近红外光谱法快速测定鲜木薯中淀粉含量

Rapid Determination of Starch in Fresh Cassava by Near-Infrared Spectrometry

提出了用于现场快速测定鲜木薯中淀粉含量的近红外光谱法。取不同品种的鲜木薯样品90个,按国家标准方法(化学分析法)测得其淀粉含量。用近红外光谱法对此90个样品所制作的柱状样块的横截面进行光谱扫描,得其光谱图谱,并转换得到其一阶导数图。用CAUNIFT软件QPLS分析模块建立数学模型。结果表明:验证样品中淀粉的化学法测定值与近红外模型的预测值之间呈线性关系。用5份未知样品对所建模型进行外部验证,预测值与化学法测定值之间的绝对误差在2%以内,相对误差均小于5%。

A NIRS method for use in field or rapid analysis of fresh cassava for its starch content was proposed.Ninety samples of various species were taken and their contents of starch were determined by the chemical method given in GB-standard.NIR spectra of these samples in shape of cyclindrical cubes were obtained by scanning through their corss section,and transformed into their 1st derivative graphs.Mathematical model for NIRS was established by using the QPLS pathern cube of the CAUNIFT software.It was shown that linear correlationship was obtained between the values of starch contents found by the chemical method and the predicted values obtained by the math.model.Accuracy and feasibility of the math.model were checked further by analyzing 5unknown samples,and as shown by the results,absolute errors of within 2%and relative crrors of less than 5% were found between the values of starch contents(w%)found by chemical method and the predicted values obtained from the NIRS math.model.