中国激光, 2017, 44 (11): 1111001, 网络出版: 2017-11-17
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 下载: 786次
Measurement of Iodine Value of Pork′s Subcutaneous Adipose Tissue by Interval Partial Least Square and Raman Spectroscopy
光谱学 碘值 拉曼光谱 区间偏最小二乘法 猪皮下脂肪 spectroscopy iodine value Raman spectroscopy interval partial least square pork′s subcutaneous adipose tissue
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300~2000 cm-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1106~1470 cm-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 for evaluating quality of the fatty acid. In order to research the feasibility of measuring unsaturation degree of fatty acid of intact fat sample by using the Raman spectroscopy and chemometrics method, we use pork′s subcutaneous adipose tissue as research object to obtain the Raman spectra in the wavelength range of 300-2000 cm-1 with utilization of self-constructed Raman spectroscopy detection system. Both of preprocessing methods and iodine value related variables are optimized. Using the iodine value obtained by traditional Wijs titration as reference, we build the calibration model of iodine value in fat sample by partial least square algorithm. The experimental results show that the optimal preprocessing method is the 8th order polynomial fitting method. The optimal combination band, 1106-1470 cm-1, is obtained by interval partial least square method. Based on the optimized pretreatment method and selected variables, the iodine value prediction model is developed, the prediction set coefficient (Rp) and root mean square error of prediction (RMSEP) of the model are 0.9463 and 2.5391×10-2, respectively. The study results indicate that optimized variable can be used in rapid and nondestructive measurement of iodine value of intact pork fat, which provides theoretical basis for on-line, rapid, and nondestructive measurement of unsaturation degree of fatty acid in pig carcasses based on Raman spectroscopy.
赵芳, 彭彦昆. 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[J]. 中国激光, 2017, 44(11): 1111001. Zhao Fang, Peng Yankun. Measurement of Iodine Value of Pork′s Subcutaneous Adipose Tissue by Interval Partial Least Square and Raman Spectroscopy[J]. Chinese Journal of Lasers, 2017, 44(11): 1111001.