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FIXED OILS

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OLIVE OIL: CONSTANTS If the fruits used to produce the oil have been allowed to ferment, the acid value will be higher than is officially permitted. – PowerPoint PPT presentation

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Title: FIXED OILS


1
FIXED OILS
2
FIXED OILS PLANT FATS
  • Fixed plant oils (e.g. olive oil) may be either
    liquid or solid.
  • The terms oil or fat therefore do not have a
    precise significance.
  • Fixed oil when the fat is liquid at room
    temperature.
  • Plant fat when the fat is solid or semi-solid
    at room temperature.

3
PHYSICAL PROPERTIES
  • - Cannot be distilled (unless decomposed). This
    distinguishes fixed oils from volatile oils.
  • Leaves a permanent, translucent stain on filter
    paper.
  • Specific gravity lt 1.
  • All insoluble in water. Soluble in organic
    solvents. (Except ethyl alcohol except castor
    oil).
  • Most develop a rancid odour when exposed to air,
    moisture light for prolonged periods of time
    (hydrolysis of esters liberation of fatty
    acids)
  • All have characteristic odours.
  • Varying viscosities.

4
PHYSICAL PROPERTIES
  • Some form a hard layer when exposed to air ?
    Drying oils, e.g. linseed oil.
  • Semi-drying oils, e.g. Sesame seed oil forms
    a slight film.
  • Non-drying oils e.g. olive oil does not
    form any hard layer.
  • Drying oils consist mostly of unsaturated fatty
    acids such as linolenic acid. The more
    unsaturated fatty acids the oil contains, the
    more drying it is.

5
FIXED OILS CHEMICAL COMPOSITION
  • All fixed oils are chemically identical.
  • Fixed oils may be either liquid or solid (or
    both, e.g. coconut/olive oil). Generally trigs
    consisting of saturated FA solid, while those
    consisting of unsaturated FA liquid.
  • When both types are present (cod-liver oil),
    cooling of the oil results in deposition of
    saturated trigs such as stearin. In most
    medicinal oils, these are removed by freezing
    filtration.
  • Trigs can be hydrolysed by heating with caustic
    alkali forms soaps and glycerin.

6
FIXED OILS
  • Fixed oils (plant lipids) are natural substances
    ? mainly esters of fatty acids and
    alcohols/polyols.
  • Fxs
  • Constituents of cell structures (membrane lipids
    phospho/glyco)
  • Coating elements (waxes/cutins)
  • Reserve substances/energy sources for the plant
    cell

7
FIXED OILS
  • Plant lipids are hydrophobic (sometimes
    amphophilic).
  • Soluble in apolar or slightly polar organic
    solvents.
  • Non volatile (hence fixed),

8
TYPES OF FIXED OILS
  • SIMPLE LIPIDS
  • Esters of a fatty acid an alcohol.
  • E.g. Glycerol, triglycerides constituents, or
    waxy esters
  • COMPLEX LIPIDS
  • E.g. Phospholipids/glycolipids
  • Play an NB role as membrane lipids.
  • Lecithins are the only fixed oil that has a
    pharmaceutical/ industrial use.

9
TRIGLYCERIDE STRUCTURE
  • Trigs are triesters of a
  • -triol
  • -glycerol
  • -fatty acids
  • ? Aliphatic carboxylic acids of variable length,
    normally with an even number of C-atoms.

10
NATURE OF FATTY ACIDS
  • Vegetable fatty acids can be one of 2 types
  • Saturated Fatty Acids
  • Unsaturated Fatty Acids
  • In both these groups, chains of 16 or 18 C-atoms
    are most common.

11
FATTY ACIDS
  • SATURATED Fatty acids with 12 Cs are rare in
    plants, but they do occur
  • E.g. C8 C10 ? trigs of palm seeds (lauric
    myristic acid)
  • 12 C atoms Bay butter nutmeg butter
  • 20 Cs peanut oil
  • Palmitic acid major constituent of vegetable
    oils
  • UNSATURATED The most NB ones are those
    consisting of C18

12
GLYCEROL ESTER STRUCTURE
  • Trigs may be either homogeneous/ heterogeneous,
    depending on if the fatty acid moieties that
    esterify the 3 alcohol fxs of glycerol are
    identical or different.
  • Generally trigs are heterogeneous vegetable
    oils are a complex mix of triesters.
  • Homogeneous (simple) trig E.g. tripalmitin

13
TRIGLYCERIDES
  • Non-existent in leaves.
  • Stored as oily inclusions (oleosomes) which form
    from the ER ? form a source of energy reserve
    for cells, especially in seeds.
  • Trig content of seeds increases during the
    maturation process while the phospho-
    glycolipids decrease.
  • Some fruits concentrate trigs in their pericarp
    (olive, avocado, bay berry)

14
PRODUCTION OF FIXED OILS
  • ORIGINAL METHOD Expression of the plant
    material yields the oil.
  • CURRENT METHODS Use organic solvent
  • Both methods The crude oil undergoes various
    refining steps.

15
BEFORE EXTRACTION
  • Plant material to be pressed undergoes strict
    quality control.
  • - absence of foreign matter deterioration
  • GENERAL PRELIMINARY PROCEDURES
  • Cleaning drying
  • SPECIFIC PRELIMINARY PROCEDURES (depends on the
    seeds botanical structure)
  • Olives washed
  • Cotton Delintering
  • Castor seeds ground nuts decorticating.
  • Peanuts, soybeans, sunflower seeds Shelled.

16
METHODS OF EXTRACTION
  • Extraction by Expression
  • Cold Expression
  • Hot Expression
  • ii. Extraction by Solvents

17
1. EXTRACTION BY EXPRESSION
  • Screw presses are normally used to express oils
    from plant material because they give a better
    yield than older hydraulic presses.
  • They also operate at higher pressure and
    continuously (not in batches).
  • Before undergoing expression, seeds rich in
    proteins are cooked at 90ºC ? frees the oil by
    bursting the cell structures coagulates the
    proteins. A fast drying step normally follows.

18
a. COLD EXPRESSION
  • Oils for medicinal uses are extracted at room
    temperature. Only a portion of the oil is
    obtained.
  • Oil is normally less viscous with less odour
    than with hot expression (better quality).
  • The remaining pressed material may then be
    ground, heated and pressed to express any
    remaining oil.
  • The pressed material has nutritive value and is
    used as cattle feed.

19
b. HOT EXPRESSION
  • The residue left after cold expression is broken
    down and treated with steam. This causes the
    remaining oil cells to rupture.
  • Even after hot expression, 10 of the oil
    remains in the plant material.

20
TYPES OF MACHINES USED FOR EXPRESSION
  1. Hydraulic Press
  2. Oil Expeller

21
HYDRAULIC PRESS
  • Series of corrugated plates between which the
    plant material is placed.
  • As the ram rises, the P forces the oil out is
    collected in a gutter around the ram.
  • The plates are deeply corrugated to provide
    channels for the oil to escape, but also to
    prevent the spreading of the material during
    pressing.
  • This type of press is used for seeds not
    containing a very high amount of oil.
  • DISADVANTAGE This method is not continuous
    (plates have to be cleaned after every pressing).

22
OIL EXPELLER
  • The material is spread continuously through a
    perforated steel cylinder through which it is
    forced by a spiral screw. The pressed material
    then escapes at the opposite end though a choking
    cone.
  • ADVANTAGE Continuous process lt manual labour.
  • DISADVANTAGE Suitable only for seeds with a
    high amount of oil.

23
ii. EXTRACTION BY SOLVENTS
  • This type of method is used only for technical
    oils (not medicinal oils).
  • Seeds used Intact or partially extracted by
    expression.
  • Solvent Normally hexane (BP 65 ºC)
  • Method Solvent is added to the cleaned, hulled
    roughly milled seeds. The organic phase is
    recovered. (Organic phase solution containing
    the oil in the solvent (called miscella) , and
    also solvent soaked defatted meal).
  • Oil recovery 95 99

24
REFINING OF CRUDE OIL
  • Crude oil obtained from the miscella may contain
    water, FFAs, lecithins, resins, pigments
    (carotenes, chlorophyll), sterols, waxes,
    substances with odours tastes, and external
    contaminants (pesticides).
  • Refining consists of the following processes
  • Degumming
  • Neutralization
  • Bleaching
  • Wax removal
  • Deodorizing

25
DEGUMMING
  • Degumming Mucilage removal
  • Fx To remove lecithins, proteins other
    constituents present in the oil in colloidal
    suspension.
  • Method Hot oil is hydrated ? colloids form a
    dense gel which separates from the lighter oil.
    The gel is discarded the oil is dried under
    vacuum.
  • In most cases, this treatment is replaced by an
    injection of phosphoric acid into the hot oil ?
    phospholipids then precipitate when neutralized
    by NaOH.

26
NEUTRALIZATION
  • FFAs, always present in crude oil, are
    neutralized by dilute NaOH.
  • The soap formed (soap stock) adsorbs part of the
    impurities colouring matter, phenols, sterols,
    wax esters, traces of metals and miscellaneous
    oxidation products.
  • Excess soap NaOH are removed by washing with
    hot water.

27
BLEACHING
  • Method Oil is passed through diatomaceous
    earths or activated charcoal.
  • The bleaching agent (charcoal/earth) is then
    removed by filtration.

28
WAX REMOVAL
  • Crude oil is rich in waxes (sunflower, corn
    cotton seed oils).
  • When cooled (frozen), waxes solidify.
  • The crystallized waxes are then removed by
    filtration.

29
DEODOURIZING
  • Aldehydes ketones are responsible for
    unpleasant odours of crude oils.
  • These are eliminated by injecting steam into the
    very hot oil (gt200ºC) under high vacuum.

30
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31
ADDITIONAL OIL TREATMENTS
  • Additional treatments of the oil take place
    mainly in the food industry.
  • Includes
  • Hydrogenation
  • Interesterification
  • (margarine industry).
  • In all cases, the exhausted plant material is
    recovered, treated (solvents removed), and if
    needed detoxified. It is then used as cattle
    feed. Only in very specific cases will it be
    used for purposes other than animal feed.

32
QUANTITATIVE CHEMICAL TESTS
  1. Physical Constants
  2. Chemical Constants

33
PHYSICAL CONSTANTS
  1. Specific Gravity
  2. Melting / Congealing Point
  3. Refractive Index
  4. Viscosity
  5. Optical Rotation

34
SPECIFIC GRAVITY
  • Fixed oils and fats all have a specific gravity
    of lt 1.
  • They are therefore all lighter than water.

35
MELTING / CONGEALING POINT
  • This physical constant is only used for 2 oils
    (only 2 fixed oils are solid at room
    temperature).
  • Oil of Theobroma
  • Oil of Hydrocarpus

36
REFRACTIVE INDEX
  • DEFINITION This is the ratio of the velocity of
    light in a vacuum to the velocity of light in a
    substance.
  • Refractive index varies with the wavelength of
    light and temperature.
  • Lab wavelength is kept constant with using a
    Na-lamp, T 20 ºC. Refractive index is measured
    with a refractometer.
  • The refractive index varies considerably for
    every oil and is expressed as a range

37
VISCOSITY
  • 1. Viscosity is the measure of a material's
    resistance to flow. Viscosity is a result of the
    internal friction of the material's molecules.
  • 2. The tendency of a fluid to resist internal
    flow without regard to its density.
  • 3. The resistance of fluid substance to flowing,
    quantitatively characteristic for an individual
    substance at a given temperature and under other
    definite external conditions.

38
OPTICAL ROTATION / ACTIVITY
  1. The angle through which the plane of polarization
    of light is rotated when the polarized light
    passes through a layer of liquid.
  2. Optical rotation is the rotation of linearly
    polarized light as it travels through certain
    materials.

39
CHEMICAL CONSTANTS
  1. Acid Values
  2. Saponification Value
  3. Ester Value
  4. Iodine Value
  5. Unsaponifiable Matter
  6. Acetyl value

40
ACID VALUE
  • Acid value Refers to the number of mg of KOH
    needed to neutralize the free acids in 1 g of
    oil.
  • High acid values occur in oils which are rancid.

41
SAPONIFICATION VALUE
  • The hydrolysis reaction of lipids (with KOH
    above) can be used to determine the
    saponification value of the oil.
  • Saponification value is expressed as the number
    of mg of KOH needed to neutralize the free acids
    in, and to hydrolyse the esters in, 1 g of the
    substance (oil).

42
ESTER VALUE
  • Ester value The difference between the
    saponification and acid values.

43
IODINE VALUE
  • Iodine value Gives the measurement of the
    unsaturation of the oil. Oils which partially
    resinify on exposure to air are known as drying
    oils.
  • These oils have high iodine values.
  • E.g. linseed oil

44
UNSAPONIFIABLE MATTER
  • Unsaponifiable matter consits of compounds such
    as sterols, which remains after saponification of
    the triglycerides and the removal of the glycerol
    and soaps (by using solvents).

45
ACETYL VALUE
  • Acetyl value The number of mg KOH needed to
    neutralize the acetic acid freed by the
    hydrolysis of 1 g of the acetylated fat.
  • The oil is first acetylated with acetic
    anhydride, which combines with any hydroxyl group
    present.
  • Because these are absent from most fatty acids,
    the small acetyl values usually obtained are due
    to relatively small amounts of sterols.
  • But In an oil such as castor oil, the acetyl
    value is high (146-150), due to the large amounts
    of the hydroxyl acid ricinoleic acid.

46
SIGNIFICANCE?
  • These constants are important general tests to
    ensure
  • That the oil is genuine
  • To detect adulteration of fixed oils and fats.
  • REASON Because they are chemically complex,
    fixed oils fats are not easily assayed.

47
ADULTERATION OF FIXED OILS
  • Cheap oils are often mixed with more expensive
    oils as a form of adulteration.
  • 3 of the most commonly used to adulterate are
  • Sasame oil (detected by Baudouins test).
  • Cotton seed oil (Halphens test)
  • Arachis oil (Belliers test)

48
PLANTS CONTAING FIXED OILS
  • Olive oil
  • Cod-liver oil
  • Castor oil
  • Theobroma oil
  • WAXES
  • Wool fat
  • Beeswax

49
OLIVE OIL
  • DEFINITION Olive oil is the oil expressed from
    the ripe fruits of Olea europea (Oleaceae
    Family). The latifolia variety bears larger
    fruit, but the longifolia variety yields the best
    oil.
  • COMMON NAMES Salad oil, sweet oil
  • GEOGRAPHICAL SOURCES Mediterranean, California,
    Spain, France, Greece Tunisia.

50
OLIVE OIL COLLECTION PREPARATION
  • The methods used for preparations vary according
    to the local conditions. In modern factories
    hydraulic presses are widely used but in more
    remote districts the procedure is the same as it
    had been for hundreds of years.
  • 1st oil expressed Virgin oil
  • Subsequent extractions marc is solvent
    extracted lower quality oil.
  • Superior grades of oil Extra-virgin, Virgin,
    Pure, or Refined.

51
OLIVE OIL CHARACTERISTICS
  • Olive oil Pale yellow liquid, sometimes with a
    green tint.
  • Oil has a slight odour bland taste.

52
OLIVE OIL CONSTANTS
  • If the fruits used to produce the oil have been
    allowed to ferment, the acid value will be higher
    than is officially permitted.
  • Oil should comply with the tests for absence of
    arachis, cotton-seed, sesame tea-seed oil (C.
    sasanqua).

53
OLIVE OIL CONSTITUENTS
  • Oils from different sources differ slightly in
    their constituents (composition). This may
    result due to the different varieties of olive
    used, or to climate differences.
  • 2 types of oil are distinguished
  • That produced in Italy, Spain, Asia CA
  • (contains more olein less linolein)
  • ii. Produced in Tunisia

54
Type I Type II BP Limits _______________________ _________________________________________ Oleic Acid 78-86 65-70 56-85 Linoleic Acid 0-7 10-15 3.5-20 Palmitic Acid 9-12 15 7.5-20 Stearic Acid 9-12 15 0.5-5.0
55
OLIVE OIL USES ACTIONS
  • Used in the preparations of soaps, plasters etc.
  • Salad oil
  • May protect against colonic cancer (due to its
    action on prostaglandins).

56
COD-LIVER OIL
  • DEFINITION Medicinal cod-liver oil is a fixed
    oil prepared from the fresh liver of the cod,
    Gadus callarias, other Gadus spp. (Gadidae
    Family), under conditions which make it palatable
    containing a certain amount of Vitamins.
  • GEOGRAPHICAL SOURCES Norway Iceland
  • NOTE Fish-liver oils should not be confused
    with fish-body oils.

57
COD-LIVER OIL HISTORY
  • Cod-liver used to be exported from Norway to
    Europe during the Middle Ages, although for
    non-medicinal purposes.
  • The original method of preparation was the
    rotting process, in which the livers where
    allowed to rot in barrels. The oil rising to the
    surface was skimmed off.
  • The more modern process of steaming was
    introduced in 1850.

58
COLLECTION EXTRACTION
  • Cod-livers (contain 50 oil), are removed
    immediately after the fish are caught
    transferred to steamers stored at low
    temperature.
  • Process normally takes place in Norway or Iceland.

59
PREPARATION
  • Main processes involved in the preparation of
    cod-liver oil include
  • Refining
  • Drying
  • Winterization
  • Deodourization
  • Standardization of the vitamin content

60
REFINING OF THE CRUDE OIL
  • The quality flavour of cod-liver oil are
    improved by refining the oil under air-free
    conditions to avoid oxidation.
  • Method Crude oil is rapidly heated to 77 ºC. A
    reagent is then added to remove impurities. This
    also causes further dissolution of the small
    amount of liver tissue present. The oil water
    are removed without contact with air. This
    process is then repeated another 2 times.

61
DRYING
  • Drying is carried out in a vacuum drying tower
    which continuously evaporates any small amount of
    residual water.
  • Result a clear bright, highly refined oil.

62
WINTERIZATION
  • All medicinal veterinary oils are cooled to 0
    ºC, which causes the stearin to separate. The
    solid is removed by filtration and a
    polyunsaturated product is left.

63
DEODORIZATION
  • Final deodorization is achieved by steaming under
    vacuum. This removes aldehydic ketonic
    impurities.
  • It also protects the oil from oxidation.

64
STANDARDIZATION
  • The medicinal oil is standardized for vitamin
    content by blending.
  • BP standards 1 g oil should contain at least
  • 600 IU vitamin A
  • 60 IU vitamin D

65
STORAGE OF COD-LIVER OIL
  • Cod-liver oil should be stored in well-fitted
    airtight containers.
  • It should be protected from light stored in a
    cool, dry place.

66
COD-LIVER OIL CHARACTERS
  • Medicinal cod-liver oil is very pale yellow
    liquid with only a slightly fishy odour taste.
  • The acid value should not exceed 1.2 but it
    varies with age.
  • Iodine Value high (150-180).
  • Unsaponifiable matter low (1.5) unlike
    halibut-liver oil.

67
COD-LIVER OIL CONSTITUENTS
  • The oil consists of glycerides of unsaturated
    (85) and saturated (15) acids.
  • Polyunsaturated acids play an important role in
    human health
  • Saturated fatty acids myristic acid, palmitic
    acid traces of stearic acid.

68
ACTIONS USES
  • The medicinal properties of cod-liver oil are
    mainly due to the Vitamins A D.
  • It is widely used in underdeveloped countries for
    the prevention treatment of rickets.
  • Europe USA Traditionally used as a vitamin
    supplement.
  • Recent research relief of rheumatic pains
    joint muscle stiffness.
  • Reduces blood cholesterol.
  • Protects against CVD

69
COD-LIVER OIL ALLIED DRUGS
  • Halibut-liver oil the fixed oil obtained from
    the livers of the Halibut, Hippoglossus vulgaris
    (Pleurnectideae).
  • It is a pale yellow liquid containing large
    amounts of vitamin A D.
  • Unsaponifiable matter is not less than 7.
  • Uses similar to cod-liver oil (smaller doses).
  • Many other fish-liver oils resemble cod-liver
    oil, shark-liver oil, Oleum Selachoidei, is
    included in the Indian Pharmacopoeia.

70
CASTOR OIL
  • DEFINITION Castor oil is a fixed oil obtained
    from the seeds of Ricinus communis
    (Euphorbiaceae).
  • GEOGRAPHICAL SOURCES Native to India. Produced
    in Brazil, India, China, Russia Thailand.

71
CASTOR SEEDS BOTANICAL CHARACTERISTICS
  • Seeds show considerable difference in colour
    size. They are oval, slightly compressed
  • Colour uniform grey, brown or black, mottled
    with brown or black.
  • If grown in good conditions, they have very
    little odour the taste is slightly acrid.
  • If the testa are broken, rancidity will develop.

72
CASTOR OIL PREPARATION
  • 90 of the worlds castor oil is prepared in
    India Brazil. Small amounts of raw seeds are
    now exported.
  • Method of preparation Seeds are removed from
    the testa. Kernels are cold-pressed with a
    hydraulic press. Oil is then refined by
    steaming, filtration bleaching.
  • Cold-expression yields 33 of medicinal oil.
    Further amounts of lower quality oil may be
    obtained by other methods

73
CASTOR OIL CHARACTERISTICS
  • Medicinal castor oil is a colourless or pale
    yellow liquid, with a slight odour faintly
    acrid taste.
  • Acid value increases with age. If initially
    high indicates the use of damaged sees or
    careless extraction or storage.
  • Viscosity Extremely high

74
CASTOR OIL CONSTITUENTS
  • Castor seeds contain 46-53 fixed oil.
  • These fixed oils consist of the glycosides of
  • Ricinoleic
  • Isoricinoleic
  • Steric
  • Dihydroxystearic acids
  • The cake, after expression, contains extremely
    poisonous toxins (ricins) ? unfit for cattle
    feed. In the body they produce and anti-toxin
    (anti-ricin).
  • Ricin D is a sugar protein with a strong lethal
    toxicity.

75
CASTOR OIL USES ACTIONS
  • Once widely used as a domestic purgative.
  • Now more restricted to hospital use for
    administration after food poisoning as a
    preliminary to intestinal examination.
  • Because of the ricin, the seeds have a much more
    violent action than the oil and is not used as a
    purgative in the West.
  • Non-pharmaceutical uses of oil Turkey Red Oil,
    soaps, paints, varnishes lubricants.

76
CASTOR OIL ALLIED DRUGS
  • Croton seeds obtained from Croton triglium
    (Euphorbiaceae) a small tree producing similar
    capsules to those of castor. The seeds resemble
    castor in size and shape but have a dull,
    cinnamon-brown colour.
  • Oil contains 50 fixed oil. Contains croton
    resin crotin a mixture of crotin-globulin
    crotin-albumin comparable to ricin. Also
    contains diterpenes, capric, lauric palmitic
    acids. These are anti-inflammatory vesicant.
  • Esters potential anti-HIV activity.
  • Should be used with caution. Not used
    medicinally in the West. Internally violent
    cathartic.

77
CASTOR OIL ALLIED HERBS
  • Physic nuts or Purging nuts seeds of Jatropho
    curcas (Euphorbiaceae). Contain 40 fixed oil
    contain a substance similar to ricin called
    curcin. Both the seeds the oil are powerful
    purgatives.
  • Abrus sees (prayer beads) are the seeds of Abrus
    precatorius (Leguminosae). Contain a toxic
    glycoprotein (abrin) resembling ricin. Also
    contain indole-alkaloids. Used in folk medicine
    in Asia, Africa S. America to treat many
    ailments, to procure abortion to hasten labour.
    In India they are also used as an oral
    contraceptive. (weigh 1 carat 200mg
    traditional weights).

78
ALMOND OIL
  • DEFINITION Almond oil is the fixed oil obtained
    by expression from the seeds of Prunus amygdalus
    (Roseceae) var. dulcis (sweet almond) or var.
    amara (bitter almond).
  • GEOGRAPHICAL SOURCES Mediterranean countries
    North Africa, France, Spain, Italy)

79
SWEET BITTER ALMONDS
  • Young fruit have a soft, felt-like pericarp, the
    inner part of which gradually becomes
    sclerenchymatous as the fruit ripens to form a
    pitted endocarp (shell), also consisting of
    sclerenchymatous cells. This is sometimes ground
    and used to adulterate powdered herbs.
  • The testa of the seed is removed by soaking it in
    warm water (known as blanching).
  • Bitter almonds are sometimes found in samples of
    sweet almonds, especially in those from N.
    Africa. Their presence may be detected the
    sodium picrate test for cyanogenic glycosides.

80
ALMOND OIL CONSTITUENTS
  • Both varieties contain 40-55 fixed oil, 20
    protein, mucilage emulsin.
  • Bitter almonds contain 2.5-4 cyanogenic
    glycoside, amygdalin.
  • Olein
  • Glycosides of linoleic other acids

81
ALMOND OIL PRODUCTION CHARACTERS
  • Almond oils is produced by grinding the seeds
    expressing them in a canvas bag between slightly
    heated iron plates.
  • They are sometimes ground before expression (no
    added advantage). The oil is then clarified by
    filtration.
  • Oil is pale yellow liquid with a slight odour
    bland, nutty taste.

82
ALMOND ESSENTIAL / VOLATILE OIL
  • Essential oil is obtained from the cake left
    after expressing bitter almonds. This is
    macerated with water for some time to allow for
    the hydrolysis of amygdalin. The benzaldehyde
    and hydrocyanic acid are separated by steam
    distillation.

83
ALMOND OIL ACTIONS USES
  • Almond oil is used in the preparation of many
    ablution articles.
  • When taken internally, it has a mild laxative
    action.
  • Volatile almond oil is used as a flavouring agent.

84
ARACHIS OIL
  • DEFINITION Arachis oil is obtained by
    expression from the seeds of Arachis hypogaea
    (Leguminosae).
  • COMMON NAMES Earth-nut, ground nut, peanut.
  • GEOGRAPHICL SOURCES Tropical Africa, India,
    Brazil, S. USA Australia.

85
PREPARATION
  • During ripening, the fruits bury themselves in
    the sandy soil in which the plants grow. Each
    fruit contains1-3 red-brown seeds.
  • Fruits shelled by machine.
  • Kernels contain 40-50 fixed oil.
  • Because of the high oil content of the seeds,
    when crushed, it is difficult to express.
    Therefore, after boiling, part of the oil is
    removed in a low pressure expeller and the
    remaining cake is solvent extracted. The 2 oil
    fractions are then mixed together before
    undergoing purification.
  • The pressed cake makes excellent cattle feed.
  • The ground pericarp is used as an adulterant for
    powdered herbs.

86
ARACHIS OIL CONSTITUENTS
  • Glycosides of
  • Oleic
  • Linoleic
  • Palmitic
  • Arachidic
  • Stearic
  • Lignoceric
  • And other acids

87
ARACHIS OIL ACTIONS USES
  • Similar properties to olive oil.
  • It is an ingredient of camphorated oil.
  • Mainly used in the production of margarine
    cooking fats.
  • Hydrogenated oil is also official.
  • Arachis oil is the most likely oil to be used to
    adulterate other types of oil.

88
LINSEED LINSEED OIL
  • DEFINITION Linseed is the dried ripe seed of
    Linum usitassimum (Linaceae).
  • COMMON NAMES Linseed, flaxseed
  • GEOGRAPHICAL SOURCES S. America, India, USA,
    Canada, England.

89
LINSEED CONSTITUENTS
  • 30-40 fixed oils
  • Mucilage
  • Protein
  • Small amounts of cyanogenetic glycosides
    Linamarin Lotaustralin
  • Flavonoids
  • Lignan potential cancer preventative

90
LINSEED OIL
  • DEFINITION Extraction of linseed oil is done by
    hot expression of linseed meal. The cake is
    adjusted to leave in sufficient oil to make it
    suitable for cattle feed.
  • Linseed oil is a yellow-brown drying oil with a
    characteristic odour bland taste.

91
LINSEED OIL CONSTANTS
  • On exposure to air it gradually thickens forms
    a hard varnish.
  • Iodine value high (at least 175) has high
    amounts of unsaturated acid glycosides.

92
LINSEED OIL CONSTITUENTS
  • Linolenic acid
  • Linoleic acid
  • Oleic acid
  • Myristic
  • Stearic
  • Palmitic acids

93
USES ACTIONS
  • Crushed linseed is used as a poultice and whole
    seeds are used to make demulcent preparations.
  • Oil is used as a liniment.
  • Research anti-bacterial properties in topical
    applications effective against Staphylococcus
    aureus strains resistant to anti-biotics.
  • Linseed cake is a valuable cattle feed.
  • For use in paints, linseed oil is boiled with
    driers such as Mangenese resinate (by forming
    metallic salts, the oil is dried more rapidly
    not safe for medicinal use)

94
OIL OF THEOBROMA
  • DEFINTION Theobroma oil is obtained from the
    ground kernels of Theobroma cacao (Sterculiaceae)
    by hot expression. The oil is filtered and
    allowed to set into moulds.
  • COMMON NAMES Cocoa butter
  • GEOGRAPHICAL SOURCES Holland

95
THEOBROMA OIL CONSTITUENTS
  • Glycerides of
  • Stearic
  • Palmitic
  • Arachidic
  • Oleic
  • And other acids
  • It is the most expensive of all the fixed oils,
    and is commonly adulterated with waxes, stearin,
    animal or vegetable tallows.

96
THEOBROMA OIL CONSTANTS USES
  • Boiling point 31-34 ºC.
  • This makes it ideal for the use in the
    preparation of suppositories.

97
WAXES
98
WAXES
  • Wax is sometimes used to describe hard paraffin
    (HC mixture), but it is best confined to natural
    mixtures containing large amounts of esters
    derived from higher monohydric alcohols of the
    methyl alcohol series combined with fatty acids.
  • In this series the alcohols change from liquids
    to solids, become less soluble in water have
    higher melting points MWs.

99
WAXES - EXAMPLES
  • Vegetable products
  • (e.g. carnauba wax)
  • Animal products
  • e.g. beeswax wool-fat.
  • Waxes are abundant in nature (epidermal surfaces)
    but only a limited number have commercial
    significance.

100
FATS VS WAXES
  • Fats may be saponified by either aqueous or
    alcoholic alkali, but waxes are only saponified
    by alcoholic alkali.
  • This is used to determine if fats were added to
    adulterate waxes.

101
WAXES - COMPOSITION
  • Fats consists almost entirely of esters.
  • Waxes esters (palmitate type), free acids,
    HCs, free alcohols sterols.
  • Acid values of waxes also tend to be higher than
    those of fats.

102
WOOL FAT
  • DEFINITION Wool fat (anhydrous lanolin) is a
    purified fat-like substance prepared from the
    wool of the sheep, Ovis aries (Bovidae).

103
WOOL FAT PREPARATION
  • Raw wool contains considerable quantities of
    wool grease or crude lanolin, the potassium
    salts of fatty acids earthy matter.
  • Raw lanolin is separated by cracking with
    sulphuric acid purified to be fit for
    medicinal use. Purification may be done by
    centrifuging with water by bleaching.

104
WOOL FAT CHARACTERS
  • Wool fat is a pale yellow, tenacious substance
    with a faint but characteristic odour.
  • It is insoluble in water.
  • Melting point 36-42ºC
  • Soluble in ether chloroform.
  • Like other waxes, it is not readily saponified by
    aqueous alkali, but with a alcoholic solution of
    alkali.
  • Saponification value 90 105.
  • Iodine value 18 32.
  • Acid value not more than 1

105
WOOL FAT CONSTITUENTS
  • 25 water
  • Cholesterol isocholesterol (main active
    constituents).
  • Unsaturated alcohols
  • Fatty acids
  • (- lanoceric
  • - lanopalmitic
  • - carnaubic fatty acids)

106
WOOL FAT USES
  • Wool fat is used as an emollient base for creams
    ointments.

107
BEESWAX
  • DEFINITION Beeswax is obtained by melting and
    purifying the honeycomb of Apis mellifica and
    other bees.
  • GEOGRAPHICAL SOURCES West Indies, California,
    Chile, Africa, Madagascar India.
  • Separate monographs exist for yellow and white
    beeswax.

108
BEESWAX PREPARATION
  • Wax is secreted by worker bees in cells on the
    ventral surface of the last 4 segments of their
    abdomen. The wax passes out through pores in the
    chitinous plates of the sternum is used,
    particularly by the young workers, to form the
    comb.

109
PREPARTION OF YELLOW BEESWAX
  • Yellow beeswax is prepared, after removal of the
    honey, by melting the comb under water. This
    causes solid impurities to sink to the bottom
    while any residual honey is dissolved). This is
    then strained and the wax is allowed to solidify
    in suitable moulds.

110
PREPARATION OF WHITE BEESWAX
  • White beeswax is prepared from yellow beeswax
    which is treated with charcoal, potassium
    permangante, chromic acid, or chlorine, by the
    slow bleaching action of light, air moisture.
    In this method the melted wax is allowed to fall
    on a revolving cylinder which is kept moist.
    This then slowly becomes bleached. This is then
    repeated at least one more time. The wax is
    finally cast into circular cakes.

111
BEESWAX CHARACTERS
  • Beeswax is a yellow-brown or yellow-white solid.
  • It breaks with a granular fracture has a
    characteristic odour.
  • It is insoluble in water slightly soluble in
    cold alcohol, but dissolves in chloroform and
    also in warm fixed volatile oils.

112
BEESWAX CONSTITUENTS
  • Beeswax is a true wax
  • Consists of 80 myricin
  • (myricyl palmitate)
  • Contains a little myricyl stearate.
  • Free cerotic acid
  • Aromatic substances

113
BEESWAX ADULTERANTS
  • Japan wax not a true wax, but a fat (may be
    saponified by means of boiling aqueous sodium
    hydroxide waxes are unaffected by aqueous
    alkali).
  • Japan wax is prepared from the fruits of Rhus
    (Anacardiaceae).

114
BEESWAX USES
  • Beeswax is used for the preparation of plasters,
    ointments and polishes.

115
COOKING OILS
  • Do not use fresh, unrefined, mechanically
    pressed, light oxygen protected EFA-rich seed
    oils for cooking.
  • Labels Cholesterol Free.
  • Opened bottles should be kept in the fridge
    used with 3-6 weeks. Olive oil can keep well for
    up to 2 years.
  • NB Cooking method influences the type of oil
    you use.

116
OIL TEMPERATURE OF SMOKING POINT C
Flaxseed oil Pumpkin seed oil Sunflower oil Olive oil Macadamia oil Canola oil Sesame seed oil Grapeseed oil Coconut oil Peanut oil Avocado oil 107 120 160 185 205 198 204 232 215 216 232 232 220 - 250
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