Our research was designed in aim to elaborate a thermo-stable fruit filling for bakery products. In order to test the heat-stability of prepared fruit fillings with a minimal number of experiments while reducing time, materials and energy we investigated and determined the optimal ratio of recipe components through experimental design technique. This paper deals with a practical study of thermo-stable properties of fruit fillings through experimental design method that allows to describe the main interactions between the response variable expressed through bakery index which defines fruit filling’s heat-stability and two critical factors that affect it.