Effects of desalted duck egg white peptides and their products on calcium absorption in rats

The effects of desalted duck egg white peptides (DPs), phosphorylated DPs (PDPs) and DPs-calcium complexes (DPs-Ca) on calcium absorption in vivo were investigated. Ninety fast-growing male rats were divided into 10 groups and treated with different dosages of CaCO3, calcium gluconate, DPs-Ca as well as CPPs, DPs and PDPs supplemented with CaCO3. Eight-week oral administration results indicated that the high dosage PDPs+CaCO3 group was significantly higher than the high dosage DPs+CaCO3 group in calcium absorption, bone calcium content, BMD and maximum stress, but lower in ALP activity (P < 0.05). Additionally, the high dosage DPs-Ca group showed higher bone indices than the high dosage DPs+CaCO3, calcium gluconate and CaCO3 groups (P < 0.05). These results suggest that in vivo, phosphorylated DPs are more effective than DPs in improving calcium absorption and bone strength, and DPs-calcium complexes are more beneficial to bone tissues than the DPs and CaCO3 mixture.