Investigation of phenolic, flavonoid, and antioxidant recovery and solubility from Roselle using supercritical carbon dioxide: Experiment and modeling

Abstract

The purpose of this work was to determine the optimal conditions for recovering high yields of total phenolic compounds (TPC), total flavonoid compounds (TFC), and antioxidant activity (AA) from roselle (Hibiscus sabdariffa) by employing supercritical carbon dioxide (ScCO2). The solubility of yield, phenolic, and flavonoid in ScCO2 was estimated using solubility models. Pressure (10 to 20 MPa), temperature (40 to 60°C), and flow rate (3 to 5 ml/min) were used as factors in this investigation. According to the response surface methodology (RSM), the optimal conditions were 20 MPa, 40°C, and 4.875 ml/min, yielding 14.11%, 935.48 mgGAE/L TPC, 812.16 mgQUE/L TFC, and 98.59% antioxidant activity, respectively. With 5.29%, 1.28%, and 1.34% of average absolute relative deviation (AARD), the Putra model provided the best connection to the yield extract, phenolic, and flavonoid solubility. The use of RSM and modeling was effective in attaining a high production and concentration of phenolic compounds. Practical applications: Roselle (Hibiscus sabdariffa) comprises several beneficial components, including phenolic, flavonoid, and antioxidant substances. It is used to treat pyrexia, liver damage, hypertension, and leukemia, among other conditions. Toxic and conventional solvents, on the other hand, have often been utilized to recover these valuable compounds. To alleviate these disadvantages, the important chemicals in roselle are extracted using supercritical carbon dioxide (ScCO2). The solubility behavior of oil yield, phenolic, and flavonoid compounds was determined in this work using a semi-empirical model. The data indicate that an endothermic process occurred to enhance the solubility of yield extract and the exothermic process is suitable for the phenolic and flavonoid recovery.