College of Engineering, Shenyang Agricultural University, Shenyang 110866, China.
College of Water Conservancy, Shenyang Agricultural University, Shenyang 110866, China.
Molecules. 2022 Jul 10;27(14):4421. doi: 10.3390/molecules27144421.
To explore the drying characteristics of soybean dregs and a nondestructive moisture content test method, in this study, soybean dregs were dried with hot air (80 °C), the moisture content was measured using the drying method, water status was analyzed using low-field nuclear magnetic resonance (LF-NMR) and the moisture content prediction models were built and validated. The results revealed that the moisture contents of the soybean dregs were 0.57 and 0.01 g/g(w.b.), respectively, after drying for 5 and 7 h. The effective moisture diffusivity increased with the decrease in moisture content; it ranged from 5.27 × 10 to 6.96 × 10 m·s. Soybean dregs contained bound water (), immobilized water () and free water ( and '). With the proceeding of drying, all of the relaxation peaks shifted left until a new peak (') appeared; then, the structure of soybean dregs changed, and the relaxation peaks reformed, and the peak shifted left again. The peak area may predict the moisture content of soybean dregs, and the gray values of images predict the moisture contents mainly composed of free water or immobilized water. The results may provide a reference for drying of soybean dregs and a new moisture detection method.
为了探究豆渣的干燥特性和一种无损水分含量测试方法，本研究使用热空气（80℃）对豆渣进行干燥，使用干燥法测量水分含量，利用低场核磁共振（LF-NMR）分析水分状态，并建立和验证水分含量预测模型。结果表明，豆渣干燥 5 和 7 h 后，水分含量分别为 0.57 和 0.01 g/g（湿基）。有效水分扩散系数随水分含量的降低而增加，范围为 5.27×10~6.96×10 m·s。豆渣中含有结合水（）、束缚水（）和自由水（和'）。随着干燥的进行，所有的弛豫峰向左移动，直到出现新的峰（'）；然后，豆渣的结构发生变化，弛豫峰重新形成，峰再次向左移动。峰面积可以预测豆渣的水分含量，图像的灰度值可以预测主要由自由水或束缚水组成的水分含量。该研究结果可为豆渣干燥和一种新的水分检测方法提供参考。
