Process optimisation of defatted wheat germ protein extraction in a novel alkaline-based deep eutectic solvent (DES) via Box-Behnken experimental design (BBD).

This is the first study to provide a preliminary investigation into the recovery of protein from wheat germ and the prediction of their extraction conditions in microwave cavity using a novel DES solvent. The response surface methodology was used to predict the microwaved protein extraction conditions of the DWG. The effects of DES buffer-concentration (X: 0.01-1.00 g/mL), microwave power (X: 50-250 W), irradiation time (X: 1-5 min) and sample-to-buffer ratio (X: 1:10-1:50) were tested using a single factor and Box-Behnken experimental design. Under the optimized conditions (X = 0.52 g/mL, X = 186 W, X = 3.28 min, and X = 1:39) protein yield and absorbed microwave were obtained at the optimal value of 33.00 % and 677 J/min, respectively with no denaturation of the protein as validated from the SDS-PAGE gel electrophoresis profile. Consequently, this investigation provides a practical approach for the extraction of bioactive protein from DWG using a novel deep eutectic solvent.