Effect of Ultrasound-assisted Enzymolysis on Jackfruit (Artocarpus heterophyllus) Seed Proteins: Structural Characteristics, Technofunctional Properties and the Correlation to Enzymolysis

The aim of this study was to evaluate the effect of Ultrasound-Assisted Enzymolysis (UAE) on the techno-functional properties and structure of Jackfruit Seed Protein (JSP). Before the hydrolysis by alcalase (60 min), protein solutions (10%, w/v) were exposed to ultrasound pretreatment (200 W, 400 W, 600 W for 15 min and 30 min). Compared with the control JSP, UAE improved the proteolysis process, as confirmed by an increase in the degree of hydrolysis (DH; p<0.05), as well as the Oil Holding Capacity (OHC) and emulsifying stability (ES). Moreover, the UAE treatment increased the protein solubility (PS), while the Least Gelation Concentration (LGC) did not exhibit significant changes. Scanning Electron Microscopy (SEM) demonstrated that UAE disrupted the microstructure of the JSP, exhibiting larger aggregates in comparison with control JSP. Fourier transform infrared (FT-IR) spectra indicated that the UAE treatments induced molecular unfolding by increasing the α-helix, β-turn and random coil content, as demonstrated by increased surface hydrophobicity (H0-ANS). The knowledge of this study could be selectively employed in the food industry for the development of conventional or novel foods based on jackfruit seed protein.