Recovering phenolic compounds and selenium from Brazil nut bran using emerging green solvents: computational screening study, optimization and cytotoxicity of extracts

Abstract

The solid residue (torta), which is obtained from pressing Brazil nuts for oil extraction, is rich in phenolic compounds and selenium. With the aim of increasing the socio-economic and environmental importance of Brazil nuts through the extraction of bioactive compounds, the application of Deep Eutectic Solvents (DES) and Biobased Solvents for the extraction of these compounds is being proposed. The application of these solvents has been considered a promising technique because it is cheap, easy to prepare and safe for the environment and humans. To date, no studies have been reported on the extraction of phenolic compounds and selenium from Brazil nut cake using DES and Biobased Solvents. This work aims to obtain an extract rich in bioactive compounds that can be applied in food formulations. The first stage will consist of screening a set of DES and Biobased Solvents prepared with choline chloride ([Ch]Cl) and different carboxylic acids, sugars and polyols that are recognized as safe by the FDA (Food and Drug Administration). A computational screening will be carried out, using the COSMO-RS model, to evaluate the solute-solvent interaction in 870combinations of DES and 64 Biobased Solvents. Subsequently, at least 30 DES and 15 Biobased Solvents will be chosen for extractions and experimental analysis of phenolic compounds. The extractions will be optimized by applying a Plackett & Burman design to screen the variables temperature, water content, solid:solvent ratio, stirring speed and HBA:HBD molar ratio, followed by the application of a Rotational Central Composite Design (RCCD) with the significant variables. Ecotoxicity and cytotoxicity tests will assess the safety of the solvents and extracts, while the stability of the extracts will be analyzed. Finally, the extracts will be applied in emulsions for potential food formulations, and the last stage will involve studies of digestibility in vitro and bioaccessibility of the phenolic compounds. (AU)