Study on determination of starch content in rice by acid hydrolysis-Fehlings reagent titration

In this test, different regions of rice starch content was determined by acid hydrolysis-Farin reagent titration method, and compared with the results of DNS colorimetric method and GB/T 5009.9-2008 acid hydrolysis method, the accuracy of the method was studied.The determination results of acid hydrolysis-Fehlings reagent titration method and the national standard method were similar and the standard deviation and relative standard deviation of titration method were less than 0.1.The determination results of DNS colorimetric method were lower, the standard deviation and the relative standard deviation were much higher than the national standard and this law.In significant comparison, the difference between this law and the national standard was not significant, but the differences of DNS colorimetric method with national stardard method and this method were significant.In the recovery experiment, the average recoveries of national standard method, titration method and DNS colorimetric method were 99.68%, 99.14% and 100.06% respectively. It shows that this method has high stability and accuracy, and the determination result is good, which is a simple and effective method for the determination of rice starch content.