Determination of Xylose Content in Corncob Hydrolyzate by Phloroglucinol Method

[Objective] The aim was to study the determination method of xylose content in corncob hydrolyzate.[Method] The xylose content in corncob hydrolyzate was determined by phloroglucinol colorimetry and its optimum determination condition was confirmed through experiments.[Result] The results of single factor experiments showed that the product from reaction of xylose and phloroglucinol chromogenic reagent showed maximal absorption peak;the optimum color time was 8 min;when the xylose content was in 5.17-48.70 μg/ml,the xylose content showed linear correlation with absorbance and its coefficient of determination was 0.999 1.The existence of glucose showed scarcely influence on the determination of xylose content by phloroglucinol method.The optimum determination condition was as follows:5.0 ml phloroglucinol chromogenic reagent was added into 1.0 ml xylose solution;it was followed by heating in water bath at 100 ℃ for 8 min,then it was cooled with running water to room temperature and its absorbance A was determined at 554 nm immediately.The concn.range for determination by this method was 5.17-48.70 μg/ml and the xylose content in this sample of corncob hydrolyzate was 40.69 mg/ml.[Conclusion] This method was simple to operate and possessed high precision and the disturbance from glucose could be avoided in xylose content determination.This method could be applied in the rapid and accurate determination of xylose content in hydrolyzate system of lignocellulose.