Characterisation of the physicochemical, functional and antioxidant properties of house cricket (Acheta domesticus) protein hydrolysate processed with six proteases

House cricket ( Acheta domesticus ) is recognised as an emerging food source. However, improving its acceptability and nutritional value remains a notable challenge. This study compared the structures, functional properties and antioxidant activities of Acheta domesticus protein hydrolysates (ADPHs) using six different proteases. Enzymatic hydrolysis destroyed the secondary and tertiary structures of Acheta domesticus protein and decreased its molecular weight and particle size, particularly alcalase hydrolysate with the highest degree of hydrolysis and the smallest particle. Structural analyses (Fourier transform infrared spectroscopy and fluorescence spectroscopy) revealed that hydrolysis disrupted the α-helix/β-turn structures of the protein and reduced its surface hydrophobicity. In terms of functional properties, neutrase hydrolysate exhibited the highest foaming capacity, whereas pepsin hydrolysate showed superior emulsifying activity index. Meanwhile, compared with the isolated protein, the thermal stability and crystallinity of ADPH decreased. Antioxidant activities indicated that alcalase and plant-derived proteases (papain, bromelain) considerably enhanced bioactivity, whereas animal-derived enzymes (pepsin, trypsin) showed limited efficacy. This study identified alcalase as the optimal protease for producing functional ADPH, whereas papain and bromelain represent novel and promising alternatives. • This article has the following highlights: • Acheta domesticus protein was hydrolyzed by six enzymes for the first time; • The different protein hydrolysates were fully characterized; • Alcalas, papain and bromelain hydrolysates exhibits stronger physicochemical properties; • Alcalase hydrolysis exhibited superior antioxidant activity.