Fuente: PubMed "nature biotechnology" Food Chem X. 2026 Apr 2;35:103814. doi: 10.1016/j.fochx.2026.103814. eCollection 2026 Apr.ABSTRACTTraditional salted egg production relies on metal ions to regulate alkali penetration during processing. However, excessive metal ion intake poses potential health risks, highlighting the urgent need to develop metal-free processing alternatives. In this study, an ex-shell alkali-induced model was used to investigate the effects of different NaOH concentrations on the physicochemical properties, rheological behavior, and microstructure of duck egg white gels. The results showed that when the NaOH concentration was below 1.0%, gel hardness (107.98 g), elasticity (0.958), viscosity (86.51), and water-holding capacity (60.62%) were significantly enhanced (P < 0.05). Further increasing the NaOH concentration led to obvious gel liquefaction, accompanied by a sharp decline in these properties. FTIR analysis revealed that the ordered gel structure was mainly stabilized by β-sheet structures, together with the continuous transformation of α-helices. The gel formed at 0.8% NaOH exhibited the highest β-sheet content (28%) and excellent structural stability. Rheological measurements indicated that gel viscosity increased with increasing NaOH concentration, and egg white proteins treated with high alkali concentrations showed the earliest flow behavior. Control group comparisons confirmed that simply adjusting the NaOH concentration could produce protein gels with properties comparable to those induced by metal ions. These findings provide important theoretical support and practical guidance for the industrial production of safe, metal-free preserved eggs.PMID:42006654 | PMC:PMC13090318 | DOI:10.1016/j.fochx.2026.103814