Effect of dielectric barrier discharge (DBD) cold plasma-activated water pre-treatment on the drying properties, kinetic parameters, and physicochemical and functional properties of Centella asiatica leaves

Centella asiatica L. (CA) is a medicinal plant that gained significant commercial and research interest because of its bioactive compounds, which have functional properties such as antioxidant activity. However, it must be dried before use to improve its shelf life and prepare it for food and pharmaceutical applications. Therefore, in this investigation CA leaves were pre-treated with blanching and cold plasma activated water (CPAW), followed by recirculatory hot air and vacuum drying at 40, 50, and 60 degrees C. Vacuum-drying took 150-720 min, while hot-air drying took 60-180 min to dry. Page and Logarithmic models best fit for leaf drying kinetics, according to AIC, with R2 between 0.966 and 0.999 and RMSE between 0.001 and 0.069. CPAW pre-treatment increased leaf quality more than blanching in vacuum drying. Drying leaves at 40 degrees C boosted antioxidants (4021.462 mu g TE (g dw)-1 and 3.356 mg GAEAC (g dw)-1), TPC (35.049 mg GAE (g dw)-1), and TFC (311.274 mg QE (g dw)-1) and is recommended. Vacuum-drying with CPAW pre-treatment preserved leaf microstructure better than hot-air drying. This study illuminates CA leaf drying behaviour and allow mass production without damaging bioac-tive components. These results could be used as a roadmap for future technological advances that will make it possible to use the bioactive components of CA in food formulation.

Automated summary

In this study, Centella asiatica L. (CA) leaves were pre-treated with blanching and cold plasma activated water (CPAW), followed by recirculatory hot air and vacuum drying at different temperatures. The results showed that CPAW pre-treatment improved leaf quality more effectively than blanching, and vacuum drying at 40 degrees Celsius resulted in increased antioxidants and better preserved leaf microstructure. This study provides insights into the drying behavior of CA leaves and offers a technological roadmap for utilizing the bioactive components of CA in food formulation.