| Large amount of recyclable contents exist in cotton seed oil deodorizer distillate(CSODD),including fatty acids,tocopherols,phytosterols,squalene and glyceride etc.In this work,CSODD was recovered to obtain fatty acid sterol ester(FASE)and an environmental friendly synthesis process has been formed.The research of obtaining FASE from deodorizer distillate in this work provided necessary information for the industrial applications in the near future.Esterification reactions were carried out using Candida Rugosa Lipase(CRL)as catalyst,and the conversion of phytosterol was optimized using response surface methodology.The highest conversion(90.8±0.4%)was reached at 0.84 wt% enzyme load,1:25 solvent/CSODD mass ratio,and 44.2℃ after 12 h reaction.A kinetic model based on reaction rate equation was developed to describe the process of synthesizing FASE from CSODD.The kinetic parameters at different temperature were derived from experiments.The activation energy as well as the pre-exponential factor of the reaction was calculated according to Arrhenius equation.The effect of water adding quantity,adding time and adding method on the reduction of glyceride in CSODD was developed.Experimental results showed that simultaneous process of the hydrolization and the esterification came to a better result,and the mass ratio of CSODD/water was 1:2.The reduction of glyceride turned out to be 99.89% after 12 h reaction.Molecular distillation was applied to separate the reaction product,and the influence of temperature,pressure and flow rate on the separation was studied.The product in residue after three-stage molecular distillation mainly contained FASE,the purity of FASE was 94.26% and the recovery was 93.69%.Experimental results showed that the proposed process was a promising alternative to recycle sterol esters from vegetable oil deodorizer distillates in a mild,efficient and environmental friendly method. |
