Nondestructive determination of soluble solids content of persimmons by using dielectric spectroscopy
Nondestructive determination of soluble solids content of persimmons by using dielectric spectroscopy
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介电谱无损测定柿子可溶性固形物含量
DOI：
10.1080/10942912.2017.1381114
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发表时间：
2018-01-01
影响因子：
2.9
通讯作者：
Guo, Wenchuan
中科院分区：
文献类型：
--
作者：
Liu, Dayang;Guo, Wenchuan
为探讨介电光谱法预测柿子采后贮藏期间可溶性固形物含量(SSC)的可行性，在20MHz~4500MHz范围内测量了105个水柿的介电常数谱和介电损耗因子谱。基于联合x-y距离算法，将柿子样本分为两组：校准组70个样本和预测组35个样本。通过无信息变量消除（UVE）、连续投影算法（SPA）和竞争性自适应重加权采样（CARS），分别从全介电谱（FS）中提取了174、14和24个变量作为特征变量。应用偏最小二乘法（PLS）和最小二乘支持向量机（LSSVM）利用FS和UVE、SPA和CARS提取的特征变量构建SSC预测模型。结果表明，在相同的输入变量下，LSSVM 模型比 PLS 模型具有更好的性能。 CARS-LSSVM具有最佳的SSC判定性能，预测集的相关系数和均方根误差分别为0.970和0.494度Brix。本研究表明介电谱技术结合特征变量选择方法有望用于测定柿子的SSC。
To explore the feasibility of dielectric spectroscopy in predicting soluble solids content (SSC) of persimmons during postharvest storage period, the dielectric constant spectra and dielectric loss factor spectra of 105 Shui' persimmons were measured from 20MHz to 4500MHz. Based on the joint x-y distances algorithm, the persimmon samples were divided into two sets: 70 samples in calibration set and 35 samples in prediction set. One hundred and seventy-four, 14, and 24 variables were extracted as characteristic variables from full dielectric spectra (FS) by uninformative variables elimination (UVE), successive projection algorithm (SPA), and competitive adaptive reweighted sampling (CARS), respectively. Partial least squares (PLS) and least squares support vector machine (LSSVM) were applied to build SSC prediction models using FS and characteristic variables extracted by UVE, SPA, and CARS. The results indicated that LSSVM models offered better performance than PLS models at same input variables. CARS-LSSVM had the best SSC determination performance with the correlation coefficient and root-mean-square error of prediction set of 0.970 and 0.494 degrees Brix. This study indicates that dielectric spectroscopy technique combined with characteristic variables selection methods is promising for determining SSC of persimmons.