Studies on the physicochemical characteristics of volatile oil from pepper (Piper nigrum) extracted by supercritical carbon dioxide

Pepper (Piper nigrum L) volatile oil was extracted with supercritical fluid carbon dioxide at pressures of 8 and 10 MPa and at two different temperatures, 40°C and 60°C. The mass transfer rates are presented at different supercritical conditions of extraction, together with the fractionation effect that was observed. The volatile oil obtained was analysed for its physical constants: specific gravity, refractive index and optical rotation. The samples were fractionated by column chromatography, and both the samples and fractions were subjected to TLC, gas chromatography and sensory analysis. It was observed that pepper oil obtained with supercritical fluid carbon dioxide at 10 MPa and 60°C was superior to steam‐distilled oil.