草菇鲜味肽的分离鉴定及呈味特性分析

通过超滤、凝胶过滤色谱结合电子舌与感官引导对草菇水提物进行初步分离纯化，得到鲜味最佳组分F1，利用反相高效液相色谱结合主成分分析从F1中分离出更接近草菇原始滋味的组分F1-a，进一步采用超高效液相色谱-四极杆飞行时间质谱从F1-a中鉴定出鲜味肽；并将所鉴定的鲜味肽合成后通过感官评价与电子舌分析对其呈味特性进行研究。结果表明：草菇水提物中含有4 种鲜味肽，分别为Asp-Asp-Cys-Pro-Asp-Lys、Leu-Val-Asp-Lys-Pro-Arg、Gln-Ala-Asp-Lys-Arg-Lys、Asp-Thr-Phe-Asn-Asp-Lys，鲜味阈值分别为0.10、0.33、0.42、0.17 mg/mL；草菇中4 种鲜味肽的呈味特性是氨基酸通过肽键形成特定的结构引起，其中鲜味肽Asp-Asp-Cys-Pro-Asp-Lys对味精溶液的增鲜效果最佳，且最佳添加量为20 mg/mL。

Separation,Identification and Taste Characteristics of Umami Peptides from Straw Mushroom

To analyze umami peptides in the water extract of straw mushroom, fractionation guided by sensory evaluation and an electronic tongue of the extract was performed through sequential ultrafiltration and gel filtration chromatography. Fraction F1, which was found to make the greatest contribution to the overall umami, was further fractionated by reversed-phase high performance liquid chromatography combined with principal component analysis. Subfraction F1-a was found to have similar taste to straw mushroom. In addition the umami peptides from F1-a were identified by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. The synthetic counterparts of the identified umami peptides were evaluated for their taste characteristics through sensory evaluation and electronic tongue analysis. The results showed that the umami peptides were identified as Asp-Asp-Cys-Pro-Asp-Lys, Leu-Val-Asp-Lys-Pro-Arg, Gln-Ala-Asp-Lys-Arg-Lys, and Asp-Thr-Phe-Asn-Asp-Lys, with umami taste threshold of 0.10, 0.33, 0.42, and 0.17 mg/mL, respectively. The flavor characteristics of these four umami peptides were attributed to the formation of specific structures by amino acids through peptide bonds. Among them, the umami peptide Asp-Asp-Cys-Pro-Asp-Lys was the most effective in enhancing the umami taste of monosodium glutamate (MSG) solution at a concentration of 20 mg/mL.