Production, structure, and performance of guar gum based bacterial cellulose generated from soy sauce residue hydrolysate by in-situ fermentation

Guar gum based bacterial cellulose (GG-BC) was generated from the soy sauce residue hydrolysate by in-situ fermentation, and its structure and performance were learned systematically. The GG concentration of 0.2 % was most suitable for GG-BC production with the yield of 1.21 g/L. During the in-situ fermentation, GG was implanted into the nano network of BC and thus altered its microstructure and properties. According to the FT-IR and NMR results, GG-BC had similar functional group structure and cellulose structural framework to those of BC. The degree of polymerization (DP) of GG-BC was 526.32-832.16, which was higher than that (426.32) of BC. Also, the GG-BC with low GG addition (0.2 % and 0.4 %) had a higher crystallinity than BC. Moreover, the GG-BC had a better heat tolerance than BC based on its higher temperature reaching the maximum degradation rate. The GG-BC with suitable GG addition had better texture characteristics, UV barrier property, swelling rate, and antioxidant activity than those of BC, showing that the in-situ fermentation with GG addition could promote the performance of GG-BC. Overall, this study can provide an attractive technology for both solving the environmental issue brought by soy sauce residue and producing high value-added GG-BC with good performance efficiently.