近红外光谱法结合化学计量学测定油茶籽油中脂肪酸组成.pdfVIP

※分析检测 食品科学 2011, Vol. 32, No. 18 205 张菊华，朱向荣，尚雪波，帅 鸣 (湖南省农业科学院，湖南省食品测试分析中心，湖南 长沙 410125) 选择 97 个标称纯油茶籽油样品经过皂化、甲酯化后，先经气相色谱分析得到脂肪酸组成相对含量，然后 利用透反射模式采集所有样品的近红外光谱，采用偏最小二乘法(partial least squares analysis ，PLS)建立油茶籽油 的饱和脂肪酸(C16:0 ＋C 18:0) 、油酸(C 18:1)和亚油酸(C 18:2)相对含量的校正模型，并将模型用于预测，并对光谱预处 理方法进行优化。结果表明：C16:0 ＋C18:0 、C18:1 和 C18:2 的交叉验证均方根误差(root mean square error in cross-vali- dation of prediction ，REMSECV)分别为 0.143 、0.448 、0.392 ，预测均方根误差值(root-mean-square error value ， RMSEP)分别为 0.180 、0.598 和 0.269 ，上述3 种成分预测集相关系数(R p 2 ) 依次分别为 0.996 、0.999 和 0.999 。近 红外光谱法可作为一种快速、无损和准确的方法用于测定油茶籽油的脂肪酸组成，从而鉴别纯油茶籽油的真伪。 油茶籽油；近红外光谱(NIRS) ；化学计量学；脂肪酸组成；相对含量 Analysis of Fatty Acid Profile of Camellia Oil by Near-infrared Spectroscopy and Chemometrics ZHANG Ju-hua ，ZHU Xiang-rong ，SHANG Xue-bo，SHUAI Ming (Hunan Food Test and Analysis Centre, Hunan Academy of Agricultural Sciences, Changsha 410125, China) Abstract：In the present work, after being saponified and methyl esterified, the fatty acid composition of 97 camellia oil samples was analyzed by gas chromatography. Meanwhile, the near-infrared spectra of all samples were acquired in the transreflection mode. Calibration models for the relative contents of saturated fatty acids (C16:0 + C 18:0), oleic acid (C18:1) and linoleic acid (C18:2) were established by partial least-squares regression method were applied. Additionally, the pretreatment of spectra was optimized. The results showed that the root mean square errors of cross-validation (RMSECV) for C16:0 + C18:0, C18:1 and C18:2 were 0.180, 0.598 and 0.269, respectively. The root-mean-square errors of prediction (RMSEP) for C18:0, C18:1 and C18:2 were