Commercial mixes for gluten-free dough contain mostly carbohydrates, which have a negative influence on the quantity of protein present in the diet of celiacs, because the bakery products are an important source of amino-acids in a diet of healthy people. The lack of gluten protein in this type of food has negative consequence on bread structure, as gluten normally provides a viscoelastic matrix in traditional products.

Polish Researchers published on Journal of Food Science and Technology. 53, (1): 571-580, 2016 a study aimed to evaluate the effects of selected protein isolates and concentrates on quality and staling of gluten-free bread, in the absence of other structure-forming agents such as guar gum and pectin.

The applied preparations included albumin, collagen, pea, lupine and soy. Their addition had various effects on rheological properties of the dough and volume of the bread. Volumes of the loaves baked with soy and pea protein were smaller, while those with albumin significantly larger than control. Presence of non-gluten protein caused changes in crumb structure (higher porosity, decrease in cell density, higher number of pores with a diameter above 5 mm) and its color, which was usually darker than of unsupplemented starch-based bread. The least consumer's acceptance was found for bread baked with soy protein.

The presence of pea and lupine preparations improved sensory parameters of the final product, providing more acceptable color and smell in comparison to control, while soy caused a decrease of all analyzed consumer's scores. The addition of protein caused an increase in bread hardness and in enthalpy of retrograded amylopectin, during bread storage.