POLYSACCHARIDE DETERMINATION IN CORN SILK WITH 3,5-DINITROSALICY LIC ACID COLORIMETRY

Bing Li, Yaping Li, Hongli Zhou

ABSTRACT:Contents of reducing sugars in crude polysaccharides from corn silk were measured by 3,5-dinitrosalicylic acid (DNS) colorimetry with incident wavelength at 492 nm, amount of DNS = 1.5 mL, coloration temperature at 90 °C and coloration time = 7 min. The standard curve equation of glucose was y=3.9163x-0.0292; the glucose solubility ranged from 0.07332 to 0.25662 mg/ml, and the absorbance and glucose content were well linearly related. The DNS colorimetry was outstanding with easiness, fast speed, accuracy, safety, low cost, high stability and reproducibility. The polysaccharide content in the cornstarch (reducing sugar) was 18.16%.

Keywords:Corn silk, 3,5-Dinitrosalicylic acid, Colorimetry, Polysaccharides.