Tackling postharvest tomato losses in Uganda using a passive cooling blanket
Description
In Sub-Saharan Africa, over 40% of fruits and vegetables are lost between farm and consumer. Cooling produce after harvest is key to reducing these losses. Evaporative passive cooling offers a promising solution, especially for smallholder farmers in low- and middle-income countries, but challenges related to cost, scalability, and complexity limit its adoption. To address these challenges, it was developed the charcoal cooling blanket (CCB), an affordable and scalable solution. In a pilot study on Uganda’s tomato supply chain, we tested the CCB against natural shade, aiming to improve tomato storage and transportation. We also evaluated pre-harvest factors such as ripening stage and irrigation scheduling, along with postharvest attributes like weight, firmness, color, soluble solids content (SSC), and acidity. The CCB reduced the average ambient temperature by 1.5°C, with a maximum reduction of up to 20°C during the hottest periods. Relative humidity increased by 10%, reducing tomato shriveling. Storage using the CCB led to up to 10% less weight loss, 20% less firmness loss, slower color change, and a 4% increase in the SSC/pH ratio compared to ambient conditions. Moderate water stress during cultivation, combined with CCB storage, reduced weight loss in green tomatoes by 17%. Overall, the CCB increased the quality index and shelf life of tomatoes by up to 60%. The CCB has shown significant potential in reducing postharvest losses, making it a viable option for preserving fresh produce and improving food security in low- and middle-income countries.