Establishing the function of proteins on the rheological and quality properties of rice based gluten free muffins

The incorporation of proteins has been long established in the bakery industry to obtain enriched products, but they also take active part on the making process of sweet baked goods. This study was focused on assessing the role of proteins on the rheology and quality of wheat free muffins by using rice flour. Six rice based formulations were used: one without added protein (No-Protein) and five with different protein sources: soy protein isolate (SPI), pea protein isolate (PPI), egg white protein (EWP), casein (C), and for comparing purposes vital wheat gluten (VWG) was included. Proteins effects were established by evaluating the rheological behaviour of batters measuring the storage modulus (G') and the loss modulus (G ''), and the technological characteristics of the muffins obtained (specific volume, colour, and texture). The addition of SPI, PPI and C significantly (P < 0.05) increased G', but this was not modified in batters containing EWP. Casein and EWP increased the specific volume of the muffins. SPI did not have effect on hardness, springiness, cohesiveness, chewiness, and resilience of the muffin, while PPI containing muffins were softer and springier. The overall results indicated that both the rheological properties of the batters and the technological characteristics of the muffin are dominated by the presence of the type of protein used in the formulations. Therefore the source of protein included in the formulation is fundamental to ensure the proper texture and other technological properties of these products. (C) 2013 Elsevier Ltd. All rights reserved.