近红外光谱法测定DDGS中粗蛋白含量的试验研究

Experimental study on the determination of crude protein content in DDGS by near infrared spectroscopy

试验建立DDGS粗蛋白含量测定的近红外光谱分析定标模型。采用化学分析法测定72个DDGS样品中的粗蛋白含量,利用FOSS InfraXact型近红外光谱分析仪采集样品光谱,光谱经2,4,4,1导数和标准正常化+散射处理(SNV+Detrend),用改进最小二乘法(MPLS)回归,获得了较好的定标模型,校正决定系数(RSQ)、交叉验证决定系数(1-VR)、校正标准误差(SEC)、交叉验证标准误差(SECV)分别为0.982 5、0.932 8、0.266 2、0.389 5。利用30个验证集的DDGS样品进行外部检验,预测值与真实值之间差异不显著(P>0.05)。结果表明,定标模型的预测性能较好,可以替代化学分析法快速测定DDGS中的粗蛋白含量。

The aim of this study was to establish a NIRS calibration model for determination of crude protein content in DDGS.The crude protein contents in 72 samples of DDGS were analyzed by the standard chemical analysis method.The near infrared spectra of the samples were collected by FOSS InfraXact NIR spectrometer and pretreated by standard normal variant＋detrend（SNV＋Detrend） and 2,4,4,1 derivate.The multiple correlation coefficients（RSQ）,1-variance ratio（1-VR）,standard error of the calibration（SEC） and standard error of cross validation（SECV） of the calibration model established by MPLS were 0.982 5、0.932 8,0.266 2 and 0.389 5 respectively.30 DDGS samples in the validation set were used for external inspection.There was no significant difference between the true value and the prediction value（P0.05）.The results indicated that NIRS was comparable to chemical methods in accuracy and was reliable in the rapid determination of crude protein content in DDGS.