Assessment of inhibitory factors on bioaccessibility of iron and zinc in pearl millet (Pennisetum glaucum (L.) R. Br.) cultivars

The variations in iron and zinc bioaccessibility as influenced by inhibitory factors in 13 pearl millet cultivars were evaluated. The results indicated that iron and zinc contents ranged between 5.59–13.41 and 2.11–5.19 mg/100 g. Polyphenols, flavonoids and phytic acid were highest in GHB744 (781 mg/100 g), HHB223 (116 mg/100 g) and HHB226 (1.080 g/100 g) respectively. Insoluble fiber content range from 9.36 to 12.89 g/100 g. Iron and zinc bioaccessibility was the highest in local Anantapur (17.95%) and GHB744 (15.19%) cultivar with low phytic acid. HHB226 exhibited high β-carotene and phytase activity. In this study, the cultivars with high iron and zinc content also possessed high inhibitory factors which affected bioaccessibility. However, the bioaccessibility of iron did not seem to depend on the phytic acid: iron ratio alone. Further, a trend was observed in cultivars with low iron: zinc ratio had increased iron bioaccessibility. On the contrary, phytic acid: zinc ratio appears to play a significant role in zinc bioaccessibility. Certain cultivars with high iron content also had high phytase activity and β-carotene content which could be exploited for further technological treatments to enhance the bioaccessibility of iron and zinc.