碾米工艺对米糠关键组分影响研究初探

为了提高米糠利用水平,开展米糠中关键组分的精准化分离研究至关重要。通过砂轮型号、碾磨转速和碾磨时间等参数对米糠中关键组分如蜡、粗脂肪和粗蛋白等组分含量影响变化进行研究,并通过扫描电镜、多元回归分析和相关性分析等手段进行表征和建模。结果表明:糙米中各组分电镜表征呈现层级交替分布的特点,从外到里依次为蜡酯层、纤维层、脂肪-蛋白层和淀粉层;米糠关键组分最高含量及其碾米工艺组合分别为:蜡0.67%(860 rpm,1.0 min)、粗脂肪18.37%(1060 rpm,1.0 min)、粗蛋白18.59%(960 rpm,2.0 min)、粗纤维16.85%(760 rpm,0.5 min)和淀粉41.12%(1060 rpm,2.5 min);砂轮型号对于蜡含量和粗纤维含量有极显著影响(P<0.01),而碾磨时间对米糠得率和淀粉含有极显著影响(P<0.01),碾磨转速除粗蛋白含量外均具有显著性的影响(P<0.05);粗纤维与其余变量整体上具有更高的极显著相关性,相关性系数分别为0.84(蜡)、0.83(粗脂肪)、0.73(粗蛋白)、–0.69(淀粉)和–0.42(米糠得率)。采用细碾和粗碾相结合的方式可以实现米糠关键组分的精准分离。

Preliminary study on the effect of milling technology on the key components of rice bran

To improve the utilization level of rice bran,it is very important to study the accurate separation of key components in rice bran.In this paper,the influence of grinding wheel type,grinding speed and grinding time on the contents of key components in rice bran,such as wax,crude fat and crude protein,was studied,and was characterized and modeled by scanning electron microscopy(SEM),multiple regression analysis and correlation analysis.The results showed that the key components in brown rice were distributed alternately from the outside to the inside,which were wax ester layer,fiber layer,fat-protein layer and starch layer.The highest content of the key components in rice bran and its milling technology combination were of wax 0.67%(860 rpm,1.0 min),crude fat 18.37%(1060 rpm,1.0 min),crude protein 18.59%(960 rpm,2.0 min),crude fiber 16.85%(760 rpm,0.5 min)and starch 41.12%(1060 rpm,2.5 min),respectively;Grinding wheel type had a very significant impact on wax content and crude fiber content(P<0.01),milling time has a very significant impact on rice bran yield and starch content(P<0.01),except for crude protein content,milling speed has a significant impact(P<0.05);Crude fiber had the highest significant correlation with other variables as a whole,correlation coefficient scores were of 0.84(wax),0.83(crude fat),0.73(crude protein),–0.69(starch)and–0.42(rice bran yield),respectively.The accurate separation of key components of rice bran can be realized by the combination of fine milling and coarse milling.