Effects of hydrolyzed eggshell membrane and hydrolyzed egg white on the coloration of cured cooked sausages

This study aimed to investigate the effects of hydrolyzed eggshell membrane (HESM) and hydrolyzed egg white (HEW) on the reddening of cured meat products, focusing on their reducing properties. HESM significantly enhanced meat redness of the model sausage, as indicated by the increased redness (a*) values observed compared with those obtained with treatments using HEW, egg white (EW), and control samples. Although HEW improved redness relative to EW and control samples, its efficacy was less than that of HESM. Additionally, 70 % ethanol-extract of HESM effectively reduced Fe³⁺ and lowered the oxidation-reduction potential. The HESM extract also significantly facilitated the formation of nitrosyl myoglobin (NOMb) in myoglobin solutions. However, this effect was significantly lower than that of the maleimide-treated HESM extract, indicating that the thiol groups in HESM are crucial for NOMb formation. Therefore, HESM enhances the coloration of cured meat products by the reducing potential of its thiol groups.