Saltiness perception mechanism and salt reduction strategies in food

Globally, dietary risk factors cause far more deaths and disability-adjusted life years than any other risk, including smoking. Although salt, sugar and fat have been the main foci of dietary policy debates over the past two decades, the major contributing factor is high salt intake, which causes more than 2% global annual mortality, amounting to more than 160 million people. These shocking statistics highlight the necessity of reducing the salt content of food, which is a key challenge for the food industry. Here, the mechanisms by which taste cells, brain and organs perceive saltiness are reviewed. Then, we summarize the research progress of several salt reduction strategies and assessment methods for saltiness. NaCl is transmitted through amiloride-sensitive pathway and amiloride-insensitive pathway. The electrical signal generated by the salt receptors is transmitted to the central nervous system and saltiness perception can be enhanced by interaction with odor and taste substances. Strategies for reducing salt intake include salt substitutes, modifying food texture, changing the shape and size of salt crystals, modifying processing technology and multi-sensory synergism in perception, which enhance the perceived intensity of saltiness without otherwise affecting taste. To evaluate saltiness, most established animal models involve mice. In addition to taste bud cells in vivo, cell models in vitro are being explored. This review provides a scientific basis for the practice of salt reduction in the food industry and a theoretical basis for the evaluation of saltiness perception.