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PHAN 1 LEC > FIXED OILS AND FATTY SUBSTANCES > Flashcards

FIXED OILS AND FATTY SUBSTANCES Flashcards

1
Q

value or number of physical and chemical
property. Correctness of these values determines the
quality of substances judged

A

CONSTANT

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2
Q

CONSTANTS INCLUDE:

A

❖ specific gravity
❖ melting point
❖ congealing point
❖ refractive index
❖ optical activity
❖ acid value, saponification value, ester value, iodine value,
acetyl value, hydroxyl value, unsaponifiable matter,
water and sediment

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3
Q

The purity of fixed oils, fats, waxes, resins, etc. can not be
ascertained by the usual methods based on

A

gravimetric
or volumetric processes

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4
Q

The determination of these constants are made in conjunction
with the study of ______
tests for the substance analyzed and for the presence of
adulterants serve as a basis of the purity and quality of such
substances

A

color, odor, taste and special identity

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5
Q

compounds consisting of fatty acids combined with
glycerol via ester linkages

A

FATS

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6
Q

Fats – compounds consisting of

A

fatty acids combined with
glycerol via ester linkages

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7
Q

an ESTER derived from
glycerol and three fatty acids

A

TRIGLYCERIDES

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8
Q

are mixture of glyceryl esters
of high molecular weight fatty acids like palmitic (16),
stearic (18) and oleic( 18) acids.

A

Fixed oils and fats

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9
Q

Contain relatively high quantities of liquid
glycerides (glyceryl oleate)

A

FIXED OILS

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10
Q

Fixed oils contain relatively high quantities of

A

liquid
glycerides (glyceryl oleate)

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11
Q

contain large amounts of solid glycerides (glyceryl
stearate).

A

FATS

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12
Q

Fats contain large amounts of

A

solid glycerides (glyceryl
stearate)

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13
Q

HAVE DOUBLE BONDS

A

OILS

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14
Q

are esters of high molecular weight
monohydric alcohols and high molecular weight fatty acids.

A

WAXES

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15
Q

Waxes are

A

esters of high molecular weight
monohydric alcohols and high molecular weight fatty acids.

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16
Q

Sources include both plants (soybean, carnauba) and animals
(spermaceti, Ambergris

A

WAXES

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17
Q

are natural or induced solid or semi-solid
exudates from plants characterized by being insoluble in
water, soluble in alcohol and ether, crystallizable and softening or
melting at a moderate heat.

A

RESINS

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18
Q

are substances containing benzoic or cinnamic
acids or esters of these

A

BALSAMS

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19
Q

The fats and oils to be employed in the
determination of their chemical constants
should undergo preliminary treatment if they
are ______ due to separation of stearin.

A

turbid

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20
Q

oils should be made clear by ______
their container on a water bath at 50°C until
the turbidity disappears

A

heating

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21
Q

ACID value -also called

A

Acid Number or Acidity
Index

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22
Q

Defined as the number of milligrams of potassium
hydroxide required to neutralize the free acids in one
gram of oil, fat, wax, resin, balsam or other similar
substances of complex composition.

A

ACID VALUE

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23
Q

It may be expressed as the number of milliliters of
0.1-N sodium hydroxide required to neutralize the free
acids in 10 grams of sample

A

ACID VALUE

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24
Q

are due to hydrolysis of the esters that
compose them

A

FREE ACIDS

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25
Q

The hydrolysis is caused by

A

BACTERIAL OR CATALYTIC ACTION

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26
Q

If a substance has a high acid value, it does not
indicate _____ but _____
during their preparation, purification or storage.

A

rancidity

hydrolytic decomposition

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27
Q

Saponification Value
❖ Also known as the

A

Saponification Number or
Koettsdorfer Number

28
Q

Defined as the number of mg of potassium hydroxide
required to neutralize the free acids and saponify
the esters in 1 gram of fat, fatty oil, wax, resin, balsam or
other substances of similar composition.

A

SAPONIFICATION VALUE

29
Q

Determination of this constant helps in the detection of
the presence of glycerides of fatty acids which contain
less than 16 or more than 18 carbon atoms

A

SAPONIFICATION VALUE

30
Q

saponification value is ______proportional to the
average of the molecular weights of the fatty acids
found in the sample

A

inversely

31
Q

High SV, samples contain ______

A

low MW fatty acids

32
Q

HCl cannot be substituted with ____because
K2 SO4 which would be the product of the
neutralization will not dissolve in the alcoholic
solution and interfere with the observation of the
endpoint

A

H2 SO4

33
Q

______ is more advantageous than the
aqueous solution because the alcohol acts as a
solvent for the oil and the products of
saponification which are insoluble in water.

A

Alcoholic KOH

34
Q

is performed to eliminate errors from all
sources like those produced by absorption of CO2 by the
alkali or by the alkalinity of the glass vessels.

A

BLANK TEST

35
Q

Defined as the number of mg of potassium hydroxide
required to saponify the esters in 1 gram of fatty oil, fat,
wax, balsam, resin or other similar substances

A

ESTER VALUE/ NUMBER

36
Q

Substances, which do not contain free acids, have_____
ester and saponification values.

A

equal

37
Q

Substances containing free acids have their ester values
equal to the

A

difference between the acid value and
saponification value.

38
Q

The ester value is important in the analysis of ____,
which serves to indicate the presence of adulterants like
_____

A

beeswax

paraffin

39
Q

The determination of ester value of waxes is made in
conjunction with the determination of the

A

ACID VALUE

40
Q

Adulterant would abnormally increase the ____ values and lowers the _____ value

A

acid

ester

41
Q

These are substances that are not saponified by alkali
hydroxides but are soluble in ordinary fat solvents

A

unsaponifiable matter

42
Q

After the saponification of oils and fats a small amount of
residue is left consisting of ______ if the oils or fats
are of vegetable origin and _____ if they are of
animal origin.

A

phytosterol

cholesterol

43
Q

Determination of this constant will indicate the presence
of unsaponifiable adulterants such as petroleum oil added
to linseed oil.

A

Unsaponifiable Matter

44
Q

Defined as the number of grams of iodine absorbed
under specified condition by 100 grams of oil, fat,
wax or other substance.

A

Iodine Value

45
Q

This value is a quantitative measure of the proportion of
unsaturated fatty acids present both free and
combined

A

iodine value

46
Q

Linseed, cod iodine value

A

> 120

47
Q

Cottonseed,
sesame iodine value

A

100-120

48
Q

Olive, almond iodine value

A

<100

49
Q

In conjunction with the saponification value of a fat or oil, iodine
value also serves as a means of detecting

A

adulteration

50
Q

Method I

A

Hanus method – Iodobromide, CHCl3

51
Q

Method II

A

Wijs method – Iodochloride, CCl4

52
Q

is used to prevent other side reaction
from taking place in which iodine monochloride is
consumed.

A

iodine flask

53
Q

Defined as the number of milligrams of potassium hydroxide
equivalent to the hydroxyl content of one gram of the
substance.

A

hydroxyl value

54
Q

hydroxyl value constant gives an indication of the identity and purity of
fatty substances possessing ______

A

alcoholic hydroxyl groups

55
Q

An abnormally low hydroxyl value is indicative of
_____ with higher molecular weight
alcohols or with non-alcoholic fatty substances

A

adulteration

56
Q

It is expressed as the number of mg of potassium
hydroxide required to neutralize the acetic acid
obtained by the saponification of 1 gram of acetylated
fatty acids.

A

acetyl value

57
Q
A
57
Q

The Acetyl Value corresponds closely to the ______ of fatty alcohol and the two constants have much
the same significance with respect to identity and purity
of substances

A

hydroxyl
value

58
Q

Acetyl Value of Fatty Acids
❖ The acetyl value is determined by acetylating ____ e.g hydroxystearic acid or hydrogenated castor
oil and determining the saponification value of the
product ACETYLATED SAMPLE

A

hydroxy
fatty acids

59
Q

From the saponification value of acetylated fatty acid and
acid value of the original fatty acid, ____ is
determined

A

acetyl value

60
Q

defined as the reactive oxygen contents expressed
in terms of milliequivalents (meq) of free iodine per kg of fat

A

peroxide value (POV)

61
Q

a measure of the aldehyde levels in an oil or fat,
in particular those that are unsaturated (and principally the 2–alkenals)

A

anisidine value (AnV)

62
Q

Combined PV and Anisidine value (2PV
+ AV)

A

Total oxidation Value (TotOx)

63
Q

Congealing point

A

Solidification Temperature of FA

64
Q

mEq of iodine

A

0.127

65
Q

mEq in mg of KOH

A

56.11

PHAN 1 LEC (13 decks)

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