Effect of Nut Treatments on Shea Butter Physicochemical Criteria and Wrapper Hygienic Quality Influence on Microbiological Properties

Abstract

The increasing importance of traditional shea butter led to standards criteria establishment. Nevertheless, criteria are difficultly achieved because traditional processes are generally uncontrolled. In this study, optimal processing conditions in order to get shea butter in conformity with standard were determined. Hence, the drying duration and mode, the kernel quality and roasting time were varied. The wrapper hygienic quality effect was also considered. Resulting shea butters of each variation was analyzed and the ANOVA test performed on characteristics to evaluate variations effects. The peroxide index increased continuously (2.79 ± 0.05 to 10.30 ± 0.05 mEg O 2 /kg) from the first week to the fourth sun drying week, while unsapnifiable matter decreased (17.60 ± 0.05 to 1.55 ± 0.05%). Both peroxide and acid index were higher after five minutes of roasting than they were before; and shea butter conserved in sterile wrapper was germs free, compared to other wrappers. Moreover, the process taking into account all these optimal conditions conduced to shea butter with moisture (0.15%), acid (11.94 mg KOH/g), peroxide (2.79 ± 0.05 mEg O 2 /kg), saponifiable (196.10 ± 0.15 mg KOH/g), refractive (1.465 ± 0.005) index and melting point (35.0 ± 0.1 °C) conforming to international standard. Moreover, it was heavy metal and germs free, and its unsapnifiable content (17.61 ± 0.25%) was high.