Liu Yang, Chai Zhenlin, Haixia Yu
Zhejiang Academy of Forestry (Zhejiang Provincial Key Laboratory of Biological and Chemical Utilization of Forest Resources), 399 Liuhe Road, Xihu District, Hangzhou, Zhejiang, 310023, China.
Heliyon. 2023 Jul 21;9(8):e18532. doi: 10.1016/j.heliyon.2023.e18532. eCollection 2023 Aug.
Edible vegetable oils are produced either by mechanical pressing or extraction. Although pressing retains the inherent flavor and nutritional value of the oil, the oil yield is low and the process expensive. Extraction methods have high oil yields, low processing costs, and economic benefits; however, No. 6 solvent, which may pose potential risks to human health, is commonly used in the extraction and cleaning process. Differentiating extracted oil containing these solvents from pressed oil, for quality control, based on visual appearance is difficult. Hence, in this study, an identification method using the characteristic components of solvent No. 6 under optimized headspace Gas chromatography-mass spectrometry (GC-MS) conditions was established. It also provided a reference for quality control of industrial production by estimating the amount of solvent present in the oil. Results showed that, in addition to five main components (2-methylpentane, 3-methylpentane, and -hexane, Methylcyclopentane, Cyclohexane), accounting for 97% of the solvent, No. 6 solvent also contains 16 types of organic substances, such as olefins, aromatic hydrocarbons, and polycyclic aromatic hydrocarbons. Under optimized headspace GC-MS conditions (headspace sampler equilibrium temperature = 150 °C), the No. 6 solvent exhibits high linearity over a concentration range of 0.05-1 mg/kg with a correlation coefficient of 0.999 and a detection limit of 0.01 mg/kg. Pressed and extracted oils can be determined as follows: If three or fewer main components of the No. 6 solvent are detected, and the total content of No. 6 solvent is less than 0.5 mg/kg, it is a pressed oil; if four or more main components of No. 6 solvent are detected, or the total content of No. 6 solvent is ≥0.5 mg/kg, it is confirmed as an extracted oil.
食用植物油可通过机械压榨或萃取两种方式生产。虽然压榨能保留油的固有风味和营养价值，但出油率低且成本高。萃取方法出油率高、加工成本低且经济效益好；然而，在萃取和精炼过程中通常使用的6号溶剂可能对人体健康构成潜在风险。基于外观区分含有这些溶剂的萃取油和压榨油以进行质量控制很困难。因此，本研究建立了一种在优化的顶空气相色谱-质谱联用（GC-MS）条件下利用6号溶剂特征成分的鉴定方法。它还通过估算油中溶剂的含量为工业生产的质量控制提供了参考。结果表明，6号溶剂除了含有占溶剂97%的五种主要成分（2-甲基戊烷、3-甲基戊烷、正己烷、甲基环戊烷、环己烷）外，还含有16种有机物质，如烯烃、芳烃和多环芳烃。在优化的顶空GC-MS条件（顶空进样器平衡温度 = 150°C）下，6号溶剂在0.05 - 1 mg/kg的浓度范围内具有高线性，相关系数为0.999，检测限为0.01 mg/kg。压榨油和萃取油可按以下方法判定：如果检测到的6号溶剂主要成分少于或等于三种，且6号溶剂总含量小于0.5 mg/kg，则为压榨油；如果检测到的6号溶剂主要成分有四种或更多，或者6号溶剂总含量≥0.5 mg/kg，则确认为萃取油。
