Relationship between the chemical composition and the biological activities of food melanoidins

In this work the relationship between the chemical composition and the biological activities of food melanoidin-rich fractions has been investigated. Melanoidin-rich fractions were extracted by ultrafiltration (10 KDa cut-off) from coffee, barley coffee, dark beer and traditional balsamic vinegar. All the food melanoidin-rich fraction were formed mainly of carbohydrates, phenolic compounds and proteins. In dark beer, barley coffee and traditional balsamic vinegar melanoidins, glucose was the most important sugar incorporated in melanoidins. Coffee melanoidins contained the highest amount of phenolic groups, followed by traditional balsamic vinegar melanoidins. We tested radical scavenging, Fe2+-chelating and heme binding abilities of food melanoidins under gastric conditions. Melanoidin-rich fraction extracted from coffee were the most active, showing the highest radical scavenging activity, Fe2+-chelating and heme binding abilities compared to barley coffee, dark beer, and traditional balsamic vinegar. We assigned radical scavenging and Fe2+-chelating abilities to the phenolic groups present in food melanoidins.