Asian Journal of Food Research and Nutrition

Aims: This study aimed to survey whether the reduction in salt concentration of miso soup, which was covertly and gradually decreased, was perceived by consumers, and whether the miso soup with reduced salt was accepted by consumers in a company cafeteria where meals were continuously served to nearly the same people.

Methods: The salt concentration in miso soup served in the cafeteria was covertly decreased at 0.1% per week, from 1.0% to 0.7%, over a period of 4 weeks (baseline and phases 1–3). The questionnaire based on miso soup’s taste was administered four times (at the end of every week). The saltiness and hedonic liking levels of the miso soup were rated using a 7-point saltiness score (“1−way too little” to “7−way too much” and “4−just about right”) and a 7-point hedonic liking score (“1−dislike very much” to “7−like very much” and “4−neither like nor dislike”), respectively.

Results: The participants were divided into three groups (high-, medium-, and low-conscious groups) according to the salt reduction-consciousness level. The saltiness and hedonic liking scores significantly decreased after weeks 1 and 2, respectively, compared to the baseline. The saltiness scores significantly differed between the conscious groups in all the four surveys, being consistently higher in the high-conscious group. Contrarily, the hedonic liking scores demonstrated a different decrease pattern based on the salt reduction-consciousness levels. The hedonic liking score in the high-conscious group did not decrease significantly.

Conclusion: The saltiness and hedonic liking ratings for the miso soup decreased with decreasing salt concentration and were associated with the consumers’ salt reduction-consciousness level.