Authors

Abstract

Soluble solids content (SSC) is one of the most important quality attributes affecting the taste and maturity of fresh fruit. In this study, with the cerasus humilis fruit as the research object, a prediction model of soluble solid content (SSC) in cerasus humilis (CH) is established based on visible / near-infrared spectroscopy to explore a nondestructive testing method of the interior quality of CH. The visible / near-infrared spectral info (350-2500nm) of 160 CHs was collected to extract the reflection spectrum, establishing the linear model (PLSR) and non-linear model (LS-SVM) of CH’s spectral info and SSC. The prediction performance and stability of the model were justified using several statistical indicators namely correlation coefficient of the prediction set (Rp), the root mean square error of the prediction set (RMSEP), and the residual predictive deviation (RPD) index. Results showed that multiplicative scatter correction (MSC) was proved to be the best preprocessing method, UVE-CARS was the optimal method of dimension reduction, the quantities of characteristic wavelengths was 10 and the optimal model was UVE-CARS-PLSR, in which Rc is 0.8995, Rp is 0.8579, RMSEC is 0.8897, RMSEP is 0.9059, and RPD is 1.8766, indicating that the redundant data of the original spectrum can be reduced, the wavelength dimensions can be reduced, valid info can be retained and data processing can be simplified as UVE-CARS extracts characteristic wavelengths. Reference and theoretical basis are provided in this research for future research and development of portable detector and online sorting detection of CH internal quality.

Abstract in Chinese

可溶性固形物含量(SSC)是评价鲜果口感和成熟度的重要品质指标之一。本研究以欧李果实为研究对象，基于可见/近红外光谱技术结合化学计量学方法建立欧李果中SSC含量的预测模型，探究欧李果内部品质的快速无损伤检测方法。采集160个欧李果的可见/近红外光谱信息（350~2500nm），建立欧李果光谱信息和SSC的线性模型(偏最小二乘回归算法)和非线性模型(最小二乘支持向量机)预测模型，通过预测集相关系数(Rp)、预测集均方根误差(RMSEP)和剩余预测偏差(RPD)等指标来评价模型的预测性能及稳定性。结果表明，多元散射校正为最佳预处理方法，最佳降维方法为UVE-CARS，特征波长个数为10，最优模型为UVE-CARS-PLS，其中Rp为0.8579，RMSEP为0.9059，RPD 为1.8766。说明UVE-CARS提取特征波长可减少原始光谱的冗长数据，降低波长维数，保留有效信息，简化数据处理。本研究为欧李果内部品质后续便携式检测仪和在线分选检测研究提供了参考和理论基础。