Sodium reduction is an important public health goal. Individual and population approaches are necessary for reducing the sodium content of processed foods and meals. The aim of the present study is to affirm the effect of monosodium l-glutamate (MSG), an umami substance, on the saltiness or palatability of low-salt solutions and to explore the preferred salt concentration in soup. Five hundred and eighty-four healthy participants from nineteen regions in Japan tasted 0.3, 0.6, and 0.9% NaCl solutions with or without 0.3% MSG. Evaluations of saltiness and palatability for each solution were conducted using a visual analog scale in a double-blinded randomized manner. Saltiness gradually increased depending on the concentration of NaCl. The saltiness of the 0.3% NaCl solution with MSG was rated significantly higher than that without MSG. The palatability ratings were higher for the solutions with MSG than for those without MSG for all NaCl concentrations. In particular, the palatability rating of the 0.3% NaCl solution with MSG was twice as high as that without MSG and was significantly higher than that of the other five test solutions. Furthermore, these results were observed to be approximately the same, irrespective of sex, age, region, etc. Salt reduction is believed to result in a loss of palatability. However, our results suggest that umami can compensate for the loss of palatability caused by salt reduction and that the addition of an appropriate amount of an umami substance can facilitate salt reduction from 0.9 to 0.3% without sacrificing palatability.

中文翻译：

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基于日本多个地区的随机盲法实验验证汤中首选盐浓度——鲜味（L-谷氨酸）对低盐溶液的咸味和适口性的影响

减钠是一项重要的公共卫生目标。减少加工食品和膳食的钠含量需要个体和群体方法。本研究的目的是确认 l-谷氨酸单钠 (MSG)，一种鲜味物质，对低盐溶液的咸味或适口性的影响，并探索汤中的首选盐浓度。来自日本 19 个地区的 584 名健康参与者品尝了 0.3、0.6 和 0.9% 的 NaCl 溶液，含或不含 0.3% 味精。使用视觉模拟量表以双盲随机方式评估每种溶液的咸味和适口性。咸味随着NaCl的浓度逐渐增加。含味精的 0.3% NaCl 溶液的咸味等级明显高于不含味精的。对于所有 NaCl 浓度，含有味精的溶液的适口性评级高于不含味精的溶液。特别是含味精的 0.3% NaCl 溶液的适口性等级是不含味精的两倍，并显着高于其他五种测试溶液。此外，无论性别、年龄、地区等如何，观察到这些结果大致相同。据信减盐会导致适口性的损失。然而，我们的研究结果表明，鲜味可以弥补因盐分减少而导致的适口性损失，加入适量的鲜味物质可以在不牺牲适口性的情况下将盐分从 0.9% 减少到 0.3%。含味精的 0.3% NaCl 溶液的适口性等级是不含味精的两倍，并显着高于其他五种测试溶液。此外，无论性别、年龄、地区等如何，观察到这些结果大致相同。据信减盐会导致适口性的损失。然而，我们的研究结果表明，鲜味可以弥补因减盐而导致的适口性损失，加入适量的鲜味物质可以在不牺牲适口性的情况下将盐分从 0.9% 减少到 0.3%。含味精的 0.3% NaCl 溶液的适口性等级是不含味精的两倍，并显着高于其他五种测试溶液。此外，无论性别、年龄、地区等如何，观察到这些结果大致相同。据信减盐会导致适口性的损失。然而，我们的研究结果表明，鲜味可以弥补因盐分减少而导致的适口性损失，加入适量的鲜味物质可以在不牺牲适口性的情况下将盐分从 0.9% 减少到 0.3%。不分性别、年龄、地区等。据信减盐会导致适口性的损失。然而，我们的研究结果表明，鲜味可以弥补因盐分减少而导致的适口性损失，加入适量的鲜味物质可以在不牺牲适口性的情况下将盐分从 0.9% 减少到 0.3%。不分性别、年龄、地区等。据信减盐会导致适口性的损失。然而，我们的研究结果表明，鲜味可以弥补因盐分减少而导致的适口性损失，加入适量的鲜味物质可以在不牺牲适口性的情况下将盐分从 0.9% 减少到 0.3%。