Structural reconfiguration and functional enhancement of detoxified plum kernel proteins via high-intensity ultrasound treatment

Plum kernels remain underutilized due to toxic cyanogenic glycosides. Detoxified plum kernel meal is a promising plant-based protein source; however, its extracted proteins exhibit limited techno-functionality, restricting their applications in food systems. This study investigates the effects of high-intensity ultrasound (HIUS) at varying durations (10, 20, 30, and 40 min) on the techno-functional, biochemical, structural, morphological, and thermal properties of detoxified plum kernel protein isolates (PKPI). Varying HIUS duration significantly (p < 0.05) enhanced solubility (1.08-fold), emulsifying capacity (1.21-fold), and foaming capacity (1.16-fold), with the most pronounced improvements observed in the PKPI sample treated at 30 mins (US-PKPI-30). Moderate HIUS treatment effectively maintained a balanced secondary structure of β-sheets (53.87 %), α-helix (9.08 %), and β-turns (16.87 %), optimizing flexibility and structural integrity. Structural changes and surface analysis indicated enhanced molecular flexibility due to HIUS treatment. US-PKPI-30 exhibited a ζ-potential of -18.3 mV, indicating improved dispersion and colloidal stability. Molecular weight distribution analysis showed that the primary structure of the protein remained intact after treatment. Particle size distribution and surface morphological analysis revealed reduced particle sizes, suggesting protein aggregate disruption. Detoxified plum kernel proteins are promising, and HIUS treatment could be an effective strategy for enhancing their techno-functionality as well as the utilization of plum processing waste.