Enzymatic Browning Control in Minimally Processed Mushrooms

Treatments to control discoloration of minimally processed mushrooms were investigated. Whole or sliced mushrooms were immersed in browning inhibitor solutions and evaluated for color change during storage. Browning was more intense in first break mushrooms than in second, and in unwashed mushrooms compared to washed. However, washing sometimes induced purple discolorations, associated with bacterial lesions. Other discolorations were induced by hypochlorite, 4-hexylresor-cinol, and acidic dips. The most effective treatment was a combination of sodium erythorbate, cysteine, and EDTA at pH 5.5. Addition of preservatives to browning inhibitor dips did not improve storage life. However, dipping in 5% hydrogen peroxide prior to application of browning inhibitors significantly increased shelf-life.