Effects of the interaction between bacterial cellulose and soy protein isolate on the oil-water interface on the digestion of the Pickering emulsions

This work was aimed at engineering and modulating oil-in-water (O/W) composite interfaces by controlling the interaction between cellulose and protein to delay the lipid digestion. The insoluble bacterial cellulose nanofibrils/soy protein isolate (BCNFs/SPI) complexes were fabricated at pH 3.0. The interfacial adsorption characteristics of SPI particles were improved in the presence of BCNFs, resulting in the enhanced interfacial pressure and dilatational viscoelastic moduli due to the rigid and compact layers. O/W Pickering emulsions stabilized by BCNFs/SPI complexes were prepared, and the prepared emulsion presented improved stability by tuning BCNFs/SPI ratios. Moreover, the emulsions stabilized by BCNFs/SPI complexes displayed lower amount of free fatty acid (FFA) released than that of SPI stabilized emulsion after in vitro simulated digestion, with the minimum amount of FFA released of 58.0% at the BCNFs/SPI ratio of 1:5. Main mechanisms were proposed for the results: (1) the compact interfacial layers formed by complexes partially restricted interfacial displacement by bile salts or lipases; (2) bridging structure and interconnected networks formed by BCNFs reduced the surface area available for binding with lipases and bile salts. This work would be suggestive for the development of cellulose-protein interface to modulate the digestion of Pickering emulsified lipids.