Identification and Quantitation of New Glutamic Acid Derivatives in Soy Sauce by UPLC/MS/MS
作者:Eric Frerot、Ting Chen
DOI:10.1002/cbdv.201300150
日期:2013.10
Glutamic acid is an abundant amino acid that lends a characteristic umami taste to foods. In fermented foods, glutamic acid can be found as a free amino acid formed by proteolysis or as a non-proteolytic derivative formed by microorganisms. The aim of the present study was to identify different structures of glutamic acid derivatives in a typical fermented protein-based food product, soy sauce. An
谷氨酸是一种丰富的氨基酸,可赋予食品独特的鲜味。在发酵食品中,谷氨酸可以作为通过蛋白水解形成的游离氨基酸,也可以作为由微生物形成的非蛋白水解衍生物。本研究的目的是鉴定典型的基于蛋白质的发酵食品酱油中谷氨酸衍生物的不同结构。用阴离子交换固相萃取(SPE)制备酸性级分,并通过UPLC / MS / MS和UPLC / TOF-MS进行分析。在酱油的酸性馏分中鉴定出了α-谷氨酰,γ-谷氨酰和焦谷氨酰二肽以及乳酰氨基酸。化学合成了它们以确认它们的出现,并在选定的反应监测(SRM)模式下对其进行了定量。焦谷氨酰二肽占酱油的770 mg / kg,其次是乳酰氨基酸(135 mg / kg)和γ-谷氨酰二肽(70 mg / kg)。此外,食品中的N-琥珀酰谷氨酸首次被鉴定为酱油中的次要化合物(5 mg / kg)。