CS245562B1 - Method of sterols and tocopherols insulation from deodorant condensate - Google Patents

Abstract

Process for isolating sterols and tocopherols deodorant condensate based on. \ t hydrolysis of deodorant condensate with hydroxide calcium at the boiling point of the reaction mixtures in an inert atmosphere, extraction of unsaponifiable matter with ethanol or acetone and processing the extract into sterol a tocopherol in an inert atmosphere.

Description

The invention relates to a process for the isolation of sterols and tocopherols from deodorizing condensate, obtained in considerable quantities in the fat industry in the purification of vegetable oils and the production of edible fats. The deodorizing condensate contains an economically interesting amount of a mixture of sterols whose chemical structure depends on the vegetable origin of the processed oil and where beta-sitosterol and campesterol predominate. These sterols have utility in the pharmaceutical industry as a raw material for the production of pharmacologically active steroid compounds, since microbial degradation of sterols can yield steroid grafts in high yields of C-19 and C-22, which can be converted to desired substances by further chemical or chemico-microbiological processes.

In addition, deodorant condensate always contains a mixture of natural tocopherols, which are used in the therapy of various diseases, in gerontology and as antioxidants in the food industry.

The isolation of sterols and tocopherols from deodorizing condensate is of considerable interest to workers of various industries worldwide. The process of isolation of these substances consists of several basic operations: hydrolytic release of ester-bound condensate components, isolation of unsaponifiable fraction and separation of sterols and tocopherols from unsaponifiable fraction. Hydrolysis of the deodorizing condensate is performed with alkali hydroxides in lower aliphatic alcohols (Brown: British Patent 1,030,792; Miller and Berry: US Patent 2,759,655; Smith: US Patent 3,335,154; Brown and Meng: Franc, Patent 1,315,565) enzymatically (Kuwayama and Usui: Japan Kokai 74 00 489), or mineral acids, followed by esterification by hydrolysis of the released fatty acids and fractionation thereof from unsaponifiable fraction (Brown and Smith: British Patent 1,030,514; Brown and Smith: Franc, Patent 1 360 759;

U.S. Patent 2,516,834; Brown and Rawlings: U.S. Patent 2,843,610; Brokaw: Brit. U.S. Patent 774,855; Mattikow and Perlman: U.S. Patent 2,704,764). A review article on the treatment of deodorizing condensates was published by Niewiadomski (Nahrung 19, 525, 1975).

The actual extraction of the unsaponifiable matter and its fractionation depends on the type of hydrolysis of the deodorizing condensate and is usually carried out by liquid-liquid extraction (Brown and Smith: British Patent 1,030,514; Brown: British Patent 1,030,792; Brown: Franc, Patent 1,360 Brown and Smith: Franc, Patent 1,360,759; Becker: Franc, Patent 2,182,299), molecular fractionation fractionation (BOH: US Patent 2,516,834), or solid-liquid extraction after hydrolysis of the deodorizing condensate with alkaline hydroxide. by converting the resulting alkaline soaps into calcium soaps by the action of calcium chloride and silicate and extracting with acetone (Brown and Meng: Franc, patent 1 315 565). The main problem of all types of deodorizing condensate treatment to isolate sterols and tocopherols is the volatility of tocopherols in an alkaline environment in the presence of air oxygen; however, sterols also undergo autooxidation (Niewiadomski: Nahrung 22, 525, 197-5). This is the reason why the yields of sterols and tocopherols are not satisfactory, respectively. why it is necessary to carry out the processing of deodorizing condensate by a complicated process.

The above-mentioned disadvantages are eliminated by a process for the isolation of sterols and tocopherols from the deodorizing condensate according to the invention, characterized in that the deodorizing condensate is hydrolyzed by calcium hydroxide in an inert atmosphere, optionally in the presence of aliphatic C 1 -C 3 alkanols, boiling. the resulting calcium soaps are extracted with an aliphatic ketone having 3 to 5 carbon atoms or an aliphatic alkanol having 1 to 3 carbon atoms and treating the extract under an inert atmosphere to obtain a sterol and tocopherol fraction. The process according to the invention is further characterized in that the hydrolysis is carried out under a nitrogen atmosphere and the treatment of the extract under a carbon dioxide atmosphere.

Commercially available calcium hydrate, which is as effective as the alkali hydroxide under the conditions set forth in the Examples, can be successfully used to effectively deodorize condensate. It has been found that the unsaponifiable fraction obtained after hydrolysis of the deodorizing condensate with alkaline hydroxide (even in an inert atmosphere) always contains a lower content of tocopherols than is the case after hydrolysis with calcium hydroxide. It can be assumed that the alkali hydroxides form phenolates, which secondary to processing promote the oxidation of tocopherols more strongly than a weaker base such as calcium hydroxide.

A further change from previously published processes is the use of a protective nitrogen atmosphere in hydrolysis. The hydrolysis itself is carried out either without a solvent, i.e. by reacting the deodorizing condensate with moist calcium hydroxide at elevated temperature or in a lower aliphatic alcohol, preferably ethanol, the hydrolysis temperature being determined by the boiling point of the reaction mixture.

The isolation of sterols and tocopherols from the unsaponifiable fraction is carried out by known methods. However, we have found experimentally that the isolation of these substances in an inert atmosphere increases the yield of the process and the quality of the products as opposed to the prior art processes. The inert atmosphere can advantageously be realized by adding solid carbon dioxide to the mixture at each stage of the extraction and separation process. For the isolation of unsaponifiable matter and the separation of sterols and tocopherols, two alternative processes have been developed, differing in the hydrolysis conditions and providing reproducible and comparable results.

In the first embodiment, the deodorizing condensate is mixed with wet calcium hydroxide to a slurry and heated under a nitrogen atmosphere to a temperature of about 95 ° C for 8 to 10 hours. After cooling, the solid hydrolysis product is crushed and extracted with acetone, the acetone extract is concentrated, cooled and the crystallized mixture of phytosterols is filtered off with suction. Repeated freeze-drying of sterols, aspiration and thickening of mother liquors leads to an enriched tocopherol fraction. In a second treatment, the deodorizing condensate, calcium hydroxide and ethanol are heated to boiling under stirring under a nitrogen atmosphere for 8-10 hours, then stirring is discontinued, the hydrolyzed condensate is repeatedly extracted with hot ethanol, the combined extracts are crystallized, the mother liquors are concentrated to dryness. The residue was dissolved in acetone and cooled to give an additional portion of sterols. The tocopherol-enriched fraction is then recovered from the mother liquors.

The following examples illustrate the invention but do not limit it.

Example 1

200 g of de / deodorizing condensate W / 77 Milo Olomouc is mixed by mechanical kneading with 200 g of moist lime hydrate and the mixture is heated in a water bath at 95 ° C under nitrogen atmosphere for 10 hours. The resulting product is extracted repeatedly at room temperature with acetone in a total amount of about 1.4 liters of acetone, whereby the initially semi-solid mass becomes a solid powder. The combined acetone extracts were mixed with 10 g of solid carbon dioxide and the solvent was distilled off to give 20 g of residue. The residue is stirred with 650 ml of acetone, the solid is filtered off, washed with 150 ml of acetone, 5 g of solid carbon dioxide are added to the filtrate and the solvent is distilled off to obtain 48 g of a residue. The filtered material is extracted with 200 ml of acetol, the suspension is filtered and the filtrate is freed from the solvent by distillation to give 20 g of a residue. The first residue (20 g) was dissolved in 150 ml of acetone. After cooling to 0 ° C, 1.9 g of a crystalline substance is obtained.

In the mother liquors, the remaining two evaporators (48 g and 20 g) were added, 5 g of solid carbon dioxide were added to the solution, and the product was crystallized to give 3.2 g of crystalline solid. After cooling the mother liquors to -10 ° C, 18.5 g of crystalline material are obtained. By concentrating the remaining mother liquors and cooling them to -10 ° C, 1.5 g of product are obtained.

The total yield is 25.1 g of a crude mixture of phytosterols. The filtrate was saturated with carbon dioxide and evaporated to dryness. The liquid residue (30 g) was allowed to stand in a carbon dioxide atmosphere. It is divided into two layers, the upper (27 g) being a tocopherol content. The crude mixture of phytosterols (25.1 g) was recrystallized from 160 ml of acetone. 13.5 g of purified product are obtained, and the mother liquors yield 2.3 g of crystalline material. A total of 15.8 g of a mixture of phytosterols containing predominantly beta-sitosterol is obtained.

Example 2

A mixture of 200 g of deodorizing condensate, 250 ml of ethanol and 200 g of lime hydrate was added

The X was stirred under reflux for 8 hours under a nitrogen atmosphere. After stirring and cooling to 70 [deg.] C., after the bottom layer has settled, the ethanol layer is withdrawn into a collecting vessel and 1 g of solid carbon dioxide is added thereto. 300 ml of ethanol are added to the remaining bottom layer and extraction is carried out under reflux under nitrogen for 15 minutes. This procedure is repeated 3 more times.

The combined ethanol extracts were allowed to crystallize. 10.5 g of X. fraction were obtained, from mother liquors 21.4 g of II. and finally 2.8 g of III. share. A total of 34.7 g of crude sterol fraction was obtained, which after crystallization from acetone gave 20.6 g of sterols. Treatment of the combined filtrates gave a tocopherol fraction (25 g). In all operations, solid carbon dioxide as in Example 1 was used.

Claims (3)

Process for the isolation of sterols and tocopherols from deodorizing condensate, characterized in that the deodorizing condensate is hydrolysed in an inert atmosphere with calcium hydroxide, optionally in the presence of aliphatic alkanols having 1 to 3 carbon atoms, while boiling the reaction mixture. a C 3 -C 5 ketone or a C 1 -C 3 aliphatic alkanol, and treating the extract under an inert atmosphere to obtain a sterol and tocopherol pod. 2. The process of claim 1, wherein the hydrolysis is carried out under a nitrogen atmosphere. 3. The process of claim 1 wherein the extract is treated in a carbon dioxide atmosphere.