Effect of hydrocolloids (Tragacanth & Xanthan) on frozen dough characteristics and volumetric (hamburger) bread

Backgrounds and One of the most efficient methods of slowing down staling is consumption of frozen bread dough. In this study, the effect of tragacanth and xanthan gums in two levels (0.5% and 1.5% w/w base on wheat flour) on dough rheological properties and volumetric (hamburger) bread that produced from frozen stored dough (-18oC & 2 weeks) and its sensory quality was investigated. The dough rheological properties were evaluated by farinograph and bread firmness was analyzed by Instron at first, third and fifth day. Bread specific volume was determined by rapeseed displacement methods. Sensory evaluation including staling (24, 48 and 72 hours) was investigated by panelists. Hydrocolloids (tragacanth and xanthan) increased water absorption, the highest one was observed in xanthan at 1.5%. The highest dough development time (DDT) and stability time belonged to tragacanth and xanthan at 1/5%. Hydrocolloids decreased bread firmness and the most reduction was observed in tragacanth at 1.5%. Hydrocolloids addition increased bread specific volume compared to control and their staling rate slowing down the best value belonged to tragacanth at 1.5%. Hydrocolloids addition (tragacanth and xanthan 0.5% & 1.5% w/w) improved dough rheological characteristics and stability, consumption of tragacanth gum at 1.5% is recommended as best additive to production hamburger bread by frozen dough.