650HUMAN MILK IMMUNOGLOBULIN CONCNTRATIONS IN THE FIRST WEEK OF POSTPARTUMHuman milk is considered the optimal nutritional source for infants. It contains numerous immune system and growth factors as well as essential nutrients that protect it from destruction in the GI tract. The objectives of the present research were to precipitate the immunoglobulin (Igs) from human milk samples to determine the concentrations of IgA, IgG and IgM. Individual milk samples were collected from six lactating mothers at 0, 0.5, 1, 2, 3, 4, 5, 6 and 7 days postpartum. The obtained results showed that the concentration of total Igs in human milk were significantly higher during 0-0.5 day when compared with the other days. The concentrations of human IgA, IgM and IgG were significantly higher during 0- 12 h postpartum then dropped markedly with time progress of lactation. IgA, IgM and IgG concentrations were 36.53±6.72, 14.05±2.78 and 0.88±0.42 g/L at 0-12h postpartum, respectively, while at the end of the first week (7th day), it were 4.23±0.61, 0.37±0.03 and 0.13±0.07 g/L, respectively. The total amino acids values of human milk Igs were highest at 0-12h and dropped markedly with time progress of lactation aamohammed@su.edu.saResearch682015Human milk,Colostrum,Immunoglobulin (Igs),Amino acidsMohammed Mansour El Lolly,Khaled Meghawry El-zahar,Azza Abdel-ghany Sobuih,Ahmed M. Abdel-Zaher,Ahmed M. Abdel-ZaherDairy Dept., National Res. Cent., Dokki, Giza, Egypt,Department of Food Science, Faculty of Agriculture, Zagazig University, 44511 Zagazig, Egypt, College of Science and Arts at Shaqra- Shaqra University- Saudi Arabia,Department of Biochemistry, Faculty of Science, Zagazig University, 44511 Zagazig, Egypt,Department of Biochemistry, Faculty of Science, Zagazig University, 44511 Zagazig, Egypt