Abstract: The objective of this study was to establish a method for extraction and determination of reducing sugars in Qaidam Chinese wolfberry.Meanwhile,the contents of polysaccharides and reducing sugars in wolfberry samples from different habitats and different picking periods were analyzed.The developed phenolsulfuric acid method and optimized 3,5dinitrosalicylicacid (DNS) method were used to analysis the contents of polysaccharides and reducing sugars,respectively.The results show that the optimum parameters of DNS method for reducing sugars are as follows:wavelength was 550 nm,the dosage of DNS solution was 3.0 mL and the color reaction time was 5 min.The contents of polysaccharides and reducing sugars was 2.1833.863% and 49.3965.15%,respectively.The contents of polysaccharides and reducing sugars in Qaidam Chinese wolfberry in different habitats and different picking periods didn’t display significant effect (P> 0.05).The developed method was simple,fastand little interference,and is suitable for the determination of reducing sugars.By comparing analysis of polysaccharides and reducing sugars in Qaidam Chinese wolfberry from different habitats and picking periods,this study effectively provide evidence for the quality evaluation and quality control of Qaidam Chinese wolfberry.

Key words: Qaidam Chinese wolfberry, polysaccharides and reducing sugars, developed phenolsulfuric acid method, DNS method, content analysis