Fortification of wheat flour with purslane seed powder: Studying flour characteristics and dough rheological properties

Purslane seeds are rich sources of alpha-lineoic acid (omega-3) in all green plans that ever examined. This plant also contains substantial amounts of lignans، dietary fibre and natural anti-oxidants such as tocopherols. Health benefit of such components in prevention of certain diseases is the major reason for fortification of functional food products with purslane. In this study، effect of the addition of purslane powder on physicochemical (particle size distribution، protein، fiber، wet gluten and zeleny number) properties of wheat flour as well as rheological properties (in farinograph and extensograph) of the corresponding doughs was investigated. Purslane seeds powder was used to replace 50، 10، 150 and 200 g kg-¹ of wheat flour. Total protein and crude fiber contents of supplemented flours increased while wet gluten content and zeleny number of flour blends decreased as the amount of purslane seeds powder increased. Farinograph results showed lower water absorption، farinograph quality number، shorter stability time a higher softening degree for purslane supplemented flours compared to those of control flour. This indicates the weakening of dough rheological properties upon the addition of purslane seeds powder. Extensograph experiments revealed a significant increase in maximum resistance to extension (Rmax) for supplemented flours، except for 5 and 15% supplementation. Dough extensibility and extension energy were declined for all treatments، except for 5% supplemented flour.