Phytochemistry and agro-industrial potential of native oilseeds from West Africa: African grape (Lannea microcarpa), Marula (Sclerocarya birrea), and butter tree (Pentadesma butyracea)

Abstract

Ethnobotanical investigations on local oilseed species in Burkina Faso revealed that oils from tree oilseeds are frequently used for food, cosmetics and traditional medicine by local people. To test the bio-preservative capacity, the effect of the oilseed extracts on the stabilization of Shea butter was evaluated. Levels of bioactive phyto-components were evaluated through several methods. Some aspects of the quality of oilcakes were evaluated based on their inhibitory capacity on the endogenous digestive enzymes of cattle. For fat stabilizing quality, the extract from Lannea microcarpa Engl. & K. Krause has showed the largest increase (91.47%) in the Rancimat induction time (TIR) of Shea butter. Using DPPH and FRAP methods for prevention or scavenging of free radicals, the results evidenced the highest activity with extracts of L. microcarpa. With respect to the feed quality of the oilcakes, the IC50 obtained with α-amylase and trypsin have showed that the ethanolic extracts of Pentadesma butyracea Sabine (1824) is less toxic for cattle. These results suggest that phenolic compounds extracted from these native oilseeds, especially those of Lannea microcarpa, can be used as biological antioxidants for bio-preservation of edible fats. In addition, the by-products of the oil-extraction can be valorized as nontoxic and protein-rich oilcakes for livestock feed.