Improving the textural properties of camel milk acid gel by treatment with trisodium citrate and transglutaminase

Abstract

This study aimed to solve the problems of the weak acid-induced gelation ability of camel milk by the synergistic effect of trisodium citrate and microbial transglutaminase (mTGase). As the trisodium citrate concentration increased from 0 to 30 mmol/L, the final storage modulus of mTGase-treated camel milk acid gels increased from 11.9 ± 0.3 to 72.5 ± 2.4 Pa, the firmness increased from 0.7 ± 0.2 to 1.8 ± 0.1 N, and water holding capacity increased from 41.0 ± 1.8% to 99.6 ± 0.8%. A denser gel network structure with the smallest pore size was observed with 30 mmol/L trisodium citrate, which was selected as the optimum concentration. The number average diameter of the casein particles decreased significantly from 183.5 ± 5.9 to 37.4 ± 3.0 nm and the degree of crosslinking of the acid gel increased significantly from 19.3 ± 1.2% to 38.9 ± 2.4% in the presence of trisodium citrate. This study indicated that smaller casein particles with a higher level of covalent crosslinking can form a camel milk gel with better textural properties, which has enormous potential for manufacture of acid-induced camel milk gel products.