Phytosterols fractionation

The concentration of fats and related substances in molasses is low analytical values depend on the extracting solvent.126 These tenaciously retained materials can be removed by fractionation of blackstrap on fuller s earth clay.70 Chromatography on a calcium silicate of the fat fraction of Cuban molasses led to the isolation of melissyl alcohol, a phytosterol fraction, chlorophyll a and a fat fraction containing a glyceride of linoleic acid.70 Stigmasterol and syringic acid are reported as ether-extractable constituents of molasses.127... 

Fermentation of a mixture of soy sterols, sitosterol, stigmasterol and traces of related compounds with Microbacteria sp. produces androstenedione (1-6). Relatively recent patents describe the production of the steroid from phytoserols from various crude vegetable oils, bypassing the need for prior isolation of the phytosterol fraction. 

Plant lipids contain 0.15-0.9% sterols, with sitosterol as the main component (Table 3.52). In order to identify blends of fats (oils), the data on the predominant steroids are usually expressed as a quotient. For example, the ratio of stigmas-terol/campesterol is determined in order to detect adulteration of cocoa butter. As seen from Table 3.53, this ratio is significantly lower in a number of cocoa butter substitutes than in pure cocoa butter. The phytosterol fraction (e. g. sito- and campesterol) has to be determined in order to detect the presence of plant fats in animal fats. 

In the initial black Hquor concentration, saponified fatty and resin acid salts separate as tall oil soaps (see Tall oil). These soaps can be skimmed from the aqueous spent Hquor, acidified, and refined to give a cmde tall oil composed of resin acids, chiefly abietic and neoabietic fatty acids, chiefly oleic and Hnoleic and an unsaponifiable fraction made of phytosterols, alcohols, and hydrocarbons. Tall oil is fractionated primarily into fatty acids (see... 

Noguchi, S. Fujioka and A. Sakurai. Identification of teasterone and phytosterols in the lipid fraction from seeds of Cannabis sativa L. Nihon Yukagakkaishi 1997 46(12) 1499-1504. 

Doepke, W., and U. Hess. Obtaining phytosterol mixtures from oil fraction... 

Some of the tests involved relatively simple colour reactions such as the Baudouin reaction for sesame oil, and the Halphen test for cottonseed oil. In both cases a compound characteristic to an oil is used to determine the presence of the oil. Here again the test detected a component that today would be detected and quantified by gas chromatography (GC) or high performance liquid chromatography (HPLC). It was even possible to determine the presence of cholesterol or phytosterols, although, after separation, the identification as to which type was present depended on microscopic examination and fractional... 

Extraction of free phytosterols and steryl conjugates In principle, sterols are extracted with common organic solvents like hexane, heptane, methanol, and chloroform, but the more polar conjugates (SFs, SGs, and ASGs) require more polar extraction solvents to be quantitatively extracted from plant sample materials. Therefore, if only selected class(s) of steryl conjugates with similar polarity are analyzed, one solvent extraction can be sufficient. However, for a total lipid extraction for a later fractionation to the individual classes of phytosterol conjugates, one must utilize combinations of extraction solvents to ensure maximum recovery. 

STEROLS Phytosterols are mostly associated with unrefined vegetable oils and exist as derivatives of phenolic acids (e.g., ferulic acid). Several studies are available on antioxidant activity of sterols and their derivatives from sources such as corn fiber, oats, and rice. These compounds can be obtained from the unsa-ponifiable fraction that is removed during vegetable oil refining. Triterpene alcohols and hydrocarbons (131), or sterols (Figure 20) from oats (132, 133), rice (134, 135),... 

Commercial com oil has been recognized as having the highest levels of unsaponifiables (1.3-2.3%) of all commercial vegetable oils (6). The three most abundant chemical components in the unsaponifiable fraction of corn oil are phytosterols, tocopherols, and squalene. 

Walnuts contain about 65% lipids, however, considerable differences exist among varieties (range 52-70%, w/w) (1,40). Walnuts also contain 15.8% protein, 13.7% carbohydrate, 4.1% water, and 1.8% ash (w/w) (1). The fatty acid composition of walnut oil is unique compared with other tree nut oils for two reasons walnut oil contains predominantly linoleic acid (49-63%) and a considerable amount of ot-linolenic acid (8-15.5%). Other fatty acids present include oleic acid (13.8-26.1%), palmitic acid (6.7-8.7%), and stearic acid (1.4—2.5%) (Table 5) (40). The tocopherol content of walnut oil varies among different cultivars and extraction procedures and ranges between 268 mg/kg and 436 mg/kg. The predominant tocol isomer is y-tocopherol (>90%), followed by a-tocopherol (6%), and then (3- and 8-tocopherols (41). Nonpolar lipids have been shown to constitute 96.9% of total lipids in walnut oil, whereas polar lipids account for 3.1%. The polar lipid fraction consisted of 73.4% sphingolipids (ceramides and galactosylcera-mides) and 26.6% phospholipids (predominantly phosphatidylethanolamine) (42). Walnut oil contains approximately 1.8g/kg phytosterols (1), primarily p-sitosterol (85%), followed by A-5-avenasterol (7.3%), campesterol (4.6%), and, finally, cholesterol (1.1%) (42). 

Unsaponifiable Components Wheat germ oil is quite rich in unsaponi-fiable compounds, in particular phytosterols and tocopherols (Table 7). Small quantities of triterpenols, n-alkanols, carotenoids, and hydrocarbons are also present in the unsaponifiable fraction of the oil. Tocopherols and n-alkanols are commercially the most important unsaponifiable components in WGO. 

S.3.3. Sterols Phytosterols constitute a major fraction of the WGO unsaponi-fiables (about 35%) (Table 7). According to Itoh et al. (38), WGO contains a... 

Animal fats, such as milkfat, tallow, and fish oils, are characterized by the exclusive presence of cholesterol, whereas the sterol fraction in vegetable oils consist of a wide group of compounds also known as phytosterols. 

Supercritical CO2 column fractionation of soybean (57, 86, 88, 89) and rice bran oil (57) deodorizer distillates has been investigated to enrich their sterol and tocopherol contents. Brunner et al. (89) reported that the FFA were enriched in the top (in the extract), whereas the monoacylglycerols, tocopherols, and diacylglycerols were enriched in the bottom (in the raffinate) fraction during the fractionation of soybean oil deodorizer distillate. Saure and Brunner (88) achieved a tocopherol concentration of more than 70% (w/w) using continuous column fractionation of soybean deodorizer distillate where squalene was almost completely found in the top product, whereas sterols and tocopherols were enriched in the bottom product. King and Dunford (57) developed a two-step column fractionation scheme (13.6 MPa and 27.2 MPa at 313 K) for the enrichment of phytosterols from soybean and rice bran oil deodorizer distillates such that the FFA were removed in the first step and sterols were enriched in the oil fraction in the second step. 

Squalene and phytosterols are components present in the unsaponifiable lipid fraction of foods (as tocopherols). Squalene is an intermediary in cholesterol biosynthesis, and 33.9-58.4 mg/100 g of it was found in the lipid fraction of quinoa (Jahaniaval et al., 2000 Ryan et ah, 2007) squalene is the biochemical precursor of the whole family of steroids, and besides their effective antioxidant activity, tocotrienols have other important functions, in particular in maintaining a healthy cardiovascular system and a possible role in protection against cancer (Nesaretnam, 2008). Squalene is used as a bactericide and as an intermediate in many pharmaceuticals, organic coloring materials, rubber chemicals, and surface-active agents (Ahamed et ah, 1998). 

In order to understand the growth retardation mechanism of S-uniconazole, the shoots of Pisum sativum L. treated with S- and R-uniconazoles were analyzed in terms of the levels of the endogenous GAs, BRs, and phytosterols. Only referring to BRs, it is of interest to examine whether uniconazoles modify the biosynthesis of BRs. BRs contained in the shoots of P. sativum L. were extracted, purified, and analyzed by the GC/MS. GC/MS analysis of the active fraction led to the identification of CS m/z (rel. int.) 512 (M+, 54%), 155 (100%). GC/SIM quantitation using an internal standard (d6-CS) revealed that the content of CS in the control plants was 0.9 ng/g fir. wt. and, after treatment with S- and / -uniconazoles, reduced to 54% and 34% of the controls, respectively. The result suggests that the altered metabolism of BRs is likely to be involved in the action mechanism of S-uniconazole. 

It is a relatively recent observation that Colchicum species contain numerous chemical constituents of diverse chemical properties. Recognition of this fact has led to more efficient methods of isolation. In addition to neutral, phenolic, and basic alkaloids, 0. autumnale contains fatlike substances which are removed by a preliminary ligroin extraction of the pulverized, dry material. From such an extraction of the flowers of C. autumnale, Santavy and Herout (293) have isolated a paraffin, Ca7-28H5g 58, m.p. 58-60° an alcohol, CaaH450H, m.p. 66-67° and a phytosterol, m.p. 139-140°. Benzoic, salicylic, and 2-hydroxy-6-methoxybenzoic acids may be separated from the alkaloid mixture by virtue of their solubility in ether and aqueous base (294). The alkaloids themselves may be separated into neutral, phenolic, or basic fractions by standard extraction techniques. Pure alkaloids may be obtained from each fraction by fractional crystallization and chromatography on... 

Sterols are crystalline alcohols present in oils, either in the free form or esterified with fatty acids. In CNO they amount to about 1000 mg/kg (ppm) and make up about 20% of the unsaponifiable fraction. Those present in the major oils do not seem to have any strong effect on their behaviour, but they do have important nutritional effects. Cholesterol, for example, which occurs overwhelmingly in animal fats, elevates serum cholesterol, and recently it has been found that phytosterols reduce it. This has led to the appearance of phytosterol-enriched margarines on the market. 

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