Sterols isolated from commercial

The quaHty, ie, level of impurities, of the fats and oils used in the manufacture of soap is important in the production of commercial products. Fats and oils are isolated from various animal and vegetable sources and contain different intrinsic impurities. These impurities may include hydrolysis products of the triglyceride, eg, fatty acid and mono/diglycerides proteinaceous materials and particulate dirt, eg, bone meal and various vitamins, pigments, phosphatides, and sterols, ie, cholesterol and tocopherol as weU as less descript odor and color bodies. These impurities affect the physical properties such as odor and color of the fats and oils and can cause additional degradation of the fats and oils upon storage. For commercial soaps, it is desirable to keep these impurities at the absolute minimum for both storage stabiHty and finished product quaHty considerations. 

Full identification of isolated sterols from commercially consumable fats performed by GC/MS, and quantitative estimation of cholesterol content by capillary GC with flame ionization detection. 

Sterol standards were either purchsaed from commercial sources or were isolated from C. maxima seeds as previously described >2. 

Phytosterol dealkylation can be harnessed in insects to release a fluoroacetate equivalent from a 29-fluorinated sterol. Moreover, the fluorocitrate which then results from the "lethal synthesis" can be isolated and chemically characterized. hope that the range of insects susceptible to the 29-fluorophytosterols and more commercially viable analogs will be further explored. Furthermore, we urge wider scrutiny of insect biochemical pathways in search of possible targets for suicide substrates or latent toxin release. 

Provitamin D2. Ergosterol is isolated exclusively from plant sources. The commercial product is ca 90—100% pure and often contains up to 5 wt % of 5,6-dihydroergosterol. Usually, the isolation of provitamin D2 from natural sources iavolves the isolation of the total sterol content, followed by the separation of the provitamin from the other sterols. The isolation of the sterol fraction iavolves extraction of the total fat component, its saponification, and then reextraction of the unsaponifiable portion with an ether. The sterols are ia the unsaponiftable portion. Another method is the saponification of the total material, followed by isolation of the nonsap onifiable fraction. Separation of the sterols from the unsap onifiable fraction is done by crystallization from a suitable solvent, eg, acetone or alcohol. Ethylene dichloride, alone or mixed with methanol, has been used commercially for recrystallization. In the case of yeasts, it is particularly difficult to remove the ergosterol by simple extraction, thereby obtainiag only ca 25% recovery. Industrially, therefore, the ergosterol is obtaiaed by preliminary digestion with hot alkaUes or with amiaes (28—33). Variations of the isolation procedure have been developed. Eor example, after saponification, the fatty acids may be precipitated as calcium salts, which tend to absorb the sterols. The latter are then recovered from the dried precipitate by solvent extraction. 

Some examples of successful commercial selective extractions are the removal of caffeine from coffee or the solubilization of nicotine from tobacco both accomplished on moist matrices to aid in selectively solubilizing the alkaloid component. Selective extraction has been demonstrated for the segregation of essential oil from other lipid components in natural extracts derived from fruits and for the separation of aroma components in cocoa butter from the base oil. Other enrichment SEE schemes that have been reported include the fractionation of carotenoid from leaf protein concentrate [25], the fortification of sterols in seed oils [26], and the isolation of lecithin (phospholipid-containing fraction) from triglycerides [27]. 

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