微波技术在烟草游离态及蛋白质结合态氨基酸分析中的应用研究

Application research of microwave-assisted technology for analysis of free and protein amino acids in tobacco

研究了微波萃取烟草中游离氨基酸和微波水解烟草蛋白质的样品前处理方法,对微波萃取和微波水解条件进行了优化。微波萃取后的游离氨基酸及微波水解后的氨基酸总量采用氨基酸分析仪测定,蛋白质中的氨基酸用差减法计算。微波萃取氨基酸的最佳条件为:盐酸浓度0.05 mol·L-1,物料比1∶20,微波萃取温度50℃,微波萃取时间10 min,该条件下得到的游离氨基酸萃取率与超声30 min的结果基本一致;微波水解蛋白质的最佳条件为:盐酸浓度6 mol·L-1,物料比1∶100,水解温度140℃,水解时间60 min,与传统水解24 h的结果基本一致。用微波辅助法萃取烟草中的游离氨基酸及水解烟草蛋白质,样品前处理时间大大缩短,分析结果令人满意。

An efficient microwave-assisted extraction and hydrolysis method was developed to determine the free and protein amino acids in tobacco. The conditions in the microwave process were optimized. The samples were pretreated with microwave extraction and hydrolysis and determined by amino acid analyzer. The results showed that 10 min irradiation at 50℃ with 0. 05 mol.L-1 HCl led to comparable results in terms of total and individual amino acid recovery as the ultrasonic mehtod requiring at least 30 min. The digestion was performed with 6 mol.L-1 HCl（with 1%phenol）for 1h in a microwave at 140 ℃ and the results were in agreement with those obtained by traditional method（110 ℃,24 h）.