Comparative extraction and recovery of Zophobas morioprotein using deep eutectic solvents and conventional alkaline methods: Effects on structure, functionality, and antioxidant properties.

This study explored eco-friendly deep eutectic solvents (DES) for the efficient extraction of Zophobas morio protein (ZMP), followed by different recovery methods. Various DESs, including acid-, neutral-, and alkaline-based DESs were screened, and alkaline deep eutectic solvent (ADES), consisting of potassium carbonate: glycerol (1: 11 M), showed the highest extraction performance among all DESs. Response surface methodology (RSM) optimized the ADES extraction conditions as water content of 56 % (v/v), an extraction temperature of 94 °C, and an extraction time of 115 min. Under these optimal conditions, ZMPs were recovered from ADES using four methods: acidic precipitation (ADES-AP), dialysis bag (ADES-DB), ethanol precipitation (ADES-EP), and macroporous resin (ADES-MR). The recovered ZMPs were compared to the protein obtained from the conventional alkaline extraction-acidic precipitation (AE-AP) method. ADES-DB and ADES-MR methods had higher protein content (84.93 % and 81.88 %) than the AE-AP (79.79 %) and other methods (14.28-31.11 %). Compared to AE-AP, ADES-based methods preserved the ordered structure content (β-sheet), and enhanced thermal stability and amino acid profile of ZMPs. Notably, ADES-DB showed comparable protein solubility and digestibility, and emulsion properties with AE-AP, whereas ADES-MR exhibited superior antioxidant activities. Our findings provide novel extraction and recovery methods using ADES as sustainable alternatives for extracting insect protein.