Modification of structure and digestibility of chestnut starch upon cooking: A solid state C-13 CP MAS NMR and enzymatic degradation study

The modification of starch, which is the major component of the polysacchar ide fraction of chestnuts (Castanea sativa), has been studied from the poin t of view of structure and digestibility to understand the modifications in duced by cooking and, specifically, by the Maillard reaction. The study was carried out by enzymatic degradation kinetics, monitoring the glucose rele ased upon time, and by solid state C-13 CP MAS NMR, which has the potential of monitoring the solid state phase changes occurring upon chemical modifi cation due to the cooking process. Results obtained reveal that large chang es are induced in the macromolecular structure of starchy materials and tha t these changes are correlated with changes of digestibility in terms of en zymatic degradation resistance. In the system studied, the extension of the Maillard reaction is not such as to exert a significant influence on struc ture and/or digestibility of chestnut starch.