Sarah Maria Pires Camargo, Helder Freitas de Oliveira, Júlia Marixara Sousa da Silva, Karolyne Moura Nascimento, Deibity Alves Cordeiro, Frederico Lopes da Silva, Renata Rodrigues Gomes, Aline Mondini Calil Racanicci, José Henrique Stringhini
The extension of laying cycles has increased the importance of understanding how eggs produced by older hens respond to storage conditions. This study evaluated the effects of hen age, temperature, and storage duration on internal egg quality, albumen viscosity, and oxidative stability. Eggs from laying hens aged 31, 62, and 88 weeks were maintained under refrigeration or at room temperature and evaluated at the initial assessment and after 10, 20, and 30 days of storage. Internal quality was assessed using the yolk index (YI), albumen index (AI), and Haugh unit (HU). Albumen viscosity, yolk lipid oxidation, and protein oxidation were also determined, consisting of the same three laying hen ages and two storage condition, but considering only two storage periods (1 and 30 days). Storage duration and temperature significantly affected all quality parameters evaluated. Refrigerated eggs maintained relatively high YI, AI, and HU values throughout storage, whereas storage at ambient temperature accelerated quality deterioration. After 30 days, eggs stored at ambient temperature showed marked reductions in internal quality compared to refrigerated eggs. Descriptive patterns suggested a decrease in albumen viscosity during storage, particularly at room temperature, with an apparently greater decline in eggs from older hens. Lipid oxidation increased during storage and was more pronounced in eggs kept at ambient temperature. Refrigeration preserved higher concentrations of free thiol groups in both the albumen and yolk, indicating greater protein stability during storage. It is concluded that storage duration affecting egg quality deterioration, while refrigeration effectively preserved their physical, functional, and oxidative characteristics. Eggs produced by older laying hens are more susceptible to storage-related quality losses, highlighting the importance of refrigerated storage during extended laying cycles.