Abstract:[Objective] This study aimed to investigate the impacts of enzymatic immobilization strategies on the thermal stability, pH tolerance, and storage stability of transglutaminase (TGase), thereby extending its application range in the food industry and related sectors. [Method] Porous starch (PS), prepared by enzymatic modification, was used as a carrier to immobilize TGase. The immobilization process was optimized by response surface methodology. Fourier transform infrared spectroscopy, differential scanning calorimetry, and enzymatic property experiments were employed to characterize the structure and test the performance of the TGase-PS composite system. [Result] Under optimal conditions (PS at a mass fraction of 12%, pH 7, and TGase at a volume fraction of 42%), the encapsulation efficiency of TGase was 73.93%. Immobilization significantly improved the thermal stability, pH stability, and storage stability of TGase. The TGase-PS composite system retained the relative activity of 69.99% (3.41 times that of free TGase) after incubation at 50 ℃ for 1 h. After 14 d of storage at 25 ℃, its relative activity was 71.01% (1.84 times that of free TGase). Furthermore, the relative activity was still 81.20% after the system was placed under pH 10 for 2 h. [Conclusion] This study significantly enhanced the stability of TGase by constructing a TGase-PS composite system, providing an efficient and green solution for the continuous catalytic application of TGase under high temperatures or extreme pH conditions.
