Increasing the stewing temperature promoted digestion and absorption of edible bird's nest glycoprotein

BACKGROUND: This study investigated the effect of the stewing temperature on digestion and absorption of edible bird's nest. Specifically, edible bird's nest was stewed at 95, 105 and 115 °C, respectively, and the resultant edible bird's nest soups were digested. RESULTS: The contents of free and bound sialic acid, protein and free amino group in the edible bird's nest soup were positively correlated with the stewing temperature, suggesting that increasing the stewing temperature promoted the dissolution of edible bird's nest. After digestion, the protein content in groups stewed at different temperatures was in the order 95°C > 105°C > 115°C, and the free amino group content was in the reverse order. Electrophoretic analysis demonstrated that glycopeptides were produced after digestion, and increasing the stewing temperature led to more low-molecular-weight peptide products and fewer high-molecular-weight peptide products. These results show that increasing the stewing temperature promoted digestion of edible bird's nest. Subsequently, the absorption ratio of sialic acid was measured by the Caco-2 cell transport assay. It was found that bound sialic acid was absorbed, and a higher stewing temperature led to a higher absorption ratio. CONCLUSION: The results of the present study suggested that sialylated glycopeptides from digestion of edible bird's nest were absorbed, and increasing the stewing temperature promoted their absorption because of the increased production of small fragments. © 2026 Society of Chemical Industry.