Comparative Evaluation of Mechanical and Solvent-Based Shea Nut Oil Extraction from Shea Nut Seeds

Solvent extraction and mechanical extraction are the two main methods for oil extraction from oil-bearing materials, each with unique advantages and drawbacks. Understanding these differences is crucial for businesses seeking efficient oil recovery. Ongoing global research aims to enhance the quantity and quality of essential oils, including shea butter derived from the seeds of the shea tree (Vitellaria paradoxa), which is prevalent in Africa. This study specifically focused on these two extraction techniques: mechanical extraction and optimized solvent extraction. In this study, the extraction of shea nut oil was optimized using Box-Behnken Design (BBD) and Response Surface Methodology (RSM). Key factors included reaction temperature (50 to 100°C), duration (30 to 60 minutes), and solid-to-liquid ratio (2 to 10). The optimized process yielded 44.39% shea nut oil through solvent extraction, with properties such as density (0.9336), viscosity (92), acid value (26.367 mg KOH/g), free fatty acids (13.184 mg KOH/g), saponification value (213.567 mg KOH/g), peroxide value (172 meq O₂/kg), iodine value (114.21 g I₂/100 g), flash point (230°C), pour point (15°C), and cloud point (17°C). The yield of 36.23 % shea nut oil was achieved by mechanical extraction with density of at 0.914, viscosity of 94, acid value of trace mg KOH/g, FFA of trace mg KOH/g, saponification value of 220.2 mg KOH/g, peroxide value of 169 milli equivalent O2/kg, iodine value of 116.3 gram I₂/100g, flash point of 235oC, pour point of 170C, cloud point of 190C. The mechanically and solvent extracted shown to meet global standards. The mechanical extraction technique yielded superior oil compared to the solvent extraction method, making it preferable for food, biodiesel, cosmetics, medicine, and pharmaceuticals. FTIR analysis identified key functional groups, confirming the oil's moisturizing properties. Additionally, with optimal conditions at 75°C and a solid-to-liquid ratio of 6 w/v, and 45 minutes reaction time, the highest yield for solvent extraction reached 44.39%, while mechanical extraction yielded 36.23%.

Response surface methodology, solvent extraction, shea nut seeds

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