:1 ratio)
169
Q

What is the ratio of LDL to HDL in egg yolks?

A

LDL: 68%
HDL: 14%

170
Q

Does LDL or HDL contain phosvitin? What is it?

A
  • HDL

- Phosphorus-rich, lipid-free protein

171
Q

Associate these words:

1) LDL
2) HDL

A) Lipovitellin
B) Lipovitellenin

A

LDL: Lipovitellenin
HDL: Lipovitellin

172
Q

What are the three main components of egg yolk phospholipids?

A
  • Phosphatidylcholine/Lecithin (73%)
  • Phosphatidylethanolamine/Cephalin (15%)
  • Lysophosphatidylcholine (6%)
173
Q

What leads to discolouration of dried whole egg and loss of palatability?

A

The reaction between cephalin and glucose (Maillard)

174
Q

Fish is an important contributor to what types of omega-3 fatty acids? What are the benefits and downsides?

A
  • Omega-3-polyenic acids (5 or 6 double bonds)
  • Nutritional value
  • Preservation is difficult because of their easy peroxidation
175
Q

What is the fatty acid profile of soybean oil?

A
  • Saturated FA (14%)

- Unsaturated FA (81%)

176
Q

What is the main saturated FA in soybean oil? What are the main unsaturated FA in soybean oil?

A
  • Palmitic acid (10%)
  • Linoleic acid (51%)
  • Oleic acid (23%)
177
Q

When are lecithins removed in the processing of oil? Why?

A
  • Removed from degumming

- To use their emulsifying power for other means

178
Q

What are the unsaponifiables contained in soybean oil? When are they removed?

A
  • Partially removed in deodorization

2) Food Chemistry I (31 decks)

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