Dissecting dietary melanoidins: formation mechanisms, gut interactions and functional properties

Dietary melanoidins are late stage Maillard reaction products (MRPs), browning colorants and predominantly high molecular weight (HMW) chemicals. They originate through polycondensation reactions of reducing sugars and proteins or amino acids upon thermal processing. Their presence in several daily food and beverages (i.e. coffee, beer, honey, bakery products, chocolate, grilled meat) contribute to food sensory characters (i.e. color, aroma, and flavor). Additionally, melanoidins exhibit many biological attributes (i.e. antioxidant, anti-obesity, antibacterial activity and impact on gut microbiota as prebiotics). However, dissecting melanoidins specific biological and functional characteristics in relation to their metabolism and gut interaction with link to their chemical structures has yet to be reported in literature. For a better understanding of melanoidins benefits and flavor properties in processed foods, this review represents a state of the art comprehensive insight of its formation mechanism and chemistry in relation to their functionalities and health effects. Further, a compile of the factors affecting melanoidins production to optimize for the best flavor attributes while minimizing hazardous compounds is presented. This study presents the first analysis of melanoidins gut interaction in context to its different action mechanisms.