Shea Shells and Press-Cake as New Sources of Bioactive Phenolic Compounds: GC MS Profile and in vitro Antioxidant Activity

Shea nuts shells and press cake are shea butter processing byproducts. Their content in phenolic bioactive compounds and their antioxidant capacity were studied. The total phenolic and flavonoid contents ranged between 16.962-21.395 mg GAE/100g DM and 0.243-1.83 mg QE/100g DM, for press-cake and shells, respectively. Antioxidant capacity values assessed by EC50 using DPPH, ABTS and FRAP methods were in the range of 0.398-0.235 mg/mL, 0.623-0.465 mg/mL and 0.137-0.154 mg/mL for shea press-cake and shells, respectively. Shea shells recorded the highest total phenolic and flavonoid compounds positively correlated with DPPH and ABTS radical scavenging. Catechins, arbutin and gallic acid were the most abundant phenolic compound identified by GC-MS chromatography with 10.4; 2.1 and 0.8 g/100 g in shea shells and 2.2; 2.6 and 2.6 g/100 g in press-cake. Based on this phenolic composition shea nuts shells and press cake could be of great importance in cosmetic and pharmaceutical industries, and also contribute to preventing metabolic and cardiovascular diseases.