The Use of Soy Flour in Yellow Maize-Amaranth Gluten-free Bread Production

Abstract Celiac disease is a permanent enteropathy caused by the ingestion of gluten, a protein occurring in wheat, rye, and barley. Gluten-free products often have a shorter shelf life, lower quality, and not so pronounced flavour. Therefore, it is necessary to develop new gluten-free products with higher quality and pronounced taste. The aim of this study was to investigate the influence of soy flour on the yellow maize-amaranth dough rheological properties and bread quality. To determine the influence of soy flour on gluten-free dough rheological properties and bread quality, soy flour was added at 45%, 50% and 60% to yellow maize flour basis. To study the effect of the amount of water used in the recipe on dough rheological properties and bread quality, each sample (n=7) was prepared in two versions: one with the dough yield 196, and the other with the dough yield 252. The main quality parameters of dough and bread were determined using the following methods: the firmness and resilience of dough, as well as the hardness of bread slice – with a TA.XT.plus Texture Analyser; moisture content of dough – with a thermostat; moisture content of bread crumb – with a Precisa XM 120 at the temperature of 110 °C; and color of bread crumb – in the CIE L*a*b* color system using a ColorTec-PCM/PSM. The best results of dough rheological properties were obtained for samples with dough yield 196, but the best quality of bread – for samples with dough yield 252. It was proved that soy flour improves not only the dough firmness and resilience but also the volume, texture, hardness, moisture content and color of gluten-free bread. No significant differences in the influence of soy flour on dough rheological properties and bread quality were found between the samples with various added amounts of soy flour (45%, 50%, or 60%).