Influence of pistachio by-product from edible oil industry on rheological, hydration, and thermal properties of wheat dough

Abstract

The objective of this work was to study the effect of pistachio by-product flour (PBF) addition to wheat flour on the rheological properties of dough. Pistachio levels used were: 0 (C), 5 (P5), 15 (P15), and 25 g/100 g (P25). Alveographic and farinographic assays, gluten, moisture content (H), and dough pH were studied. In addition, texture profile analysis, dynamic rheology and relaxation of dough were performed. The farinographic water absorption, development time, and stability decreased with PBF, whereas the degree of softening increased. Moreover, tenacity, extensibility, and deformation work decreased with PBF. Wet gluten (WG) content was not modified, while dry gluten (DG) increased with the PBF level, decreasing the WG/DG ratio. C dough had higher moisture and pH than dough with PBF, and both parameters decreased when PBF content increased. P5 dough was softer and less consistent but with similar adhesiveness and elasticity to C. Dough hardness and elasticity increased with an increase in PBF content. The elastic moduli also increased, while relaxation times were not significantly modified with higher amounts of PBF. The study of hydration and rheological properties of pistachio-wheat dough is important from the technological point of view because pistachio components could affect the final bread quality.