PITC柱前衍生HPLC法测定黄精红曲酒中游离氨基酸含量

Determination of Free Amino Acids Content in Polygonatum-Monascus Wine by PITC Pre-Column Derivatization HPLC

建立了一种快速有效的检测自酿黄精红曲酒中的游离氨基酸含量的方法。经异硫氰酸苯酯衍生后,利用美国SMA氨基酸分析柱对17种氨基酸混合标准溶液进行了分离,结果显示,所有氨基酸在36 min以内均得到了基线分离,检测时间优于已经报道文献中氨基酸的检测时间;所有氨基酸在0.16~2.5 mmol/L范围内具有较好的线性关系;17种氨基酸平均加标回收率在73.6%~102.5%之间,检测方法的相对标准偏差RSD在0.2%~0.7%范围以内,此方法重复性较好。利用此方法对自酿黄精红曲酒和市售黄精红曲酒中的游离氨基酸种类和含量进行了检测,结果发现自酿黄精红曲酒中的氨基酸种类要少于市售黄精红曲酒;但自酿黄精红曲酒中氨基酸总量却要比市售黄精红曲酒高出近50%。从氨基酸的呈味特征来分析,苦味氨基酸和甜味氨基酸占据了两种酒样中氨基酸总量的绝大部分,涩味氨基酸仅占近10%的比例。本研究建立的方法能快速有效地检测自酿黄精红曲酒中的氨基酸含量,为红曲酒生产企业研究其风味物质来源提供了理论依据。

A rapid and effective method for the determination of free amino acids content in self-made Polygonatum-Monascus wine by PITC pre-column derivatization HPLC had been developed.After derivatization with phenyl isothiocyanate,17 amino acids were separated from the standard solution by American SMA amino acid analysis column.The results showed that all amino acids were separated at baseline within 36 minutes,and the detection time was better than that in all reported literatures.All amino acids had a good linear relationship in the range of 0.16 mmol/L to 2.5 mmol/L.The average recovery was between 73.6%and 102.5%.The relative standard deviation of the detection method was within the range of 0.2%to 0.7%.This method had good repeatability.Then the method was used to detect the kinds and content of free amino acids in self-made Polygonatum-Monascus wine and a commercially available Polygonatum-Monascus wine.The results showed that,the varieties of amino acids in self-made Polygonatum-Monascus wine were less than those in commercially available Polygonatum-Monascus wine,but the total amount of amino acids was nearly 50%higher.According to the flavoring characteristics of amino acids,bitter amino acids and sweet amino acids accounted for the majority of the total amino acids in the two wine samples,while astringent amino acids accounted for less than 10%.The method can quickly and effectively detect the content of amino acids in self-made Polygonatum-Monascus wine,which provided theoretical basis for the study of the source of flavoring substances for Monascus wine manufacturers.