Effects of solid-state fermentation and extraction solvents on the antioxidant properties of lentils

Abstract

Plant-based foods may have their nutritional and biological properties improved through biotransformation processes; becoming more beneficial to health and attractive to consumers. Fermentation is a process widely applied to legumes which can improve their antioxidant properties. This work investigated the antioxidant potential (ABTS, DPPH, and FRAP methods) and total phenolic compound content (TPC) of extracts derived from lentils fermented with Aspergillus oryzae; using water, methanol and ionic liquids (choline acetate, choline hydroxide and choline lactate) as solvents. The results showed that the antioxidant properties and TPC content of the extracts obtained after fermentation were significantly (p ≤ 0.05) higher than those of non-fermented samples. Approximate increases of 143, 54, 52 and 500% were detected for ABTS, DPPH, FRAP and TPC after fermentation, respectively. The solvents applied in our work demonstrated different abilities in antioxidant and phenolic compound recovery. The foremost positive results were obtained using water as a solvent for extraction from fermented lentils. In addition, important information about the use of ionic liquids for recovery and their effects on the content of antioxidant properties of plant extracts was provided.