Bioactive chitosan based coating incorporated with essential oil to inactivate foodborne pathogen microorganisms and improve quality parameters of beef burger.

Abstract

The aim of this study is to assess the impacts of chitosan (CH) coating with oregano essential oil (OEO) and thyme essential oil (TEO) (0.5%-1.0%; v/w) on the foodborne pathogens and physicochemical parameters of beef burger during refrigerated storage. Preliminary experiment (in vitro) demonstrated that 0.5% OEO and TEO were inhibited all or some of S. aureus, S. Typhimurium, and E. coli O157:H7. On day 30, the E. coli O157:H7 of burger coated with CH + OEO and TEO (1%; w/v) declined by 4 and 5 log₁₀ CFU g^-1, respectively, S. Typhimurium and S. aureus decreases (4,5-6 log₁₀ CFU g^-1) when compared to the control sample. The quality parameters of beef burger were also enhanced after the coating treatment of CH and essential oils (EOs), including pH value, TBARS, and TVB-N in burger during storage (4 °C/30 d). Besides, CH + EOs coating also reduced the deterioration of the sensory attributes of beef burger, including color, odor, and overall acceptability. The chitosan coatings with EOs have superior mechanical qualities than the control sample, also, the structure of the films was evaluated by SEM. In conclusion, CH coating with EOs (OEO, ETO; 1%) regarded as a successful strategy to improve the quality and prolong the shelf life of beef burger.