Microencapsulation-Based Valorization of Galgal (Citrus pseudolimon L.) Peel Oil: Toward Sustainable Food Protection Solutions.

Abstract

This study aimed to valorize galgal (Citrus pseudolimon L.) peel waste by extracting and microencapsulating its essential oil (EO) for potential food applications. The EO yield was 3.5%, with D-limonene (42.94%) as the major compound. Emulsions were prepared using maltodextrin/gum Arabic in varying ratios with soy lecithin as an emulsifier. The most stable emulsion, based on creaming index, was spray-dried to obtain microcapsules. The powder exhibited 2.52% moisture, 0.243 water activity, 19.78% total oil, and 90.23% encapsulation efficiency. It showed strong antioxidant activity (85.23% DPPH inhibition) and antibacterial activity against S. aureus and E. coli (zones of inhibition: 24.47 mm and 23.75 mm). Particle size ranged from 1-100 µm, with a zeta potential of -15.9 mV, and FE-SEM confirmed uniform morphology. Among LDPE-packed samples, room temperature storage maintained better stability. The study demonstrates that microencapsulated galgal EO offers promising antioxidant and antimicrobial properties for food preservation.