Effect of citric acid dips and packaging materials on browning in button mushroom

This study revealed that citric acid dips (0.5, 1.0, 1.5 and 2.0%) were effective in controlling browning reactions during the storage. A significant reduction in browning was observed by aqueous dip with citric acid up to a concentration of 1.5%, but the browning was minimum in the mushrooms treated with 1% citric acid dips. Maximum inhibition of browning associated enzymes (tyrosinase, laccase and peroxidase) was observed in mushrooms treated with 1% citric acid and stored at 4±1^oC with 85% relative humidity. In comparison to control, citric acid dips and packaging showed a significant reduction in lipoxygenase activity which was accompanied by reduction in electrolytic leakage. In case of packaging materials, mushrooms stored in punnet trays with PVC cover exhibited minimum enzyme activity, browning index and electrolytic leakage followed by carton trays and polypropylene bags. Thus, this study indicates that treatment of mushrooms with 1% citric acid dips, followed by packing in punnet trays, can be used as an effective strategy for delaying the browning reactions in mushrooms.