Effect of phytase supplementation on zinc, iron and calcium status in rats fed with diet containing Iranian high phytate bread [Sangak]

ABSTRACT

Restricted mineral bioavailability of minerals in Iranian breads due to high levels of phytic acid has been reported for more than 50 years. Bread intakes still provide over one-third of the food energy through out the country. Hence improving bread mineral bioavailability can play an important role in decreasing the prevalence of many mineral deficiencies. The aim of this study was to assess the effect of phytase supplementation on blood, liver and bone zinc, blood and liver iron and femur bone calcium in growing Wistar male rats, fed a diet containing high phytate Iranian bread [Sangak]. Thirty weaning Wistar rats were assigned to the phytase [Aspergillus niger] or the control group for 6 weeks. The diet was designed based on Iranian food patterns and 34.2% of energy was supplied from Sangak bread with high amount of phytic acid. Feed intakes, weight gain, liver and femur bone weight did not differ between the groups. Blood zinc was higher in the phytase group [p=0.03], indicating the positive effect of phytase supplementation on blood zinc levels, independent of the growth process. Other variables did not show any differences between groups. We conclude that the addition of high phytate Iranian bread phytase to the diet can improve blood zinc status in growing rats