Effect of alkaline treatment duration on rapeseed protein during pH-shift process: Unveiling physicochemical properties and enhanced emulsifying performance

This study aims to investigate the influence of alkaline treatment duration (0-5 h) on the physicochemical properties and emulsifying performance of rapeseed protein during pH-shift process. Results showed that a 4-h alkaline treatment significantly reduced the particle size of rapeseed protein and led to a notable decrease in disulfide bond content, as well as alterations in subunit composition. Moreover, solubility of rapeseed protein increased from 18.10 +/- 0.13% to 40.44 +/- 1.74% post-treatment, accompanied by a similar to 40% enhancement in emulsifying properties. Morphological analysis revealed superior plasticity and sharper contours in 4-h alkali- treated rapeseed protein emulsions compared to untreated counterparts. Rheological analysis indicated higher viscosity and elasticity in the alkali-treated group. Overall, 4-h alkaline treatment markedly enhanced the multifaceted functional attributes of rapeseed protein during pH-shift process, rendering it a promising emulsifier in the food industry.