The Inhibition of Maillard Browning by Different Concentrations of Rosmarinic Acid and Epigallocatechin-3-Gallate in Model, Bakery, and Fruit Systems.

Rosmarinic acid and Epigallocatechin gallate concentrations were studied as natural inhibitors of Maillard browning in glucose/glycine model systems, and in bakery rolls and applesauce. The concentrations of the inhibitors were varied to determine the highest level of inhibition without a pro-oxidant/browning effect. UV absorbance and gas chromatography/mass spec (GC/MS) with solid phase microextraction (SPME) sampling was used to study browning in the model systems. Hunter L*, a*, b* was used to analyze the color change results of the inhibitors on applesauce and bakery rolls. It was determined that a 1.0% solution of either antioxidant in the glucose/glycine system produced the greatest inhibition and a synergistic effect was not apparent when the two were combined. Inhibition of browning and a lack of synergy between the antioxidants were also determined in food systems consisting of applesauce and bakery rolls. GC/MS analysis of the model system revealed a high level of pyrazine formation in no-inhibitor control samples and the absence of pyrazines in inhibitor-containing samples. Natural browning inhibitors, that is Rosmarinic acid and Epigallocatechin gallate, can be added to food items to inhibit browning over a prolonged period of storage in order to increase product shelf stability. The concentrations of the inhibitors require optimization since a pro-oxidant effect and increased browning will occur at high levels.