Design of bioactive biopolymer coating based on Latilactobacillus curvatus 54M16 producer of bacteriocins to preserve the safety of minimally processed fennel

In this study Latilactobacillus curvatus 54M16 (LAB) producing bacteriocins has been incorporated into a sodium caseinate (SC)/guar gum (GG)/beeswax (BW) blend to develop a bioactive film/coating. Moreover, the coating capacity of preserving the safety and quality of minimally processed fennel has been investigated. Results showed significant antimicrobial activity of the bioactive film against L. innocua C6 during 28 days of storage at 4 degrees C, 10 degrees C, 20 degrees C and 30 degrees C. The presence of LAB did not affect the moisture content, thickness, color, and solubility of the SC/GG/BW films, whereas caused a reduction of the film's stiffness and water vapor permeability. Counts of L. innocua on fennels processed with the active coating showed a significant reduction of about 2 log cycles at the end of storage with respect to the control samples for which L. innocua ranged from 3.42 to 4.13 log CFU/cm2. Moreover, microbial diversity dramatically decreased in samples coated with antimicrobial film, that were dominated by Lactobacillus sp. In conclusion, the developed bioactive coating can be used as an antimicrobial coating to improve minimally processed fennel safety.

Automated summary

In this study, a bioactive film/coating was developed by incorporating Latilactobacillus curvatus 54M16 (LAB) producing bacteriocins into a sodium caseinate (SC)/guar gum (GG)/beeswax (BW) blend, and its coating capacity for preserving the safety and quality of minimally processed fennel was investigated. The bioactive film showed significant antimicrobial activity against L. innocua C6 during 28 days of storage at different temperatures. The presence of LAB did not affect the properties of the SC/GG/BW films, but decreased the film's stiffness and water vapor permeability, contributing to the reduction of L. innocua counts and microbial diversity in the coated fennel samples.