As the result of the increase of the level of the consumers’s awareness, recent years have witness the emphasis which the food experts and researchers have placed on producing minimal processing and sustainable high quality products as their main objectives. Modified atmosphere packaging is considered to be one of the most effective and applicatory food technology outcomes in response to this need of consumers. The foundation of this method is the replacement of the closed air with an appropriate gas composition to increase the shelf life of the product. Currently about 30 percent of wheat production in the country, is wasted in the chain of wheat, flour and bread. Since the inappropriate conditions of bread production and its maintenance, is one of the most important reasons for the amount of waste, prolong the shelf life of Sangak bread as one of the best bread in the world in terms of nutritional value and flavor and aroma characteristics, was considered in this study. So that baked-off technology as an effective way of staling and modified atmosphere packaging to increase shelf life was used. For this, part-baked Sangak bread was packaged with three combinations gas included %100 CO 2 , %50 CO 2 : %50 N 2 , %25 CO 2 : %75 N 2 and air as a control and storage at 25 ° C for 21 days. During storage, quality and microbial features of product such as color, volume, moisture, texture, total count and mold and yeast count was assessed at intervals of three days. On the other hand, the gas composition in the packages is changing during storage due to the dynamic nature of microbial and chemical of food and changes caused by permeability of packaging film, gas solubility in food, moisture evaporation etc. So, In order to optimize packaging conditions to achieve maximum shelf life of the product, modified atmosphere packaging systems modeling seems necessary. Hence, heat and mass transfer phenomena in order to predict the profiles of temperature and gas composition was studied. In this regard, a one-dimensional mathematical model was developed to describe simultaneous heat and mass transfer in part-baked Sangak bread packaged in modified atmosphere packaging during storage. Statistical analysis of the results of part-baked Sangak bread quality characteristics during storage showed that, carbon dioxide in headspace of package No significant effect was on product color, texture, volume and moisture, while the microbial load of the samples were thoroughly impressed by the atmosphere of the package. So that with increasing concentrations of carbon dioxide, the growth of total microorganisms, mold and yeasts was more limited. Also was observed all product quality characteristics changes significantly during storage time. So that the reduced moisture, increased crumb firmness, reduced crust firmness, reducing the volume, increased L * and a * values and reduced b * value color of part-baked Sangak bread was observed during 21 days. Finally, the high correlation between the temperature profiles, gas and relative humidity predicted and measured, indicated that developed model is able to predict changes temperature in different points of part-baked bread, surface of package, head space, gas composition in package and concentration of each gas in product during storage at different temperatures. Keywords: Modified atmosphere packaging, part-baked Sangak bread, Mass transfer, Heat transfer, Mathematical modeling, Thermophysical properties, quality characteristics, Microbial growth