The Determination Of Pentosans In Cereal

The content of pentosans in cereal was less, but a large number of scientific studiesshowed that pentosans had an important role in grain quality of identification, foodprocessing production and genetic breeding. Due to the complexity of the grain pentosans,there was no uniform standard about determination of the content of pentosans. The datamade of a different determination could not be comparable, which brought a lot ofinconvenience to the practice of scientific research and production. Therefore, establishing thestandard method about an accurate determination of the content of pentosans in the graincould standardize and improve standard system of grain quality evaluation, and promote thedevelopment of the pentosans in cereal breeding and food processing.The subject aimed that the determination of the pentosans content was not uniform incereal. Refered to foreign standards and existing literature and combined with theexperimental conditions of the enterprises and scientific researches, the subject made ananalysis about the preparation of the required reagents and optimized the key parameters ofthe method. It was recommended that the optimized the Orcinol-hydrochloric acid methodwas the most suitable method for determining the pentosans content as the agriculturalindustry standard. Moreover, the research measured the standard curve, sensitivity, precision,spiked recoveries, detection limits and lowest detection limit of the method based on fiverepresentative grains. The experimental results showed that: Orcinol-hydrochloric acidmethod was a feasible method for determining the content of pentosan in cereal.In this subject, the main results were as follows:Reference to the existing Orcinol-hydrochloric acid method, the subject unified theconcentration of the reagents as4mol/L HCl,2mol/L HCl,1%FeCl₃-HCl and0.1%Orcinol-ethanol. Obtained by observing the stability of the solution within a week and under thetemperature of20℃:4mol/L hydrochloric acid solution and2mol/L hydrochloric acidconcentration which were stable within a week, can be used within a week;1%FeCl₃-HClsolution which had less effects on the determination results could be used in one week；0.1%Orcinol-ethanol solution which had a greater impact on the determination results should beprepared before with detecting.The absorbance difference was taken as an index by the single factor experiment. The key parameters for the determination of conditions were studied. The results showed the bestparameters of the experimental conditions: the best acidolysis time120min, the optimaltemperature100℃, the best coloration time30min, the coloration temperature100℃, the bestdetermination time of the sample with cold water was cooled to room temperature, the bestFeCl₃-HCl solution0.1%;After optimizing the measurement conditions, write themeasurements into standard operating procedures in details.In order to measure the reliability of detection methods, the subject measured the variousindicators of the standard method of detection, getting the conclusion that the standard curvemethod in the sample between40μg/mL²00μg/mL was significantly related; precision of0.81%⁵.85%the repeated conditions, precision of1.64%⁵.45%under the conditions of,the recovery rate84.75%¹04.98%, detection limit and the lowest determination limit andwere19.16μg/mL and20.98μg/mL:this optimization method was accurate.