Developments and pitfalls in the characterization of phenolic compounds in food: From targeted analysis to metabolomics-based approaches

The review describes the state of the art of phenolic characterization in food by liquid chromatography and mass spectrometry. From conventional targeted analysis, a special attention was devoted to metabolomics-based strategies, which are becoming increasingly popular in the characterization of phenolic compounds. Most works in the field exploit the profiling approach by annotation of full scan high resolution mass spectrometric data. To improve the confidence, the use of tandem and multistage mass spectrometry is emerging as a valuable strategy which can provide more insight in the structure and help differentiating the many isomeric compounds which are typical of this class. The efficiency, however, is strictly connected with data handling and bioinformatics to search databases and match product ion spectra. The different approaches, from profiling, through suspect screening to untargeted analysis, are described with a discussion on the limitations of each approach and future developments needed to improve identification confidence.