## 2 Methodology of the Study
### Drying Procedure  
The drying tests were conducted using a laboratory rotary hybrid dryer constructed by PROMIS-TECH (Wroclaw, Poland), as shown schematically in Figure 1.  
The dryer has two different techniques for drying: hot air-convective (CV) and microwave (MW). Convective drying utilizes air drawn in by a blower (Figure 1(1)) from the dryer's environment, which, after passing through a heater (5), is forced directly into the dryer drum (12). After passing through the drum, the moistened air leaves the dryer through the outlet duct (7b). Microwave drying is implemented using electromagnetic waves at 2.45 GHz, generated continuously by two water-cooled magnetrons (10), produced by [PERSON] (Reichelsheim, Germany). Additionally, each of the drying techniques may be supported by high-power ultrasound (US) generated by a transducer mounted on the side of the dryer (13) and delivered through the air directly to the material. In the experiment, the frequency of the acoustic waves was 26 kHz, and the maximum acoustic intensity reached 160 dB. The operation of the transducer is controlled by two of the airborne ultrasound system's (AUS) other units, specifically the controller (2) and the preamplifier (3). The system was developed and manufactured by P The research included four drying schemes. Each drying schedule was elaborated on the basis of the convective process (CV) supported by microwaves (MW) and/or ultrasound (US). The temperature and the velocity of the drying agent (air) was constant during the whole research process. The power of the microwave and ultrasonic enhancement was selected in accordance with the results of preliminary experiments. Each drying procedure was carried out in triplicate. Details about the drying conditions for the specified schedules of drying are given in Table 1.  
The weight loss of the samples being dried was measured automatically throughout the whole operation at 5 min intervals using a laboratory balance (Figure 1(11)) model APP/25c (precision 0.01 g), produced by Radway (Radom, Poland). To prevent any potential interference that might affect the accuracy of the mass measurement, the drum of the dryer was temporarily stopped, and the drying air was redirected through a pneumatic valve (6) to the outlet (7a), thus bypassing the chamber. The drying agent's parameters, such as temperature, velocity, and humidity, were also measured throughout the process using two sensors (A, B) models HD29371 TC1.5 and HD4817 ETC1.5 (precision 0.01 m/s, 0.1 \({}^{\circ}\)C, 0.01%), produced by DeltaOHM (Selvazzano Dentro, Italy). All measured data were collected by data acquisition software running on a personal computer (PC). The temperature of the samples during drying was measured using two methods, depending on the process variant. In the convective and convective-ultrasound (CV, CVUS) processes, the temperature (\(T\)) was measured using a standalone HTDL-20 recorder produced by DWYER (Michigan City, IN, USA). Before the test, a single slice of carrot was impaled on the rigid external probe of the device and the whole was placed in the dryer with the other samples. After the drying process, the temperature recorded over time (at one-minute intervals) was read from the device. For the convective-microwave processes (CVMW, CVMWUS), the surface temperature (\(T^{*}\)) was measured using a model B1 infrared thermal camera made by FLIR (Wilsonville, OR, USA). At preset intervals (every 10 min), the drying process was paused in order to take a thermal image--a thermogram--of the