籼粳杂交稻变温-缓苏干燥工艺优化及蛋白结构研究

Optimization of Variable Temperature-Tempering Drying Process andStudy on Proteins Structure of Indica Japonica Hybrid Rice

为提升稻谷干燥品质,本实验以籼粳杂交稻为对象,通过爆腰率、整精米率、能耗、干燥时间进行评价,结合单因素、响应面分析优化干燥工艺;同时采用差示扫描量热仪、傅里叶红外光谱、荧光光谱等技术手段,探究了变温-缓苏干燥对籼粳杂交稻蛋白结构及热特性的影响。结果显示:变温-缓苏干燥(变温区间30~60℃)在升温温度5℃、风速1 m/s、缓苏比0.6条件下可使稻谷始终保持在玻璃态,干燥后的爆腰率和整精米率比恒温组(60℃)分别降低79.89%和提高39.54%。在此条件下稻谷蛋白质发生极性减弱、分子间聚集现象,提高了蛋白质热稳定性,α-螺旋含量由16.21%提升至17.64%;扫描电镜结果表明,变温-缓苏干燥未对蛋白质表面结构造成明显影响。实验探究并验证了杂交稻谷变温-缓苏干燥机制,为杂交稻谷高品质干燥研究提供了理论和实践参考。

In order to improve the drying quality of rice,Indica and japonica hybrid rice were taken as the object and evaluated by waist burst rate,head rice rate,energy consumption and drying time in this experiment.Single factor and response surface analysis were combined to optimize the drying process.The effects of variable temperature-tempering drying on proteins structure and thermal properties of indica and japonica hybrid rice were investigated by differential scanning calorimetry.Fourier infrared spectroscopy and fluorescence spectroscopy.The results showed variable temperature-tempering drying(temperature range 30~60℃)that under the conditions of temperature rise 5℃,wind speed 1 m/s and tempering ratio 0.6,the rice could be kept in the glassy state,and the waistband burst rate and head rice rate after drying were 79.89%lower and 39.54%higher than those in the constant temperature group(60℃),respectively.Under these conditions,the polarity of rice proteins decreased and intermolecular aggregation occured,which improved the thermal stability of rice proteins,and theα-helix content increased from 16.21%to 17.64%.Scanning electron microscope results showed that the surface structure of protein was not significantly affected by variable temperature-tempering drying.The experiment explored and verified the drying mechanism of hybrid rice with variable temperature-tempering drying,which would provide a theoretical and practical reference for the research of high quality drying of hybrid rice.