Studies on stabilized mechanism of high internal phase Pickering emulsions from the collaboration of low dose konjac glucomannan and myofibrillar protein

Abstract

In this study, the effects of different concentrations (0%, 0.25%, 0.5%, 1%, 1.5%, w/v) of konjac glucomannan (KGM) on the structure and interfacial adsorption of myofibrillar protein (MP) and the mechanism of co-emulsification of high internal phase Pickering emulsions (Pickering HIPEs) by KGM and MP were investigated. The results showed that for interfacial MPs, KGM addition promoted MP structure unfolding and improved MP wettability with a three-phase contact angle from 73.69° (control) to 89.41° (0.5% KGM), thereby lowering the energy barriers to MP penetrating and rearranging at the interface. Furthermore, the adsorption kinetics and protein adsorption percentage (AP%) indicated that KGM (≤1%) facilitated the adsorption of MP from the aqueous phase to the oil-water interface. For MP in the aqueous phase, KGM induced a denser MP network structure by promoting “concentrated” MP and connecting MP through hydrogen bonding, which formed a stronger spatial site resistance and hindered oil droplet aggregation. KGM (≤1%, especially 0.5%) resulted in reduced droplet size, relaxation time (T2), lipid oxidation, and improved storage stability and energy storage modulus of Pickering HIPEs. However, the competitive adsorption of KGM (>1%) significantly decreased the interface MP, and the formation of continuous KGM hydrogel formed an unaggregated MP network structure, decreasing the emulsion performance further. Overall, KGM could modulate the physical properties of MP-stabilized Pickering HIPEs by altering the interfacial adsorption and network structure.