Determination of the phosphorus content in potato starch using an energy-dispersive X-ray fluorescence method

Potato starch is unique because of its high starch phosphorus content. The textural characteristics of potato starch change due to the presence of the starch phosphate. Thus, the measurement of phosphorus in potato starch is needed, but conventional methods require a considerable amount of time and labour. In this investigation, a simple and fast analytical procedure has been developed for the determination of the phosphorus content of potato starch with a non-destructive energy dispersive X-ray fluorescence (ED-XRF) technique. Potato starch samples were analyzed as pressed pellets using detection times of 200 s. Reference values, measured by a conventional method, namely, wet chemical analysis, were used to calibrate the ED-XRF. Calibration was done using 20 potato starch samples, and the results were validated using a second set of 15 samples. The results indicated the validity of ED-XRF as a rapid and non-destructive method for the quantitative determination of phosphorus content of potato starch. Based on the combined results of ED-XRF and Rapid Visco-Analyzer (RVA), ED-XRF is promising for predicting the peak viscosity, by RVA, of potato starch paste through the measurement of starch phosphorus content.