Actividad antimicrobiana de recubrimientos de Quitosano y Ɛ-polisina en moras inoculadas con Escherichia coli, Salmonella enterica y Botrytis cinerea

Abstract

The aim of this research was to study the antimicrobial activity of chitosan and ε-polylysine coatings on blackberries (Rubus glaucus Benth) inoculated with Escherichia coli, Salmonella enterica (103 cfu•g-1) and Botrytis cinerea (103 conidias•ml-1). The inoculated blackberries were stored at 6 ± 1 °C for 10 days and microbiological analyses were evaluated every two days. Maximum inhibition of E. coli growth with chitosan coating was 3,22 log cfu•g-1 and S. enterica was 3,24 log cfu•g-1 for ten days of evaluation while growth of B. cinerea was inhibited in day 8. Likewise, ε-polylysine coating inhibited S. enterica growth during ten days and, on days 8 and 10, it reduced also the proliferation of E. coli (2,88 and 3,22 log cfu•g-1, respectively) and B. cinerea. Blackberries’ acid pH enhanced both, pathogenic bacteria’s inhibition and growth of the mold B. cinerea. From this work, it was concluded that chitosan and ε-polylysine coatings have antibacterial and antifungal activity and that this activity was higher as the exposure time of the coating with the microorganisms was longer.