LAUSR

ABSTRACT We investigated the grinding kinetics of purple-fleshed potato (PFP) and the effects of particle size and damaged starch content of PFP powder (PFP flour [PFPF]) on rheological and microstructural characteristics of noodle dough. Grinding kinetics of PFPF determined maximum grinding yield for each particle size. Before cooking, the particle size decrease of PFPF significantly increased dough hardness and elasticity while none of the differences showed between the doughs after cooking except ball-milled PFPF noodle dough. Maxwell and Peleg models for stress relaxation characteristics were found to be suitable for interpreting viscoelastic behaviour of dough with various sizes of PFPF. Additionally, microscopic structure based on SEM showed connectivity and gelatinization characters of the dough. Results of this study suggest that changes in physical properties of noodle dough prepared with PFPF associated with particle size and starch damage during grinding of PFPF must be considered for noodle processing.