Valorization of byproducts of the food industry for the production of functional foods by microbial fermentation

Nowadays, the research for new functional foods is focused on synbiotic products obtained by combining probiotic microbes and prebiotic molecules to further improve human health benefits. Food industry processes often generate considerable amounts of by-products, most of which still retain good amounts of beneficial compounds. Such byproducts can be exploited as substrate for growth of specific microbes due to the presence of sugars and other nutrients. In turn, the fermented products obtained could become enriched with a high number of beneficial microbes and molecules produced by their metabolism. We studied some byproducts such as milk whey, “scotta” (the by-product of the production of ricotta cheese), chicory and onions, alone or in combination, as growth substrates for some selected Lactic Acid Bacteria (LAB), which are the most widely used microorganisms for the production of fermented foods. These microbes, that include many probiotic strains, are widely recognized for their beneficial effects towards gastrointestinal diseases, human immune system, lactose intolerance, allergies and fungal infections as a consequence of their metabolic activities, immunomodulation, and interaction with the intestinal microbiota. On the food side, the action of LAB can enhance shelf-life, safety, organoleptic and nutritional properties. These characteristics are linked to pH reduction, due to the production of organic acids, and to a wide array of bioactive compounds produced during growth. The number and functions of bioactive molecules known is continuously increasing: antioxidants, ACE-inhibiting peptides, antimicrobial substances, hypocholesterolemic peptides, just to cite some. Results from our studies, together with an increasing number of scientific papers on the matter, evidence how this approach can be exploited for the obtainment of interesting new products.