Effect of particle size and drying temperature on drying rate and oil extracted yields of <i>Buccholzia coriacea</i> (MVAN) and <i>Butyrospermum parkii</i> ENGL

Abstract

Summary The effect of particle size and drying temperature on drying rate and oil extracted yields of Buccholzia coriacea (MVAN) and Butyrospermum parkii (ENGL) was investigated. Air drying studies carried out on B. coriacea and B. parkii , tropical food sources subject to high post‐harvest losses, have resulted in the establishment of a significant difference between oil yields extracted from samples of various particle size pretreatments (paste, 4 mm, 8 mm and whole kernels) dried at 45 and 60 °C with the highest oil yield given by the 4 mm thick slices dried at 45 °C. The influence of temperature and particle thickness on the drying rate has been evaluated. The drying constants were found to depend on both temperature and particle thickness. Analysis of the oil extracted from the 4 mm thick slices dried at 45 °C showed that apart from the acid value (52.4%), the saponification (181.2 mg g −1 KOH), peroxide (8.6 meq kg −1 ) and the unsaponifiable (7.43%) matter values of the extracted shea butter remain within the limits cited in the literature while a close analysis of the cake suggests that it could be a good mineral source.