不同压榨工艺下花生油风味成分的变化

该研究采用顶空固相微萃取-气相色谱-质谱联用仪（HS-SPME-GC-MS）及电子鼻对不同压榨工艺下花生油挥发性风味成分和脂肪酸组成进行分析。6种不同压榨工艺花生油中共检测到10类38种挥发性成分，其中包含19种风味成分。在热榨花生油中以呋喃类（63.43%~66.68%）、醛类（10.04%~5.47%）、酚类（8.83%~7.18%）为主要的挥发性成分，在冷榨花生油中以酯类（26.43%）、醛类（23.47%）、酸类（22.10%）为主要的挥发性成分。此外，热榨花生油检测出少部分吡嗪、吡啶、酮类关键风味成分，其在冷榨花生油中并没有检出。电子鼻结果基本与GC-MS一致，硫化物、芳香化合物、氮氧化合物和甲基类化合物对花生油整体风味贡献率较大，通过主成分分析和K-mean聚类分析结果显示6种花生油挥发性成分变化差异显著。6种花生油脂肪酸组成都以油酸、亚油酸、棕榈酸为主，含量可达到90%以上。然而通过对比不同温度下花生油脂肪酸组成发现随着压榨温度的升高，不饱和脂肪酸的氧化加速。综上，对比不同压榨工艺下花生油风味和营养成分的变化发现高温条件压榨下花生油的风味成分显著增加，花生油品质略有下降，利用电子鼻可快速区分不同压榨工艺花生油。

Changes in the Flavor Components of Peanut Oil Caused by Different Pressing Processes

In this study, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and electronic nose were used to analyze the volatile flavor components and fatty acid compositions of the peanut oils produced by different pressing processes. A total of 10 types of 38 volatile compounds were detected in the peanut oils from 6 different pressing processes, including 19 flavor components. Furans (63.43%~66.48%), aldehydes (10.04%~5.47%) and phenols (8.83%~7.18%) were the main volatile components in the hot-pressed peanut oil, whilst esters (26.43%), aldehydes (23.47%) and acids (22.10%) were the main volatile components in the cold-pressed peanut oil. In addition, small amounts of key flavor components such as pyrazins, pyridines and ketone were detected in the hot-pressed peanut oil, which were not detected in the cold-pressed peanut oil. The results obtained by the electronic nose were essentially in agreement with those of GC-MS, with the sulfides, aromatic compounds, nitrogen oxides and methyl compounds making greater contributions to the overall flavor of peanut oil. The results of principal component analysis and K-mean cluster analysis showed that there were significant differences in the volatile components of 6 peanut oils. Oleic acid, linoleic acid and palmitic acid were the main fatty acids in 6 kinds of peanut oil (whose contents were over 90%). However, the comparisons of the fatty acid compositions of the peanut oil produced at different temperatures revealed that the oxidation of unsaturated fatty acids accelerated with an increase of pressing temperature. In summary, the comparisons of the changes in the flavor and nutrient components of the peanut oils produced by different pressing processes revealed that the contents of the flavor components in peanut oil increased significantly under high-temperature pressing conditions, with its quality decreased slightly. Electronic nose can distinguish rapidly peanut oils produced by different pressing processes.