Recent trends in the analysis of amino acids in fruits and derived foodstuffs.

The amino acid content of fruit and fruit-derived foods is studied intensely because of the contribution to nutritional value, aroma, taste and health-promoting effects and their possible use as markers of origin and authenticity. In this review, based on 101 references, the most recent trends in the analysis of amino acids are presented: the most important techniques, the different sample treatment procedures (including derivatisation) and the most frequent applications are described and compared. Pertinent publications were retrieved from Scopus and Web of Knowledge database searches lastly performed in February 2012 with the keywords "amino acid", "analysis", "liquid chromatography", "gas chromatography", "electrophoresis", "fruit", and "vegetables"; the time limit was set from the year 2000 onwards. Although amino acids have been analysed in foods for decades, new technical possibilities and advancements have allowed ever-increasing accuracy and targeting of the methods in order to overcome the challenges posed by the complex plant matrices and their high intrinsic variability.