Determination of Microbial Activity and Quality Traits of Eggs Coated with Propolis

Abstract

Eggs were coated with propolis in order to determine its effect on egg quality and total bacterial count. Effect of storage time prior to propolis coating was also studied. Eggs were obtained from a local farm, coated with 0, 3, 6 or 9% of propolis and stored at 4 ºC with a humidity of 75% for 30 days. A total of 18 eggs were used for egg quality traits and 6 eggs were chosen for microbial activity for each group. Bacteria were recovered with sterile cotton swabs from egg surfaces. Colonies with different morphology and color were detected. 11 bacterial species were determined following the characterization of 14 isolates. Elevated levels of bacterial counts were detected for daily eggs, which were significantly higher than those stored for 30 days. The quality traits of the daily eggs have also been found higher compared with the other groups. It was observed that coating the eggs with varying concentrations of propolis lead to significant differences in the total bacterial counts of the eggshells. Moreover, the egg quality traits which decreased with the increase in storage time have not been further affected with propolis coating.