BALL MILLING AS A GREEN MECHANO-CHEMICAL TECHNOLOGY FOR TUNING TECHNOLOGICAL FUNCTIONALITY OF STARCHES OF DIFFERENT BOTANICAL ORIGIN

Background: Ball milling (BM) is a mechano-chemical technology that, in recent times, has shown potential applications in modifying food biomolecules properties, and functionalities. The high-energy mechanical shocks imparted during BM treatments can induce structural modifications altering molecular interactions and causing phase transitions. Native starch undergoes extensive chemical or physical modifications to overcome technological limitations, enhancing its applicability in the food sector and facilitating the development of innovative ingredients and food structuring. The aim of this study is to investigate the effects of BM on the technological functionality of native starches of different botanical origins. Method: Corn, potato, tapioca, and wheat native starches were subjected to BM at varying rotating times (5, 15, and 30 min) and constant speed. Analyses included assessments of damaged starch, thermal properties, gelatinization behaviour, water absorption capacity (WAC), oil absorption capacity (OAC), swelling power (SP), and cold-water solubility (CWS) for both native and BM-treated samples. Native and BM starch solutions were heated to synthetise hydrogels, that have been evaluated for their rheological properties (storage modulus (G'), loss modulus (G"), and tan δ). Results: All BM starches showed a lower gelatinization temperature and enthalpy of gelatinization compared to their native counterparts. Functional properties were significantly affected by BM, with a positive correlation to the treatment time apart from OAC. BM tapioca starch exhibited a threefold higher SP than other varieties, while potato starch demonstrated increased cold-water solubility (CWS) (P < 0.05). As regards WHC, tapioca starch displayed a sharp increase after a 30-minute treatment. The rheological evaluation indicated a weakened gel formation characterized by a lower G’ in BM starches with respect to native references. These changes in technological functionalities were linked to amylose/amylopectin ratios and granule size distributions. Conclusion: Ball milling shows the potential in modifying food biomolecules, especially native starches, through induced structural changes. The findings lead to the potential development of novel food ingredients.