Optimised methodology for the extraction of protein from quinoa (Chenopodium quinoa Willd.)

Summary Quinoa is a highly appreciated Andean pseudo‐cereal and has sparked attention worldwide due to its excellent nutritional value. The protein extraction parameters for defatted quinoa seed meal ( DQSM ) were optimised in this study. Initially, a Plackett–Burman design was applied to screen the factors displaying a potential effect on the quinoa protein extraction yield ( Y %, g soluble protein/100 g total protein) being the main evaluated factors: pH , NaCl concentration, time, temperature, solvent type, particle size and solvent/meal ratio. Four main factors: temperature, solvent/meal ratio, pH and time selected from the screening step were optimised with a central composed design ( CCD ). The obtained response surface model ( RSM ) produced a satisfactory fitting of the results ( R 2 = 0.9308). Optimal quinoa protein extraction conditions of 36.2 °C, solvent/meal ratio of 19.6/1 (v/w) and 90 min resulted in a protein yield of 62.1% (9.06 g of protein/100 g DQSM ) which closely agree with the predicted value of 62.5%.The model was experimentally validated by extracting the quinoa protein using the optimal conditions revealed by RSM . The optimised conditions could be successfully employed in the design process of protein extraction from quinoa seed meal to obtain optimal yields.