Hollow salt-nanoemulsion composites: A novel carrier for Zanthoxylum flavor construction with simultaneous sodium reduction and flavor retention

Designing hollow salt products has become an emerging means of reducing sodium, which can achieve sodium reduction without losing its salty taste. Compared with existing hollow salt technology, this study aims to construct a hollow salt carrier that can preserve the Zanthoxylum flavor. Furthermore, the nanoemulsion formed by SPI-(−)-epigallocatechin-3-gallate (EGCG) complex and Zanthoxylum oil was used to produce hollow salt with Zanthoxylum flavor through spray drying. The hollow salt prepared by the nanoemulsion containing 2 % (w/v) SPI-EGCG complex and an oil-water ratio of 2:8 exhibited a uniform particle size distribution, with an average microsphere diameter of 7.57 ± 1.60 μm. It has a sodium content of 223 mg/g, a yield of 41 %, and a Zanthoxylum oil embedding rate of 60 %. The findings from the sensory evaluation showed that when hollow salt and traditional sodium chloride (NaCl) were compared at an equal mass, there was no substantial disparity in terms of the perceived saltiness (P > 0.05). By analyzing the in vitro release of sodium and measuring sodium retention on a pig's tongue surface, sodium can be rapidly released from hollow salts with the extended retention on the tongue surface, providing an enhanced salty sensation even at low sodium concentrations. Furthermore, headspace gas chromatography-ion mobility spectrometry analysis revealed that the flavor retention rate in hollow salt is highly dependent on the oil-water ratio formulations by spray drying. Notably, the 2 % SPI-EGCG-2:8 oil-water hollow salt formulation has the best performing for preserving the volatile organic compounds of Zanthoxylum flavor. This study demonstrates the feasibility of developing novel low-sodium hollow salt product with the enhanced salt-taste perception.