Lime peel essential oil microcapsules in alginate-gelatin for antimicrobial use in Musa spp. micropropagation

Abstract

Tissue culture micropropagation is the most effective method for propagating Musa spp. explants; however, microbial contamination poses a major obstacle. Lime peel essential oil (LPO) has demonstrated antimicrobial activity against contaminants in Musa spp. cultures, though its effectiveness is limited by instability and rapid release. Encapsulation technology using sodium alginate and gelatin biopolymers addresses these limitations by protecting active compounds, enabling controlled release, and extending shelf life. In this study, LPO was encapsulated with a yield of 42.35 %, encapsulation efficiency (EE) of 93.01 %, and oil content (OC) of 76.02 %. The resulting microcapsules were spherical, averaging 1.37 µm in size, and exhibited release kinetics consistent with the Avrami model, confirming delayed LPO release. The microcapsules showed thermal stability up to 100 °C, maintaining 45.75 % OC and 56.16 % EE over three weeks. LPO effectively reduced contamination rates (CR) and improving survival rates (SR) in Kepok Tanjung and Barangan explants. Encapsulated LPO provided moderate CR reductions and SR improvements. Both LPO and its encapsulated form significantly enhanced biomass addition and relative growth rate, with higher concentrations yielding the most pronounced effects. These results indicate that LPO, particularly in its encapsulated form, is effective for promoting growth and reducing contamination in Musa spp. tissue cultures.