Valorization of agri-food by-products as functional ingredients for soft cheeses.

Huge amounts of by-products and wastes are yearly generated by the food processing industry all over the world. While several issues are related to their management and disposal due to their environmental impact, numerous investigations are carried out aiming at their valorization through the extraction of valuable components or the production of bio-based products, e.g. for the food, feed, chemical or nutraceutical sectors. In general vegetable residues and byproducts are sources of micro- and macro-nutrients, bioactive compounds, e.g. antioxidants and antimicrobials, and dietary fibres which have recognised beneficial effects on human health. Furthermore, they may be characterised by some relevant technological properties, e.g. water binding and gelling capacity, which overall make them as potential functional ingredients. In this study some food by-products, i.e. citrus and pomegranate residues, chitin, chitosan and horsetail (Equisetum arvense), were initially screened for some desired properties for their use as functional food ingredients, i.e. antimicrobial activity against some food-borne pathogens, prebiotic activity, ability to support the growth of lactic acid bacteria (LAB) used as starters for food fermentations or probiotics. Based on the results, the most promising ones were selected and used as ingredients for a functional soft cheese added with probiotic LAB. Overall, results showed that growth over refrigerated storage of spoilage psychrotropic population was slower in cheeses with added the agri-food by-products than in control ones, while viability of probiotic LAB was unaffected by the added ingredients. Moreover, the antioxidant activity and the profile in volatile compounds were improved resulting in higher acceptability and taste as assessed by a preliminary panel test thus confirming the potentials of the agri-food by-products to be used as multi-functional ingredients