Bread with whole quinoa flour and bifidobacterial phytases increases dietary mineral intake and bioavailability

Abstract

The purpose of the present work was to provide further information on how replacing wheat flour by whole quinoa flour (at 25 and 50 g/100 g of flour) affects bread performance and to assess its potential as a nutritious ingredient. Bread with quinoa resulted in a depreciation in quality in terms of loaf specific volume (from 4.48 to 3.46/2.63 cm3/g), crumb firmness (from 0.77 to 1.55/2.64 N) and acceptability (from 7.94 to 7.58/5.94). Quinoa increased the bread nutritional value, raising fibre (from 5.5 to 7.2 g/100 g) and minerals (Ca from 0.35 to 1.28 mg/g, Fe from 17 to 34 μg/g, and Zn from 23 to 48 μg/g). The phytates were controlled by bifidobacterial phytase treatment during breadmaking (from 4.7 μmol/g to below the detection limit), which decreased phytate/mineral molar ratios to values lower than the threshold for inhibition of Fe and Zn absorption.Quinoa could partially replace wheat flour in bread, increasing its nutritional value in terms of dietary fibre, minerals, proteins of high biological value and healthy fats, with only a small depreciation in bread quality at 25 g/100 g of flour substitution. The high phytate contents were efficiently removed by phytase treatment and the breads were accepted by consumers.