不同加工方式对富硒大米硒损失、形态及体外生物利用度影响

Effects of different processing methods on selenium loss,form and bioavailability in vitro of selenium-enriched rice

为探究不同加工方式对富硒大米中硒的影响,以重庆市江津区高硒含量大米为实验原料,使用常用加工方式处理,并比较分析处理前后富硒大米硒含量、硒形态及硒生物利用度的差别。结果表明,挤压处理导致硒含量损失43.05%,常压蒸煮、高压蒸煮、微波处理不会对硒含量产生显著影响(P>0.05);4种加工方式均可降低大米中硒代蛋氨酸(selenomethinonine,SeMet)含量;亚硒酸盐经微波、高压蒸煮及挤压处理后完全损失;微波处理使甲基硒代半胱氨酸含量增加;体外模拟胃肠消化实验结果发现,常压蒸煮、高压蒸煮及微波处理后的样品胃肠消化总硒生物利用度分别为74.99%、67.93%、50.38%及40.08%,都显著高于未处理样品(P<0.05);富硒大米中SeMet的生物利用度在加工处理后显著提高(P<0.05),其中常压蒸煮后SeMet的生物利用度最大,达到47.49%。常压和高压蒸煮方式对富硒大米总硒含量及形态影响较小,有利于机体对硒的吸收利用,实验结果为富硒大米加工过程中硒的变化情况提供数据支撑,同时为富硒大米加工后机体对硒的消化吸收效果研究提供了理论参考。

In order to explore the effects of different processing methods on the loss of selenium,selenium forms and bioavailability of selenium-rich rice.The rice with high selenium content in Jiangjin district,Chongqing city was used as the experimental raw material with common rice processing methods.And after extrusion,the selenium content,selenium form and bioavailability of selenium-rich rice before and after processing were compared and analyzed.The results showed that extrusion treatment caused a loss of 43.05%of selenium,and atmospheric cooking,high-pressure cooking,and microwave treatment would not have a significant impact on the selenium content.All four processing methods reduced the selenomethinonine(SeMet)content in rice.Selenite[Se(IV)]was completely lost after microwave,high-pressure cooking and extrusion treatment.Microwave treatment will increase the content of methylselenocysteine(MeSeCys).The results of in vitro simulated gastrointestinal digestion experiments showed that the total selenium bioavailability of gastrointestinal digestion after normal pressure cooking,high pressure cooking and microwave treatment was significantly higher than that of untreated samples(P<0.05),which were 74.99%,67.93%,50.38%and 40.08%respectively.The bioavailability of SeMet in selenium-enriched rice was significantly improved after processing(P<0.05),and the bioavailability of SeMet was the largest after atmospheric cooking reaching 47.49%.Above experimental results showed that the normal pressure and high-pressure cooking methods had little effect on the total selenium content and form of selenium-rich rice,which was beneficial to the body's absorption and utilization of selenium.The result provides data for the changes in selenium during the processing of selenium-rich rice,and provides a theoretical reference for the digestion and absorption of selenium after the processing of selenium-rich rice.