The influence of plant protein on the properties of dough and the quality of wholemeal spelt bread

The paper presents the effect of a soy protein concentrate (protein content 65%) as a substituent (substituting 20% wholegrain spelt flour) and a pea protein isolate (protein concentration 90%) as a substituent (substituting 5% and 10% wholegrain spelt flour) on the rheological characteristics of spelt dough and on the physical and sensory characteristics of spelt bread enriched with proteins. The stability of dough supplemented with a soy protein concentrate has turned out to be higher than the stability of dough supplemented with pea protein isolates. It is probably the result of different protein behaviour in soybeans and peas. The applied ingredients have manifested different effects on the specific bread volume. In comparison to the control bread, the specific volume of bread samples have been reduced significantly with addition of a 20% soy protein concentrate and a 10% pea protein isolate (from 1.83 ml/g to 1.39 and 1.38 respectively). On the other hand, addition of a 5% pea protein isolate has not brought to a significant decline in the specific bread volume. Addition of a 10% pea protein isolate has increased the chewiness while this parameter has not changed significantly in relation to the control bread with addition of 5% pea protein and 20% soy protein. Spelt bread with 5% pea isolated protein is the most acceptable according to the overall sensory acceptance among all the analysed samples