Rain tree (Samanea saman) seed oil: Solvent extraction, optimization and characterization

The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree. The optimization of the factors affecting the extraction process has been carried out by Response Surface Methodology (RSM) technique, and a Box-Behnken Design (BBD) consisting of three process variables has been developed to optimize the yield of oil. Using the RSM technique, the predicted optimum oil yield of 11.15% at an optimized condition of powder weight of 20 g, volume of solvent of 380 mL, and extraction time of 6 h. The physiochemical properties of the oil showed liquid greenish-yellow with 0.88, 1.473 of specific gravity and refractive index, respectively. Similarly, the moisture content, free fatty acid, acid value, saponification value, iodine value, and peroxide value were found to be 0.16%, 13.615, 27.23, 187.1 mg KOH per g oil, 65.8 g I2 per 100 g, and 4.02 meq O2 per kg, respectively. From the obtained results, it was found that the extracted oil could be used for various applications.