From laboratory proof of concept to pilot reality: technical bottlenecks for glucosinolate extraction from Brassica carinata press cake

Source abstract

Glucosinolates (GSLs) from Brassica carinata press cake are of interest both as antinutritional factors to be removed from feed and as precursors of bioactive compounds for biocontrol, but their selective recovery must contend with the dual constraints of myrosinase activity and protein preservation. This study investigates hydro-ethanolic extraction and miscella concentration at laboratory and pilot scales on industrial-type press cakes and finely milled powders. At laboratory scale, when press cake was ground, fully dispersed in solvent and extracted after thermal myrosinase inactivation, GSL yields above 90% were achieved with low residual levels in the final meal, showing that neither diffusion nor thermal degradation is an intrinsic barrier. In contrast, pilot-scale percolation on intact cakes plateaued at about 70% overall recovery, with roughly 30% of initial GSLs remaining in spent cakes despite extended extraction times and high solvent-to-solid ratios, highlighting strong mass-transfer and percolation limitations. Incomplete myrosinase inactivation further caused substantial and variable GSL losses, particularly during miscella concentration, where up to 60–70% of solubilized GSLs could no longer be accounted for under some evaporation conditions. Clarification of extracts by centrifugation prior to evaporation allowed miscella concentration without measurable additional losses in selected trials. Overall, a carinata-based GSL “biorefinery brick” appears technically feasible only within a very narrow operating window and at a processing cost that is difficult to justify for bulk feed applications, unless high-value outlets for GSL-rich fractions can be secured.