INDEX unsaponifiables

On the other hand, for the detection of resin oils in mineral oils or in the unsaponifiable parts of the above mixtures, use may be made of the colour reactions of section 8 and of determinations of certain physical and chemical characters, such as sp. gr., refractive index and rotation—which are higher with resin oils than with mineral oils—and iodine and Maumeni numbers, which are almost zero with mineral oils (see observations below). 

In India, small seeds generally had higher oil content than larger seeds and the main characteristics were specific gravity (15°C), 0.9304 refractive index (15°C), 1.4795 optical rotation, +35° saponification value, 181.2 iodine value (Wijs), 99 unsaponified material, 3.7%. The expressed oil is classified as semi-drying and is a source of lauric and adipic acids (Weiss, 2002). Table 12.4 gives the average physico-chemical properties of fennel volatile oil. 

A descriptive report of OEP produced in China states the following information about OEP refractive index (20°C) of 1.48, specific gravity (20°C) of 0.93, iodine value of 140, saponification value of 188, thiocyanogen value of 84, and unsaponifiable matter of 1 % (3). 

Table III gives the physical and chemical properties of the M. oleifera oil. Some of the properties of the oil depend on the extraction medium. The M oleifera oil is liquid at room temperature and pale-yellow in colour. Electronic nose analysis shows that it has a flavor similar to that of peanut oil. The melting point estimated by differential scanning calorimetry is 19°C (15). The chemical properties of the oil depicted in Table III below are amongst the most important properties that determines the present condition of the oil. Free fatty acid content is a valuable measure of oil quality. The iodine value is the measure of the degree of unsaturation of the oil. The unsaponifiable matter represents other lipid- associated substances like, sterols, fat soluble vitamins, hydrocarbons and pigments. The density, iodine value, viscosity, smoke point and the colour of Moringa oil depends on the method of extraction, while the refractive index does not. Varietal differences are significant in all physical characteristics apart from refractive index and density (2). The heating profile of the M. oleifera seed oil using the differential scanning calorimetry (DSC) conventional scan rate shows that there is one major peak B and, two small shoulder peaks A and C...

Properties D 0.907 (25/25C), refr index 1.471 (20C), flash p 380F (193C) (OC), acid number 192, saponification number 194, unsaponifiable matter 2.5%, rosin acids 4.5%. Combustible. 

Properties Color, odor, and taste characteristic of source. D 0.84-0.89, refr index 1.473-1.478, optically active, unsaponifiable. Soluble in alcohol, vegetable oils, mineral oil orange and lemon oils are soluble in glacial acetic acid. Combustible. 

Heat of fusion (unhydrogenated) Refractive index (n ) 40°C) Unsaponifiable lipids... 

The Codex Alimentarius standard includes limits for acidity, volatile matter, insoluble impurities, peroxide value, colour, odour, taste, iron, copper, K27o, AK, permitted additives, contaminants (lead, arsenic, halogenated solvents), refractive index, saponification value, iodine value and unsaponifiable matter. Physical and chemical constants, such as iodine value and saponification value, are not found in the EU regulation. This is explained by the fact that more definite information is obtained by determining fatty acid composition, sterol and wax composition, trans fatty acid content, stigmastadiene, and so on. 

Golden yellow oil, difficult to bleach. Not affected by temporary heating to 160 . dg 0.916-0,921. nS 1.470-1.473 n J 1.465-1 468. Titer (solidification pt) 24-28. Saponification value 1S -189. Acid value 4 120 (see above comments on the lipase content of the bran). Iodine value 99-108. Thiocyanogen value 69-76. Hydroxyl value 5-14. Reichert-Meissl value <0.5. Polenskd value <0.5. Hehner value 95.3. Unsaponifiable matter 3-5%. The high refractive index is ascribed to the presence ol squalene. Also contains other antioxidants such as tocopherols. Miscible frith hexane and other fat solvents. 

Some chemical and physical characteristics that may vary with fatty acid modification include relative density, refractive index, saponification value, iodine value, and unsa-ponifiable matter. Appropriate methods for these procedures are available from ISO or AOCS. Refractive index can be conducted according to ISO 6320 2000 (ISO< 2005) or AOCS Cc 7-25 (02) (AOCS, 2005). Saponification value procedures are available as ISO 3657 2000 (ISO, 2005) or AOCS Cd 3-25 (02) (AOCS, 2005). Unsaponifiable matter can be conducted according to ISO 3596 2000 (ISO, 2005) or ISO 18609 2000 (ISO, 2005) or AOCS Ca 6b-53(01) (AOCS, 2005). 

Relative density Refractive index ( d ) Saponification value Iodine value Unsaponifiable matter (%) Oil content of dry kernel (%) Not available 1.4596 192,198" 58,51" 0.4 55-65... 

Cocoa fat and lipids In AOAC methodologies, the composition of fat and fatty acids in cocoa fat extracts are analyzed and characterized by physicochemical methods, including refractive index, melting point, saponification value and unsaponifi-able material, iodine number, Reichert-Meissl and Polenske values. 

The Committee maintains that it is almost impossible to obtain complete extraction with light petroleum in the case of some of the marine animal oils, and also that, although titration of the unsaponifiable matter gives an index of the free fatty acids present, to apply a correction involves the use of an arbitrary equivalent of such acidic material which, if acid soap is present, may be far from the correct figure. 

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