Effect of Olive Pomace Fiber on the Baking Properties of Wheat Flour and Flat Bread (Barbari Bread) Quality

Abstract

The current study is aimed at fortifying Barbari bread with different levels ( $T_{\text{Co}}$ : 0, $T_{5\%}$ : 5%, $T_{10\%}$ : 10%, and $T_{15\%}$ : 15) of olive pomace dietary fiber (ODF) and investigating the quality properties of enriched bread. The fiber of the defatted olive pomace powder was extracted by an enzymatic process as a green extraction method (α-amylase, protease, amyloglucosidase, and cellulase; incubation time: 4.5 h, 40°C). The effect of ODF addition on the thermal (based on differential scanning calorimetry (DSC)), rheological, physical, textural, and sensory properties of samples was investigated. The DSC curves of samples were a broad endothermic transition peak ( $T_{\text{onset}}~43$  °C and $T_{\text{peak}}=123.58-125.74$  °C). By increasing the ODF level, the water absorption rate of the dough increased while softening degree reduced. There was a negative significant correlation between baking loss and crumb moisture ( $R>-0.94$ ) and aw ( $R=-0.769$ ). By increasing ODF, sample porosity and specific volume decreased. There was a significant difference between hardness and springiness of $T_{15\%}$ and $T_{\text{Co}}$ . Replacement of wheat flour with 10% ODF had no significant effect on the sensory parameters of Barbari bread.