Exposure to cellulose acetate films incorporated with garlic essential oil does not lead to homologous resistance in Listeria innocua ATCC 33090

• Published in: Food research international 2022-10, Vol.160, p.111676-111676, Article 111676
• Main Authors: Marques, Clara Suprani, Arruda, Tarsila Rodrigues, Silva, Rafael Resende Assis, Ferreira, Ana Luiza Valadares, Oliveira, Wilton Luiz de Andrade, Rocha, Felipe, Mendes, Luiza Alves, de Oliveira, Taíla Veloso, Vanetti, Maria Cristina Dantas, Soares, Nilda de Fátima Ferreira
• Format: Article
• Language: English
• Subjects: Active packaging; Bacterial resistance; Cell injury; Cheese; Essential oil; Food preservation; Sustainable packaging
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2022.111676

[Display omitted] •Cellulose acetate-based films with garlic essential oil reduced L. innocua counts.•Exposition to films with 10% of GEO for 10 days at 7 °C injured L. innocua cells.•Homologous resistance was not verified in L. innocua after contact with films.•The active films did not cause significant microbial load reduction in cheese.•GEO could be a safe preservative from the point of view of homologous resistance. Essential oils (EOs) have been considered potential green additives for active food packaging. However, sub-lethal concentrations of EOs may lead to bacterial resistance, which is a concern. In this sense, the effects of 1% (GEO1) and 10% (GEO10) of garlic EO in cellulose acetate-based films regarding homologous resistance in Listeria innocua were investigated after incubation at 37 °C/24 h and 7 °C/10 d. The films were also characterized and tested on sliced mozzarella cheese as interfold packaging for 8-days storage at 7 °C. The EO did not alter the mechanical properties of the films nor their thermal degradation profile. However, GEO10 was less permeable to water vapor than GEO1. When tested against L. innocua, the incubation at 7 °C enhanced the films’ antimicrobial effect: log reductions of 4.3 and 5.7 were obtained for GEO1 and GEO10, respectively. Moreover, 86.3% of L. innocua cells were injured at sub-lethal level when exposed to GEO10. Despite this, no occurrence of homologous resistance was found. When the active films were tested on cheese against the natural microbiota, they resulted in slices of mozzarella with fewer contaminants, however the reduction was not significant. Nevertheless, we considered this an important finding to the food industry since this work suggested that GEO is a safe active compound from the point of view of homologous resistance to be used against Listeria.