ANÁLISE QUÍMICA DO ÓLEO BRUTO DE Pennisetum glaucum (L.) R. Br

Abstract

ABSTRACT Millet oil, obtained from the grains of a cereal grown predominantly in arid and semi-arid regions, stands out for its high resistance to adverse climatic conditions and its significant nutritional value. In this study, the chemical composition and functional potential of this oil for applications in the food industry were investigated. The crude oil was obtained by exhaustive extraction, followed by analyses to determine the fatty acid profile, physical-chemical parameters, oxidative stability by the Rancimat method, thermogravimetric evaluation (TG/DTG), and thermal characterization by differential scanning calorimetry (DSC). The fatty acid composition revealed 22.09% saturated fatty acids, with a predominance of palmitic acid (17.30%), 26.42% monounsaturated fatty acids, with elaidic acid (26.16%) standing out, and 50.83% polyunsaturated fatty acids, with linoleic acid (48.03%) prevailing. The physical-chemical parameters showed acidity of 3.30 mg KOH/g, peroxide value of 9.01 mEqO₂/kg, and saponification index of 22.79 mg KOH/g. Oxidative stability, determined by Rancimat, indicated induction periods of 6.41 and 6.50 hours. TG/DTG analysis showed a mass loss of 2.7% in the range of 180–280 °C and 97.3% between 280–480 °C, associated with the thermal degradation of fatty acids. Thermal characterization by DSC showed exothermic crystallization peaks at -41 °C and -18 °C, and endothermic melting peaks at -4 °C and -32 °C, reflecting the phase transitions of the lipid matrix. These results provide fundamental information for understanding the physicochemical properties and stability of millet oil, supporting its potential use in food formulations and industrial applications.