Salt-induced cellulose nanocrystal networks modulate the stability and digestion behavior of AMP/HPMC water-in-water...

Salt ions play a key role in governing the property of food system. In this work, the effects of salt ions on physicochemical property of cellulose nanocrystals (CNCs) and their stabilization behavior in Amylopectin/Hydroxypropyl methylcellulose (AMP/HPMC) water-in-water (W/W) emulsions were investigated. The addition of NaCl significantly reduced the absolute value of zeta potential of CNCs and resulted in particle aggregation, forming of network structures. These structure changes promoted the droplet clustering and bridging flocculation of AMP/HPMC W/W Pickering emulsions and enhanced their stability during long-term storage (60 days). Rheological analysis revealed that increasing NaCl concentration resulted in enhanced viscosity and obvious viscous-dominated behavior due to the synergistic interaction between salt-induced CNCs network and thermal-induced aggregation of HPMC. Furthermore, in vitro digestion results showed that salt-induced structural changes of CNCs effectively limited enzyme accessibility, thereby reducing AMP digestion and glucose release. This work demonstrates that salt ions could regulate the structure-function relationship of CNCs-stabilized W/W Pickering emulsions, and provides new insights to design novel food systems with controlled digestion properties.