与哈姆林甜橙果实内在品质主要参数同步相关的特征光谱研究

基于光谱分析的甜橙内在品质检测技术近年得到较快发展，但目前采用的大多为单一品质指标的光谱分析，而甜橙果实品质往往取决于果实多项品质指标的共同作用。本研究的目的在于研究甜橙果实反射光谱与果实内在品质的相关性，筛选与哈姆林甜橙果实多个品质指标同步相关的特征光谱，为建立甜橙果实在内品质的实时检测技术提供依据。以哈姆林甜橙(Citrus sinensis (L) cv. Hamlin sweet orange)成熟果实为试材，逐个果实进行果实反射光谱和果实可溶性固形物(TSS)、柠檬酸、维生素C(Vc)含量和固酸比等在内品质主要参数的分析，对所获数据采用Excel，Spss Statg和View SpecPro软件进行统计与分析。结果表明，哈姆林甜橙果实TSS、固酸比和Vc均与波长988 nm近红外光反射光谱呈极显著或显著正相关，相关系数分别为0.387**，0.440**和0.309*，TSS和固酸比与该波长反射率的最佳拟合方程分别为y＝13.957x+5.405和y＝75.120x+37.256;可见光429 nm光谱二阶导数与TSS和Vc呈显著和极显著正相关，相关系数分别为0.350 72*和0.386 9**。波长944 nm近红外光谱倒数对数与固酸比呈显著正相关(r＝0.304*)。试验结果为柑桔果实内在品质主要参数的同步、快速无损检测奠定了基础。

Study on Synchronous Correlation between Fruit Characteristic Spectrum and the Parameter of Internal Quality for Hamlin Sweet Orange Fruit

The purpose of our study is to study the relationship between the reflective spectrum of fruit and the internal quality of the orange fruit and find the suitable mark spectrum that can synchronously measure the several fruit quality index at same time to lay a foundation for the development of a rapid and nondestructive field fruit quality analysis technique by analyzing the visible-near infrared spectrum. Mature Hamlin orange (Citrus sinensis(L)cv. Hamlin sweet orange) fruits were individually mensurated for their reflective spectrum by using FieldSpec-HH spectrometer and for their contents of total soluble solid (TSS), citric acid and vitamin C (Vc) by chemistry analysis. The experiment results showed that the fruit reflectivity values (x) at 988 nm was significantly correlated to both TSS (y)(r=0. 387~(**), y=13. 957x+5. 405), TSS/acid ratio(y)(r=0. 440~(**), y=75. 120x+37. 256), and Vc(r=0. 309~*). Both of TSS and Vc contends were positively correlated with the second derivatives of the reflec-tive spectrum at 943 nm, with correlation coefficients of 0. 339~* and 0. 355~(**). TSS/acid ratio was positively correlated only with the reciprocal log values of the reflective spectrum at 944 nm(r= 0. 304~*). The results in this study indicated that fruit quality indexes TSS, Vc and TSS/acid can be synchronously, rapidly and nondestructively field measured at the same time by the 988 or 429 nm reflective spectrum test and special regress equation operation.