应用近红外漫反射光谱法的猕猴桃品质无损检测

Non-Destructive Qualification of Kiwi-Fruit by Near Infrared Diffuse Reflection Spectrometry

应用近红外漫反射光谱技术和化学计量学,研究成熟期猕猴桃内部品质与其近红外漫反射光谱之间的关系。在室温(24±2)℃下,采集猕猴桃赤道区域不同测试部位在4 000~10 000 cm^(-1)范围内的光谱数据,用基于平滑处理、归一化及基线校正的组合式处理方法对原始光谱进行预处理;另应用偏最小二乘(PLS)法、主成分回归法和多元线性回归法等方法分别建立猕猴桃硬度、可溶性固形物含量(SSC)的校正模型。结果表明:采用组合预处理方法和PLS法建立的校正模型精度最高;硬度校正集相关系数R_c、均方根误差RMSEC和预测集相关系数R_p、均方根误差RMSEP达到了0.976 5,0.548 3,0.943 2,0.612 7;SSC校正集相关系数R_c、均方根误差RMSEC和预测集相关系数R_p、均方根误差RMSEP达到了0.916 6,0.539 6,0.901 2,0.619 0;试验结果验证了本法的可行性。

The relationship between quality of kiwi-fruit in maturity and its near infrared diffuse reflection spectra was studied by near infrared diffuse reflection spectrometry and chemometrics. At room temperature of （24±2） ℃ , the NIR spectra in the range of 4 000 to 10 000 cm^-1, from different sites in the equatorial region of each kiwi-fruit were collected and pre-treated by the combined processing of smoothing, normalization and baseline correction. On the other hand, calibration models for hardness and soluble solid contents （SSC） of the kiwi-fruit were established by applying the methods of partial least squares （PLS）, principal component regression （PCR） and multiple linear regression （MLR）. As shown by the results, the accuracy of the calibration model established by the combined processing of pretreatment and PLS method was the highest. Values of Rc, Rp, RMSEC and RMSEP for hardness testing attained to 0. 976 5, 0. 946 2, 0. 548 3 and 0. 612 7, respectively. And values of Re, Rp, RMSEC and RMSEP for SSC testing were up to 0. 916 6, 0. 901 2, 0. 539 6 and 0. 619 0. The feasibility of the method was thus verified.