Development and Performance Evaluation of a Vacuum-Assisted Stirred Dehumidification Machine for Stingless Bee Honey

Stingless bee honey is a premium natural product with high nutritional and medicinal value; however, its naturally high moisture content (30–35%) promotes microbial fermentation, shortens shelf life, and restricts commercial production. This study presents the development of a compact vacuum-assisted dehumidification machine integrated with a drying-time prediction model for community-scale stingless bee honey processing. The system combines indirect hot-water heating, vacuum evaporation, and mechanical agitation to accelerate moisture removal while maintaining stable operating conditions. Drying experiments were conducted using 10 L of a honey-like sugar solution with an initial moisture content of 35%, targeting a final moisture content of 20%. The effects of heating temperature (50 and 70°C), operating pressure (0 and − 80 kPa), and agitation speed (0 and 60 rpm) on drying performance were investigated. Moisture content, soluble solids (°Brix), thermal efficiency, electrical energy consumption, and drying time were determined. Drying kinetics were analyzed using Newton's drying equation, and an empirical regression model was established to predict drying time under different operating conditions. Vacuum pressure was identified as the dominant factor governing moisture removal, followed by heating temperature and agitation speed. The optimum condition (70°C, -80 kPa, and 60 rpm) reduced the moisture content from 35% to 20% within 9 h, whereas 168 h was required under atmospheric pressure at 50°C without agitation. Soluble solids increased from 64 to 79 °Brix during dehydration. Vacuum operation improved thermal efficiency by 4.21–7.76 times and reduced electrical energy consumption to 0.12–0.14 USD kg ^-1 . The proposed machine and predictive model provide an energy-efficient and practical solution for producing high-quality stingless bee honey and support process design, optimization, and scale-up for community enterprises.