Study of replacing wheat flour with rye flour on Sangak Bread shelf-life

At present one of the bread problems in our country، is its quality that has an important role in wastage. Among traditional breads، sangak has a better nutritional value and organoleptic properties، but unfortunately it''s shelf-life is short and stales quickly. Addition of rye flour to wheat flour IS one of the methods which is used in retarding bread staling. Since rye flour has a high amount of pentosan، its addition to wheat flour improves bread shelf-life. In this research the effect of adding rye flour to wheat flour on sangak bread shelf life also its influence on sensory characteristics of produced breads was investigated. At first rye and wheat four properties including moisture، ash، protein content، falling and zeleni number، and physical properties i. e particle size was determined. Then mixture samples were prepared by adding different ratios of 5، 10، 25 percent of rye flour to wheat flour. Physical، chemical and rheological properties of the samples and mixtures were determined. Doughs were prepared and composite breads were baked. Finally، rye breads were examined organoleptically by a trained sensory evaluation panel، one، 24 and 48 hours after baking for acceptance and staling rate. The results indicated that: addition of rye flour to wheat flour did not have significant influence on dough rheological properties such as farinographic and extensographic properties، however sensory characteristics of samples were affected i. e increasing rye flour resulted in form، shape and porousness improvement of samples but it had a negative effect on upper and bottom surface properties، coincidence no change was observed about samples chewing ability and hardness.