Encapsulation of lime peel extract in alginate–gelatin microbeads and its potential for browning inhibition in Musa spp. tissue culture

Abstract

Abstract Tissue culture micropropagation is the most effective method for propagating Musa spp. explants; however, enzymatic browning poses a major obstacle. Lime peel extract (LPE) has demonstrated antioxidant activity against browning 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, LPE was encapsulated with a yield of 79.5%, encapsulation efficiency (EE) of 80.93%, and extract content (EC) of 24.2%. The resulting microbeads were approximately spherical, although their surface is slightly irregular, averaging 1.2 μm in size, and exhibited release kinetics consistent with the Korsmeyer-Peppas model, confirming delayed LPE release. The microbeads showed thermal stability up to 100 °C, maintaining 23.26% EC and 77.8% EE over three weeks. LPE microbeads were more effective in reducing the browning index in Kepok Tanjung and Barangan explants compared to unencapsulated LPE. These findings indicate that LPE, particularly in its encapsulated form, can effectively suppress browning in Musa spp. tissue cultures.