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

Abstract

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