区间偏最小二乘法结合拉曼光谱测定猪肉皮下脂肪的碘值

发布时间：2018-10-05 20:45

【摘要】：碘值是评价脂肪酸品质的重要指标,为探究拉曼光谱技术结合化学计量学方法对完整脂肪样本中脂肪酸不饱和程度测定的可行性,以猪肉皮下脂肪为研究对象,利用实验室自主搭建的拉曼光谱检测系统,获取其300~2000cm-1波段的光谱,进而利用该光谱进行预处理方法的优化研究和碘值相关变量的优选研究,并以传统韦氏滴定法测定得到的碘值为参考值,采用偏最小二乘法建立了完整脂肪样本中碘值的校正模型。结果表明:8次多项式拟合基线校正为最优预处理方法;经区间偏最小二乘法筛选得到的优选变量为1106~1470cm-1;结合最优预处理方法和优选变量建立碘值预测模型,其预测集相关系数Rp和预测均方根误差(RMSEP)分别为0.9463和2.5391×10-2。研究结果证明,优选的拉曼光谱变量可用于完整脂肪中碘值的快速无损测定,为基于拉曼光谱的猪胴体脂肪酸不饱和程度的在线、快速、无损检测提供了理论依据。
[Abstract]:Iodine value is an important index to evaluate the quality of fatty acids. In order to explore the feasibility of determining the unsaturated degree of fatty acids in intact fat samples by Raman spectroscopy and chemometrics, the subcutaneous fat of pork was taken as the research object. The spectrum of 300~2000cm-1 band is obtained by using the Raman spectrum detection system which is built independently in the laboratory, and then the optimized pretreatment method and the optimal selection of iodine value related variables are studied by using the spectrum. The calibration model of iodine value in complete fat samples was established by partial least square method with the iodine value determined by traditional Wechsler titration method as the reference value. The results show that the fitting baseline of the 8 degree polynomial is the optimal pretreatment method, the optimal selection variable is 1106 ~ 1470 cm ~ (-1) selected by the interval partial least square method, and the iodine value prediction model is established by combining the optimal preprocessing method with the optimal selection variable. The correlation coefficient Rp and root mean square error (RMSEP) are 0.9463 and 2.5391 脳 10 ~ (-2), respectively. The results show that the selected Raman spectrum variables can be used for fast nondestructive determination of iodine value in whole fat, which provides a theoretical basis for on-line, fast and nondestructive detection of the unsaturated degree of fatty acid in pig carcass based on Raman spectrum.
【作者单位】：中国农业大学工学院;
【基金】：国家重点研发计划(2016YFD0401205)
【分类号】：O657.37;TS251.7

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