Model-based optimization of extraction processes of bioactive compounds from plant sources

In recent years, the utilization of natural compounds has gained significant importance, primarily due to the increasing resistance to antibiotics and the prevalence of chronic diseases associated with the use of synthetic substances. Bioactive components are structures naturally found in different parts of plants and possess various biological activities. The extraction of these components from plants using appropriate methods without degrading their bioactive structure and with high efficiency is of critical importance. Additionally, determining the antioxidant properties of the extracted material and/or components is important. In this study, samples of pomegranate peel, licorice root, and menengiç seeds were extracted using traditional and green methods. The in vitro antioxidant capacity of the extracted materials (DPPH (2,2 diphenyl-1-picrylhydrazil) analysis, ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) analysis), iron (III) reduction capacity (FRAP), total phenolic content (TPC), total flavonoid content (TFC), and saponin content. The highest antioxidant capacity was generally obtained using the ultrasonic-assisted extraction method for pomegranate peel and licorice root, while solvent extraction was more effective for menengiç seeds. In antimicrobial analyses, the most effective extract for S. aureus was pomegranate peel TFVM extract, for E. coli it was pomegranate peel DPPH extract, and for P. digitatum it was pomegranate peel TFVM extract. When the component profiles of the extracts obtained at the optimum points were analyzed by GC-MS, it was observed that the extracts obtained by ultrasonic-assisted extraction had a greater variety of components for pomegranate peel and licorice root, followed by microwave-assisted extraction, soxhlet extraction, and solvent extraction. For menengiç seeds, extracts obtained using both ultrasonic and solvent extraction showed a high variety of components, followed by microwave and Soxhlet extraction. In conclusion, it was determined that the appropriate extraction method and working conditions may vary for each plant species and/or component group, and that antioxidant and antimicrobial activities may also vary depending on the component profile obtained under these conditions.