Changing food waste regimes in Tanzania's avocado trade

A new study conducted by researchers from the Universities of Sheffield and Leeds explores the food waste regime in Tanzania’s avocado trade.

Avocados on a market stall
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Fresh fruit is one of the most wasted food items and contributes significantly to food loss in global food supply chains. 

Although there has been a growth in the export of many fruits and vegetables such as onions, tomatoes, green beans, peppers) and spices (cloves), avocados have seen a steady growth like no other. 

A new paper published in the Agriculture and Human Values journal explores the social factors behind food waste in Tanzania's avocado trade, as Africa’s export industry continues to grow. Co-authors of the study include, Dr Megan Blake from the University of Sheffield, and Dr Jonas Cromwell (previously at the University of Sheffield), Professor Claire Quinn and Dr Stephen Whitfield from the University of Leeds. 

The study was conducted between 2018 and 2021, across several sites in Tanzania- Kilimanjaro and Arusha regions, Mbeya and Njombe regions, and Dar es Salaam- and coincided with the main harvesting seasons for domestic and export avocados.

Using the ‘follow the thing’ approach for this study (researchers trace the journey of a specific product throughout its entire lifecycle in the supply chain, from its origin to its consumption, to understand the complex social, economic, and environmental factors involved with its production and distribution), the team tracked avocados from farms to markets (domestic supply chain) and pack houses (export supply chain).

Following the avocado through the supply chain provided crucial insights into how relationships between farmers, brokers, wholesalers, and exporters, along with the perishable nature of avocados, all contribute to waste.

Unequal power dynamics within the supply chain result in some disproportionately bearing the risks and costs associated with food waste more than others. 

In the domestic supply chain, the burden of waste falls heaviest on farmers who are often exploited by those higher up in the chain who use the fruit’s perishability to reject produce and force sales at low prices. The fruit typically ripens within 3-5 days after harvest. 

Once the avocados have been harvested, farmers have to sell at all costs for any price. If disagreements over price lead to increased handling of the fruit, this causes further damage and leads to an increase in product waste. 

In rural–urban wholesale markets, buyers also exploit the perishability of avocados over local brokers, frequently changing prices at short notice. 

The impact of this power imbalance leads to significant food losses and waste, loss of income and is economically time consuming for brokers who, if unable to sell to wholesalers, spend days selling the fruit in small quantities at local retail markets where there’s lower demand. 

In regional markets, agents often use credit systems to shift risk to wholesalers. They exploit situations, such as over-ripened avocados, bad weather, and established norms about causes of losses and who bears those costs. 

Brokers’ and wholesalers’ handling practices can also cause losses and waste further down the supply chain, when they pack as much fruit as possible into sack bags, and reduce transportation and storage-related costs, causing bruising and mechanical damage to the avocados. 

While export markets and their regulations can empower farmers through protecting fair trade and worker’s rights, in practice, food quality regulations can burden farmers with extra costs and compliance requirements who are mainly responsible for meeting Global Good Agricultural Practices (GAP) or retailer regulations. These regulations can also be used by exporters to justify lower prices, fruit rejections, and other actions that shift risk onto the farmers. 

By entering commercial export supply chains, even through farmer associations, this carries significant risks and can create several lines of dependency for producers, especially those in remote locations with limited resources.

Institute for Sustainable Food member and co-author of the study, Dr Megan Blake from the School of Geography and Planning, said, “This research demonstrates that food waste is not always something that just happens accidentally. It is intimately linked to how we design our food systems and what (and who) we value.  It also is a physical by-product of inequalities. It was a great pleasure to have been able to support and work with Jonas Cromwell with this insightful research.” 


Funding

This research was funded by the Economic and Social Research Council [ES/J500215/1] and conducted as part of the four-year White Rose DTP funded PhD project. It was supported by the Food System in Southern Africa for One Health (FoSTA-Health) project and the European Commission’s Horizon Europe programme.

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