Effect of different milling methods on isolation of pinto bean starch, and the characteristics of the isolated starches

This study investigated the effects of various dry milling methods (blade mill (BLM), stone mill (SM), hammer mill (HM), and burr mill (BM)) at different milling severities on pinto bean flour properties, influencing the starch isolation process and isolated starch characteristics. BLM and HM produced fine flours (<180 μm) with lower starch damage (<1 %) compared to SM and BM. The starch isolation yield and efficiency increased with a reduction in flour particle size. The highest isolation yield (38 %) and efficiency (85 %) were observed from flours of BLM at 5 min. The milling-induced changes in the starch properties of the flour also altered the characteristics of starch isolated from the flour. The gelatinization and pasting properties of flour were affected by the presence of non-starch components, and starch damage while in isolated starch, they were affected only by starch damage that occurred during milling. Both the flour and isolated starch exhibited changes in crystallinity based on particle size. The water and oil holding capacities were not significantly affected by milling.