Abstract:The nutritional value of tragacanth gum and the antioxidant capacity of tragacanth gum polysaccharide were studied from the aspects of the composition of trace elements and amino acids，the evaluation of active polysaccharides and their antioxidant activity.Trace elements test method was established by inductively coupled plasma-mass spectrometry （ICP-MS）.The amino acids content of tragacanth gum was analysised with automatic amino acid analyzer.The polysaccharide was extracted by water extraction and alcohol precipitation and the condition was optimized；the monosaccharide components were analyzed by high performance liquid chromatography；and the antioxidant effects of the extracted polysaccharide was also studied.The results showed that tragacanth gum was rich in trace elements and amino acids，such as cesium（1.06×10-2g/100 g），manganese（2.87×10-3g/100 g），aspartic acid（9.28 g/100 g），leucine（7.01 g/100 g）and glutamic acid（5.49 g/100 g）；the optimum extraction technology of tragacanth gum polysac-charide were extraction temperature 60℃，extraction time 3.5 h，and pH value 2.0.Under the condition，the extraction rate of polysaccharide reached 13%；the monosaccharides in tragacanth gum polysaccharide were rhamnose，galac－tose，galacturonic acid，glucuronic acid，and their relative mass percentages were 22.1%，20.0%，5.66% and 1.64% respectively.The DPPH free radical scavenging rate of tragacanth gum polysaccharide was 23.84%，and it had good antioxidant activity.Tragacanth gum has rich nutritional value and good antioxidant capacity.This study will provide theoretical basis for the development of tragacanth gum functional food.