Nanoencapsulation of ultrasound-assisted extracted lemongrass essential oil and bioactive from residues using gum arabic and maltodextrin as wall material.

Gum arabic and maltodextrin are excellent wall material for encapsulating essential oil and bioactives due to their strong emulsifying and film forming ability to form stable matrices that protects the volatile compounds. Lemongrass essential oil (LEO), rich in bioactivity, is extensively used across industries. This study employs green ultrasound-assisted extraction to recover LEO and bioactive compounds from residues, followed by their encapsulation for enhanced stability, presenting a novel strategy to fully utilize lemongrass by-products. Nine ultrasound treatments, varying in amplitude (20, 40, 60 %) and duration (20, 40, 60 min), were analyzed for yield, chemical composition (GC-MS), antioxidant and antimicrobial activities. The treatment A3T2 (60 % amp, 40 min) achieved most favorable treatment with highest oil yield, optimal IC50 value, and demonstrated highest bacterial inactivation, further confirmed by GC-MS profiling. Following LEO extraction, residual lemongrass was methanol-macerated to recover bioactives. Treatment A3T2 showed the highest bioactive yield, and DPPH activity indicating effective recovery of bioactives. For nanoencapsulation, gum arabic showed superior encapsulation efficiency, with lowest particle size and highest zeta potential for oil and bioactives respectively. FTIR spectra of LEO and bioactives showed successful encapsulation in both the wall matrix. The developed nanoencapsulated coating were successfully applied to strawberries, effectively extending shelf life.