Phytate reduction in bread containing oat flour, oat bran or rye bran

Abstract

Phytate reduction in bread baked with oat flour and in bread with rye bran or oat bran addition was examined in scalded bread and bread made with varying amounts of sour dough. A considerable decrease in phytate content was observed in bread containing rye bran, ranging from 66-97 % of the initial phytate content in the raw materials. The most marked phytate reduction, of 96-97 %, occurred in bread made with 10 % sour dough (pH 4·6) or in bread in which the pH had been adjusted in the scalding with lactic acid, resulting in a pH between 4·4 and 5·1 in both dough and bread. In absolute amounts, more phytate was hydrolysed in the scalded breads with pH between 4·4 and 5·4 than in breads made with sour dough. The most effective phytate decomposition in bread with oat flour or oat bran occurred in bread made from scalded oat flour and which had a sour dough content of 20 or 30 %. In these breads, with pH values between 4·3 and 4·6 in dough and breads, the phytate was reduced from the initial content by 96%. The phytate content in unsoured bread with scalded oat bran was reduced at most to 62% of the initial amount.