Effects of Sodium Tripolyphosphate on the Gel Properties of Whole Egg by Thermal Induction

In this paper,the effects of sodium tripolyphosphate(STPP)on the gel properties of heat-induced whole egg gel were investigated using fresh whole egg liquid as the experimental material. Results showed that the heating temperature and STPP concentration had an influence on the texture,color,the presence of water,water holding capacity and LF-NMR of egg gel. As the heating temperature increased from 80 ℃ to 95 ℃,the structure of the protein gel network became more stable,with coinciding increase in the gel strength. While the STPP concentration increased from 0.0% to 0.6%,the hardness and springiness of the gel increased first and then decreased. Thereinto,the gel got the highest hardness and springiness at the addition amount of STPP 0.2%. Moreover,the state of different water inside the gel was detected by low-field nuclear magnetic resonance(LF-NMR)technology. When the heating temperature was raised from 80 ℃ to 90 ℃,the peak relaxation time of T₂₁ and T₂₂ remained unchanged,while T₂₃ increased gradually. The free water content increased,the intermediate water decreased when the heating temperature was 95 ℃. When STPP was added from 0.2% to 0.6%,the immobilized water combined more closely,and the content of intermediate water gradually increased. Combined with various indicators analysis,the results showed that the addition of STPP can improve the texture,color characteristics and the water holding capacity of the heat-induced whole egg gel. The results provided reference for the development and improvement of thermal coagulation egg products.