微波处理对高粱理化性质及蛋白质结构特性的影响研究

为改善高粱蛋白质理化性质，采用微波技术对三种高粱进行处理，结合扫描电镜和傅里叶变换红外光谱仪等方法，测定微波处理对高粱理化性质及蛋白质结构特性影响。结果表明，微波处理对高粱蛋白质等理化性质具有显著影响。微波处理减小了高粱蛋白粒径，蛋白表面出现缝隙，但处理前后的红外光谱具有相似的结构特征，属于物理变性。微波处理显著提高了三种高粱的总蛋白质含量约0.6%（P<0.05），降低可溶性蛋白质含量0.97~1.87 mg/g，且显著降低体外消化率15.55%~43.63%（P<0.05）。此外，微波处理后，高粱粉的持水力显著提高0.32~0.40 g/g（P<0.05），持油力显著降低0.08~0.18 g/g（P<0.05），表面菌落总数和霉菌数分别显著降低了98.75%和98.94%（P<0.05），色度变暗。本文可为高粱食品的开发及应用提供一定的参考。

Effects of Microwave Treatment on Physicochemical Properties and Protein Structure Characteristics of Sorghum

In order to improve the physicochemical properties of sorghum protein, three kinds of sorghum were treated with microwave technology, and the changes of physicochemical properties and protein structural properties of sorghums before and after microwave treatment were measured by scanning electron microscopy and Fourier transform infrared spectrometer. The results showed that microwave treatment had significant effects on the physicochemical and protein structural properties of sorghum. Microwave treatment reduced the grain size of sorghum protein and caused cracks on the protein surface. However, the infrared spectra of sorghum protein before and after treatment had the similar structural characteristics and belonged to physical denaturation. Microwave treatment significantly increased the total protein contents of the three sorghums species by 0.6% (P<0.05), decreased soluble protein contents by 0.97~1.87 mg/g, and significantly decreased in vitro digestibility by 15.55%~43.63% (P<0.05). In addition, after microwave treatment, the water holding capacity of sorghum powder was significantly increased by 0.32~0.40 g/g (P<0.05), the oil holding capacity was significantly decreased by 0.08~0.18 g/g (P<0.05), the total number of bacterial colonies and the number of molds on the surface were significantly decreased by 98.75% and 98.94% (P<0.05), respectively. And the color darkened. The present research can present reference for the development and application of sorghum food.