Membrane separations and targeted functionalities of protein fractions: towards an eco-design approach

Faced with industrial competition and current environmental and regulatory challenges, the agri-food industry is being driven to develop more efficient and environmentally friendly production methods. Against this backdrop, and given the considerable interest in milk proteins (which possess remarkable functional, nutritional and biological properties), protein fractionation processes have been extensively studied over the past forty years or so. Membrane separation processes are mainly used on an industrial scale to produce protein concentrates and isolates, whilst chromatographic techniques are the gold standard for obtaining purified and functional fractions (enzymes, proteins with biological activity, etc.). However, an analysis of the literature and recent research highlights the potential of membrane processes for producing enriched fractions with high functionality: membrane-based operations preserve protein integrity and may become complementary to, or even competitive with, chromatographic processes. Initial studies on the environmental assessment of such processes (Life Cycle Assessment, LCA) also show that their impact, which is mainly linked to energy consumption, is lower than that of chromatographic techniques. The optimisation strategies identified for membrane processes (cold operation, optimisation of cleaning) should enable the future development of eco-designed membrane fractionation processes.