Electrochemical determination of free amino nitrogen in aged lean beef by the measurement of surplus acid after neutralization
Electrochemical determination of free amino nitrogen in aged lean beef by the measurement of surplus acid after neutralization
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DOI：
10.1007/s44211-022-00197-1
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发表时间：
2022-10
影响因子：
1.6
通讯作者：
Akira Kotani;Kaito Shimomura;Kazuhiro Yamamoto;K. Machida;H. Hakamata
中科院分区：
文献类型：
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作者：
Akira Kotani;Kaito Shimomura;Kazuhiro Yamamoto;K. Machida;H. Hakamata
基于酸碱返滴定和醌还原酸的电化学传感原理，提出了一种测定瘦牛肉中游离氨基氮的电分析方法。为了进行牛肉样品中FAN的电化学测定，研究了3，5-二叔丁基-1，2-苯醌（DBBQ）在酸存在下的伏安行为：（1）DBBQ在盐酸（iH）作用下的阴极前峰高与电解质溶液中盐酸的浓度成正比;（2）用过量HCl中和氨基酸后，iHis随电解质溶液中氨基酸浓度的增加而线性下降。通过本电分析方法，测定瘦牛肉样品中的FAN为4.70 mgN g− 1，重复性为3.4%相对标准偏差（n= 5）。本电分析方法的这一结果与使用茚三酮试剂的比色法非常一致。此外，本电分析方法能够监测湿老化过程中瘦牛肉样品中FAN的增加。这些结果表明，目前的电分析方法可以帮助开发现场分析，通过测定FAN来估计老化牛肉样品。图形摘要
In this study, an electroanalytical method, which is based on the concept of acid–base back titration and the electrochemical sensing of acids by means of the reduction of quinone, is proposed for determining free amino nitrogen (FAN) in lean beef samples. To perform the electrochemical determination of FAN in beef samples, the following voltammetric behaviors of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) in the presence of acid have been applied: (1) A cathodic prepeak height of DBBQ caused by HCl (iH) is proportional to the HCl concentration in the electrolyte solution. (2)iHis linearly decreased with an increase in amino acids concentration in the electrolyte solution after the amino acids are neutralized by excess HCl. By the present electroanalytical method, FAN in a lean beef sample was determined to be 4.70 mgN g−1with a repeatability of 3.4% relative standard deviation (n= 5). This result by the present electroanalytical method was in good agreement with a colorimetric method using a ninhydrin reagent. Moreover, the present electroanalytical method was able to monitor increases of FAN in lean beef samples during wet-aging. These results demonstrate the present electroanalytical method could help in the development of an on-site analysis for estimating aged beef samples via the determination of FANs.Graphical abstract