The present study aims to optimize the enzymatic hydrolysis condition and determine the
functional properties of eel (Monopterus albus) protein hydrolysate (EPH) at different
hydrolysate concentrations (0.1%, 0.5%, 1.0%). The enzymatic hydrolysis (using alcalase)
condition; namely, temperature (°C), enzyme to substrate concentration (%) and pH on both
the yield and degree of hydrolysis (DH), as responses, was optimized using the response
surface methodology (RSM) by employing three factors, 3-level, Central Composite Design
(CCD). The optimum hydrolysis condition suggested was a temperature of 55.76 °C, enzyme
concentration of 1.80% and pH of 9. The experimental result for yield (9.45%) was higher while
the experimental result for DH (15.01%) was lower than the predicted values of the responses
using the quadratic model, which were 5.67% and 16.73%, respectively. The findings for the
functional properties showed that the Nitrogen Solubility Index (NSI) of EPH was 85%. The
emulsion stability index (ESI) of EPH was shown to decrease with the increase hydrolysate
concentration (0.1%, 0.5%, 1.0%) while the foam expansion of EPH showed an increase with
the increase in concentration. High solubility and the ability of EPH to emulsify and form foam
show its potential for use as a natural binding and emulsifying agent.