Thermodynamics and kinetic studies for the microwave-enhanced extraction of phenolics from Phyllanthus niruri leaves

Phyllanthus niruri is a well-known medicinal plant with diverse pharmacological properties. This medicinal plant possesses different bioactive compounds that include phenolic compounds. In this study, the kinetics on the extraction of phenolics from P. niruri leaves using the microwave-enhanced method was examined to understand the impact of microwave power, sample-to-solvent ratio, and extraction temperature on the second-order model by varying the extraction time. Additionally, the effective diffusivity and functional groups in the leaf extract of P. niruri were determined. The outcome of this study indicated that the intensified microwave-enhanced extraction process yielded total phenolic content of 135.05 mg GAE/g extract. Moreover, the effective diffusivity ranged between 2.619 x 10(-12) and 2.684 x 10(-12) m(2)/s. The results from this study can help in predicting the estimation operation conditions for implementation in the industry. Likewise, fingerprints of the P. niruri leaf extract showed the existence of functional groups related to phenolic compounds.