pH-shift treatment enhances stability and functional properties of rapeseed protein high internal phase emulsions

This study investigates the impact of pH-shift treatment on the properties of rapeseed protein high internal phase emulsions (HIPEs). The results demonstrate that pH-shift treatment significantly enhances the functional characteristics of HIPEs. Morphological and confocal laser scanning microscopy (CLSM) observations reveal that treated HIPEs exhibit superior gel-like semi-solid characteristics with smaller, closely packed droplets and a more compact structure, showing no oil phase separation. Rheological analysis indicates that pH-shift treated HIPEs possess better viscoelasticity and gelation properties, reflected in a higher storage modulus (G'). The pH-shift treatment also increases the centrifugal stability of HIPEs, indicating enhanced oil binding capacity. Furthermore, treated HIPEs demonstrate significantly improved freeze-thaw stability compared to untreated samples and mitigate the destabilizing effects of thermal processing, preventing the decline in viscoelasticity post-heating. These findings underscore the effectiveness of pH-shift treatment in improving the stability, structure, and functional resilience of rapeseed protein HIPEs, making them suitable for applications requiring high stability and consistent performance.