Antimicrobial Effectiveness of Bioactive Packaging Materials from Edible Chitosan and Casein Polymers: Assessment on Carrot, Cheese and Salami

MARIA DEL ROSARIO MOREIRA; MARIANA PEREDA; NORMA E. MARCOVICH; SARA I. ROURA

JOURNAL OF FOOD SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Chicago, USA; Año: 2010

0022-1147

Antimicrobial packaging is one of the most promising active packaging systems for controlling spoilage and pathogenic microorganisms. In this work, the intrinsic antimicrobial properties of chitosan (CH) were combined with the excellent thermoplastic and film-forming properties of sodium caseinate (SC) to prepare SC/CH film-forming solutions and films. The antimicrobial effectiveness of SC, CH and SC/CH coatings on the native microfloras of cheese, salami and carrots was evaluated.  In vitro assays through the test tube assay indicated that the most significant antimicrobial effect was achieved by CH and SC/CH solutions on carrot and cheese native microfloras. SC film-forming solutions did not exert antimicrobial activity on any of the native microflora studied. SC, CH and SC/CH films stored in controlled environments showed that the retention of the antimicrobial action was observed until 5 days of storage, at 65% relative humidity in both temperatures (10 ºC and 20 ºC).             In vivo assays were also performed with SC, CH and SC/CH applied as coatings or wrappers on the three food substrates. CH and SC/CH applied at both immersion and wrapper exerted a significant bactericidal action on mesophilic, psychrotrophic and yeasts and molds counts, showing the three microbial populations analyzed a significant reduction (2.0 to 4.5 log CFU g-1). An improvement of the bactericidal properties of the CH/SC blend respect to those of the neat CH film is reported. The ionic interaction between both macromolecules enhances its antimicrobial properties.