Preventing alkali-injury in heavy metal-free preserved eggs: Model development

The development of heavy metal-free preserved eggs (HMF-PE) has become a focal point of interest. Given the absence of plugging effect of heavy metals, the key in HMF-PE process is to quickly remove HMF-PE from the curing tank when the gel quality of its egg white (PEW) reaches peak to prevent "alkali injury". Our research confirms that the free alkalinity in the PEW conforms to a first-order kinetic model at 15, 20, and 25 ℃. Ultimately, based on the Gaussian equation, a predictive model for the comprehensive quality score of the PEW based on free alkalinity was constructed. Using this model to determine the optimal tank exit timing has resulted in a quality of HMF-PE that rivals commercial products, especially for those cured for 11 days at 25 ℃. This study establishes a theoretical foundation for the strategic harvesting of HMF-PE at the peak of their gel quality.