Socio-productive diagnosis and solar dryer co-design for post-harvest loss reduction in rural communities

Food loss in rural Latin American communities is aggravated by limited postharvest infrastructure and poor market access, reducing food security and constraining opportunities for value addition. In northeastern Colombia, this particularly affects crops whose transformation could generate income but is restricted by deficient roads and limited governmental support. Solar dehydration represents a sustainable alternative to extend shelf life, facilitate transport, and strengthen short food supply chains. This study aimed to design, construct, and evaluate a passive solar dryer adapted to local productive, social, and environmental conditions through a participatory co-design process. A socio-productive diagnosis revealed land-use restrictions, precarious infrastructure, and a diversified but fragile economy dependent on perishable products. These findings guided decisions on materials, structure, load capacity, and modularity of the dryer. The co-designed solar dryer achieved an overall thermal energy efficiency of 49 %, consistent with values reported for passive solar drying systems under comparable climatic conditions, maintaining internal temperatures up to 13 °C above ambient and relative humidity below 40 %. Drying tests for plantain and banana reached safe moisture levels in 9.4 h and 8.9 h, respectively. Products showed acceptable physicochemical composition and absence of pathogens. To our knowledge, this is the first report in Colombia that explicitly integrates a socio-productive diagnosis with a participatory co-design, construction, and evaluation of a passive solar dryer, providing a replicable model for reducing post-harvest losses and strengthening local value chains.