Response Surface Method Optimizes the Preparation Process of Frozen Chicken Blood Tofu

To efficiently utilize chicken blood, one of the by-products of broiler chickens, the fresh chicken blood was as the main raw material in this study. The peak area of immobilized water in low field nuclear magnetic field was used as the evaluation standard. The effect of different varieties and concentrations of anti-freezing amendments was investigated in the peak area of immobilized water for the frozen chicken blood tofu. Moreover, the preparation process of frozen chicken blood tofu was optimized by response surface design. Furthermore, the water loss rate, texture and color index were analyzed in the optimized frozen chicken blood tofu, which could provide scientific basis for the development of frozen chicken blood tofu products. The results showed that the optimized preparation process of frozen chicken blood tofu was as follows, 0.1% (w/v) of sodium fatty acyllactate, 0.1% (w/v) of potassium alginate, and 2% (w/v) of cassava modified starch. Under this process condition, the low-field nuclear magnetic non-flowing water peak area of frozen chicken blood tofu was 2143, which was the largest compared with the blank group and other treated groups. Therefore, the water retention effect in this study was best. The hardness, chewability, gelability and brightness of the optimized frozen chicken blood tofu were significantly (P<0.05) higher than that of the blank group, which the hardness of the optimized group was 17 times and the brightness was 1.13 time as that of the blank group. Therefore, the preparation process of frozen chicken blood tofu could significantly improve the quality of thawed chicken blood tofu and promote the development of high-value by-product products of broilers.