Residual solvent or intrinsically formed during production: analysing volatile compounds in unrefined vegetable oils using headspace gas chromatography coupled with mass spectrometry

Vegetable oils are an essential part of a healthy and balanced diet and have major economic significance. The type of production, whether performed by extraction with solvents, or by mechanical techniques, significantly influences the quality of the oil and its potential field of use. Occasionally, volatile organic substances, which are considered indicative for an oil that has been produced by solvent extraction, are detected in unrefined vegetable oils. This can have a negative impact on high-quality oil mills and their reputation. The goal of the study was to analyse unrefined oils of different raw materials for such compounds. A previously developed and validated method using headspace gas chromatography coupled with a mass spectrometry was used for this task. Another aim was to determine the origin of any solvent residues in the vegetable oils and to find ways to avoid them. Complementary measurements by solid phase micro extraction gas chromatography were conducted to compare the results of the measurements to an orthogonal methodology. Multivariate data analysis was used to find correlations between the spectrum of substances in the oil and other parameters like the producer of the oil or the pattern of fatty acids.

植物油是健康均衡膳食的核心组成部分，同时具备重要的经济价值。植物油的生产工艺——无论是溶剂萃取法还是机械压榨工艺——均会对油品质量及其潜在应用领域产生显著影响。在未精炼植物油中，偶尔可检测到挥发性有机物质，这类物质可作为溶剂萃取法生产油品的特征标志物，而此类残留会对优质油脂加工厂的声誉造成负面影响。本研究旨在针对不同原料来源的未精炼植物油，开展上述特征化合物的检测分析，为此采用了此前开发并经过验证的顶空气相色谱-质谱联用法（Headspace Gas Chromatography-Mass Spectrometry）。此外，本研究的另一目标为明确植物油中溶剂残留的来源，并探索有效规避此类残留的技术路径；为将所得检测结果与正交方法进行比对，研究团队同时开展了固相微萃取气相色谱法（Solid Phase Micro Extraction-Gas Chromatography）的辅助测定。最终，研究人员采用多变量数据分析方法，探究了油品中物质谱与其他参数（如油脂生产商、脂肪酸组成模式）之间的相关性。