Ball milling: Green approach for improving the technological performance of starch from different botanical sources

Starch, a renewable biopolymer derived from various plant sources, serves as a major ingredient for food formulations. However, native starch has inadequate functionality which makes it not ideally suitable for direct food processing. To address this limitation, modification of the starch native structure could be imparted exploiting ball milling (BM), an innovative and more sustainable physical technique. The aim of this study was to investigate the changes in properties and functionalities of starches from different botanical sources (potato, tapioca and wheat) induced by BM treatment for different time (5, 15, and 30 min) at a constant speed (350 rpm). Swelling power (SP), cold water solubility (CWS), water and oil holding capacity (WHC & OHC), rheological and thermal properties were investigated. Generally, all starches showed a significant modification (p < 0.05) of the technological functionalities tested at different BM time. CWS and SP increased (p < 0.05) for all variety of starches subject to BM compared to their native analogous. Tapioca starch BM for 30 min exhibited a threefold higher SP than the other botanical origins treated for the same time. Limited was the effect of BM on OHC (P> 0.05) for starches milled 5 and 15 min, however, all samples BM for 30 min showed higher OHC compared to native counterparts. Generally, the WHC was positively correlated with BM milling time, nevertheless, the extent of the effect depended on the botanical origin of the samples. As regards thermal properties the increasing in BM time led to lower gelatinization enthalpy and onset temperature compared to the native analogous, suggesting a reduction of the starch granule crystallinity. The rheological analysis revealed a weaker gel formation (lower G’) in ball-milled starches compared to corresponding native starches. This trend was consistently observed across all starch samples. The results highlight the effects of ball milling on starches from different botanical sources providing scientific support for its potential use for starch modification.