Safety Evaluation On Rice Bran Oil Processing

Rice bran is the most valuable byproduct during rice processing.In general,the yield of rice bran is about 7%,and the oil content of rice bran is 18%~20%.The fatty acid composition of rice oil is reasonable.The content of linoleic acid and oleic acid is 39%and 41%respectively.The ratio of linoleic acid to oleic acid is about 1:1.1.Rice bran oil also contains abundant natural bioactive substances such as oryzanol,vitamin E,phytosterol and so on.The purpose of this research is to optimize and improve the rice bran oil(RBO)refining technology to maximally remove the harmful ingredients from RBO and retain the nutrients in RBO,then healthy and high quality RBO would be obtained.The removal of benzopyrene(BaP),3-chloro-1,2-propanediol(3-MCPD),phthalate(PAEs)and trans fatty acid(TFA)during the RBO production were studied.The nutrients such as oryzanol,sterols and VE were reserved as much as possible.The main research contents and conclusions were listed as follows:(1)Response surface method(RSM)was used to optimize the optimal process conditions for physical deacidification of BaP in RBO:It was found that the deacidification process had a significant effect on the removal of BaP from RBO.The optimum conditions were as follows:the steam deacidification temperature 240 ~oC,deacidification time 2 h and deacidification pressure 130-260 Pa,the removal rate of BaP was 97.5%;the retain rates of oryzanol,sterol and VE were 97%,92%and 87%,respectively.(2)The bleaching process had a significant effect on the removal of 3-MCPD and PAEs from RBO.The optimum conditions were as follows:carclazyte 5%,acticarbon 0.5%,bleaching temperature 105 ~oC,bleaching time 30 min,the loss rate of 3-MCPD was 87.2%,PAEs were not detected.The retain rates of oryzanol,sterols and VE were 95%,81%and 72%,respectively.(3)The deodorization process had a significant effect on the removal of TFA from RBO.The optimum conditions were as follows:the deodorization temperature200-230°C,the deodorization time 30min,the relative content of TFA in RBO was0.65%.The retain rates of oryzanol,sterols and V_E were 93%,82%and 64%,respectively.