Abstract: In this study, in order to solve the problem of quality deterioration in Agaricus bisporus during freezing and thawing, the effects of citric acid, L-cysteine, ascorbic acid, sodium erythorbate on the browning of Agaricus bisporus were evaluated. Furthermore, we determined the effect of different freezing temperatures (?80, ?40 and ?20 ℃) and thawing temperatures (25 and 4 ℃) on some quality indexes, such as drip loss, texture characteristics, microstructure, moisture content and distribution, and peroxidase activity. The results showed that the optimal combination of browning inhibitors was 3.0 g/L sodium erythorbat, 1.5 g/L L-cysteine, 0.4 g/L ascorbic acid, and 10 g/L citric acid. The drip loss of Agaricus bisporus with the browning inhibitor mixture frozen at ?80 ℃ and thawed at 4 ℃ was 1.98%, significantly lower than that in other treatment groups. However, moisture content and texture characteristics showed a pronounced increase compared with other frozen-thawed groups. Thus, the optimal freeze-thaw temperatures were determined as ?80 and 4 ℃. This study provides a basis for developing freeze-thaw techniques for the production of frozen Agaricus bisporus products.

Key words: freezing, Agaricus bisporus, browning inhibitor mixtures, browning, microstructure