In-depth understanding of the effects of different molecular weight pullulan interacting with protein and starch on...

This work clarified the positive effects of pullulan on dough structure and application properties varied with its molecular weight. Pullulan with different molecular weights were introduced into dough system to explore their intervention effects on structural and technological properties of dough as well as physical and digestion properties of biscuits. Results showed that HPL (pullulan with molecule weight of 100- 300 kDa) could increase the intermolecular collisions, prompt the protein aggregation and limit the water migration in dough system, resulting in an integrate, continuous and dense network structure of the gel with strengthened elasticity and weakened extensibility, which caused an increase in biscuit thickness, hardness and crispness. On the contrary, LPL (pullulan with molecule weight of 3- 100 kDa) could go against the formation of stable and elastic dough through breaking down cross-linkage between protein and starch so as to provide biscuits with decreased hardness and crispness during baking. Both HPL and LPL delayed starch pasting and retrogradation process while HPL had the stronger retarding effect on starch digestibility of biscuits than LPL. These findings dedicated to a better understanding of pullulan function in dough system and provide suggestions for fractionation applications of pullulan in food field.