Physicochemical, Phytochemical and Gas Chromatography- Mass Spectrometric Analyses of Gmelina Arborea Root Hexane Extract

Abstract

This study investigates the physicochemical properties, phytochemical composition, and gas chromatography–mass spectrometric (GC-MS) profile of the hexane extract of Gmelina arborea root (GARHE) to evaluate its potential for industrial applications. GC-MS analysis identified five major components. Of these, (9Z,12Z)-octadeca-9,12-dienoic acid (Linoleic acid), a polyunsaturated fatty acid (PUFA), was the most abundant natural compound at 30.90%. Also present were 2,4-Di-tert-butyl-6-nitrophenol (an antioxidant additive) at 2.19% and (9Z)-octadeca-9,17-dienal (an unsaturated aldehyde) at 0.23%. Notably, diisobutyl phthalate (37.47%) and di(2-ethylhexyl) phthalate (29.21%) were identified as significant processing contaminants.The physicochemical properties revealed an acid value of 66.30 mg/g, an iodine value of 61.48 mg/g, and a free fatty acid (FFA) content of 32.07 mg/g. These values suggest a moderate degree of unsaturation and significant hydrolysis, indicating the oil's suitability for applications such as biodiesel production and lubricant formulations rather than direct nutritional uses. Additional parameters, including a peroxidation value of 34.63 mg/g, saponification value of 43.39 mg/g, and esterification value of 22.92 mg/g, further support the extract's industrial relevance due to its oxidative characteristics and high non-saponifiable matter content. Phytochemical screening indicated the absence of alkaloids, flavonoids, phlobatannins, anthraquinones, carotenoids, and glycosides in this hexane extract. However, significant concentrations of terpenoids (133.90 mg/g), saponins (83.00 mg/g), and phenols (18.62 mg/g) were detected, suggesting potential functional benefits in cosmetic and surfactant applications. This comprehensive analysis provides foundational data supporting the industrial utility of Gmelina arborea root hexane extract, particularly in biofuel and lubricant formulations, while highlighting the importance of contamination control during processing.