Optimization and characterization of oil extracted from Croton macrostachyus seed for antimicrobial activity using experimental analysis of variance

Abstract

The aim of this study was to optimizing the process variables, assessing the phytochemical constituents and antimicrobial activity of the extracted oil from Croton macrostachyus seed by Soxhlet extraction using n-hexane as a solvent. The maximum oil yield of 45.89 % extracted from Croton macrostachyus seed was obtained at a reaction temperature of 70 °C, particle size of 0.5 mm, reaction time of 5 h, and solute to solvent ratio of 0.06 g/ml. The physicochemical properties of the extracted Croton macrostachyus seed oil investigated were; specific gravity of 0.9, the density of 900 kg/m3 at 15 °C, refractive index of 1.461, acid value of 3.5 mg KOH/g, and free fatty acids of 1.75 mg KOH/g, match the relevant international standards of oil quality. The qualitative test analysis of the extracted Croton macrostachyus seed oil showed that the presence of different phytochemical constituents of an antimicrobial activity were flavonoids, alkaloids, tannins, saponins, terpenoids, and phenols. The functional groups and composition of the extracted oil from Croton macrostachyus seeds were determined using FT–IR and GC-MS respectively. The results exhibited that the oil obtained from Croton macrostachyus seeds can be used for modern medicine instead of traditional purposes.