Comparative Study of the Physicochemical and Microbiological Quality of Liquid, Freeze-Dried, Hot Air-Dried, and Pasteurized Quail Eggs Produced in Benin

Abstract

Nutrients in quail eggs can be affected by egg product processing technologies. However, freeze-drying would be the most suitable, but it is very costly and difficult to transfer to the quail egg production actors. This study is aimed at comparing the physicochemical and microbiological qualities of liquid, pasteurized, hot air-dried, and freeze-dried quail eggs. Liquid quail eggs were used as controls. The physicochemical and microbiological qualities were evaluated by conventional methods. The results showed that freeze-dried and hot air-dried quail eggs differed ( $p<0.05$ ) from liquid and pasteurized quail eggs for all the evaluated parameters. On the other hand, pasteurized quail eggs were more concentrated ( $p<0.05$ ) in dry matter ( $45.2\pm 0.06\%$ ) and fat ( $25.8\pm 1.33\%$ ) with a more basic pH ( $7.9\pm 0.20$ ) than liquid eggs. As for microbiological parameters, only total mesophilic aerobic germs were present with a significant difference ( $p<0.05$ ) between liquid ( $2.0\pm 1.4$ log10 CFU/g), hot air-dried ( $2.1\pm 1.5$ log10 CFU/g), and freeze-dried ( $1.8\pm 1.0$ log10 CFU/g) quail eggs, but the load was much lower than the standard (5.7 log10 CFU/g). Total coliforms (0 CFU/g), Enterobacteriaceae (0 CFU/g), yeasts (0 CFU/g), molds (0 CFU/g), Salmonella, and Staphylococcus aureus were absent in all the egg products, while the standards provided 2.0 log10 CFU/g for total coliforms, 1.0 log10 CFU/g for Enterobacteriaceae, Salmonella absent in 25 g, Staphylococcus aureus absent in 1 g, and 2.0 log10 CFU/g for yeasts and molds. In conclusion, hot air-drying and pasteurization are transferable and suitable for the processing of quail eggs.