Effect of enzymatic-ultrasonic hydrolyzed chitooligosaccharide on rheology of gelatin incorporated yogurt and 3D printing

Bioactive chitooligosaccharide from enzymatic-ultrasonic hydrolysis of chitosan could work as modification agent for functionalizing the stirred yogurt and promoting the practical application. Microstructure, rheological property, texture, sensory quality, storage stability and 3D printability of the functionalized yogurt were investigated. Compared with chitosan, the obtained chitooligosaccharide has microscopic spherical shapes, more active groups and higher antioxidant activity. Introducing chitooligosaccharide-gelatin composite into yogurt in proper sequence could induce the great microscopic morphology, outstanding particle size distribution of yogurt and satisfactory gel structure. Rheology results further indicate that chitooligosaccharide could promote the structured matrix, great shearing-thinning performance, excellent deformation resistance, enhanced network, high thermo-reversible recuperative structure, great thixotropy and outstanding mechanical strength of yogurt. The fitted flow index and yield stress by Power-law and Herschel-bulkley illustrate the favorable shearing dependence, good extrudability, and satisfactory structure maintainability. Moreover, the prepared yogurt has satisfying texture and sensory quality, and could maintain probiotics at high level and thus great storage stability. The further 3D printed yogurt products on bread, and the further developed yogurts with bioactive ingredients suggest the promise in accelerating more types of nutritional dairy products with high quality and high application value.