Extrato de própolis vermelha na conservação de ovos: qualidade interna e análise microbiológica

Abstract

The egg is a food of high nutritional value consumed worldwide. However, it is a perishable product, which soon loses its quality. Thus, studies have been carried out looking for alternative methods that can contribute to maintaining its quality during the storage period and that can control microbial contamination. In this context, the objective was to evaluate the effect of using different concentrations of red propolis residue extract on the internal and microbiological quality of laying hen eggs stored for a period of up to 35 days at room temperature. 432 eggs from commercial laying hens were used, distributed in six treatments with different dilutions of the propolis residue (T1-0%, T2-20%, T3-40%, T4-60%, T5-80% and T6-100%). The design used was completely randomized in a factorial scheme (6 surface treatments x 6 storage periods), with 12 replications. At each storage period, 48 eggs were broken to evaluate: egg weight loss, specific gravity, albumen and yolk pH, Haugh unit and 24 eggs for microbiological analysis: count of viable aerobic mesophilic bacteria (BMAV), total coliforms and Salmonella spp. Different dilutions of red propolis residue and storage periods linearly influenced (P<0.05) weight loss, egg yolk and albumen pH and Haugh unit. There was no effect (P>0.05) of different concentrations of propolis residue on specific gravity. However, it was found that specific gravity values were linearly reduced (P <0.05) the longer the storage time for eggs conditioned at 27.6oC. Contamination by viable aerobic mesophilic bacteria was not observed in samples of eggs coated with different concentrations of red propolis residue extract. Regarding the Total Coliforms count, it was verified that all egg samples, covered with different concentrations of propolis residue, presented values lower than 3 MPN/g. Those found for Salmonella spp indicate that the samples are within microbiological standards. According to the results of the present study, it is concluded that the use of the red propolis residue extract, as an alternative in the coating of the eggshell, maintained the same in an excellent quality standard until the 30th day of storage, being also efficient in maintaining the microbiological quality over the 35 days of storage at room temperature, ensuring safety and desirable characteristics for consumption.