Obtenção de concentrado de tocoferois a partir do destilado da desodorização do oleo de soja




The deodorizer distilled, a refining by product of soybean oil, the DDOS, is a highly complex compounds mixture, incl uding the tocopherols. That is the reason it is largely used as a raw material to obtain tocopherols or vitamin E concentrates, as much as in chemist, cosmetic and food industries. The main objective of this present research work was the development of methods to obtain a tocopherol concentrate. Several techniques have been employed for tocopherol extraction as follow: isothermal crystallization with different solvents and their azeothropic mixtures, saponification with calcium hydroxide, saponification plus isothermal crystallization. The DDOS evaluated contained about 11% tocopherols, mainly y-tocopherol, being a suitable source of this compound. In the extractions by isothermal crystallization at -20Co with 20% DOOS in acetone, have given a tocopherol concentration factor close to theoretical value (1,35), whereas the removed solids rate was quite low (27,8%). Regarding the azeothropic mixture of solvents, ethyl-cetone, under the same condi tions, also, ethanol:methylshowed resul ts close to theoretical value, with concentration factor of 1,25 for and 37,7% removed solids. The crystallization method, but at -80Co with 10% of DOOS, including acetone, have shown a very high rate of removed solids (64,4%) and also the highest concentration factor (1,47). The same process, but employing hexane plus and DDOS at 15 and 20% also indicated a very high percentage of removed solids (above 70%), but a low concentration factor. In the use of saponification method the influence of Ca(OH)2 ; acetone and water solutions; percentage of DOOS and extraction temperature have been evaluated. The process using solvents with 85 to 92,5% of acetone at OCo resulted in highest saponification influence in tocopherol extraction. Also the saponification with a 15g/L Ca (OH)2 at OoC plus DOOS at 20 and 25% in acetone (90 and 95%) produced a concentration factor twice as much as the other methods. Among several concentrations of Ca (OH)2 evaluated the most efficient was 16g/L showing a concentration factor of 2,5. The temperature influence in saponification was higher at -20°C, 92,5% acetone plus 20% DDOS, resulting in a final product with 26,5% tocopherol. The method employing saponification with Ca(OH)2 (l%w/v) followed by crystallization at -20°C, 5% DDOS and acetone produced a high solids removing result (72%) and concentration factor (2,51), better than hexane and methanol. The liquid-liquid extraction method was carried out through hexane DDOS solution (25%w/v) plus ethanol solution at 50% with 1% of KOH, in the following preparation: hexane/ethanol at 1,00/1,93. Next step, isothermal crystallization at -27Co was of good efficiency in solids removing ( 68 , 4 ) but low concentration factor ( 1, 52) . The studies obtain have demonstrated that the most efficient method to tocopherol concentrate was saponification with Ca (OH) 2 (15g/L) of a 20% DOOS in a 92,5% acetone:water solution at -20Co, which carried out to a final concentrate of 26% tocopherol


extração (quimica) oleo de soja vitamina e

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