Modeling and optimization of solar-assisted heat pump drying of pumpkin slice

To reduce energy consumption, the time needed of drying, and the loss of ß-carotene content, and ascorbic acid content, response surface methodology (RSM) was employed for optimization.

To reduce energy consumption, the time needed of drying, and the loss of ß-carotene content, and ascorbic acid content, response surface methodology (RSM) was employed for optimization.

The results show that the optimum solar-assisted heat pump drying (SAHPD) conditions for drying pumpkin slice were: drying temperature of 67.40 °C, loading density of 1.05 kg/m³, and material thickness of 4 mm. Under these conditions, slice of pumpkin were dried in 440.637 min, where the unit energy consumption, ascorbic acid content, and ß-carotene content were 16.737 kJ/g, 25.682 mg/ (100–g dried sample), and 10.202 mg/g, respectively. The structure of the samples dried using the optimized SAHPD method exhibited a more complete cell morphology than those dried using heat pump drying when examined using scanning electronic microscopy.

This suggests that the optimized SAHPD conditions used in this study are important for production and processing.