Development of solar-powered drying system for small-scale spice processing

Abstract:

When you compare two ways of doing the same job drying spices in the open sun versus inside a purpose-built solar dryer the differences in quality and consistency are striking. This research designed, fabricated, and evaluated a low-cost natural-convection solar dryer for small-scale spice processing at JNKVV, Jabalpur, India. Four spices (turmeric, chilli, coriander, cumin) were dried in the solar dryer and under open sun simultaneously. The solar dryer reduced drying time by 28-34% compared to open sun drying, while retaining 18-23% more volatile oil and producing significantly brighter colour (higher L* values). The dryer operated at 52-64°C during peak hours with no external energy input. Construction cost was ₹12,400 (approximately $150), making it accessible to small-scale processors. The solar dryer is a practical, zero-energy solution for improving spice quality in central India.