Impacts of sodium chloride reduction in tomato soup system using potassium chloride and amino acids

Five different salt mixtures were prepared for the aim of lowering the sodium content of tomato soup and effects of using these mixtures on sensory, rheological, microbiological and physico-chemical properties of the final products were evaluated. The results showed that the use of salt substitutes did not affect flow behaviour of soup samples. Sensory profiling revealed that any group could not manage to reach the same saltiness level with the regular salt tomato soup (reference); nevertheless, tomato soups with salt formulation D (60% NaCl, 28% KCl, 6% l-lysine hydrochloride and 6% l-glutamic acid) and E (60% NaCl, 28% KCl and 12% l-glutamic acid) had the most similar sensory evaluation with the reference. No differences were observed among groups in terms of aw (P > 0.05). On the other hand, the lowest average pH value and the highest aerobic mesophilic counts (87 CFU/g) were observed in the soup with salt formulation E (P < 0.05). The findings suggest that the partial replacement of 40% sodium chloride (NaCl) by 28% potassium chloride (KCl), 6% l-lysine hydrochloride and 6% l-glutamic acid (salt formulation D) seems an alternative approach for reducing the sodium content of tomato soups although it may cause a bit decrease in saltiness and an increase in the number of aerobic mesophilic bacteria (68 CFU/g).