Evaluating the effects of insoluble dietary fibres on pea protein-based extruded meat analogues

Date fruit (Phoenix dactylifera L.) fibre, a by-product from the date syrup industry, is rich in nutrients and has been increasingly explored as a value-added ingredient for industrial applications. This study investigated the incorporation of date dietary fibre (DF) in pea protein isolate (PPI)-based meat analogues (HMMA) using high-moisture extrusion as a structuring technique. The DF amount was varied at five different concentrations: 0, 5, 10, 20 and 30 % w/w. The moisture content of the HMMAs reduced significantly, as fibres could facilitate the binding of free water. As a result, the addition of DF reduced the thermal stability of HMMAs, as shown by the earlier shifting of water evaporation temperature. Rheological results indicated that the elastic properties of HMMAs were lower with 5 to 10 % DF addition, indicating the formation of a brittle network, signified by an increase in hardness and chewiness. The inclusion of 5 to 10 % DF significantly increased the fibrousness of HMMAs, as shown by the increase in the degree of texturization, which was contributed by protein-fibre and fibre-fibre interaction, which bridged the protein network closer. This study shows the potential of DF influencing the fibrous formation in meat analogues produced using PPI as the primary ingredient.