Electrosprayed hydroxypropyl methylcellulose microcapsules containing Rhus microphylla fruit extracts and their application in strawberry (Fragaria × ananassa) preservation

Abstract

Encapsulation is used to incorporate a wide range of compounds, which is beneficial for protecting and improving the bioactivity of plant extracts. In this study, the objectives were to develop hydroxypropyl methylcellulose microcapsules containing two different extracts from Rhus microphylla fruit namely RmA (obtained by conventional agitation) and RmO (obtained by ohmic heating) using electrohydrodynamic processing. The microcapsules were then characterized through Scanning Electron Microscopy (SEM), ATR-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Additionally, the study aimed to evaluate their influence on strawberry shelf life parameters. Spherical microcapsules with a particle size ranged from 2.05 to 2.41 μm were successfully obtained, and FTIR analysis confirmed the proper incorporation of the extracts. The microcapsules containing RmA extract (MC-RmA) exhibited superior antioxidant and antifungal activities in vitro. Consequently, their efficacy in preserving the quality of strawberry fruits during storage at 4 ± 1 °C and 85% relative humidity (RH) was evaluated at concentrations of 0.25% and 0.50% (w/v). After 14 days, the MC-RmA-treated fruits showed reduced weight loss, improved firmness, and unchanged color. Furthermore, the gradual release of antifungal activity from MC-RmA suggests their potential as a novel solution to mitigate postharvest losses in strawberry fruits.