Phytate determination in various cultivars of Korean rice

Abstract

To determine the amount of phytate in rice grains from various cultivars, two methods were employed and compared in respect of the accuracy and conveniency. Phytate in rice samples was extracted with HCl, and then the extracts were subjected to an anion-exchange column. Finally, the phytate in eluate was quantitated using two methods: one method is based on the complex formation between ferric ion and sulfosalicylic acid in the presence of phytate, and the other is the prior acid digestion of phytate sample, followed by the colorimetric determination of liberated phosphorus. Although two methods showed similar values of phytate in rice samples, the former method is simpler and more precise than the latter. Moreover, the former is more reliable for the samples with lower phytate levels. Especially, the dilution condition of rice sample before anion exchange column separation was important for the recovery of phytate in rice samples. Based on the former method, the amount of phytate in rice of various cultivars was estimated to range from 7.3 mg/g to 12.4 mg/g rice. This method would be useful for the determination of phytate in crop samples with a lower level of phytate, one of anti-nutrients in some agricultural plants.