Multimodal modification of Jack bean protein using physical, chemical, and thermal approaches to stabilize red fruit oil emulsions.

Abstract

The utilization of jack bean protein isolate (Canavalia ensiformis) and its modification as an emulsifier for stabilizing red fruit oil (Pandanus conoideus) emulsions remains underexplored. This study investigated the effects of pH-shifting, heat treatment, ultrasonication, and their combinations on the structural, interfacial, and emulsifying properties of jack bean protein isolate (JBPI). The modification treatments significantly enhanced protein solubility, flexibility, and surface hydrophobicity, resulting in increased interfacial protein adsorption from 13% in the native protein to as high as 55% after modification. While all modified proteins exhibited improved emulsion stability, the pHH treatment displayed a unique stabilization behavior, with a flocculation index approximately 1375% while maintaining a coalescence index below 10% after 14 days of storage. The observed behavior is likely attributable to bridging flocculation; however, additional stabilization mechanisms, including Pickering-like stabilization and synergistic interfacial adsorption between jack bean proteins and the native surface-active compounds in red fruit oil (RFO), may also have contributed to the enhanced emulsion stability. These findings demonstrate the potential of multimodal modification to improve the performance of jack bean protein isolate as a natural emulsifier for bioactive oil emulsions.