Potato Starch Extrusion and Roasting with Apple Distillery Wastewater as a New Method for Resistant Starch Production

Potato starch was extruded and roasted with apple distillery wastewater to produce starch esters substituted with malic acid residues. The starch esterification degree was higher at the higher roasting temperatures. Starch modification contributed to its darker color, its increased resistance to the action of amylolytic enzymes, and its decreased solubility and heat of phase transition. The changes in the other starch properties examined depended on the extrusion and roasting temperatures. The process, which was conducted without a chemical agent—in this case, the process of starch extrusion and roasting with apple distillery wastewater—should be deemed a novel method for resistant starch production.