Sustainable fungi-based protein extraction from agro-waste mushroom stem using deep eutectic solvents

Abstract

This study evaluated the nutritional and functional qualities of the mushroom stem (MS) powder and its protein concentrates, which were extracted using alkaline and deep eutectic solvent (DES)-based methods. MS powder is rich in protein (23.02 %) and carbohydrates (63.01 %). Alkaline extraction yielded the highest protein content (45.90 %) but lower recovery rates (15.39 %) compared to DES extractions using a 1:2 molar ratio of choline chloride: glycerol (DES-CG) and choline chloride: lactic acid (DES-CL), which had recovery rates of 22.04 % and 21.47 %, respectively. DES solvents provided strong hydrogen bonding, as indicated by FTIR analysis, and produced uniform, smooth particles according to SEM imaging. Both DES and alkaline methods achieved similar protein solubility values (72-75 %). However, DES methods better preserved emulsion capabilities and balanced foaming properties, enhancing foam capacity and maintaining stability. The findings suggest that DES methods are more sustainable and efficient for extracting proteins from MS powder, optimizing both functional properties and environmental sustainability in food applications.