A review of Maillard reactions in spray dryers

Abstract

Maillard reactions in liquid systems have been studied extensively, while those occurring during the spray-drying process have been less well studied. Current studies on Maillard reactions in spray dryers have been focussed heavily on empirical studies of the effects of the operating parameters. However, only modest attention has been paid to the fundamental reactions or to the interactions with the fundamental spray-drying process. Studies on the spray-drying process have shown that component segregation occurs during the process. Component segregation causes different ratios between various reacting components in different parts of particles, and this segregation process may change the kinetics of Maillard reactions. Particle residence times and the re-entrainment of wall deposits may also affect the extent of Maillard reaction since they determine the reaction time in spray dryers. Improving the design of spray dryers may also help to reduce the extent of the Maillard reactions in spray-dried products. • Kinetic studies for Maillard reactions for spray drying have been reviewed. • Features of Maillard reactions related to spray drying have been reviewed. • The importance of component segregation has been highlighted. • The importance of the particle-wall interaction has been discussed. • Techniques for measuring particle RTD in spray dryers have been reviewed.