The study, published in Food Quality and Preference, suggests that the ability of Odour-Induced Saltiness Enhancement (OISE) to enhance perceptions depends on the salt concentration in foods, noting that once sodium levels pass a threshold then aroma enhancement has very little effect.
The authors from the centre for food taste at the INRA, University of Burgundy, reported that the saltiness of a low concentration of sodium chloride in water increased significantly when subjects perceived the matching OISE aroma. However, when salt concentration increased and led the panellists to report a high salty intensity, no benefit was from OISE was observed.
“Although OISE remains a relevant way to maintain saltiness in low-salt food, it is important to consider that the strategy could be useless if the saltiness of the food product is too high,” said the author, led by Thierry Thomas-Danguin.
The researchers said that this effect “must be taken into account when using OISE as a compensation strategy in low-salt food.”
“In that case, one possibility could be to combine different compensation strategies, such as the use of salt substitutes or flavour enhancers in addition to the use of saltiness-inducing aromas,” they added.
In recent years, health concerns related to salt have led to a industry investing heavily in salt reduction strategies.
However, decreasing the salt content in food products can have major consequences on food processing, due to sodium’s multiple functions in foods – including preservation and water and fat binding.
Beyond these technical challenges, Thomas-Danguin and his colleagues also noted that salt reduction has “a major impact on food acceptance because low-salt food usually exhibits altered sensory characteristics.”
“This is a major issue in terms of nutritional recommendations associated with low-salt food development … Indeed, it is useless to develop processed food with a reduced salt level that conforms to recommendations but will not be eaten by consumers because of a taste barrier,” they said.
Thomas-Danguin and his co-workers noted that the use of “well-selected odours has been proposed to compensate for sodium chloride reduction in food, due to the cross-modal interactions between odour and taste.”
However, they added that understanding the interactions between salty tastes and odours, is an area that remains “poorly investigated.”
The new study determined how the level of saltiness (concentration of sodium chloride in aqueous solutions) influenced odour-induced saltiness enhancement (OISE).
Thomas-Danguin and his team used a panel of 64 untrained volunteers to evaluate the saltiness of water solutions in three concentrations in conjunction with three aroma conditions.
They found that the perceived saltiness of a low- or medium- sodium solutions increased significantly when subjects simultaneously perceived a congruent salty aroma (in this case sardine).
However, OISE was reported to be ineffective with solutions containing high- levels of sodium.
“Our results also show that the solution including no salt but only the salt-associated sardine aroma was significantly saltier than pure water …Nevertheless, when salt concentration reached a higher level [0.04 M] … then OISE was no longer significant,” said the researchers.
They added that the results of the study “could have important implications in salt-reduction sensory-compensation strategies.”
Source: Food Quality and Preference
Published online ahead of print, doi: 10.1016/j.foodqual.2011.05.001
“Cross-Modal Interactions Between Taste and Smell: Odour-Induced Saltiness Enhancement Depends on Salt level”
Authors: N. Nasri, N. Beno, C. Septier, C. Salles, T. Thomas-Danguin