Abstract: The effects of the five extraction methods, including enzymatic hydrolysis, dilute alkali hydrolysis, organic solvent extraction, ultrasonic-assisted organic solvent extraction, and water-boiling extraction on the quality of turtle oil were studied. The turtle fat was chosen as raw material, and the turtle oils extracted by different methods were compared in terms of physicochemical characteristics, sensory properties, fatty acid composition, and volatile compounds based on gas chromatography (GC) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). As a result, the performance of turtle oils obtained with the five methods showed significant difference (P value < 0.05, n=3). Among them, the extraction yield of ultrasound-assisted solvent method was the higest(78.51%), in which acid value (0.97 mg KOH·g^-1) and peroxide value (2.16 m Eq·kg^-1) were better than those from other methods. Furthermore, it was also rich in the health beneficial fatty acids including oleic acid, EPA, and DHA. The relative contents of the key characteristic flavor compounds, such as nonanal, hexanal, 2-nonanone, 2-undecone and 1-penten-3-ol, were lower, which endowed the turtle oil with light fishy taste and translucent color. The results indicated that the quality of turtle oil extracted by the ultrasonic-assisted solvent was superior to the other four extraction methods and could provide a theoretical basis for industrial processing of turtle oil in the future.

Key words: turtle oil, extraction method, fatty acids composition, volatile compound, physicochemical characteristics

摘要： 为探究酶解法、淡碱水解法、溶剂法、超声辅助溶剂法及蒸煮法这5种提取方法对甲鱼油品质的作用效果,以甲鱼脂肪为原料,采用气相色谱仪(GC)和顶空固相微萃取-气质联用仪(HS-SPME-GC-MS)对甲鱼油中脂肪酸组成及挥发性成分变化进行测定分析,并结合感官评价及理化指标分析。结果表明,5种提取方法对甲鱼油的感官与理化特性、脂肪酸组成及挥发性成分存在显著性差异(P<0.05),其中,超声辅助溶剂法的甲鱼油提取率最高,达78.51%,该方法提取的甲鱼油酸价(0.97 mg KOH·g^-1)、过氧化值(2.16 m Eq·kg^-1)均优于其他方法,并含有丰富的油酸、EPA和DHA。此外,超声辅助溶剂法的甲鱼油壬醛、己醛、2-壬酮、2-十一酮及1-戊烯-3-醇主体特征风味化合物的相对含量均较低,鱼腥味较淡,色泽透亮。综上表明,超声辅助溶剂法提取的甲鱼油品质优于其他提取方法。本研究可为今后优化甲鱼油提取方法提供理论依据。

关键词: 甲鱼油, 提取方法, 脂肪酸组成, 挥发性成分, 理化指标