Mechanistic Insights Into Transglutaminase Crosslinking Induced Thermal Stability Enhancement in Ambient‐Temperature Solidified Goat Yogurt

This study aims to address the limitations of solidified goat yogurt (SGY) including poor thermal stability and weak gel properties in formulating ambient‐temperature‐stable products. This study systematically investigated the influence of transglutaminase (TG) crosslinking time on the physicochemical properties, gel structure, rheological behavior, and thermal stability of SGY. The results demonstrated that TG crosslinking time exhibited a biphasic effect, initially enhancing and subsequently diminishing the response. Among the tested treatments, TG‐6 showed the most favorable overall performance, with the highest water‐holding capacity (76.06 ± 0.72%), improved springiness and adhesiveness (0.92 ± 0.02, −21.03 ± 3.54 g·sec), a broader linear viscoelastic region (γc = 0.97 ± 0.08%), and the highest thermal transition temperature ( T _m = 140.12°C). The treatment promoted the formation of a tighter and more uniform gel network by facilitating covalent bonding. This was accompanied by a significant increase in intermolecular hydrogen bonding and a protein secondary structure more conducive to network stability. In contrast, the group of 8‐h treatment exhibited particle aggregation, due to excessive covalent bonds restricting molecular mobility and inducing network stress, with water‐holding capacity decreasing to 62.00 ± 4.63% and T _m dropping to 136.78°C. These findings provided valuable insights for utilizing TG to improve the quality and stability of yogurt.