Antimicrobial efficacy of liposomes containing d -limonene and its effect on the storage life of blueberries

The purpose of this study was to investigate the antimicrobial activity of unilamellar nano vesicles (liposome) containing d-limonene against selected fruit rotting fungi (Botrytis cinerea and Penicillium chrysogenum) and food borne illness causing bacteria (Escherichia coli and Listeria monocytogenes). Furthermore, the research evaluated the extended shelf life and enhanced food safety of blueberries treated with d-limonene and liposomes. Liposomal nanoparticles were created by thin lipid film hydration followed by sonication. Mean liposome radius was 100.2 ± 3.1 nm. The antibacterial activity against E. coli showed 0.99 and 1.6 log10 reductions in CFU mL−1 at 10 μM and 50 μM, respectively, within 48 h. The log10 reduction was 1.6 at 10 μM and 3.4 at 50 μM for L. monocytogenes. Germination of B. cinerea conidia was completely suppressed over 48 h by a 50 μM concentration of limonene. Liposomes exhibited 2.2 and 2.8 log10 reductions for P. chrysogenum, whereas 3.7 and 4.6 log10 reductions were observed for B. cinerea with 10 μM and 50 μM limonene, respectively. The in vivo study of liposome coatings on blueberries also revealed protection against microbial growth even after nine weeks of storage at 4 °C with liposomes reducing blueberry spoilage by more than 60% at the end of nine weeks. The results of this study can benefit the produce industry through both enhancement of food safety and extending the shelf life of blueberries, further highlighting the commercial applications of liposomes.