Process optimization for the extraction of Shorea robusta (Sal) seed oil using response surface methodology and its  characterization: A sustainable approach to oil valorization

With rising global food insecurity, underutilized oilseeds like <i>Shorea robusta</i> (Sal) offer a sustainable way to diversify edible oil sources and reduce dependence on conventional crops. This study is the first to apply Response Surface Methodology to optimize solvent extraction parameters-solvent volume, seed powder weight, and extraction time-for maximizing Sal seed oil yield. The optimized conditions (20 g seed powder, 399 mL solvent, 4.16 h) achieved a maximum yield of 20.58 %.The oil showed low free fatty acids (0.30 %) and high oxidative stability (peroxide value 1.23 meq O₂/kg). The fatty acid composition was predominantly stearic (45.06 %) and oleic (38.23 %) acids, with a significant presence of γ-linolenic acid (6.86 %), underscoring its nutritional and industrial value. Antioxidant profiling showed high flavonoid (2.01 mg QE/g) and phenolic (3.17 mg GAE/g) contents, indicating strong free radical scavenging activity. These results highlight Sal seed oil as a promising sustainable alternative for food, nutraceutical, and industrial use.