气相色谱串联质谱法测定加工工艺对毛豆硒蛋氨酸含量的影响

Effects of Processing and Storage Conditions on Selenomethionine Content in Edamame Determined by Gas Chromatography-Mass Spectrometry

采用气相色谱串联质谱(GC-MS/MS)方法,研究硒氨基酸衍生物的一级质谱以及二级碰撞离子裂解规律,建立硒蛋氨酸的GC-MS/MS测定方法,并以此为基础研究在加工和贮藏过程中毛豆中硒蛋氨酸的含量变化。结果显示:在4℃条件下冷藏4周,以硒蛋氨酸计的硒的损失约为13%;在常温保存过程中,脱水毛豆的硒蛋氨酸降解率最小,而毛豆汁的硒蛋氨酸降解率却显著升高,说明产品的形态对于硒蛋氨酸的影响是非常重要的;毛豆烫漂过程中硒蛋氨酸的损失较小,烫漂210s硒蛋氨酸的保存率仍然在85%以上,毛豆脱水工艺中冷冻干燥处理对硒蛋氨酸的保存率最高,其次是真空干燥和热风干燥,硒蛋氨酸的保存率均可达80%以上,而喷雾干燥因接触空气面积较大,造成有机硒的损失较大,会造成硒蛋氨酸的损失率达到30%～40%。

A gas chromatography-tandem mass spectrometric （GC-MS/MS） method was set up for selenomethionine determination based on the collision-induced ion fragmentation pattern of its derivatives in order to investigate the change of selenomethionine content in edamame during processing and storage.After 4 weeks of storage at 4 ℃,fresh edamame presented a selenium loss of 13% （based on the content of selenomethionine）.Throughout the whole storage of 6 months at room temperature,the selenomethionine degradation of dehydrated edamame remained lower than that of edamam juice significantly increasing.This indicates that dehydration greatly contributes to selenomethionine retention.Blanching had little effect on selenomethionine loss and the percentage retention of selenomethionine still kept over 85%.Lypholization resulted in the highest percentage retention of selenomethionine,followed by vacuum drying and hot air drying and the resultant percentage retentions of selenomethionine were all over 80%.The lowest percentage retention of selenomethionine （30%-40%） was found in edamame dehydrated by spray drying.This is probably due to large contact area with air.