Sodium Threshold in Model Reduced and Low Fat Oil-in-Water Emulsion Systems

Sodium and fat reduction in the diet are key factors in the nutrition management of hypertensive individuals. Several reduced and lower fat foods have higher amounts of sodium than their regular fat counterparts, which contradict sodium and fat reduction goals for hypertensive individuals. The objective of this research was to determine the threshold of sodium in a model reduced and low fat oil-in-water emulsion system analogous to salad dressings, so as to identify a reduction level of sodium that may not compromise consumer acceptability. Thirty panelists used the R-index by rating method to evaluate a model reduced fat emulsion system with 7 sodium concentrations (175, 200, 230, 265, 305, and 350 mg) and a model low fat emulsion system with 6 sodium concentrations (160, 170, 180, 190, and 200 mg). For both emulsion systems, 30 g servings of each concentration were presented to panelists. Panelists received 10 replicates of noise and signal samples for both fat levels. The group sodium threshold for the reduced and low fat emulsions was 241.11 and 183.56 mg, respectively. Results indicate saltiness perception is increased when fat content is decreased, and threshold for sodium in the reduced fat emulsion system is higher than the low fat emulsion system with lower fat content. Study findings show opportunities for sodium reduction in reduced and low fat food emulsion systems, particularly additional reductions of sodium without consumer detection.

Study results demonstrated sodium difference thresholds for the reduced and low fat emulsions were at levels lower than the mean sodium content found in comparable processed food emulsion systems. Results indicate sodium content can potentially be decreased in reduced and lower fat food emulsion systems without consumer detection. Having insight for where consumers are able to detect a difference in sodium levels within reduced and low fat food systems can contribute to a successful reduction of sodium in reduced and lower fat food systems and benefit individuals requiring reductions of sodium and fat in processed food systems.