Supercritical carbon dioxide extraction of Capsicum peppers: Global yield and capsaicinoid content

The objective of this study was to select a variety of pepper with high concentration of capsaicin and subject it to supercritical fluid extraction (SFE), in order to determine the best conditions of temperature (40, 50 and 60 °C) and pressure (15, 25 and 35 MPa) in terms of global yield (X0) and capsaicinoids content of the extracts. The influence of drying process (freeze and oven drying) on X0, capsaicin (C) and dihydrocapsaicin (DHC) contents and total phenolics was also analyzed. Capsicum frutescens showed the highest levels of capsaicinoids (1516 μg/g fresh fruit). For the responses C and DHC, the extraction conditions of 15 MPa and 40 °C provided the highest concentrations (C ⿿ 42 mg/g extract and DHC ⿿ 18.5 mg/g extract). The freeze drying process resulted in extracts with the highest concentration of capsaicinoids (61 mg/g extract), but in contrast, the phenolics were less susceptible to different drying processes, with a mean concentration of 35 mg GAE/g extract. The kinetics experiments indicated that the extraction rate of oleoresin was slightly slower than that of capsaicinoids at the operation conditions (40 °C and 15 MPa).