Valorisation of immature cereal grains to improve food security in Sub-Saharan Africa: a case study on pepeta in Tanzania

Cereals contributes a substantial proportion of the food supply for humans and animals globally, including in the Sub-Saharan Africa (SSA) where they form a major source of dietary energy and protein intakes as staple foods. Beside their importance to food supplies and health, they contribute to improved income among the most food‐insecure population groups in SSA countries. However, most of cereals are consumed as refined products (dehusked or polished) to improve their sensory properties. This renders the processed cereal-based products of poor nutritional quality as the refining process also removes important nutrients beneficial to health. On the other hand, there is increasing trend of consumers wanting more cereal-based healthy foods containing specific health-promoting properties. In this sense, immature cereal-based products such as pepeta, a locally processed immature rice flakes from Tanzania, appear to be among the many alternatives to pursue the goal of better cereal-based nutrition due to their nutritional potential benefits. It has been found that immature cereals and their products contain higher amount of numerous nutrients beneficial to health, including dietary fiber, vitamins, minerals and phytochemicals, compared to their mature counterparts. This thesis work focused on finding ways to improve the nutritional quality of indigenously processed immature rice-based products by using scientific approach to valorise their utilisation. The present work has increased the scientific knowledge on understanding the nutritional quality, and in-vitro starch and protein digestion properties of immature grains, as well as the changes they undergo upon processing into so-called pepeta. Besides, the best pepeta processing conditions for improvement of specific nutritional and functional properties were recommended. Furthermore, an overview of the opportunities, challenges, and future developments of the utilisation of immature cereals grains and their products was highlighted.