Assessment of the RheologicalProperties of Doughand Shelf Life of Barbary Bread Containing Sodium Alginate Hydrocolloid

In the baking industry، use of hydrocolloid technology to improve the operation and to increase the tolerance to paste fermentation conditions، improve quality and increase the shelf life of fresh as well as stored bread، is of large applications. This research was carried out to evaluate the effects of gel of sodium alginate on rheological properties of dough and quality (volume، specific volume، cooking loss and water activity)، sensory properties and staling of Babary bread. Hydrocolloidsof sodium alginate were added at 0. 5%، 1%، 1. 5% w/w levels (flour basis) towheat flour. The rheological properties measurement of the dough and of staling of breads were investigated using Farinograph and Instron instruments، respectively. Results of rheological evaluation of dough showed thataddition of gel، leades to increase in the water absorbtion capacity، dougharrival time in line of 500 BU، dough development time، dough stability، dough departure time of line of 500 BU and time to breakdown، while the dough degree of softening after 10 and 20 minutes past and mixing tolerance index got decreased in comparison with control. Results in an evaluation of bread water activity showedthat addition of hydrocolloiddecreased bread water activity. Results related to an evaluation of the properties of technology of bread showedthat an addition of gel at a level of 1. 5 percent increased volume as well as specific volume of the bread. The results of staling tests done within the three times of 24، 48 and 72 hours showed that addition of sodium alginate (0. 5، 1، and 1. 5%) on dough، the rate of bread’s crumb staling decrease significantly (p<0. 05). Also، breads containing sodium alginate benefitted from a lower rate of staling than the control samples. In other words، bread samples containing 1. 5% sodium alginate and control samples were of the least and the most staling rates. In relation to sensory evaluation of bread samples، it was revealedthat the addition of hydrocolloidof levels of 1. 5 percent exerted the strongest positive effects on some sensory properties of the bread.