Rapid fingerprinting of extractable and non-extractable polyphenols from tropical fruit peels using direct analysis in real time coupled to orbitrap mass spectrometry.

• Rapid fingerprinting of non-extractable polyphenols was carried out from tropical fruits peels. • Each hydrolysis treatment produced different phenolic profiles and signal intensities. • Enzymatic treatments were the most specific to extract non-extractable polyphenols. • Non-extractable polyphenols were identified in residues of all extractions. • Peels from tropical fruits showed a rich source of phenolic compounds. A simple and rapid direct analysis in real-time coupled to high-resolution mass spectrometry (DART-HRMS) methodology was developed to generate the extractable and non-extractable polyphenols (NEPs) fingerprint for four different passion fruits, G. mangostana , and A. squamosa peels as case-study to investigate the influence of alkaline hydrolysis and enzymatic-assisted extraction (EAE) on the recovery of NEPs. The extraction residue obtained after these treatments was also analyzed by DART-HRMS. Data compiled from DART-HRMS mass spectra were processed with principal component analysis to discriminate among the different treatments. EAE with Depol enzyme enabled to obtain NEPs with the highest signal intensity in DART-HRMS analysis from all peels except for P. edulis and A. squamosa peels. In these two cases, NEPs were better extracted by EAE with Promod enzyme and alkaline hydrolysis. Results showed that the applied treatments were efficient to extract NEPs since their signal intensities in the extraction residues were very low compared with their extracts. [ABSTRACT FROM AUTHOR]