食用油品质的检测技术进展

Detection Technique Reviews on Edible Oil Contaminated with Illegal Cooking Oil

食用植物油的质量与安全问题在国内已经长期存在,缺乏有效的检测手段是该现象得以普遍存在的重要原因。本文介绍了劣质食用油的理化指标,包括水分含量、比重、折光率、皂化值、酸值、羰基值、过氧化值、碘值重金属、脂肪酸相对不饱和度、胆固醇、残留检测、氧化产物检测等,分析了现有的常用检测技术的优缺点,包括薄层色谱技术、光谱法、水分含量法、快速检测法、色谱法、电导率法、低磁场核磁共振鉴定法、真菌霉素法和基因鉴定法。这些检测方法缺乏广泛的适用性,或特征指标专一性不强,或检测灵敏度不高,或检测准确性不高,仅能在一定范围内适用特定类型的劣质食用油的检测判定。文章提出了现代质谱技术因能够方便快捷地提供被分析样品的大量结构信息,灵敏度高、检测限低,是检测食用油品质的重要技术,而便携式质谱仪的产生将在食用油脂的快速检测中发挥作用。

In recent years, the quality of edible oils has attracted wide attention because of food safety issues. One of the important reasons is the lack of effective detection techniques to detect illegal cooking oil. In this paper, the physical and chemical characteristics for quality assessment of edible oils are introduced, including water content, specific gravity, refractive index, saponification value, acid value, carbonyl value, peroxide value, iodine value, heavy metals, relative unsaturation values of fatty acids, cholesterol content, residue determination and oxidation product determination. The routine analytical techniques for detecting illegal cooking oil in edible oils are thin layer chromatography, spectrometry, water content determination, rapid detection method, chromatography, nuclear magnetic resonance, conductivity method, fungimyein method and gene identification method. However, there are some disadvantages to these techniques, such as poor specificity, low sensitivity and inaccuracy, which were applied to limited kinds of illegal cooking oil identification. Mass spectrometry is an important technique for the detection of illegal cooking oil, not only for the large number of structure information of samples it supplied but also for the high sensitivity and low detection limit itself. The portable mass spectrometer will also play a role and show the advantages when monitoring edible oil quality in the field.