Ultrasound-assisted convective drying of white mushrooms (Agaricus bisporus)

In this study, white mushrooms were dried in a laboratory hybrid dryer, equipped with an airborne ultrasound system. The effects of ultrasound power of 100 and 200 W combined with hot air at two temperatures of 50 and 70 degrees C were analyzed. The drying processes were assessed in terms of kinetics (drying rate and time), specific energy consumption, and product quality (relative color change, water activity, total polyphenol content, and visual appearance). Moreover, based on the approximation of the experimental data the effective diffusion coefficients were estimated. It was found that the application of ultrasound improved the kinetics of convective drying (increased the drying rate and reduced the time of drying) without compromising the quality of the products obtained. After ultrasound-assisted drying the mushroom samples were characterized by smaller color changes, higher phenolic content, and softer peel. The results obtained from the approximation of the experimental data also confirmed the positive effect of ultrasound on the drying process. For the ultrasonically assisted processes, both the effective diffusion and the mass transfer coefficients were higher. Taking into account the more favorable results it was stated that the higher the ultrasound power and air temperature, the better the drying performance.

Automated summary

This study investigated the drying of white mushrooms using a laboratory hybrid dryer with an airborne ultrasound system. The results showed that the application of ultrasound improved the drying kinetics, increasing the drying rate and reducing the drying time, while maintaining the product quality. Ultrasound-assisted drying resulted in smaller color changes, higher phenolic content, and softer peel in the mushroom samples. The approximation of the experimental data also confirmed the positive effect of ultrasound on the drying process.