Antibacterial activity of chitosan biofilm for the conservation of fertile and table eggs

ABSTRACT The aim of this study was to develop a chitosan biofilm against Salmonella enteritidis, for the conservation of fertile and table eggs. Two experiments were performed. Experiment 1: 400 specific pathogen-free table eggs were divided in a completely randomized design into four treatments, five replicates and each replicate with 20 table eggs. Experimental groups were assigned to control and 1, 5 and 10% chitosan treatment. The eggs were immersed in the chitosan solution. They were then exposed to Salmonella enteritidis and stored for 1, 24, 96 and 168h at 4ºC. The eggs were then washed with 10mL of physiological saline solution. Experiment 2: 80 specific pathogen-free fertile eggs were tested, the assays were assigned to control and 1, 5 and 10% chitosan treatment. Each treatment had 20 fertile eggs. The eggs were immersed in the chitosan solution. They were individually weighed and incubated. Egg weight, humidity loss, and hatchability (weight and length of newly hatched chicks) characteristics were assessed. In Experiment 1, comparison between treatments showed differences (P< 0.05) in the total recovered of Salmonella enteritidis on eggshell, with the lower values in 5 y 10% chitosan treatment at 96 y 168h respectively. In Experiment 2, chitosan did not show any effect on the egg weight and chick weight, where the average was 57.44 and 38.23g respectively. The humidity loss and chick length showed differences (P< 0.05), with the lower values in 5 y 10% chitosan treatment. The antibacterial activity of chitosan biofilm provide a practical tool against Salmonella enteritidis in fertile and table eggs because the chitosan did not affect egg weight and chick weight, relevant parameters in the poultry industry.