The increasing availability of processed foods, rapid urbanisation, and lifestyle changes have led to significant changes in human diets. Highly processed foods are becoming more available and affordable. NaCl provides sodium and chloride ions, which both of these ions are essential nutrients to the human body. The World Health Organization recommended for adults to reduce their consumption of NaCl to less than 5 g NaCl/day or 2 g sodium/ day. However, the mean NaCl intake for most people worldwide is about 9 to 12 g/day.
There have been many reports on the detrimental effects of high daily intake of NaCl on human health in the past few years, such as hypertension, stroke, kidney disease, etc. Even though NaCl aids in the preservation, flavour, and strengthening of the texture of food products, high intake of NaCl imposes severe impacts on human health. This led to the apparent need for NaCl reduction. Dietary management, education, and diet chart are approaches taken to reduce NaCl intake in patients. Similarly, the sodium content of food products needs to be reduced, not just total substitution, especially in staple foods. The WHO has recommended interventions to reduce salt intake by reformulating food products and increasing awareness of consumers on the harmful effects of excessive intake of salt. These initiatives include increasing public awareness, reformulating food products, and various technological innovations.
Furthermore, there are various methods taken to reduce NaCl in food products, such as dietary reduction of NaCl based on sensory acceptability of food products, replacing NaCl with low-sodium blends, usage of Umami Ingredients as flavour enhancers, and the like. Elimination of adding sodium salt into processed food formulation is one of the ideal approaches to reducing the sodium content in processed food. However, sodium salt in food performs various functions including increasing consumers' appetitive, enhancing flavour, modifying textural properties and extending the shelf life of the food products. Thus, eliminating the sodium salt content while maintaining food palatability posed a challenging task for the food industry. In addition, to eliminate salt, formulators also seek ways to enhance the quality of food products without causing permanent disruption of the texture and foods produced to remain stable even during storage.
The replacement of NaCl with salt substitutes (SS) in food formulation is one of the effective strategies to reduce NaCl in food products. SS is a food ingredient that contains no NaCl, or a lower amount of sodium than NaCl, but with the same salt functions. SS is marketed to circumvent the risk of diseases associated with high salt intake. In certain staple foods such as noodles, NaCl contributes to sustainability by ensuring short cooking time. Hence to substitute NaCl, SS must then be able to perform this same function. In the replacement or substitution of NaCl, both eating and cooking properties must also be considered because sustainability is not just about health but also about optimising resources, such as the optimum usage of cooking gas. Certain work has shown the potential of using SS in place of NaCl without compromising the taste or functionalities of the final products.
Quality enhancement and extension of shelf-life remain an issue for reduced or sodium-free products. Hence, despite the usage of salt mixtures with low sodium content, there are various alternative processing methods that have been developed to reduce NaCl, such as encapsulation of NaCl in bread and sausages, changes in the size and shape of NaCl, high-pressure processing, the inhomogeneous spatial distribution of NaCl in a food matrix, and others. Certain SSs such as calcium chloride, magnesium chloride, and calcium lactate are less frequently used because of unpleasant bitter tastes even though this can be fixed with taste enhancers.
Perhaps, in future, a tax system might be considered to promote the reformulation of products with less sodium. However, until then, the industries are better off initiating efforts to reformulate with less sodium, or even better, zero-sodium.