Investigating the Effect of Quinoa Protein and Peptides on the Quality of Gluten-Free Bread

Development of the gluten-free products is important due to their role in gluten related disorders and health improvement. This study aimed to investigate the effect of quinoa (Chenopodium quinoa Willd) protein isolates and bioactive peptides on the quality of gluten-free bread. For production of the bioactive peptides, the quinoa protein isolate was hydrolyzed with alcalase for 1, 2, 3, 4 and 24 h. Production of the bioactive peptides were confirmed by OPA analysis and SDS-PAGE. The maximum antioxidant activity of the hydrolysates was found after 4 h of hydrolysis which possessed 80.42% and 56.02% ABTS and DPPH radical scavenging, respectively. Presence of the quinoa protein isolate reduced the hardness, chewiness and gumminess of the bread and bioactive peptides and its combination with quinoa protein increased these factors. The rheological measurement showed solid-elastic behavior in batters. Based on the results of this study, addition of the quinoa protein and bioactive peptides resulted in a production of antioxidant gluten-free bread and reduced the quality of bread.