Influence of soy protein hydrolysates on the rheological characteristics of wheat dough

The use of protein hydrolysates in bakery products is gaining importance due to the presence of bioactive peptides in their composition. Soy protein hydrolysates (SPHs) have gained interest due to the lack of antinutritional factors and presence of various bioactivities (antioxidant activity, cholesterol-lowering activity or immunoregulatory properties). The aim of the study was to evaluate the dough rheology parameters of wheat flour replaced by 5% with different SPHs. SPHs were obtained by enzymatic hydrolysis of soy protein concentrate with different proteases: Alcalase® 2.4L, Everlase 16.0L, Neutrase® 0.8L, Papain and Umamizyme. The rheological behaviour of flour mixtures was evaluated using a Mixolab analyzer (Chopin Technologies) with the “Chopin+” protocol. The SPH addition in the wheat flour resulted in decreases in water absorption with almost 3.9% as compared with control dough. Dough development time increased with SPH addition, with the highest value registered for umamizyme hydrolysate (5.9 min towards 1.4 min for control). Thus, SPHs prevented gluten network development. Stability and C2 value (which represents the beginning of the protein destabilization and unfolding) decreased with the SPH addition in the dough formulation, which proves the weakening of the gluten network. In the same trend, starch gelatinization (C3), stability of the starch gel (C4) as well as starch retrogradation (C5) were reduced by the addition of SPHs. These values were decreased in the order: control > alcalase ≈ everlase ≈ umamizyme > neutrase > papain. In conclusion, dough characteristics provided by Mixolab are the results of the interaction of SPHs components with the flour constituents. Papain hydrolysate could contribute to the increase of the shelf-life of bakery products. This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CCCDI – UEFISCDI and the Ministry of Education, Science and Technological Development, Republic of Serbia, project number E!9936.