Preparation and Characterization of Pickering Emulsions Stabilized by Dual-Modified Millet Starch Via Ball Milling and Cold Plasma.

Abstract

Objective: The aim of this study was to study the emulsifying capacity and stability of oil-in-water (O/W) Pickering emulsions stabilized by dual-modified millet starch using ball milling and cold plasma. Methodology: Nano starch (NS) was prepared using high-energy ball milling for 7 hours at 300 rpm. The nano starch was then modified using a multipin atmospheric pressure plasma system for 5, 10, 20, or 30 minutes at 25 kV. The modified nano starch (MNS) and MNS-stabilized Pickering emulsions were characterized for their physicochemical and functional properties, including particle size, morphology, crystallinity, wettability, droplet size distribution, and storage stability. Results and Conclusions: Ball milling reduced the size of millet starch particles from 6-10 µm to 300-600 nm, significantly decreasing their crystalline structure, as confirmed by differential scanning calorimetry and X-ray diffraction. Chemical crosslinking and rearrangement of starch molecules by plasma reactive species induced increased the water contact angle of NS. Confocal microscopy revealed that MNS particles were strongly adsorbed at the oil-water interface and exhibited enhanced storage stability over 30 days. These findings suggest that ball milling combined with CP modification is a viable and effective method for producing improved starch-based particle emulsifiers.