Glycine betaine treatment extends the shelf life and retards cap browning of button mushrooms.

This research examined the impact of exogenous Glycine Betaine (GB) at various concentrations (0, 5, 10, and 15 mM) on cap browning and the overall quality of button mushrooms during a 15-day storage period at 4 °C. The study found that a concentration of 10 mM GB resulted in the least amount of cap browning. Additionally, mushrooms treated with 10 mM GABA showed lower levels of weight loss, electrolyte leakage, and malondialdehyde (MDA) content, while maintaining higher firmness. The use of 10 mM GB also led to an increase in the accumulation of total phenolic compounds, which was associated with higher expression and activity of phenylalanine ammonia-lyase (PAL) and lower expression and activity of polyphenol oxidase (PPO). Furthermore, GB treatment effectively reduced HO content and increased proline and ascorbic acid (AsA) content. The application of exogenous GB resulted in an increase in the endogenous GB content and BADH activity. In conclusion, GB treatment can be utilized to slow down cap browning and preserve the nutritional quality and sensory of button mushrooms during chilling storage.