Method development for the quantification of ferritin in staple food crops

Biofortification is a strategy for combating iron deficiency that involves the selectivebreeding of food crops to increase total bioavailable iron. Evidence showing ferritin as agood source of bioavailable iron has created interest for enhancing ferritin content in seeds.However, the successful implementation of ferritin biofortification requires a method torapidly measure ferritin in staple food crops. The objective of this study was to develop anELISA to quantify ferritin in red beans, white beans, wheat, maize, and brown rice. Thefollowing steps were taken for ELISA development. A common amino acid sequence amongall seed ferritins was identified to produce an anti-ferritin antibody, ferritin was extractedfrom the seeds using a crude extraction procedure, and immunoblotting techniques were usedto verify the immunoreactivity of the antibodies with the ferritin sample. Using our developed ELISA with the polyclonal antibody and recombinant pea ferritin standard, the quantity of ferritin by crude extraction was found to be 10.2±1.0, 4.38±0.9, 1.2±0.3, 0.38±0.1, and 0.04±0.01 μg/g in red beans, white beans, wheat, maize, and brown rice, respectively. There was no significant correlation between ferritin and iron in red beans;