论文部分内容阅读
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。
Iodine value is an important index to evaluate the quality of fatty acids. To explore the feasibility of determining the degree of unsaturation of fatty acids in intact fat samples by Raman spectroscopy and chemometric method, subcutaneous fat of pork was taken as research object, Man spectrum detection system to obtain its 300 ~ 2000cm-1 band spectrum, and then use the spectrum optimization of pretreatment methods and iodine value-related variables of the optimal study, and the determination of iodine value by the traditional Webster titration as a reference Value, a correction model for the iodine value of intact fat samples was established using partial least squares. The results showed that: the 8-order polynomial fitting baseline correction was the optimal pretreatment method; the optimal variable selected by the interval partial least squares method was 1106-1470 cm-1; and the iodine value prediction model was established based on the optimal pretreatment method and the optimal variables, The correlation coefficient Rp and RMSEP of the prediction set are 0.9463 and 2.5391 × 10-2, respectively. The results show that the optimal Raman spectroscopy can be used for fast and nondestructive determination of iodine value in intact fat, which provides a theoretical basis for the on-line, rapid and non-destructive detection of the degree of unsaturation of pork carcass based on Raman spectroscopy.