Abstract:

With the aim to improve the stability of protein-polysaccharide blends and to broaden their application in the
food industry, we investigated the effects of the preparation parameters (substrate concentration, blending proportion, pH
and temperature) on rheological characteristics of casein-konjac glucomannan (CS-KGM) blend sol and optimized blending
proportion, pH and temperature based on sol viscosity by using response surface analysis. The results of response surface
analysis showed that when the total substrate concentration was 1.2 g/100 mL, all three selected parameters had significant
effects on sol viscosity and were optimized as follows: a KGM-CS ratio of 6:4, 60 ℃ and pH 6.5. Experiments conducted
under these conditions gave a viscosity value of 33.63 Pa·s, which was closed to the predictive value (35.12 Pa·s). In
addition, a comparative study of storage stability was also carried out, and the results showed that the phase separation times
of the optimized and original samples were 4 and 5 days, respectively. This study indicated that the stability of optimized sol
was significantly higher than that of the original one.

Key words: konjac glucomannan, casein, rheology, response surface methodology, stability