Microencapsulation via Spray-Drying of Geraniol-Loaded Emulsions Stabilized by Marine Exopolysaccharide for Enhanced Antimicrobial Activity

Ichrak Joulak; Samia Azabou; Emilie Dumas; Filomena Freitas; Hamadi Attia; Adem Gharsallaoui

doi:10.3390/life13101958

Microencapsulation via Spray-Drying of Geraniol-Loaded Emulsions Stabilized by Marine Exopolysaccharide for Enhanced Antimicrobial Activity

Life (Basel). 2023 Sep 25;13(10):1958. doi: 10.3390/life13101958.

Authors

Ichrak Joulak¹, Samia Azabou¹, Emilie Dumas², Filomena Freitas^{3

4}, Hamadi Attia¹, Adem Gharsallaoui²

Affiliations

¹ Laboratoire Analyse Valorisation et Sécurité des Aliments, Université de Sfax, ENIS, Sfax 3038, Tunisia.
² CNRS, LAGEPP UMR 5007, University of Lyon, Université Claude Bernard Lyon 1, 43 Bd 11 Novembre 1918, 69622 Villeurbanne, France.
³ Associate Laboratory i4HB-Institute for Health and Bioeconomy, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.
⁴ UCIBIO-Applied Molecular Biosciences Unit, Department of Chemistry, School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal.

Abstract

The current study investigates the formation of microencapsulated geraniol powder, with the exopolysaccharide EPS-K1B3 produced by Halomonas caseinilytica K1, as wall material, using spray-drying. Evaluation of the antimicrobial activity of the functional emulsions, prepared at either pH 5 or pH 7, was carried out against Gram-positive (Listeria innocua (ATCC 33090)) and Gram-negative (Escherichia coli (DSM682)) bacterial strains. Results showed prolonged antimicrobial efficacy until 30 days of incubation for geraniol microcapsules compared to wet geraniol emulsions, which could confirm the ability of the spray-drying process to protect encapsulated geraniol for a longer period. The highest antimicrobial efficacy of geraniol microcapsules was observed against L. innocua at pH 5. Therefore, the influence of pH on the functional property of geraniol microcapsules could be highlighted beside the targeted bacterial strain.

Keywords: antimicrobial activity; exopolysaccharide; geraniol; microencapsulation; oil/water emulsion; spray-drying.

Grants and funding

This work was supported by the Ministry of Higher Education and Scientific Research, Tunisia, through the scholarship program under the project” Mobility to Encourage Young Tunisian Researchers” (No. 19PEJC07-02, 2019). This work received financial support from FCT—Fundação para a Ciência e a Tecnologia, I.P. (Portugal), in the scope of projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO, and project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB.