Effects of gum incorporation on the properties of sodium alginate-based composite hydrogel beads for encapsulating lactic acid bacteria

To investigate the effects of gum incorporation on the performance of sodium alginate (SA)-based composite hydrogel beads (CHBs) in protecting Limosilactobacillus fermentum , gum arabic, κ-carrageenan, low methoxyl pectin, konjac glucomannan (KGM), low acyl gellan gum, and xanthan gum were compounded with SA to prepare CHBs of A-A, C-A, P-A, K-A, G-A and X-A, respectively. The encapsulation efficiency of CHBs for L. fermentum ranged from 80 % to 100 %, with P-A and X-A showing the greatest encapsulation efficiencies of 94.6 % and 99.3 %, respectively. P-A had the highest L. fermentum survival rate of 8.1 log CFU/g, and the leakage rates of A-A, C-A, P-A, and K-A compared to SA hydrogel beads were 85.74 %, 70.06 %, 87.49 %, and 87.66 %, respectively. Gum incorporation improved the water retention capacity and reducing hardness. Rheological analysis revealed that the addition of gum arabica, κ-carrageenan, and gellan gum increased the critical strain of hydrogel, xanthan gum and KGM reduced the γ C , whereas low methoxyl pectin had no effect on γ C . The introduction of L. fermentum changed the hydrogel properties and increased elasticity, suggesting probiotics might positively influence the hydrogel network. The comprehensive analysis revealed that the CHBs incorporated low methoxyl pectin with SA provided the best protection for L. fermentum .