Physicochemical properties of flour recovered from broken rice noodles during production

Flour recovered from broken rice noodles was evaluated by microscopy, X-ray diffractometry, differential scanning calorimetry, in vitro starch digestibility, pasting and gel texture analyses. Rice noodle making processes destroyed the granular and crystalline structures of rice flour (RF), but the process-induced recrystallised amylopectin and amylose-lipid complexes were observed. Higher level of resistant starch in broken rice noodle flour (BRNF) was due to the retrograded amylose, which formed during noodle making. The absence of pasting temperature and low pasting viscosity of BRNF were distinct from those of RF, whereas gel textures of both flours were similar. BRNF-added rice noodles showed lower hardness, but the other cooking and texture qualities were close to the one without BRNF. Up to 17% of BRNF could be incorporated into composite rice noodle making. This study thus provided an approach to the management and utilisation of food processing wastes.