Valorization of Pomegranate Waste and By-Products for New Models of Circular Economy

In the current context of affirmation of the concept of the circular economy as a new paradigm of sustainability, the present research aimed to enhance and innovate the pomegranate supply chain. From the perspective of optimizing a multifunctional platform, two samples were studied obtained from pomegranate waste: a lyophilized aqueous extract from the pericarp and a micronized powder obtained by grinding the pericarp after freeze-drying. The HPLC-DAD-MS chemical characterization revealed a content of hydrolysable tannins of 23.1% by weight for the lyophilized extract and 20.8% for the micronized pericarp. The antimicrobial activity was evaluated on five fungi of agricultural and food interest (Alternaria sp., Fusarium oxysporum f. sp. radicis-lycopersici, Mucor sp., Penicillium digitatum, and Pythium ultimum). In all cases, we observed an inhibition of the fungal mycelium proportional to the sample concentrations, with average higher efficacy for the lyophilized extract compared to the micronized powder. These results will allow to assess the possible applications of waste and by-products from pomegranate processing to obtain, within integrated platforms for the recovery of active ingredients with functional properties, innovative semifinished and finished products for use in diversified commodity sectors.