Rational hydroalcoholic extraction strategy for the recovery of intact glucosinolates from rapeseed cold-pressed cake

• Glucosinolates and myrosinase are preserved and concentrated in cold-pressed cake • Efficient inhibition of myrosinase is observed > 40% ethanol and 60°C • Optimal extraction conditions were found at 75% ethanol,60°C • 3-step extraction yields high-protein concentrate with low residual glucosinolates • Process enables the recovery of about 75% intact glucosinolates The valorization of cold-pressed rapeseed cake requires innovative approaches to remove and recover antinutritional compounds, particularly glucosinolates. Unlike conventional hexane-deoiled industrial meal, emerging cold-pressing cake preserves and concentrates glucosinolates while failing to inactivate endogenous myrosinase, making the recovery of intact glucosinolates extremely challenging. This study developed and optimized a water–ethanol extraction process, systematically assessing the effects of ethanol concentration (0–99.5%) and temperature (20–60 °C) on glucosinolate recovery and degradation. A mass-balance approach revealed that water or low ethanol (<40%) promoted extensive enzymatic hydrolysis of glucosinolates (90–95% degradation) due to residual myrosinase activity. Pure ethanol was ineffective, whereas ethanol concentrations between 60% and 80% at 60 °C offered a dual advantage: inhibition of myrosinase activity and efficient extraction of intact glucosinolates. Using a central composite design, extraction conditions were optimized to achieve >40% intact glucosinolate extraction yield with <20% degradation. Optimal conditions (75% ethanol and 60 °C) implemented in a three-step extraction yielded a protein-rich concentrate (∼60% dry matter) with low residual glucosinolates (<4 µmol/g). Furthermore, about 90% of progoitrin, the most toxic rapeseed glucosinolate, was removed. These conditions also enabled the recovery of ∼75% intact glucosinolates in the liquid extract. Overall, this strategy significantly improves the nutritional and organoleptic quality of rapeseed protein concentrate for food and feed applications while opening valorization opportunities for intact glucosinolates in biocontrol and agroecology.