Low-Sodium Labeling Affects Taste Perception, Salt Use

BURWOOD, AustraliaFoods carrying nutrition labels or heart healthy logos touting sodium reduction can negatively affect taste perception and salt use, according to a study published in the journal Public Health Nutrition.

Researchers at Deakin University conducted a study to investigate the effect of nutrient labels and health logos on expected and perceived liking and salt intensity of sodium-reduced soups. The study involved 50 participants, more than half of which had stated that health labels affect their food choices. Three variations in sodium content of a commercially available chicken noodle soup were tested: the benchmark product with no sodium reduction; 15% sodium-reduced soup; and 30% sodium-reduced soup. The remaining ingredients were the same. Each of the soup products was labeled with one of three labels: no health label; a nutrient label stating Now reduced in salt, great taste"; or the Tick" health logo.

On three separate days, participants tasted three soups with the three different labels in random order, with the option to add salt at their discretion from a salt shaker. Expected and perceived saltiness were measured with a 9-point just-about-right scale (1= not salty enough at all, 5= just about the right amount of salt for me, 9= far too salty for me), whereas expected and perceived liking were measured with a 9-point hedonic scale (1= not liked at all to 9= extremely liked).

Participants were shown the packaged soup and asked what they expected of it in terms of liking, desire and saltiness. Soups were then freshly prepared from the shown packs. While tasting each soup, the study participants were requested to rate it on perceived liking and salt intensity. After tasting a spoonful, they were permitted to add as much salt as they wanted from the salt shakers. Between different soups, participants had to rinse their mouth with water. In total, all participants sampled all nine combinations of soup and label.

For all types of soup, more participants added table salt when the soup carried the reduced-salt label compared to when the same soup carried either the health logo or no label. Those who did add salt, additionally added more salt when soups carried the reduced-salt label, independent of the actual sodium content of the soup. When 30% sodium-reduced soup was labeled with a reduced-salt label, participants over-compensated the reduction in sodium by adding table salt beyond benchmark levels.

The mere exposure to the reduced-salt label resulted in lower expectations and lower actual taste experience of the soups in terms of liking and saltiness. The perceived saltiness of the soups with a salt-reduction label was lower than would be expected based on the actual amount of salt in the soup. Providing the health logo or no label did not influence taste perception. Only 28% of the participants added salt to the 15% sodium-reduced soups, indicating that such a reduction may be feasible to implement if consumers are not made aware of the modification.