Monitoring the behavior of melanoidin from a glucose/l-asparagine solution

Melanoidins are final products from the Maillard reaction. This study was designed to evaluate the behavior of melanoidin formed from a glucose/l-asparagine model solution by means of different techniques, such as kinematic viscosity, dynamic light scattering (DLS), ultrasound through transmission speed measurement (SP) and transmission electron microscopy (TEM). The experimental results obtained show that the kinetics of the intrinsic viscosity at different temperatures indicates that there is no polymerization once the melanoidin acquires a molecular size that darkens the color of the solution. However, the polymer chains self-aggregated, forming particles that increase in size over time. This aggregation gives an increase in sound speed, which can be monitored on-line using ultrasound. This opens the possibility of on-line non-invasive monitoring of aggregates formed during Maillard reactions by means of ultrasonic techniques. This aggregation of melanoidin particles with time is clearly corroborated with the DLS and TEM techniques. Until now, many works on the microstructure of the melanoidin have been performed, but nothing has been published to describe their macrostructure. In this work there is a first observation about its formation and morphology, a starting point being to go in greater depth into the field of Maillard reaction products, whose interaction in health is of growing importance.

► Melanoidin formed does not increase its intrinsic viscosity with time. ► SP and DLS measures indicate an increase in the size of particles with time. ► TEM observations corroborated the results of SP and DLS.