Comparative efficacy of ultrasound-assisted and hot water extraction of papaya leaves

Introduction: This article describes the optimal process-product characteristics of a bath type sonication and hot water system based aqueous extraction of Carica papaya leaves.Methods: Ultrasound assisted extraction of papaya leaves was conducted to assess the optimal sonication time, extraction temperature and loading ratio with respect to the combinatorial extraction of optimal total polyphenols, total flavonoids and anti-oxidant activity. The experimental runs were designed with the face centred design module of the Design Expert software (Version 7.0.0) and involved 20 alternate combinations (in triplicate) of the chosen degrees of freedom and mentioned responses. Further, hot water extraction was chosen as a control with design variable values set as the optimal value data point obtained from the response surface based numerical optimisation.Results: During both pulse and normal ultrasound extraction of papaya leaves, it was found that the loading ratio followed by extraction temperature and sonication time had a hierarchal critical influence on all evaluated responses. Numerical optimisation subsequently confirmed higher loading ratio at moderate combination of extraction temperature and sonication time. Compared to the reported data, higher response values were obtained in this work. These have been attributed to the sensitive optimality of process parameters and the choice of shade dried leafy samples.Conclusion: This study showed the promising scope of ultrasound-assisted extraction based papaya leafy extraction process and its complimentary role in fostering the utility of unconventional leafy systems-based aqueous extracts in commercial dry herbal supplements.