Natural Inhibitors of Maillard Browning

Abstract : This report documents research of a novel natural means of inhibiting Maillard browning, also known as non-enzymatic browning, a complex reaction which can lead to darkening of color, off-odors, off-flavors, and nutritive degradation in food. These efforts were performed by the US Department of Defense Combat Feeding Directorate (CFD) at the Natick Soldier Research, Development and Engineering Center between 2009 and 2012. This reaction has been a consistent problem for CFD's program for extended shelf-life ration components. Many ration components such as dairy based products, cheese spreads, bakery items, and other thermally and non-thermally processed items exhibit some level of Maillard browning over time in storage. This report details initial research that was performed in the laboratory on a model buffer system with glucose and glycine added and then scaled and incorporated in food formulations. Method development and chemical assays were performed to determine the color and chemical changes found in the model systems. The concentration of inhibitor was optimized, and the most effective inhibitors (rosmarinic acid and epigallocaetechin gallate) were further studied in rations (baked rolls and sugar/protein-complexed applesauce). The natural inhibitory compounds were successful in limiting the Maillard browning in model systems and food items. The Hunter colorimeter, UV absorbance, pictorial display, and GC/MS confirmed the mitigation of the Maillard browning reaction. The addition of the inhibitor resulted in less browning.