Functional and rheological properties of protein enriched gluten free composite flours

Protein enriched composite flours comprising rice flour and soybean and pea protein isolates were made. Experimental design resulted in composite protein enriched blends with different functional, rheological, mechanical and surface related textural properties. The enzyme transglutaminase (TG) was added for reinforcing the protein network. Protein isolates induced a significant (α < 0.01) increase in the water absorption of the composite blends, having also a synergistic effect and a decrease of the storage (G′) and viscous (G′′) moduli. Protein isolates also modified the mechanical and surface related textural properties. Soybean protein isolate showed the most significant effect on the functional properties, rheometer and surface related textural responses. Crosslinking activity of the transglutaminase led to a significant decrease of the foaming activity and stability. Scanning electron micrographs of the composite blends showed that the usage of soybean, pea protein isolates and TG would be a promising approach to produce protein enriched blends for making fermented gluten free products.