Effects of incorporating different hydrocolloids on sensory characteristics and staling of gluten free bread

Effect of three different hydrocolloids, pectin, guar and carrageenan in a concentration of 1, 2 and 3% (w/w flour basis) and also their combination in concentration of 2 and 3% (w/w flour basis) on sensory characteristics and shelf life of gluten-free breads was evaluated. The results showed that all hydrocolloids used in a concentration 1% produced gluten-free breads with acceptable sensory characteristics in the first day of evaluation, compared to those of control bread (made from wheat flour). In the second day of evaluation, a relatively sensible reduction in the sensory scores of gluten-free breads produced from all hydrocolloids was observed. Nevertheless, the sensory scores of all treatments except pectin 3% and wheat starch control were in an acceptable range. However, storage for the third day caused a significant (α<0.05) reduction in the sensory scores of gluten-free breads compared to those of fresh samples, except for guar 2 and 3%, carrageenan 2%, guar-pectin 2 and 3%, guar-carrageenan 3% and pectin-carrageenan 3% treatments. Gluten-free breads produced from a combination of hydrocolloids such as guar-pectin, guar-carrageenan and pectin-carrageenan in both 2 and 3% concentrations received the highest sensory scores and remained more fresh, compared to those produced from single hydrocolloids. In general, gluten-free breads containing hydrocolloids remained less fresh compared to control breads. Among hydrocolloids evaluated in this study, guar-pectin 2 and 3% produced gluten-free breads with desired sensory characteristics and staling scores. Whereas, breads made from starch, pectin 1% and carrageenan 3% showed a rapid staling.