Abstract: The enzymatic hydrolysis technique was used to study the preparation of bird′s nest oligopeptides. The degradation behaviors of bird′s nest were studied using four kinds of enzymes. The molecular weight range, amino acid composition and sialic acid content of the bird′s nest were compared before and after enzyme digestion. Animal experiments were used to study the effects of bird′s nest oligopeptides on the activity of immune cells in mice. The results showed that the bird′s nest could be effectively degraded by trypsin and pepsin after heat denaturation at 60℃ and the degradation rate was 96% and 91%， respectively after 4 hours of enzymatic treatment. However, alkaline protease and neutral protease could only partially degrade bird′s nest. After 4 hours digestion, the residue rate of undissolved materials was 40% and 36%， respectively. The molecular weight of oligopeptides after enzymolysis was mainly concentrated in the range of 1 ku to 3 ku. The total protein content of oligopeptides was higher than that of bird′s nests. The sialic acid content after enzymolysis was 14.3%. The results of animal experiments showed that oligopeptides can significantly enhance the proliferation of concanavalin A (Con A)-induced T cell compared with bird′s nest (P>0.05). There was no significant difference in the inhibition of NK cell activity between bird′s nest and oligopeptides (P＜0.05).

Key words: bird′s nest, enzymatic degradation, oligopeptides, preparation technology, bioactivity