evaluation and comparison of qualitative properties of lavash bread types during storage by different techniques

background and objective: the quality of flat breads depends in part on the textural and structural properties of breads during storage. these properties are largely affected by flour quality. this research aimed at evaluating textural and structural properties of lavash bread types during storage by different techniques, comparing these methods and determination of correlation between their results. materials and methods: three lavash flours (named strong, medium and weak flours) with different physical, chemical and rheological properties were performed. determination of texture hardness of lavash breads (lavash a, lavash b and lavash c made of strong, medium and weak flours respectively) during storage carried out by texture analyzer, evaluation of breads porosity and their changes process during storage performed by ultrasonic nondestructive technique, assessment of breads microstructure made by sem, evaluation of starch gelatinization and retro gradation performed by dsc and the sensory evaluation of breads made by trained panelist. results: lavash b made from medium flour had less hardness, lower transition of ultrasonic wave velocity and less values of elastic modulus, reduced values of enthalpy and lower average of temperatures, more pores diameter and area of images and higher points of sensory evaluation than lavash a and lavash c breads during storage time. the results of mentioned tests (devices and sensory tests) had significant correlation to each other. conclusion: desirable quality characterization and higher shelf life of lavash b was due to flour qualitative characteristics of this type of bread to obtain dough with appropriate elasticity and excellent sheeting capability. ultrasonic non-destructive method is recommended to use instead of other methods for assessing texture, cell structure and elastic properties of bread after baking and during storage time. this method is fast, non-destructive and cheaper than other methods and can be used during production.