养殖暗纹东方鲀中7 种醇提鲜味肽的鉴定及其呈鲜特性

为进一步发掘鲜味肽并探索其构效关系，以60%乙醇溶液作为提取剂，采用超滤纳滤、凝胶色谱层析并结合人工感官评价，从养殖暗纹东方鲀肌肉中分离纯化多肽馏分，进一步利用纳升液相四极杆轨道阱质谱鉴定多肽的分子质量及氨基酸组成。将初步鉴定肽进行固相合成，结合人工感官及电子舌技术验证其呈味特性，并采用分子对接探讨多肽结构与鲜味的关系。结果表明：7 条新鉴定的鲜味肽NWDDMEK、KTGLSPDQF、KTDLNFENL、ASLDGEFKG、ALASLDGEFKG、ALTSLDGEFKG和RLGSSEVEQVQ，其分子质量范围为922.3～1 230.6 Da，鲜味阈值范围为0.38～1.04 mmol/L。鲜味肽序列上的谷氨酸（Glu）、天冬氨酸（Asp）和赖氨酸（Lys）及鲜味受体上的N69、S276、R151、R277、A302、T149和N150等氨基酸残基对多肽的呈鲜特性有重要的意义。本研究可为后期进一步探明肽的呈鲜规律提供参考。

Identification and Taste Characteristics of Seven Alcohol-extracted Umami Peptides from the Muscle of Cultured Takifugu obscurus

In order to discover new umami peptides and explore their structure-activity relationship, this study separated and purified umami peptides from the muscle of cultured Takifugu obscurus using 60% aqueous ethanol solution as the extraction solvent, as well as applying ultrafiltration and gel chromatography combined with sensory evaluation. The molecular masses and amino acid compositions of the peptides were further identified by nano-liquid chromatography-quadrupole orbitrap mass spectrometry. The taste characteristics of the peptides synthesized by the solid-phase method were evaluated by sensory evaluation combined with electronic tongue, and their structure-activity relationship was elucidated by molecular docking. The results indicated that seven umami peptides including NWDDMEK, KTGLSPDQF, KTDLNFENL, ASLDGEFKG, ALASLDGEFKG, ALTSLDGEFKG and RLGSSEVEQVQ were identified with a molecular mass in the range of 922.3–1 230.6 Da, and their umami thresholds ranged from 0.38 to 1.04 mmol/L. Glutamic acid (Glu), aspartic acid (Asp) and lysine (Lys) residues in the peptide sequences, and the amino acid residues N69, S276, R151, R277, A302, T149 and N150 in the umami receptor T1R1/T1R3 played important roles in the umami taste of the peptides. This study may guide future studies to elucidate the umami taste of peptides.