Solid-state fermentation - assisted extraction of bioactive compounds from hass avocado seeds

The effect of solid-state fermentation (SSF) of avocado seed with A. niger GH1 on the release of bioactive compounds with antioxidant capacity was studied. The growing conditions of the fungus were optimized. Subsequently, The effect of sterile water and pontecorvo culture medium was evaluated in the SSF. The optimal conditions for SSF were particle size of 2.5 mm, 60 % of humidity, and 120 h. In the assessments of antioxidant capacity by the ABTS and DPPH methods, the increase with respect to the initial values was 33 and 77 % with water and 28 and 42 % with culture medium, respectively. The analysis HPLC showed degradation of catechin and epicatechin polymers, particularly procyanidin B2 dimers resulting in the accumulation of monomers. The ability of the fungus to degrade compounds present in the avocado seed was decisive to enhance the antioxidant capacity. This degradation was related to increased cellulase and xylanase activity. (C) 2020 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.