Formulation of bread model doughs with resistant starch, vegetable proteins and transglutaminase

The rheological properties of model doughs based on a resistant maize starch, rich in amylose, and vegetable proteins (either soy or hemp) were investigated, with the aim of assessing their potential use in the production of bread without gluten and rich in new vegetable proteins and fibre. With the purpose of improving the structural properties of investigated doughs, a cross-linking enzyme, i.e. transglutaminase (TG), was also added to evaluate its potential effects on adopted proteins, whereas no further hydrocolloid was added to the mixture. A rheological characterisation based on shear tests, in linear conditions at different temperatures, and elongational tests, in non linear conditions, was performed, to evaluate the potential properties of the dough for breadmaking use. In addition, a qualitative analysis of baked samples was performed to investigate a potential relation between rheological properties and crumb texture. It was observed that doughs prepared with hemp protein exhibit properties closer to those of a wheat dough and yield loaves with higher height. TG affects the properties of dough prepared with hemp protein increasing both dynamic moduli and gelatinisation temperatures. On the other hand, when soy protein is used, relevant effects of TG are observed mainly on the onset of gelatinisation that is shifted towards higher values. Obtained results evidence that hemp protein and the adopted resistant starch can be interesting raw materials for bread production even if further work is necessary to improve the dough characteristics.