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.

Impact of Particle Size on the Physicochemical, Functional, and In Vitro Digestibility Properties of Fava Bean Flour and Bread

Fava beans, renowned for their nutritional value and sustainable cultivation, are pivotal in various food applications. This study examined the implications of varying the particle size on the functional, physicochemical, and in vitro digestibility properties of fava bean flour. Fava bean was milled into 0.14, 0.50, and 1.0 mm particle sizes using a Ferkar multipurpose knife mill. Physicochemical analyses showed that the 0.14 mm flour had more starch damage, but higher protein and fat contents. Functionality assessments revealed that the finer particle sizes had better foaming properties, swelling power, and gelation behavior than the coarse particle size. Emulsion capacity showed that for all the pH conditions, 1.00 mm particle size flour had a significantly higher (p < 0.05) oil droplet size, while the 0.5 and 0.14 mm flours had smaller and similar oil droplet sizes. Moreover, in vitro digestibility assays resulted in improved starch digestion (p ˂ 0.05) with the increase in flour particle size. Varying the particle size of fava bean flour had less impact on the in vitro digestibility of the bread produced from wheat-fava bean composite flour, with an average of 84%. The findings underscore the critical role of particle size in tailoring fava bean flour for specific culinary purposes and nutritional considerations.