A New Efficient Enzymatic Method for Producing Chitooligosaccharides and Their Biofunctional Properties Evaluation

The aim of the study is to develop an enzymatic method for obtaining chitooligosaccharides (COS) and to investigate their physicochemical and prebiotic properties. The objects of the study were commercial chitosan, chitosan-glucan complex (ChtsGK) from the fruiting bodies of Ganoderma lucidum, and probiotic strains of Lactobacillus acidophilus, L. casei, L. rhamnosus, L. plantarum, and Bifidobacterium bifidum. Enzymatic hydrolysis was performed using the available preparation Cellolux-A (cellulase – 6000 U/ml, xylanase – 1700 U/ml) at a temperature of 50 °C, pH 5.0 for 24 hours. The physicochemical properties were determined by viscometry and potentiometric titration. Prebiotic activity was assessed by submerged cultivation of probiotics on nutrient media supplemented with 0.5 % COS. The yield of COS from chitosan (94.5 %) exceeds that from ChtsGC (78.4 %). COS from chitosan were characterized by high values of intrinsic viscosity (4.1 dl • g–1), molecular weight (5.4 kDa) and the degree of deacetylation (91.5 %), exceeding the corresponding indicators for COS from ChtsGC by 7.9 %, 68.8 and 24.3 %, respectively. When cultivating probiotics, the highest number of CFU/ml was shown by media with chitosan-based chitosan-containing complexes: L. acidophilus – 2.38 • 108, L. casei – 2.51 • 108, L. rhamnosus – 4.47 • 108, L. plantarum – 4.57 • 108, B. bifidum – 7.04 • 108. An effective method for enzymatic hydrolysis of chitosan from crustaceans and chitosan-glucan complex from higher fungal biomass using an enzyme complex of cellulase and xylanase is proposed, ensuring the production of chitosan with specified characteristics. The use of cellulase and xylanase instead of specific enzymes (chitinase and chitosanase) makes it possible to reduce the costs of obtaining chitosan. The biofunctional properties of chitosan-based COSs, including physicochemical parameters (inherent viscosity, molecular weight, degree of deacetylation) and pronounced prebiotic activity, demonstrate their potential for use as prebiotics. These findings contribute to the improvement of COS-based prebiotic production technologies and the expansion of their use in agriculture and the food industry.