An Exploratory Study on the Impact of MIPEF-Assisted Extraction on Recovery of Proteins, Pigments, and Polyphenols from Sub-Standard Pea Waste

The growing demand for sustainable protein sources has intensified the need for efficient valorisation of legume by-products. This study investigated the application of moderate intensity pulsed electric fields (MIPEF; 5 kV/cm, 4 μs, 500 pulses) as a green technology for assisting the co-extraction of proteins, pigments, and polyphenols from industrial substandard peas (Pisum sativum L.). Aqueous pea dispersions (20 g/100 g) were subjected to alkalinization (pH 9–12), and MIPEF applied either before or after the pH adjustment. The highest protein recovery was achieved when MIPEF was applied after alkalinization at pH 9.0, due to the increased conductivity and energy input enhancing electroporation-driven protein release. Although higher pH levels increased energy delivery, they did not significantly improve protein extraction. Conversely, MIPEF application decreased total polyphenol and pigment concentrations in the extract, likely due to aggregation phenomena. Overall, these preliminary results indicate that combining mild alkalinization with MIPEF might represent a promising and energy-efficient approach for protein recovery from legume side-streams. Further optimization is required to improve protein recovery while preserving the stability of co-extracted bioactive compounds.