Natural biopolymer masks the bitterness of potassium chloride to achieve a highly efficient salt reduction for future foods

Potassium chloride (KCl) can be considered as the most ideal salt replacer to reduce dietary sodium intake and ease various health risks of a high-sodium diet. However, a high proportion of sodium chloride (NaCl) replacement with KCl remains a challenge, because KCl has an inherent metallic bitterness. This study demonstrates a strategy for this bitterness-masking using a natural polysaccharide kappa-carrageenan to specifically bind with K+ and reduce the amount of free K+ as bitter stimulant. The results show that carrageenan can significantly slow down the release and diffusion of K+, leading to a reduced bitter taste of KCl in the mouth. Up to 50% replacement of NaCl by KCl can be achieved. Furthermore, the use of carrageenan-KCl-NaCl complex as salt substitutes can regulate mineral absorption (Na, K, Ca) and reduce hypertension and renal injury risks in the animal tests. In conclusion, this natural biopolymer-based strategy successfully masks the bitter of salt-replacer KCl, opening a route to the universally applicable salt-reduction in future foods.