Food Melanoidins: Chemistry and Nutrition

Thermal processing of food is as old as the discovery of fire by mankind. Amongst the many chemical reactions and physical transformations that occur in foods during their thermal processing, Maillard's reaction has important implications for food processing. The brown color development of foods as a result of their thermal processing has been attributed to the formation of melanoidins, being of great interest to the food industry because of the color given to foods and because they are closely associated with high quality products with pleasant texture, aroma and taste. On the other hand, melanoidins interact with food flavor, especially volatile thiols, and therefore may negatively influence food flavor characteristics. The currently accepted definition of melanoidins is that they are the brown colored nitrogen-containing high molecular weight material formed as end products of the Maillard reactions. Melanoidins are widely distributed in the foods we consume as part of our daily diet. They are present in coffee, baked goods , chips, cocoa, roasted barley, fortified wine, beer, grilled meat, among others. Daily consumption of melanoidins from bakery products and coffee and the two main sources of melanoidins in our diet, and their melanoidins content is estimated at 6.0 g and 1.5 g respectively. In recent years, there has been renewed interest in the structure and mechanism of melanoidins formation largely due to the different beneficial biological activities that have been described for these compounds either from different foods or synthesized in model systems. However, less beneficial biological activities for melanoidins have also been described.

Despite their abundance and importance in the diet, melanoidins are still today the most enigmatic food macromolecule, as their chemical structure is still largely unknown. This lack of clear definition of what melanoidins are chemically is one of the reasons why, in the 21st century, 107 years after their first description by the French chemist Louis Camille Maillard, there are still no clear answers to the following questions: what is the chemical structure of food melanoidins, and what is the mechanism of their formation? This lack of knowledge also limits our understanding of the nutritional impact of food melanoidins consumption.

The scope of this Research Topic will include, but it is not limited to:
- Chemical characterization of food melanoidins;
- Mechanism of formation of food melanoidins;
- Effect of thermal processing in the amount and structure of food melanoidins;
- Bioactivity and bioavailibility of food melanoidins;
- Nutritional aspects of food melanoidins;
- Microbial metabolism of melanoidins, microbiome and other omics;
- Quantification of melanoidins in food products.