Antioxidant and neuroprotective potential of extracts from Hass avocado peel obtained through a biorefinery process: A sustainable strategy for the valorization of agro-food waste

This study presents a novel three-step biorefinery approach for extracting bioactive compounds from Hass avocado ( Persea americana, Mill.) epicarp. By sequentially using supercritical CO2, CO2-expanded ethanol, and subcritical water, we efficiently recovered a diverse range of extracts with distinct phytochemical profiles and potent biological activities. Our innovative extraction strategy outperformed conventional methods, demonstrating the potential of biorefinery for sustainable valorization of agricultural byproducts. Medium and high extracts exhibited strong antioxidant and anticholinesterase activity. For example, the CO2-expanded ethanol extracts demonstrated an ABTS radical cation scavenging capacity of 3.01 +/- 0.06 mmol Trolox equivalents/g and an SC50 value of 53.4 +/- 1.2 mu g/mL for anticholinesterase activity. These findings highlight the feasibility of integrating biorefinery processes into circular economy initiatives to create high-value bioproducts while minimizing waste.