Study on determination of reducing sugar from Haw Flakes with DNS colorimetry method

3, 5-dinitrosalicylic acid (DNS) method was used to analyze the content of reducing sugar by spectrophotometry, and the wave-length and some relevant factors were researched in analyzing the content of haw flakes reducing sugar with DNS method.Best conditions for analyzing the content of haw flakes reducing sugar had been established as follows :wave-length was 550nm.DNS solution was 2.0mL, and duration for color development in boiling water bath was 5 minutes.Under the above conditions, the regression equation was y=0.656x+0.076, R2=0.9927.The experiment had confirmed that the DNS method was simple, fast and undisturbed.The method could be used in common laboratories for research.