Deconstructing how the various components of emulsion creamers impact salt perception

Salt reduction remains a critical challenge in savoury liquid/semi solid products because of complex ingredient/texture interactions which alter the perceive saltiness of a food product. Following informal observations that emulsion based creamers have a complex effect on salt perception in soups, we sought to separate how different microstructural components (emulsion fat content, viscosity modification and carbohydrate wall material) impact salt perception. In general, emulsions acted to volumetrically enhance salt perception via a phenomenon known as the filler effect. Using mathematical models developed by le Révérend et al. (2013) it was found that the incomplete boosting of salt perception at high fat contents was due to the influence of matrix viscosity which slows NaCl transport to the receptors. A surprising observation was that lactose/glucose syrup present in the commercial creamer suppresses salt perception in real food systems. The strongest suppression was observed with lactose, followed by glucose syrup, no suppression of saltiness was observed when using maltodextrin. A strong correlation between perceived sweetness and suppression of salt perception was observed suggesting that lactose/glucose syrup suppress salt perception via a taste-taste interaction. It is likely that the combined effects of sweetness and viscosity are a reason why thick salsas are moderately salty even with the same salt content as sea water. In such cases, reformulation strategies should focus on balancing sweetness and product texture to allow rightly salted products that fit inside the 2000 mg Na+ WHO dietary recommendations. These important findings clearly describe some of the mechanisms limiting sodium reduction in complex liquid and semi-solid products and point towards product reformation strategies for sodium reduction whilst maintaining saltiness perception.