16 February 2011 by Brady Carter
A growing trend in the food industry is to lower the sodium content of foods. This coupled with the recent release of a Government initiative to lower salt intake has threatened common table salt (NaCl) as a functional ingredient. Formulators are faced with challenge of reducing salt levels in new and existing products while maintaining the expected flavor. However, the function of salt as an ingredient is not limited to flavor and overlooked in this process may be the potentially harmful increase in water activity that will result from removing salt and other sodium containing ingredients. It is critical to consider and measure any change in water activity that will result from alterations to a formulation, but particularly so for salt because of its considerable contribution to product water activity. There are many factors that have to be considered when identifying replacements for salt and other sodium containing ingredients, but their ability to control water activity relative to the ingredient they are replacing must be one of the considerations. Using predictive models, it is possible to calculate how much the water activity will increase as the result of removing salt. It also possible to then estimate how much of the replacement ingredient will be needed to achieve similar water activity control.
Contact the support team at AquaLab by Decagon if you would like additional help predicting changes in water activity resulting from changes in the formulation for your product. These calculations provide good estimates, but of course, it is necessary to actually the measure the water activity of reformulated products to make sure they have safe water activities. If you do not currently have a water activity instrument, need to upgrade your current instrument, or if you need to increase your current testing capacity, please contact AquaLab by Decagon.