Tray-Rotating Microwave Vacuum Drying of Scutellaria baicalensis Slices: Multivariate Links Between Bioactive Retention, Color, and Sensory Quality

To improve the drying efficiency and quality of Scutellaria baicalensis (S. baicalensis) for both medicinal and beverage purposes, this study examined the effects of temperature, vacuum degree, and rotation speed during rotary microwave vacuum drying. The study focused on drying kinetics, physicochemical properties, and sensory quality of the Scutellaria slices. Multivariate analyses, including hierarchical cluster and correlation network analyses, were used to explore the relationship between parameters and quality. Results showed that the method significantly reduced drying time and improved moisture migration. It also preserved active components like baicalin, wogonoside, total phenolics, and polysaccharides, with high antioxidant activity maintained. Temperature was the key factor. The best balance was achieved with 50 °C, −75 kPa, and 4.2 rad/s, resulting in high drying efficiency, a sensory acceptability score of 8.8, turbidity of 12.4 NTU, and strong antioxidant capacity. Cluster analysis distinguished microwave-vacuum-dried samples from those dried by traditional methods (natural air-drying and hot-air drying). Correlation network analysis revealed positive links between sensory acceptance, active components, and liquor clarity. This optimized parameter set is recommended for producing high-quality Scutellaria ingredients for consumers.