Abstract:

Pork longissimus dorsi (LD) was used as the experimental subject to investigate gel properties of transgluminase (TG) treated porcine myofibrillar protein (MP). Effects of TG concentration on gel strength and water-holding capacity of heatinduced porcine myofibrillar protein were investigated under different pH levels. Meanwhile, the microstructure of porcine myofibrillar protein gel was also observed. Results indicated that the gel strength of porcine myofibrillar protein was significantly improved with TG treatment. The optimal treatment was based on TG-catalyzed hydrolysis with an enzyme dose of 0.3% in a 0.6 mol/L NaCl environment. However, TG additions under different pH levels exhibited obvious different effects on cooking weight loss of protein, including an enhancement effect on cooking weight loss of protein at pH 5.8－6.4 and a reduction effect at pH 6.4－6.7. An improvement in microstructure of heat-induced myofibrillar protein gel was observed under scanning electron microscopy. In conclusion, the textural properties of porcine myofibrillar protein gel can be promoted by TG treatment.

Key words: transgluninase, myofibrillar protein, thermal stability, gel, texture property