Advances in the determination of non-protein amino acids in foods and biological samples by capillary electrophoresis

Abstract

There are hundreds of non-protein amino acids whose importance in food and biological matrices is still unknown. Many of these compounds mainly exist in food as products formed during food processing, as metabolic intermediates or as additives to increase nutritional and functional properties of food. Moreover, they have also demonstrated to play an important role in the pharmaceutical and clinical fields since they may be used therapeutically in the treatment of some pathologies and their levels may be related with some diseases. For this reason, the analysis of non-protein amino acids may provide relevant information in the food and biological fields. This article reviews the most recent advances in the development of analytical methodologies employing capillary electrophoresis for the achiral and chiral analysis of non-protein amino acids in food and biological samples. With this aim, the most relevant information concerning the separation and detection of these compounds by capillary electrophoresis is discussed and detailed experimental conditions under which their determination was achieved in food and biological samples are given covering the period of time from 2015 to 2018.