Abstract: A rapid strip test for the detection of reducing sugar was developed based on the fact the chromogenic reaction of reducing sugar and 3,5-dinitrosalicylic acid (DNS) is triggered by the alkaline environment and the heat generated by the reaction between calcium oxide and aqueous samples. The experimental conditions were determined and the detection range of the test system was investigated. Standard colorimetric card was prepared. The results showed that the best base paper was rapid qualitative filter paper, the concentration of chromogenic agent was 6.0 g/L and drying temperature was 50 ℃. The test required only 5 min and the detection range was 0.01–3.00 mol/L. This method had the advantages of simple operation, time saving, rapid color development and convenience. It was suitable for fast semi-quantitative detection of reducing sugar in food and medicinal fields and fermentation industry.

Key words: DNS colorimetry, strip test, reducing sugar