Effect of different drying temperatures on the rehydration of the fruiting bodies of Yu Muer () and screening of browning inhibitors.

In this study, the color of the dry fruiting bodies, fresh weight (FW): dry weight (DW) ratio, amino acids, and total phenolics, which are of nutritional or commercial interest, were compared among different drying temperature treatments. The effect of rehydration methods and color protection reagents on the fruiting body color, polyphenol oxidase (PPO) activity, and browning inhibition rate were evaluated. The results showed that drying with hot air at 65℃ was quickest and resulted in a better color without compromising the FW:DW ratio and rehydration ratio of the fruiting bodies. Furthermore, some reactions that occurred under high temperatures increased the content of protein, amino acids, and total phenolics. Soaking after boiling was the most suitable rehydration method, leading to the lowest PPO activity (39.87 ± 1.35 U/g). All of the four analyzed color protection reagents could significantly inhibit the browning of Yu Muer fruiting bodies under room temperature water rehydration conditions, with a citric acid content of 6 g/L showing the best performance. These results provide technical support for the development of the Yu Muer industry and for promoting the commercial processing of Yu Muer fruiting bodies slices.