Taste perception of sodium chloride in relation to dietary intake of salt

Normotensive young adults, categorized as having high, medium, or low dietary intakes of salt based on a food habits questionnaire, participated in a series of discrimination, perceived intensity, and preference tests of solutions of NaCl and of salted tomato juice. In ad libitum preference tests, subjects with a low salt intake added less NaCl to salt-free tomato juice, and had higher salivary sodium levels. However, large individual variability precluded discernment of a clear-cut relation among these measures. No significant correlations were obtained between salt intake and detection thresholds of 57 subjects for NaCl in water or in juice. In water solutions, salt recognition was greater for the high intake group than for the other groups, with a reverse trend for tomato juice. The experiments demonstrated that 1) discrimination, sensitivity, perceived intensity, preference, and hedonic responses to salt were independent behavioral measures; 2) few sensory measures were related to estimated salt intake; 3) patterns of response to saltiness could not be extrapolated from water solutions to the more complex juice, 4) NaCl elicited a variety of qualitative responses, depending on concentration and medium of dispersion, and 5) a more accurate test instrument is needed for estimating dietary intake of salt.