Effect of Rheological Properties of Sodium Alginate-pectin Composite Solution on the Formation and Texture of Core-shell Capsules

Based on the synergistic gel formation mechanism between sodium alginate and pectin in presence of calcium ion,the sodium alginate-pectin hydrogel beads with shell-core structure,i.e. core-shell capsule,were prepared using reverse spherification technique,by adding the calcium-containing core solution into the sodium alginate-pectin complex solution. The rheological properties of both sodium alginate-pectin complex and the core solution were tested with the texture analyzer and rheometer and their effects on the texture properties of the core-shell capsules were studied. Results indicated that the viscosity of the complex solution gradually decreased gradually with the increase of the proportion of pectin in the complex system. The sodium alginate and pectin hydrogel beads prepared with sodium alginate-pectin ratio of 7:3 (w/w)and the concentration was 0.6%,showed the highest value of maximum force((430.1±24.4) g·cm^-2)and chewability of the outer shell((1054.9±23.4) g).The optimized spherification(standard rate was 100%)and texture properties(the highest value of maximum force was(376.3±18.2) g·cm^-2 the chewability was(1104.0±43.3) g)were obtained with xanthan gum concentration of 0.4% and the calcium lactate concentration of 1.5% in core liquid.