Background: White button mushroom (Agaricus bisporus) is a sensitive agricultural crop whose antioxidant properties are decreased during postharvest storage. In this study, the effect of citric acid dipping treatment on bioactive components and antioxidant properties of sliced button mushroom (Agaricus bisporus) was investigated.

Methods: Fresh mushrooms soaked in chilled citric acid solution at different concentrations (1%, 3% and 5% w/v) for 10 min were categorized as treatment groups and those dipped in chilled distilled water were considered as control. Bioactive components and antioxidant properties of sliced button mushroom were assessed on each designated day (every 5 days up to 15 days) of storage using chemical evaluations including total phenolics, chelating power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as well as assessment of reducing power. The significance of differences among treatments was determined by one-way analysis of variance (ANOVA) and Tukey tests using Sigma Stat software (version 2.03).

Results: Incorporation of 3% w/v citric acid treatment effectively maintained bioactive components and antioxidant properties [with 4.89 mg/g, 304.31 μg/ml (EC50) and 1.69 mg/ml (EC50) in total phenolic, DPPH and reducing power assays, respectively] at higher levels compared to control [with 3.12 mg/g, 420.42 μg/ml (EC50) and 2.23 mg/ml (EC50) in the mentioned evaluations] at the last day of the experiment (p<0.05). No significant difference was observed between 3% and 5% w/v citric acid solution treated samples (p>0.05).

Conclusion: These results showed that dipping in citric acid solution prior to storage can maintain bioactive components and antioxidant properties of sliced button mushrooms during storage.