Physicochemical and perceptual interactions between composition/texture, taste and aroma: A way to enhance saltiness in foods
Résumé
Excessive salt in the human diet is a major risk factor for hypertension and cardiovascular diseases. So, the World Health Organisation (WHO) advocates sodium reduction of foods as a cost-effective strategy to improve public health. Because of important functionalities of salt (NaCl) – salty taste and flavour enhancement, solutions are being sought to lower the salt content of processed foods without altering their taste. In this PhD work, the approach proposed was to use sensory interactions between the senses, especially composition/texture – saltiness interactions (i) and aroma-saltiness interactions (ii). The first part of this work aimed to investigate food composition and oral processing influence the sodium release and saltiness perception during the eating of different model food systems. Lipoproteic matrices (model cheese system) with different compositions (proteins, fat, pH and salt contents) were produced using an incomplete experimental design and characterised by both sensory profile and rheological analyses. Sodium concentrations in saliva, saltiness and oral parameters were monitored for each subject and each food model foods system. Texture, sodium release, saltiness perception were strongly affected by the lipoproteic matrices composition. The mechanisms of saltiness perception were complex and involved both composition and physiological factors. In the second part, we investigated odor-induced saltiness enhancement in water then in a solid model food (lipoproteic matrices varying in composition) with the aim of evaluating the influence of cross-modal interactions (odor-texture-taste) on saltiness perception. Several model foods, varying in texture, were flavored with three commercial tasteless aromas (comté cheese, sardine and carrot) differently associated with salty and cheesy food products. The results revealed a significant saltiness enhancement induced by the comté cheese and sardine odors (salt associated). However, the carrot odor, not salt-associated, did not enhance saltiness. These findings revealed that well-selected aromas could enhance saltiness in low-salt-content solid-food products of various textures. To conclude, we thus propose that cross-modal interactions could be a practical way to contribute to a counterbalancing of the decrease in saltiness and thus likely acceptability of foods with reduced salt levels. Such a strategy, possibly in association with other means, should help manufacturers to follow the recommendations of public health authorities while maintaining a good acceptability of food products for consumers.