水果坚实度的近红外光谱检测分析试验研究

应用傅里叶漫反射近红外光谱技术探讨了水果坚实度无损检测的方法.利用偏最小二乘法建立了坚实度与漫反射光谱的无损检测数学模型,同时对不同光谱预处理方法和不同建模波段范围对模型的预测性能进行了对比分析.结果表明:利用傅里叶变换光谱仪采集的原始光谱的平滑预处理对结果并没有太大影响;原始光谱在800～2 500 nm范围的模型得到了最好的预测结果:校正集样本的相关系数r为0.869,校正均方根误差RMSEC为3.88 N;预测集样本的相关系数r为0.840,预测均方根误差RMSEP为4.26 N.通过本研究得出:应用近红外漫反射光谱检测水果坚实度是可行的,为今后快速无损评价水果成熟度提供了理论依据.

Detection of Pear Firmness Using Near Infrared Diffuse Reflectance Spectroscopy

The objective of the present research was to study the potential of NIR diffuse reflectance spectroscopy as a way for nondestructive measurement of the firmness of "Xueqing" pear.NIR spectral data were collected in the spectral region between 800 nm and 2 630 nm,but only the data between 800 nm and 2 500 nm were used for the analysis.Spectral data smoothing of different gaps using Savitsky-Goaly method was discussed both qualitatively and quantitatively.The results showed that the smoothing of NIR original spectra had little influence on spectral data analysis.Statistical models were developed using partial least square method.Models for three kinds of mathematical treatments of spectra(original,first derivative and second derivative) were established in three spectral regions: 800-2 500 nm,800-1 890 nm and 832-872 nm.The original spectra showed(better) results than the first derivative spectra and second derivative in all the three(spectral)(regions.) And for the three spectral regions,the full wavelength range of 800-2 500 nm offered the best result.The PLS model of original spectra in the range of 800-2 500 nm gave best predictions of pear firmness,with correlation coefficient(r) of 0.869 and root mean square errors of calibration(RMSEC) of 3.88 N for the calibration sample set and with correlation coefficient(r) of 0.840 and root mean square error of prediction(RMSEP) of 4.26 N for the validation sample set.The results of the study show that NIR diffuse reflectance spectroscopy can be used to predict the firmness of "Xueqing" pear.