Abstract: To determine the optimum conditions of γ-aminobutyric acid (GABA) treatment, the effects of GABA treatment at different concentration for different times on the weight loss, hardness and color of Agaricus bisporus were investigated during cold storage (at 4 ℃ and relative humidity of 85%). Moreover, the changes in total phenol, ascorbic acid, and polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonialyase (PAL) activities were measured. The results showed that GABA treatment could decrease the mass loss rate and maintain the hardness and color of A. bisporus, and the suitable treatment condition was 5 mmol/L GABA for 5 min. Under this condition, the mass loss rate of A. bisporus on the 12th day was 44.76%, which was lower than that of the control group, and the hardness and L* value were 28.54% and 9.41%, which were higher than those of control group, respectively. Meanwhile, GABA treatment could promote the accumulation of total phenols and ascorbic acid, decrease the activities of PPO and POD, and improve the activity of PAL. Thus, the storage quality of A. bisporus was well maintained, and the storage life was prolonged by suitable GABA treatment.

Key words: γ-aminobutyric acid (GABA), Agaricus bisporus, browning, quality