Hollow salt for sodium reduction in foods: Mechanisms, influence factors, applications and challenges

Background: Long-term consumption of high-sodium diets poses a significant threat to human health, with current global sodium intake vastly exceeding the WHO's recommended limit of 2 g/day. The escalating consumer demand for low-sodium foods has spurred research efforts aimed at reducing sodium content in food products. Hollow salt emerges as a promising method for sodium reduction, particularly in low-moisture foods. Scope and approach: This review offers an overview of sodium reduction strategies in foods, elucidating the formation mechanism and influence factors of hollow salt in the context of spray drying. Additionally, it discusses the applications and challenges of incorporating hollow salt in food products. Key findings and conclusions: Hollow salt particles boast an expansive specific surface area that enhances the availability of taste receptors for sodium, thereby amplifying the perception of saltiness. However, preparation of hollow salt in food industry demands a certain technical ability. Spray drying stands out as an efficient method for hollow salt preparation. Formation of the hollow structure significantly hinges on the surface activity of precursor components, achievable within specific process parameters encompassing droplet size of feedings (solution/emulsion), solid concentration, atomization, drying temperature, feeding rate, and aspirator rate during spray drying. Emulsion-based hollow salt exhibits notable inclusivity and holds promise in the development of diverse sodium-reduced food products through integration with other strategies, though this area necessitates further research.