Quality of shea nuts and shea (Vitellaria paradoxa) butter in relation to processing and biodiversity
Fernande Honfo Zannou
Thesis supervisors:Prof. Dr. M.A.J.S. van Boekel
Prof. Dr. M. Soumanou
Dr. Ir. A.R. Linnemann
Dr Ir. N. Akissoé
April 2010 – April 2014
In Benin, shea products constitute an important economic commodity because of their high demand, both locally and internationally. Shea nuts contain 40 to 57% fat, which is traditionally extracted by women to give butter. Their exploitation represents an opportunity for the farming women to achieve economic autonomy. To date, numerous quality problems exist that are associated with the production, the processing and the packaging of shea products. Consequently, the products do not satisfy the customers’ requirements.
This thesis focuses on the critical processing operations that affect the quality of shea products.
Literature study. This study was done to assess the state-of-the-art of shea products at national, and international level. This review focused on macronutrients and micronutrients of pulp, kernels and butter of the shea tree and also on the physicochemical properties of shea butter. Large variations are observed in the reported values for the composition of shea products. Lab methods of analysis, sample provenance and biological variation are major causes of these variations. Explorative study. This study was done to assess the indigenous knowledge of the shea and the processing of its nuts, and define butter quality according to local actors. The results showed two practices to process shea kernels (boiling followed by sun-drying and smoking) and extract shea butter. A relation between parklands, gathering period and sun-drying conditions was established. Moisture content and appearance of kernels were the selection criteria for users of shea kernels; colour was the main characteristic to buy butter. Currently some experiments are done to evaluate the impact of processing on the quality of shea kernels and butter. Future research: Next studies will focus on the assessment of the impact of storage conditions on butter quality and the impact of genetic diversity of the shea population on the quality of its products.
ReferencesHonfo G.F., Akissoe N., Linnemann A., Soumanou M., Van Boekel M.A.J.S. Nutritional composition of shea products and chemical properties of shea butter: A review. Critical Reviews on Food Science and Nutrition. (Accepted)
Honfo G.F., Linnemann A., Akissoe N., Soumanou M., Van Boekel M.A.J.S. Indigenous knowledge of shea processing and quality perception of shea products in Benin. Ecology of Food and Nutrition. (Submitted)