Green enzyme–ultrasound-membrane extraction of rapeseed protein: Enhancing purity and reducing Antinutritional factors

The objective of this study was to develop an eco-efficient strategy for extracting high-quality protein from rapeseed meal while minimizing antinutritional factors. Enzymatic hydrolysis, ultrasonication, and hybrid pretreatments were followed by membrane filtration, and their performance was compared to conventional acid precipitation. All integrated protocols significantly improved protein purity. Specifically, enzymatic pretreatment (EP) yielded the optimal outcome, producing extracts with enhanced purity and lower levels of phytic acid and glucosinolates. Ultrasound pretreatment enhanced the retention of phenolic compounds. Membrane filtration effectively removed low-molecular-weight impurities. These findings demonstrate the viability of integrated green technologies for valorising rapeseed by-products into functional protein ingredients. • Enzyme-ultrasound with membrane filtration improved protein quality. • Membrane filtration removed peptides, salts, and residual enzymes. • Integrated green processing boosted extract total phenolic content. • Enzyme-ultrasound alkaline extraction minimized phytic acid and glucosinolates. • Enzyme pretreatment provided best protein quality, cost and simplicity balance.