ULTRASOUND-ASSISTED ENHANCEMENT OF MORINGA OLEIFERA SEED PROTEIN FUNCTIONALITY: IMPACT ON ENZYMATIC HYDROLYSIS AND STRUCTURAL CONFORMATION

The increasing demand for nutritionally rich ingredients adaptable to extreme cultivation conditions has driven interest in Moringa oleifera seeds. Despite their potential, the use of these plant proteins remains limited due to low solubility. In this context, emerging technologies such as ultrasound (US) and enzymatic hydrolysis may be promising strategies to enhance their applicability. This study aimed to optimize the solubility of Moringa oleifera seed proteins processed by US using a central composite rotatable design (CCRD) varying time (5–30 min) and temperature (25–60 °C), and to evaluate the effects on hydrolysis kinetics by Alcalase using the pH-stat method, as well as on structural characteristics through analyses of zeta potential, mean particle size (MPS), polydispersity index (PDI), and intrinsic fluorescence. Results showed that US increased protein solubility by up to 65% after processing at 38 W/L, 25 kHz, at 60 °C for 30 minutes (p < 0.05). A mathematical model was obtained (R² = 0.89) and the point of maximum solubility was validated (relative error < 1.8%) to predict protein solubility as a function of sonication time and temperature.  Under optimized conditions, ultrasonic processing reduced MPS by 60% and PDI by 38%, while intrinsic fluorescence increased by 27%. The zeta potential value decreased by 23%, indicating increased electrostatic repulsion, suggesting greater uniformity, improved dispersion, and higher homogeneity, which are essential for industrial applicability due to their association with colloidal stability and process feasibility. In hydrolysis, the sonicated sample under optimized conditions showed a 38% increase in hydrolysis rate and 45% increase in degree of hydrolysis, indicating that cavitation favored partial protein unfolding, facilitating enzyme action. Therefore, ultrasound is an effective approach to improve solubility and hydrolysis susceptibility of Moringa oleifera proteins, expanding their potential application in food products such as beverages and sauces.