Investigation of the fabrication, characterization, protective effect and digestive mechanism of a novel Pickering emulsion gels

Abstract

The current research provided a simple method to construct Pickering emulsion gels based on chitosan hydrochloride-carboxymethyl starch (CHC-CMS) nanogels stabilized Pickering emulsions and curdlan, which can offer a new strategy for the design of low-fat food. The hardness, elasticity, water holding capacity and swelling ratio of emulsion gels were influenced by the mixed volume ratios and curdlan concentration. The freeze-thaw stability of the emulsion gels was better than that of the Pickering emulsions. The shear-thinning property and solid-like behavior of Pickering emulsion gels were observed in the linear viscoelastic regions. Confocal laser scanning microscopy exhibited that most of emulsion droplets with a regular spherical shape were evenly distributed, indicating that little or no coalescence happened in the process of gelation. Moreover, emulsion gels displayed a smooth and dense wave-like structure. During the storage test at 55 °C for 14 days, emulsions gels provided the better protective effect on β-carotene than Pickering emulsions. Furthermore, the degradation behavior of β-carotene in emulsion gels conformed to a first-order kinetic model. The corresponding half-life time (t1/2) of β-carotene in the emulsion gels prepared by Pickering emulsions with 50% oil phase fraction increased from 19 days to 30 days with the concentration of curdlan increasing from 0 wt% to 3 wt%. The Pickering emulsion gels had the lower free fatty acid released compared to Pickering emulsions. Overall, these results demonstrated the potentials of Pickering emulsion gels in protecting bioactive components and designing low-fat food alternatives.