Validation study of a rapid colorimetric method for the determination of phytic acid and inorganic phosphorus from seeds

Abstract

Phytate, as an important mineral storage compound in seeds, is vital for seed/grain development; it is often considered to be an antinutritional substance. The objective of this study was to develop a rapid and inexpensive colorimetric method of measuring phytate and inorganic P (Pi) concentrations from maize, soybean and sunflower seed/grain extracts, by combining adequate precision and simplicity, ideal for breeders interested in improving simultaneously Pi and phytate levels. The investigated extraction mediums: double distilled (DD) H2O, 2.4 % HCl and 5 % trichloracetic acid (TCA) were proved to be suitable for the analysis of phytic acid and inorganic phosphorus in seed extracts. The advantages of 5 % TCA over to DD H2O and 2.4 % HCl were reflected through the low limit of detection for both phytic acid and Pi and good recovery with low bias. A low detection limit for Pi is important for samples with naturally low Pi concentrations, such as soybean seeds.

Keywords

• phytic acid
• inorganic phosphorus
• seed
• validation