Microbiota Dynamics and Listeria monocytogenes Inhibition in Vacuum-Packed Brown Bear Meat Treated with β-Cyclodextrin-Encapsulated Essential Oil

Abstract

Abstract This study evaluated the microbiological quality and microbiota dynamics of brown bear ( Ursus arctos ) meat treated with β-cyclodextrin inclusion complexes of Origanum vulgare essential oil (OVEO/β-CD) and Illicium verum essential oil (IVEO/β-CD) during 21 days of refrigerated vacuum storage at 4 °C. A total of 75 meat samples were prepared and divided into six experimental variants; two variants were artificially inoculated with Listeria monocytogenes CCM 4699. The volatile profile of OVEO/β-CD investigated using HS–SPME–GC–MS technique was characterized by p-cymene (29.1%), limonene (24.2%), and thymol (14.5%), while IVEO/β-CD was dominated by trans-anethole (65.3%), 1,8-cineole (7.6%), and limonene (6.6%). Total viable count (TVC), coliform bacteria, Pseudomonas spp., and L. monocytogenes were monitored on days 0, 3, 7, 14, and 21. Microbial identification was performed by MALDI-TOF MS on isolates from all experimental variants and sampling days. The nonvacuum control showed the highest TVC increase (5.94 log CFU/g on day 21), whereas OVEO/β-CD and IVEO/β-CD groups reached 4.23 and 4.10 log CFU/g, respectively. Pseudomonas spp. were detected exclusively in the nonvacuum control. In inoculated groups, IVEO/β-CD exhibited stronger inhibition of L. monocytogenes growth (3.36 log CFU/g on day 21) compared to OVEO/β-CD (3.94 log CFU/g). A total of 1056 isolates belonging to 46 species were identified by MALDI-TOF MS. The combination of vacuum packaging with IVEO/β-CD represents a promising strategy for extending the microbiological stability of brown bear meat without synthetic preservatives.