Abstract: Glycation of the Maillard–type is now explored to modify the food proteins, aiming to induce the changes in functional property; however, potential impact of this glycation on the immune activities of protein digests in the normal mice is still unknown. In this study, a lactose-glycated caseinate was prepared using the Maillard-type glycation, caseinate, and lactose. Both glycated caseinate and caseinate were digested with trypsin to generate respective glycated caseinate digest and caseinate digest, which were then administered by the normal model mice at dose levels of 100, 200, and 400 mg/kg BW for 28 days. After that, the mice were measured for their immune status by assaying these immune indices such as spleen and thymus indices, hematological parameters, IgM, IgA, and IgG production, lymphocyte proliferation, as well as NK cell activity. The results showed that the mice administered with the two digests had the increased values of these evaluated indices, as compared with those mice administered with physiological saline. The two digests were thus evident able to improve immune statue of the mice. Furthermore, the immuno-enhancing efficacy of caseinate digest was always higher than that of glycated caseinate digest. It is thus concluded that prior caseinate glycation of the Maillard–type decreased the in vivo activity of caseinate digest to enhancing immune status of the mice.

Key words: Caseinate, Maillard reaction, Glycation, Mice, Immune activities