Preparation of casein hydrolysate by two-step enzymatic hydrolysis and its immunomodulatory activities in vitro and in vivo

In this study, casein hydrolysate was prepared by a two-step enzymatic method, and it was demonstrated that casein hydrolysate has good immunomodulatory activity in vitro and in vivo by cell and animal experiments. The casein hydrolysate prepared by two-step enzymatic method was characterized by high hydrolysis, of which 62.70% had molecular weight less than 1000 Da. The results showed that the casein hydrolysate prepared by two-step enzymatic hydrolysis could activate macrophages and promote the phagocytosis of RAW 264.7 cells and the production of inflammatory factors. The results of animal experiments showed that the two-step enzymatic preparation of casein hydrolysate restored T-lymphocyte proliferation and natural killer cell activity and promoted the production of immunoglobulins and serum cytokines (IL-6, IL-1β and TNF-α) in immunocompromised treated mice. This study provides new ideas for developing novel functional foods or nutraceuticals.