Sequential one-pot NaDES assisted extraction and biotransformation of rice bran: A new strategy to boost antioxidant activity of natural extracts

Abstract

Natural Deep Eutectic solvents (NaDES) was used to produce, after sequential one-pot extraction and biotransformation of naturally pigmented rice bran (RB), ready-to-use extracts that improve the oxidative stability of lipids in an oil-in-water emulsion. Two NaDES-based strategies were implemented. Extraction of phenolics content varied according to the NaDES. The shiftable NaDES (obtained from the acidic-NaDES based on ChCl and xylitol) stands out by showing content of 1525 mg eq gallic acid/100 g RB. The sequential one-pot biotransformation with immobilized Candida antarctica lipase B after increasing pH, was marked by a decrease in phenolics content and a lipids profile variation. These enriched extracts could be used as natural additives or ready-to-use extracts, as confirmed by the encouraging antioxidant results observed in emulsion. Omics tools should be applied to elucidate the structural rearrangement between compounds and the pool of extracted antioxidant molecules that may explain the protection against lipid oxidation.