Saponification value, oils

Sample size calculations, A-88 to 90 SANS, definition, 12-1 to 4 Saponification value, oils and fats, 7-9 to 13 Satellites of the Planets, 14-4 to 5 Saturn, orbital data and dimensions, 14-2 to 3 Scalar product, A-68 to 74 Scandium see also Elements... 

Fat or oil Solidification point, °C Specific gravity (15°C/15°C) Refractive index Acid value Saponification value Iodine value... 

Free Fatty Acid and Saponification Value. High concentrations of free fatty acid are undesirable in cmde triglyceride oils because they... 

The American Society for Testing and Materials (ASTM) and the American Oil Chemists Society (AOCS) provide standard methods for determining properties that are important in characterization of dimer acids. Characterization of dimer acids for acid and saponification values, unsaponiftables, and specific gravity are done by AOCS standard methods ... 

It is soluble in about 5 volumes of 70 per cent, alcohol. This ester has the character of being saponified much more slowly than most other esters, so that in any determination in which it is involved it is necessary to saponify the sample for two hours before it is safe to consider the reaction complete. This fact also assists in determining whether terpinyl acetate is present as an adulterant in natural essential oils, for if the saponification value as determined by thirty minutes saponification is materially lower than that as determined by a two hours saponification, it may be fairly safely inferred that terpinyl acetate or some similar ester is present. 

Strictly speaking the amount of free acids present in an essential oil should be determined, and the acid value deducted from the saponification value, the difference being the ester value. 

Terpinyl acetate in the absence of esters of high molecular weight, or ethyl esters of the fatty acids of coconut oil, is indicated by a difference to be observed in the apparent ester value by different times of saponification. This ester is far more resistant to the action of caustic alkali than is linalyl acetate, and requires two hours at least for complete saponification. Hence, if the oil shows a difference in the saponification value in thirty minutes and in two hours, which amounts to more than from 1 to 2, terpinyl acetate is almost certainly present. The following table shows the effect of this partial-saponrfication on the two esters and on adulterated oils —... 

The author has recommended the examination of the last 10 per cent, left on evaporation of the oil on a water-bath, since the heavy artificial esters accumulate in this fraction. The refractive index of this 10 per cent, should not be below 1 5090, and the saponification value should not exceed 190. The following figures (see p. 317) represent nine samples of adulterated oil, all sold as genuine bergamot oil. 

B = Saponification value of the original oil after acetylation (not of saponified oil). 

Discussion. For oils and fats, which are esters of long-chain fatty acids, the saponification value (or number) is defined as the number of milligrams of potassium hydroxide which will neutralise the free fatty acids obtained from the hydrolysis of 1 g of the oil or fat. This means that the saponification number is inversely proportional to the relative molecular masses of the fatty acids obtained from the esters. A typical reaction from the hydrolysis of a glyceride is ... 

The assay of fixed oils provides a special case of ester hydrolysis since they are triesters of glycerol. The saponification value for a fixed oil is the number of mg of KOH equivalent to 1 g of oil. A high value means rancidity, a low value possible adulteration with mineral oil. Almost all edible oils have a saponification value between 188 and 196. Hydrolysis of the fixed oil is carried out with ethanolic KOH. 

Calculate the saponification value of a sample of castor oil from the following data ... 

American Oil Chemists Society. 1993c. AOCS Official Method Cd 3-25. Saponification Value. Champaign, 111. 

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. 

Saponification Value of Fats and Oils (Cd 3-25) determines the number of milligrams of (alcoholic) potassium hydroxide necessary to saponify a 1 -g sample of a fat or oil. Schaal Test (Schaal Oven Method) an accelerated test for determining the oxidative stability of a fat or a fat-containing food product. Results are reported as the time elapsed until a rancid odor is detected. This is not an AOCS method see American Association of Cereal Chemists Method Manual. Modifications, using OSI apparatus, have been reported. 

Saponification Value after Acetylation Proceed as directed under Total Alcohols, Appendix VI, using about 2.5 g of acetylated oil, accurately weighed. Calculate the saponification value by the formula... 

Arsenic, Free Fatty Acids, Iodine Number, Lead, Mercury, Peroxide Value, Saponification Value, and Unsaponifiiable Matter Proceed as directed in the monograph for Menhaden Oil, Hydrogenated. 

Saponification Weigh accurately from 2 to 2.5 g each of the acetylated oil and of the original, untreated sample into separate 250-mL Erlenmeyer flasks. Add to each flask 25.0 mL of 0.5 N alcoholic potassium hydroxide, and continue as directed in the Procedure under Saponification Value, in this Appendix, beginning with Connect an air condenser.. .. Record the saponification value of the untreated sample as S, and that of the acetylized oil as S, then calculate the acetyl value of the sample by the formula... 

Saponification Value Determine as directed for Saponification Value under Essential Oils and Flavors, Appendix VI, using 1.5 g accurately weighed. 

Ester Determination, 817 Ester Determination (High-Boiling Solvent), 817 Ester Value, 817 Saponification Value, 817 Estragole, 484, 619 Estragon Oil, 407 Ethanal, 450 Ethanol, 136, 849 Ether Extracts, 771 Ethone, 484, 619, (S3)72 p-Ethoxychrysoidin Monohydrochloride, 860... 

---