Research of factors influencing the accuracy of determining of oil raw materials quality indicators based on the NMR pulse method

Abstract

The article presents the results of the study of factors affecting the accuracy of the results of measuring the mass fraction of oleic acid in sunflower seed oil using a pulsed NMR method. Analysis of the data obtained during the production tests has revealed factors that reduce the accuracy of the measurement results. The first factor is the different quality of the analyzed samples of sunflower seeds, which is due to the biological characteristics of the seeds and growing conditions. The second factor affecting the error of the measurement results of the quality parameters of sunflower seeds is the difference in the temperature of the seeds being analyzed and the temperature in the laboratory where the used NMR analyzer is installed. Moreover, this factor has the greatest influence on the accuracy of measurements of the mass fraction of oleic acid in sunflower seed oil. The third factor is the human factor, namely, the accuracy of sampling using a sampling cup, which is currently included in the AMV-1006M serial NMR analyzer. In order to eliminate their influence, a special sampling device has been developed. It has been established that the reduction in the influence of the identified factors is achieved by normalizing the volume of the sample of seeds and measuring its temperature. The article presents data characterizing the main nodes of the developed sampling device, as well as the results of determining the mass fraction of oleic acid in oil of sunflower seeds after the introduction of the developed sampling device in the measurement procedure. The developed design of the sampling device is simple to manufacture, has high operational characteristics, allows to increase the accuracy of sampling seeds by volume and significantly improve the accuracy of the results of measuring the mass fraction of oleic acid in oil of sunflower seeds based on the pulsed NMR method.