红外光谱法测定植物油中游离脂肪酸质量分数的方法研究  

Study on Determination of Free Fatty Acid in Vegetable Oil by Infrared Spectroscopy

作　　者：肖新生 周倓婍 高冉 蒋黎艳 陈小明 Xiao Xinsheng;Zhou Tanqi;Gao Ran;Jiang Liyan;Chen Xiaoming(College of Chemistry and Biological Engineering,Hunan University of Science and Engineering,Yongzhou 425199)

机构地区：[1]湖南科技学院化学与生物工程学院,永州425199

出　　处：《中国粮油学报》2025年第2期186-191,共6页Journal of the Chinese Cereals and Oils Association

基　　金：湖南省自然科学基金项目(2024JJ7192);永州市指导性科技计划项目(2023YZ022)。

摘　　要：游离脂肪酸的质量分数是评价植物油品质的的重要指标,红外光谱法具有快速准确、灵敏度高等特点,通过分析红外光谱图中基团的特征峰与游离脂肪酸质量分数之间的数学关系,建立了红外光谱法测定植物油中游离脂肪酸质量分数的方法。结果表明:不同种类的植物油的红外光谱谱图基本相同;以菜籽油为代表的植物油游离脂肪酸质量分数在20%以上时,脂肪酸质量分数与吸光度值在1708.7 cm^(-1)处的线性相关性较好,y=0.3323 x+0.017,R^(2)=0.9994;当游离脂肪酸在20%以下时,脂肪酸质量分数与吸光度值在1714 cm^(-1)处C=O振动吸收峰的吸光度存在良好的线性关系,y=0.2449 x+0.0243,R^(2)=0.9969;样品取样量对红外吸收光谱吸光度影响不大,经过方法重复性和实际样品检测验证,红外光谱法能够准确测定植物油的游离脂肪酸的质量分数。The content of free fatty acids is an important indicator for evaluating the quality of vegetable oil.Infrared spectroscopy has the characteristics of being fast and accurate,and having a high sensitivity.By analysis of the mathematical relationship between the characteristic peaks of functional groups in the infrared spectrum and the content of free fatty acids,a method for determining the content of free fatty acids in vegetable oil using infrared spectroscopy was established.The results indicated that the infrared spectra of different types of vegetable oils were basically the same;when the free fatty acid content of vegetable oil represented by rapeseed oil was above 20%,there was a good linear correlation between the fatty acid content and the absorbance value at 1708.7 cm^(-1),y=0.3323 x+0.017,R^(2)=0.9994;when the free fatty acids were below 20%,there was a good linear relationship between the fatty acid content and the absorbance of the C=O vibration absorption peak at 1714 cm^(-1),y=0.2449 x+0.0243,R^(2)=0.9969;the sample size had little effect on the infrared absorption spectrum absorbance.After method repeatability and actual sample detection verification,the infrared spectroscopy method could accurately determine the content of free fatty acids in vegetable oil.

关 键 词：红外光谱法 植物油 游离脂肪酸 含量测定 

分 类 号：TS21[轻工技术与工程—粮食、油脂及植物蛋白工程]