Neuroprotective Potential of Thinned Peaches Extracts Obtained by Pressurized Liquid Extraction after Different Drying Processes.

Genetic, environmental and nutritional factors are suggested as primary factors of Alzheimer's disease (AD), and secondary metabolites such as polyphenols present in thinned peaches are considered as good candidates for AD prevention. Thinned peaches are usually dried to avoid putrefaction, but the effects of the drying method and the extraction process on the polyphenol composition and the neuroprotective potential have never been addressed. In this work, a pressurized liquid extraction (PLE) method was optimized and applied to thinned peaches dried under different conditions, and their neuroprotective potential was evaluated in vitro. In addition, the PLE extracts were characterized via HPLC-Q-TOF-MS/MS, and a permeability assay was performed to evaluate the ability of the identified metabolites to cross the blood-brain barrier (BBB). The PLE extracts obtained from freeze-dried (FD) samples with 50% ethanol in water at 180 °C showed the best neuroprotective potential. Finally, among the 81 metabolites identified, isoferulic acid, 4-methyldaphnetin, coniferyl aldehyde and 3,4-dihydroxyacetophenone were found at higher concentrations in FD extracts. These metabolites are able to cross the BBB and are positively correlated with the neuroprotective potential, suggesting FD together with PLE extraction as the best combination to exploit the neuroprotective capacity of thinned peaches.