Melanoidin antioxidant and anticaries properties

Maillard reaction takes place at high rate in thermal treated foods, such as bakery products, coffee, barley coffee, beer, giving rise to a large number of compounds with different chemical features, molecular weight (MW) and health-promoting or toxicological properties. Among Maillard reaction products (MRPs), melanoidins, generally defined as brown and acidic macromolecular compounds containing nitrogen, attracted researchers’ interest for their heterogeneous and complex chemical structure, still poorly defined, and their biological properties, such as antioxidant, antiallergenic, antiadhesive, antimicrobial, antimutagenic and citotoxic capacities. In our previous investigations high molecular weight nitrogen containing components with different chemical features, were isolated from coffee and barley coffee and studied for their antioxidant and anticaries properties. As regards antioxidant capacity, five HMW coffee components and a very HMW barley coffee melanoidin showed high activity in an ex vivo system consisting of rat hepatocyte microsomes. Such activity could be attributed to radical scavenger properties, metal chelating activity and reducing power showed in different extent by the isolated components when tested in different chemical systems. Considering coffee and barley coffee melanoidin anticaries properties, they are supported by the capacity, showed also in this case in different extent by each isolated component, to prevent adhesion to hydroxyapatite (HA), to induce detachment from HA, or to prevent biofilm formation by Streptococcus mutans considered the main aetiological agent of caries.