Gratitude - Gains from Losses of Root and Tuber Crops

Gratitude will help find solutions that will reduce waste from post-harvest losses of root and tuber crops and turn unavoidable waste into something of value.


Cassava and yam are important food security crops for approximately 700 million people. However, losses after harvesting and during processing can be as high as 60% (in the case of yam, 30% for cassava), which is not only detrimental to food security and the environment but also means that opportunities to increase the value generated from these crops are lost.

Post harvest losses are significant and come in three forms:

  • physical;
  • economic (through discounting, or processing into low value products);
  • from bio-wastes.

The Gratitude project aims to reduce these losses to enhance the role that these crops play in food and income security. Post-harvest physical losses are exceptionally high (approximately 30% in cassava and 60% in yam) and occur throughout the food chain. Losses in economic value are also high (eg. Cassava prices discounted by up to 85% within a couple of days of harvest). Wastes come in various forms eg. Peeling losses can be 15-20%. Waste often has no economic value which can make processing a marginal business proposition.


The overall objective of Gratitude (Gains from Losses of Root and Tuber Crops) is to improve the post-harvest management of cassava and yams leading to reduced physical losses, reduced economic losses through value-added processing and valorization of waste products.

There are 3 impact pathways for this project:

  • Reduction of physical losses – focusing on fresh yam storage.
  • Value-added processing reducing physical and economic losses in yam and cassava.
  • Improved utilization of wastes (peels, liquid waste, spent brewery waste) producing products for consumption including snack foods, mushrooms and animal feed.

Technologies and systems developed and validated within the Gratitude project will particularly benefit small-holder households, and will support small and medium scale enterprises to increase profitability, create new jobs and develop links to large-scale industry. This project will help improve the livelihoods of people on low incomes and enhance the role that these crops play in food and income security.