红外光谱结合偏最小二乘法快速检测油茶籽油脂肪酸组成的模型建立与评价北大核心CSCD

为建立快速检测油茶籽油中脂肪酸组成的方法,利用傅里叶红外光谱仪扫描86个油茶籽油样品,红外光谱数据分别通过Savitzky-Golay平滑(SG)、多元散射校正(MSC)、标准正态变换(SNV)、一阶导数(FD)和二阶导数(SD)等5种方法进行降噪处理,然后以气相色谱测定的脂肪酸组成作为标准值,采用全波长偏最小二乘法(PLS)、区间偏最小二乘法(iPLS)和联合区间偏最小二乘法(siPLS)分别构建油茶籽油中主要脂肪酸(油酸、棕榈酸、亚油酸)的定量回归模型。结果表明:油酸、棕榈酸、亚油酸的红外光谱数据预处理分别以SG、SNV、SD较好;siPLS通过有效波段的选择可去掉更多的噪声,比PLS和iPLS建立的模型精确度高,油酸、棕榈酸、亚油酸的校正集和预测集的相关系数(R)分别为0.9479和0.8539、0.9008和0.9101、0.9793和0.9505。红外光谱结合siPLS更适用于油茶籽油脂肪酸组成的快速测定。

Establishment and evaluation of a model for rapid determination of fatty acid composition of oil-tea camellia seed oil by infrared spectroscopy

In order to establish a method for rapid determination of fatty acid composition in oil-tea camellia seed oil, 86 oil-tea camellia seed oil samples were scanned by Fourier transform infrared spectrometer, and the infrared spectrum data were denoised by Savitzky-Golay(SG) smoothing, multiple scattering correction (MSC), standard normal transformation (SNV), first derivative (FD) and second derivative (SD), respectively. Then the quantitative regression model of main fatty acids (oleic acid, palmitic acid and linoleic acid) in oil-tea camellia seed oil was established by full-wavelength partial least square (PLS), interval partial least square (iPLS) and synergy interval partial least square (siPLS), respectively with fatty acid composition determined by gas chromatography was as the standrad value. The results showed that SG, SNV and SD were the best pretreatment methods for infrared spectral data of oleic acid, palmitic acid and linoleic acid, respectively, and siPLS could remove more noise through the selection of effective bands, which was more accurate than the models established by PLS and iPLS. The correlation coefficients(R) of the correction set and prediction set of oleic acid, palmitic acid and linoleic acid were 0.947 9 and 0.853 9, 0.900 8 and 0.910 1, 0.979 3 and 0.950 5, respectively. Infrared spectroscopy combined with synergy interval partial least square method is more feasible for the rapid determination of the fatty acid composition of oil-tea camellia seed oil.