Review of novel techniques for extracting phytochemical compounds from pomegranate (Punica granatum L.) peel using a combination of different methods

Pomegranate (Punica granatum) belongs to the Punicacea family and is usually known for its bioactive and potential health-promoting properties. Bioactive compounds are secondary metabolites derived from plants that contribute to health-promoting factors. Due to its natural health-enhancing properties, it has been popularly utilized in the nutraceutical and functional food industry. Numerous studies have demonstrated the abundance of bioactive chemicals in pomegranate peel. Various extraction methods are employed to separate bioactive compounds from plant material and serve multiple purposes. Prolonged extraction methods result in the loss of polyphenols by ionization, hydrolysis, and oxidation. Emerging technologies such as high hydrostatic pressure, ultrasound-assisted, pulsed electric field, enzyme-assisted supercritical fluid, microwave-assisted, and combinations are progressively supplanting traditional methods. These methods increase extraction efficiency, improve the quality of phenolics extracted, minimize solvent loss, and reduce extraction time, enhancing the final product. These innovative approaches enhance extraction efficiency and decrease energy consumption. However, these methods face limitations, high capital investment, further optimization, and potential scalability issues. Further research and development are required to overcome these obstacles and fully realize their potential. This review highlights the benefits of combining green approaches and solvents to extract bioactive compounds. It also highlights the synergistic effect of various methods, which enhances the different properties of extracts. Using a combined extraction strategy provides an effective solution for using pomegranate peel, waste valorization, and the development of bioactive products.