Iron Bioavailability in Low Phytate Pea

Field pea (Pisum sativum L.) seeds have high nutritional value but also contain potential antinutritional factors, such as phytate and polyphenols. Phytate can store up to 80% of the phosphorus in seeds. In the seed and during digestion it can complex minerals such as iron and zinc and make them unavailable for absorption. Also, it is not well digested by monogastrics. Polyphenols are known to reduce bioavailability of some nutrients. The objective of this research was to evaluate the effects of phytate and seed coat polyphenols on bioavailability of iron from field pea seeds. To increase the nutritional value of field pea seeds, two low-phytate lines (1-150-81 and 1-2347-144) containing higher inorganic phosphorus concentration (IN-P) and lower phytate-phosphorus concentration (PA-P) than the normal phytate varieties were developed from the cultivar CDC Bronco in previous research. Total iron concentration (FECON) did not differ significantly between normal and low phytate varieties. However, iron bioavailability (FEBIO) of the two low-phytate lines was 1.4 to 1.9 times higher than that of the three normal phytate varieties as assessed using a cell culture bioassay. Environment also had a significant effect on FEBIO. Peas with pigmented seed coats had seven times lower FEBIO than peas with nonpigmented seed coats. Removal of the seed coat increased FEBIO in peas with pigmented seed coat five to six times.