The Effect of Cast Iron, Ceramic and Clay Baking Substrate on Thermal, Textural, Sensory Characteristics and the Heavy Metals in Bread

Baking bread is one of the most important stages of bread preparation. The purpose of this research is to investigate the effect of bread baking substrate to improve the quality of produced bread. In this research, the cast iron substrate was used as a reference surface and two ceramic and clay coatings were applied on the cast iron surface for comparison. In order to check the properties of coatings, microstructure, microhardness, hardness measurement, thickness measurement, and thermal shock tests were performed, and finally, the quality of the resulting bread was evaluated according to texture evaluation criteria, staleness test, measurement of heavy metals and sensory evaluation. To analyze the data, ANOVA was used to compare the mean and Duncan's test was used to group the treatments. Based on the conducted studies, it was found that the use of clay and ceramics as a coating on the cast iron substrate, with the protection mechanism of pollution transfer, reduces the transfer of chemical pollution of heavy metals to bread. The highest number of heavy metals including lead 0.565 µg/kg, cadmium 0.023 µg/kg and iron 4.470 mg/kg was obtained in bread produced in cast iron bed. The highest number of heavy metals was obtained in bread produced in cast iron bed and the lowest number of heavy metals was obtained in bread baked in ceramic bed. The samples baked on the cast iron bed had less hardness than the samples baked on the clay and ceramic bed. From the sensory point of view, the highest score for bread baked in a ceramic bed was 4.900 and the lowest score for bread baked in a clay bed was 3.126.