(1.中国农业科学院农产品加工研究所 北京 100193;2.北京工商大学食品与健康学院 北京 100048)
(1.Institute of Food Science and Technology， Chinese Academy of Agricultural Sciences， Beijing， 100193;2.School of Food and Health， Beijing Technology and Business University， Beijing 100048)
采用顶空固相微萃取(SPME)结合气相-质谱联用仪(GC-MS)测定6种草莓香精中的风味化合物。从中选取一种草莓香精，研究调制乳加工及储藏过程对其挥发性成分的影响，并对比其在水中与牛乳中的变化。以均质前、后和灭菌(137 ℃，4 s)后为3个过程点取样进行SPME-GC-MS检测，并在室温储藏第0，15，43，98天和198天时，对样品进行检测。选取5号草莓香精中3个主要挥发性化合物丁酸乙酯、2-甲基丁酸乙酯及己酸乙酯，分别按其在草莓香精中所占比例单独加入牛乳中，研究其变化。结果表明，灭菌后丁酸乙酯、2-甲基丁酸乙酯及己酸乙酯含量较均质前分别下降28.92%，35.92%和29.91%。储藏第198天与第0天相比，牛乳及水中草莓香精部分挥发性化合物含量显著上升(P<0.05)。热处理及储藏时间对草莓香精中挥发性成分的影响较大。
The flavor compounds in six strawberry flavors were determined by headspace solid-phase microextraction (SPME) combined with gas-mass spectrometry (GC-MS)， and one strawberry flavor was selected to study its volatilization during the processing and storage of modified milk. The influence rules of sexual components were compared and analyzed when they were added to water and milk. Samples were taken at three process points before homogenization， after homogenization and after sterilization(137 ℃， 4 s) for SPME-GC-MS detection， and the samples stored at room temperature for days 0， 15， 43， 98 and 198 were tested. Three main volatile compounds， ethyl butyrate， ethyl 2-methylbutyrate and ethyl hexanoate in the No. 5 strawberry flavor， were selected and added to the milk according to their respective proportions in the strawberry flavor， and their individual changes were studied. The results showed that the contents of ethyl butyrate， ethyl 2-methyl butyrate and ethyl hexanoate decreased by 28.92%， 35.92% and 29.91%， respectively， after sterilization compared with those before homogenization. On the 198th day of storage， compared with the 0th day， the content of some volatile compounds in the strawberry flavor in milk and water increased significantly (P<0.05). The results of this study showed that heat treatment and storage time had a great influence on the volatile components in strawberry flavor.