基于近红外光谱的红提内部品质无损检测研究

Non-destructive Detection of the Internal Quality of Red Globe Grapes Based on Near Infrared Spectroscopy

红提的可溶性固形物含量(Solube Solids Content,SSC)、总酸(Total Acid,TA)、pH、硬度(Firmness Index,FI)和含水率(Moisture Content,MC)等内部品质指标直接影响着果实的口感及品质,同时也是水果成熟度的评判标准。为快速获得上述内部品质指标,且避免不必要的检测损耗,本文提出了一种新的红提无损检测模型。以生长期红提为研究对象,利用Antaris Ⅱ近红外光谱仪采集了360个样本的近红外光谱信息。对采集到的光谱信息分别用SNV等算法进行预处理并通过建模确定了最优预处理方法。然后通过降维算法提取光谱信息的特征波长,最后基于偏最小二乘回归算法(Partial Least Squares Regression,PLSR)分别建立了红提的SSC、TA、pH、FI和MC的检测模型。红提的SSC、TA的最优检测模型为SG-CARS-SPA-PLSR模型,pH的最优检测模型为MA-CARS-SPA-PLSR模型,FI和MC的最优检测模为SG-CARS-PLSR模型。所建立的红提SSC、TA、pH、FI和MC的最优PLSR模型的预测集的相关系数Rp分别为0.9787、0.9811、0.9870、0.9568、0.9329,残差预测偏差RPD分别为4.8637、4.9006、6.0939、3.4453、2.5825,表明以上模型具有较高的检测精度。本文所建的红提内部品质检测模型可为红提内部品质的检测提供可靠的方法。

The internal quality indicators such as soluble solids content(SSC), total acid(TA), pH, firmness index(FI) and moisture content(MC) of red globe grapes affect the taste and quality of the fruit directly. And they are also criterion for maturity. In order to obtain the internal quality indicators showed above quickly and avoid unnecessary inspection losses, a new non-destructive detection model for red globe grapes was proposed in this paper. The near-infrared spectral information of 360 samples was collected using the Antaris Ⅱ near-infrared spectrometer for red globe grapes in the growing period. The collected spectral information was pre-processed by algorithms such as SNV and then modelled to determine the optimal spectral pre-processing method. The characteristic wavelengths of the spectral information were extracted by dimensionality reduction algorithms. Finally, the detection models for SSC, TA, pH, FI and MC of red grapes were established respectively based on Partial Least Squares Regression(PLSR) algorithm. For SSC and TA the optimal detection model was SG-CARS-SPA-PLSR, for pH the optimal detection model was MA-CARS-SPA-PLSR, and for FI and MC the optimal detection model was SG-CARS-PLSR. The correlation coefficients(Rp) of the optimal PLSR models established of the prediction sets for red globe grape SSC, TA, pH, FI and MC were 0.9787, 0.9811, 0.9870, 0.9568 and0.9329 respectively, and the residual prediction deviations(RPD) were 4.8637, 4.9006, 6.0939, 3.4453 and 2.5825respectively, indicating that the above models had high detection accuracy. The models established in this paper would provide a reliable method for the detection of the internal quality of red globe grapes.ity of red globe grapes.