Scanning electron microscopic and electrophoretic studies of the baking process of south Indian parotta―an unleavened flat bread

摘要

The changes that take place in starch and protein molecules during processing of parotta, starting from wheat flour to baked parotta, were followed by scanning electron microscopy (SEM) and electrophoresis. The microstructure of wheat flour showed that the protein matrix was broken up into aggregates and starch granules were embedded in it. At the processing stage of parotta dough into a very thin sheet, the surface of dough appeared as a fine matrix of proteins and soluble solids with dispersed starch granules. The surface of baked parotta showed a still finer distribution of all the components. The microstructure of outer and middle layers of parotta showed clear differences. In the outer layer, starch granules were distorted and embedded in the protein matrix owing to the differential heating process whereas, in the middle layer, the extent of starch granule distortion was less than in the outer layer. Electrophoretic patterns of wheat flour, parotta dough and baked parotta revealed that less intense bands were observed in HMW regions of baked parotta. SEM and electrophoresis were found to be valuable tools for understanding molecular interactions between starch and protein molecules during the baking process of parotta.