CONTRIBUTION OF MELANOIDINS TO THE ANTIOXIDANT ACTIVITY OF TRADITIONAL BALSAMIC VINEGAR DURING AGING

ABSTRACT The contribution of high‐molecular‐weight melanoidins to the overall antioxidant activity of traditional balsamic vinegar (TBV) has been determined. High‐molecular‐weight melanoidins are gradually synthesized and accumulated during TBV aging contributing significantly to the browning of the vinegar. The increase in antioxidant activity of TBV during aging is largely because of the formation of high‐molecular‐weight melanoidins and only in lesser part to the concentration of polyphenols deriving from the grape or to the formation of low‐molecular‐weight Maillard reaction or caramelization products during must cooking and vinegar aging. During aging, low‐molecular‐weight compounds are progressively incorporated into the melanoidins skeleton and may contribute significantly to the antioxidant activity of high‐molecular‐weight melanoidins. Among these compounds, it has been shown that antioxidant phenolic compounds are progressively incorporated into the melanoidins skeleton during TBV aging.PRACTICAL APPLICATIONS Recently, scientific interest in the field of high‐molecular‐weight melanoidins has increased because of their varied biological activities and functional properties. Traditional balsamic vinegar (TBV) is a potentially healthy seasoning with high melanoidins content that increases during aging resulting in a product with a strong antioxidant activity. The antioxidant activity of aged TBV is due both to high‐molecular‐weight melanoidins and to low‐molecular‐weight compounds such as polyphenols (like phenolic acids, monomeric catechins, flavonols and tannins) and Maillard reaction or caramelization products. Apart from their bioavailability, TBV melanoidins and low‐molecular‐weight antioxidants may exert their effect on the digestive tract where they can play an important role in protecting the gastrointestinal tract itself from oxidative damage.