Investigation on supercritical CO2 extraction of black nightshade berries (Solanum nigrum Linn.)

A set of supercritical extractions (SCE) using carbon dioxide (CO2) has been performed on Solanum nigrum Linn. A design of experiment (DoE) using Box-Behnken was applied to investigate the influential parameters on SCE. The relationship between extraction parameters (i.e., temperature, time, and pressure) and extraction products (i.e., phenolics-TPC, alkaloids-TAC, and flavonoids-TFC) was evaluated. It was found that temperature and pressure are the most influencing parameters in the SCE. Both give a synergistic effect in increasing the extraction yield. The optimum SCE conditions are 333 K, 30 min, and 240 bar; with extraction, yields expressed as TPC, TFC, and TAC are 55.1677 mg GAE/g extract, 28.0308 mg QE/g extract, and 5.9460 mg HYE/g extract, respectively. Solubility data correlations were done by using Chrastil’s model. The adjustable parameters of Chrastil’s model were found to be consistent with their physical meaning and can be applied in the SCE of Solanum nigrum Linn