Microalgae are promising sources of protein for human consumption, but progress needs to be made to increase their acceptability to consumers. To this end, the objectives of this work are to identify the bottlenecks in obtaining a water-soluble, lightly colored protein ingredient from Tetraselmis chui. The integration of cell disruption with purification operations units is studied and the most promising process is scaled-up. Thawing, bead milling (BM) and pulsed electric fields (PEF) are compared for the release of proteins from T.chui, and compared with Chlorella vulgaris and Arthrospira platensis. During the BM study, original results were obtained on the impacts of the physiological state of Tetraselmis chui on protein recovery. The techniques selected were thawing and BM, depending on the physiological state of T.chui. The purification of proteins from supernatants after clarification was studied using isoelectric precipitation (IEP) and membrane filtration. Ultrafiltration (UF) was more efficient than IEP on supernatant obtained after thawing and centrifugation. The process has been transferred to a semi-industrial scale for way R, a scale that has rarely been studied to date in microalgae biorefinery. The constraints associated with the scale-up affect the performance of the process, but solutions have been proposed. After bead milling of fragile T.chui, microfiltration is a promising technique to obtain a lightly colored protein product.