application of response surface methodology (rsm) for the optimization of supercritical co2 extraction of elaeagnus protein: a comparison study

Elaeagnus contains a large amount of protein which can be used as a functional ingredient. in this study, dried fruit protein was extracted using supercritical carbon dioxide method. extraction was performed at different supercritical temperatures, supercritical pressure, and solvent ratio of carbon dioxide and methanol. according to the anova results, the optimum operating condition for the extraction of protein with supercritical co2 was as following:150.85 bar, 51.06 °c, 59.80 min and methanol aqueous solvent concentration of 717.08 micro;l, leading to extracting of 47.53 mg protein per 10 g sample. compared to other extraction methods, the amount of extracted protein was high with this method. in addition, less damage was done to other physical-chemical properties of the protein, including protein structure, amino acid chains, etc. among the operating conditions, supercritical pressure had the highest effect on proteins. therefore, the results of this study suggested that the supercritical carbon dioxide extraction can be sued as an effective method for protein extraction from plants.