Screening of phenolic compounds in by-product extracts from mangoes (Mangifera indica L.) by HPLC-ESI-QTOF-MS and multivariate analysis for use as a food ingredient

Consumers are increasingly demanding natural food ingredients that are expected to be safe and healthy. Processing of mango fruits generates a significant amount of by-products such as peels and seeds which represent up to 60% of the fruit. Mango by-products are an important source of bioactive phenolic compounds. Phenolic characterization is an essential step for the utilization of mango by-products as food ingredients, and so provides an added value to mango production in Spain. In this regard, the use of high-performance liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (HPLC-ESI-QTOF-MS) with negative ion detection has shown to be a powerful technique for the characterization of phenolic compounds of peel and seed extracts of three mango varieties (Keitt, Sensation and Gomera 3) produced in Spain, obtained by different microwave-assisted extraction conditions. Thus, in the present work, thirty compounds were identified that belong to five phenolic families: gallates and gallotannins; flavonoids mainly quercetin derivatives; ellagic acid and derivatives; xanthones principally mangiferin; benzophenones and derivatives such as maclurin derivatives. The contribution of each of these groups depends on the mango variety, the part of fruit studied (peel or seed) and the extraction conditions used. PCA analysis suggested that the extraction method had a greater influence on the phenolic content than variety or the mango by-product analyzed. These results highlight the importance of mango by-products as a source of natural bioactive phenolic compounds.