Bioactive Compounds Obtained from Oilseed By-Products with Subcritical Fluids: Effects on Fusarium verticillioides Growth

Abstract

Recovery of bioactive compounds from wastes is gaining interest because they could add value to by-products arising from, for example, the oil extraction processes. In this work, green solvent extraction (water/ethanol under sub-critical conditions) was used to obtain bioactive compounds from peanut, sesame and pistachio agro-industrial by-products. Extracts were analyzed in their overall chemical composition and tested on growth, ergosterol and fumonisin FB1 production by Fusarium verticillioides. The effects of the extracts on fungal growth rate and biochemical markers were not univocal, and could be associated to differences in their chemical profiles. Extracts obtained from peanut skin—composed mainly by monomeric and dimeric flavonoids—caused significant reductions in fungal growth rate but increased FB1 production. Extracts from sesame seeds—dominated by furofuran-type lignans—did not have a clear inhibitory effect on growth rate but strongly reduced both FB1 and ergosterol production. Extracts from pistachio nuts—characterized by monomeric flavonoids and gallic acid derivatives—showed minor effects on both fungal growth rate and biochemical markers. Sub-critical fluid extraction of peanut skin and defatted sesame seeds may provide an efficient method to obtain extracts rich in phenolic and lignan compounds with potential use as antifungal agents.