Enhancement of the anti-inflammatory properties of grape pomace treated by Trametes versicolor.

The application of solid-state fermentation for production of value-added products from agro- and food- industry has been recently investigated a lot. The white-rot basidiomycete Trametes versicolor is a widely used fungi for degradation lignocellulosic material in solid-state conditions. Grape pomace constitutes the major by-product of Vitis vinifera L. and is a source of compounds with recognized benefits for health. In this work, a process of grape pomace treatment with Trametes versicolor for 15 days under solid state conditions was developed and the phenolic profile and anti inflammatory potential of grape pomace extracts before and after treatment was studied. The anti-inflammatory potential of grape pomace extracts was performed by tests based on inhibitions 5-lipoxygenase and hyaluronidase, two key enzymes in inflammatory processes. A total of 24 phenolic compounds were identified and quantified by HPLC methods. With the exception of anthocyanins, an increase of phenolic acids, flavan-3-ols and the flavonol rutin was observed after a period of 1-4 days of treatment with T. versicolor. Moreover, an increase in phenolic content was followed by an enhancement of anti-inflammatory activity of grape pomace extracts, being confirmed by a strong correlation between them. This is the first study providing evidence of the benefits of the application of fungal-based solid-state fermentation as an environmentally friendly process for enhancement of the phenolic composition and anti-inflammatory potential of the grape pomace, increasing the possibility of taking profit from the great wastes produced by the grapes processing industry.