From balsamic to healthy: traditional balsamic vinegar melanoidins inhibit lipid peroxidation during simulated gastric digestion of meat.

In this work traditional balsamic vinegar (TBV) melanoidins were characterized for chemical composition and antioxidant activity and their anti-peroxidative effect during an in vitro gastric digestion of turkey meat was studied. The most important constituents of TBV melanoidins were carbohydrates (51% w/w) of which glucose (35% w/w) and fructose (10% w/w) are the main representatives, hydroxymethylfurfural (7.2% w/w), phenolic groups (4.6% w/w) and proteins (1.2% w/w). The antioxidant capacity of melanoidins was studied, measuring lipid hydroperoxides and secondary lipoxidation products formed during in vitro gastric digestion of turkey meat. The most important mechanisms in their antioxidant activity resulted radical scavenging and Fe(2+)-chelating activities. Pepsin inhibiting ability has been excluded. TBV melanoidins were also able to bind heme under gastric conditions potentially preventing its absorption and prooxidant and cytotoxic effects. Our results support the idea that TBV melanoidins may have a role in oxidative damage prevention. Fe(2+)-chelating and heme-binding activities as well as mechanisms of antioxidant activity of TBV melanoidins were also compared with coffee, barley coffee and dark beer melanoidins.