Abstract:Polysaccharide iron complexes have the advantages of easy absorption，no intestinal irritation and directional absorption.In this study，the preparation technology of iron chelated by Klebsiella extracellular polysaccharide was studied in order to achieve the effective chelation of microbial extracellular polysaccharide with iron，and the prepared polysaccharide iron was expected to become a new iron supplement.The effects of trisodium citrate，chelating temperature，chelating time and solution pH on the content of iron in ferric polysaccharide were investigated by single factor test.The optimal chelating conditions were determined by orthogonal test.The results of single factor and orthogonal test showed that the mass ratio of Klebsiella extracellular polysaccharide to trisodium citrate was 3 ∶1，the chelating time was 0.5 h，the temperature was 60℃，and the solution pH was 7.Under these conditions，the highest iron content of the chelate was 2.88%.