American Ginseng Slice Drying and Optimization: Effect of Different Drying Methods on Drying Kinetics and Physicochemical Properties

• Published in: Processes Vol. 12; no. 6; p. 1226
• Main Authors: Wang, Dong, Ma, Minzhuo, Zhao, Zeying, Yuan, Yuejin, Chitrakar, Bimal, Li, Cunliang, Li, Pei, Xiao, Hongwei
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 15.06.2024
• Subjects: Air drying; Air temperature; Efficiency; Energy consumption; Freeze drying; Ginseng; Ginsenosides; Herbal medicine; High temperature air; Ingredients; Kinetics; Methods; Microorganisms; Moisture content; Optimization; Physicochemical properties; Predation; Process parameters; Quality management; Rehydration; Response surface methodology; Temperature; Vacuum; Water content; Beijing China; China
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr12061226

This study compared four drying methods, namely hot-air and vacuum combined drying (HAVCD), hot-air drying (HAD), vacuum drying (VD), and vacuum freeze-drying (VFD), with the aim to select a high-quality and efficient drying method to dry American ginseng slices. Drying kinetics and various physicochemical properties, such as color, rehydration ratio, total ginsenoside content, total ginsenoside residual rate, hardness, and microstructure were explored. An improved multi-indicator test formula method was used to score the experimental results quantitatively. HAVCD resulted in comprehensive advantages, with the highest product score for the dried American ginseng slices. Therefore, HAVCD was subjected to a response surface methodology (RSM) analysis and process optimization. The interaction of hot-air temperature and vacuum temperature on the comprehensive score of American ginseng drying was highly significant (p < 0.01). The optimized and validated process parameters obtained were a hot-air temperature of 57 °C, a vacuum temperature of 54 °C, and a moisture content at the conversion point of 39% (wet basis). Under these conditions, the best drying time was 170 min; the total ginsenoside content was 2.3 mg/100 g; the L* value was 91.68; the rehydration ratio was 3.10; and the comprehensive score was 96.77. The findings of this work indicated HAVCD as a promising drying method for American ginseng slices, considering the drying time and dried-product quality attributes.