Obtention of stable neuroprotective extracts from orange by-products by gas-expanded liquids extraction (GXLE) and liposomal microencapsulation

Abstract

The valorization of agrifood by-products to obtain high added-value products is an interesting research topic in the frame of Circular Economy. Moreover, the development of environmentally respectful and efficient extraction tools to obtain interesting compounds from those biomasses is a necessity today. In this contribution, a process combining gas-expanded liquids extraction together with a novel microencapsulation protocol is studied with the aim to recover and stabilize neuroprotective compounds from orange by-products. Both process conditions were optimized by means of experimental designs. After their application, optimum extraction conditions involved the use of 30 % ethyl acetate expanded into CO₂ at 50 °C,10 MPa, for 30 min in static mode. The obtained extracts showed higher bioactivities than other similar extracts obtained using pressurized liquids and supercritical fluid extractions. On the other hand, the optimization of a cryo-stirred microencapsulation protocol allowed an effective encapsulation higher than 73 %. Consequently, the overall bioactivity of the encapsulated product was reduced due to this value, although the product was demonstrated to be stable for >4 months of storage under accelerated conditions (45 °C and 80 % humidity), while the non-encapsulated original extract lost 50 % of its activity in less than a month. Thus, the obtained results demonstrated the usefulness of the combined approach to achieve the valorization of commonly found agrifood by-products into added-value extracts with potential as functional ingredients due to their bioactivity and stability.