Scaling cool boxes to enhance the shelf life of fruit and vegetables in fresh produce markets in Tanzania

Mwambi, Mercy; Mvungi, Henry; and Ernest, Zablon. 2025. Scaling cool boxes to enhance the shelf life of fruit and vegetables in fresh produce markets in Tanzania. FRESH Initiative Activity Report. World Vegetable Center. https://hdl.handle.net/10568/174073

Food loss has become a fundamental issue for nutritional security, especially in developing countries. One-third of food produced globally is lost or wasted along the food supply chain (FAO, 2011). Fruits and vegetables are very susceptible to postharvest losses. Reducing the losses of these micronutrient-rich products is essential to enhancing food security (Timmermans et al., 2014). One effective way to reduce losses is through the integration of a cold chain between farmers and consumers. However, conventional cold chain solutions, typically reliant on grid-powered refrigeration, are challenging to use, particularly in rural areas of developing countries such as Tanzania. Barriers include high technology costs, frequent power outages, and a lack of technical skills for effective management (Makule et al., 2022). Alternative solutions, such as off-grid evaporative cooling technologies and solar-powered cold storage, have shown promise. These technologies can reduce temperatures by 2 to 15 degrees Celsius and increase relative humidity to 70–100%, thus slowing down food degradation (Ambuko & Owino, 2023). However, adoption remains limited due to a lack of knowledge, inaccessibility of suitable materials, unreliable water supply, and high initial capital requirements for small-scale operators (Kanali et al., 2017). The Fruit and Vegetables for Sustainable Healthy Diets (FRESH) Initiative is working with partners to address postharvest losses and food safety challenges. The work is implemented by the World Vegetable Center (WorldVeg) in Tanzania, Wageningen University & Research (WUR) from the Netherlands, and Applied Horticultural Research (AHR) from Australia. WorldVeg piloted technologies to improve food safety and reduce postharvest losses, including plastic crates, paper-lined wooden crates, and cool boxes, through a demand-led and co-creative approach. The aim was to assess the effectiveness of these technologies and design a scaling strategy for the successful ones. The target users were middle-stream actors, including vegetable collectors, wholesalers, and retailers in the Arusha and Kilimanjaro regions. The cool box pilot (Fig. 1) showed promising results when tested with leafy vegetables and sweet peppers: retailers using the box saved an average of USD 2.90 per day. Those who did not use the technology lost USD 2.3 per day; the net benefit of using a cool box while considering variable costs was estimated at USD 168.0 per month per retailer which was more than double the amount received by non-users (USD 63); and improved quality was perceived as the biggest advantage of using the cool box because vegetables stored in the box retained freshness, color, and smell as opposed to the traditional practice of overnight storage in ambient conditions that resulted in quality deterioration. However, small-scale vendors identified the high cost of the cool boxes and a lack of awareness as constraints during the pilot (Mwambi et al., 2025). This assessment explores scaling strategies, considering the benefits and challenges of using a cool box. We applied the Scaling Scan Tool (Woltering and Valencia, 2023) - a practical tool for determining opportunities and challenges to scale innovations sustainably to formulate several alternative scaling strategies.