A huge challenge of the food industry is to effectively reduce sodium without negatively impacting the taste or functionality imparted by sodium. Many sodium alternatives are available, however most of these alternatives are not effective solutions for the food industry. Many of these salt reduction options; impart unpleasant off-flavours, are marketing-driven rather than research or evidence-driven, are not approved for use by Health Canada or are not practical either for the application or on a production scale. This section outlines common industry issues when attempting to utilize many of these salt reduction strategies.
Potassium Salts
With a similar antimicrobial efficiency to sodium (2), potassium may seem like a simple salt replacement solution in products where lowering sodium is a concern from a microbiological perspective. However, potassium has been well documented as having a very unpleasant bitter and metallic taste (3)(4), which renders many potassium substitutions completely unacceptable (1)(3)(5)(6)(7). Perceivable taste differences in food products is something food manufacturers will want to avoid, as consumers could discern this difference and as a result choose to not repurchase (1).
Besides the concern for the unpleasant flavour imparted by potassium, there exists the very relevant issue of the vulnerability of certain population sub-groups at risk to high potassium load from potassium-based salt substitutes (4). These groups at risk include individuals suffering from Type 1 diabetes, chronic renal insufficiency, end stage renal disease, severe heart failure and adrenal insufficiency (8). This can lead to the rejection of potassium based salt reduction products by individuals from at-risk sub-groups.
Sea Salt
The main difference between table salt and sea salt is where it is sourced. Table salt is obtained via mining whereas sea salt must be made from sea water. Due to this, sea salt becomes a mixture of not just sodium chloride but other mineral salts as well. Typically these mixtures of mineral salts are present only in trace amounts and therefore sea salt is not a significant source of these nutrients. Thus, sea salt does not offer any additional health benefits over table salt. Furthermore, table salt does not differ significantly in its content of sodium compared to sea salt (12). Therefore, sea salt is not an efficient alternative to regular salt when attempting to reduce sodium in a food product.
Simple Reduction of Salt
Another popular salt reduction strategy utilized by the food industry is to gradually reduce the salt in their product over time without actually replacing the sodium with anything else (1). This strategy can work in certain cases and up to a limited extent. Ultimately a level of salt reduction will be met whereby a loss in overall flavour will be perceived by the consumer (1). This poses a problem as a perceived change in flavour by the consumer runs the risk of failure to repurchase the food item. Generally food manufacturers are unwilling to utilize a strategy that will negatively impact the taste and flavour of the product. Therefore, extensive analysis of the effect of the salt reduction on sensory acceptability is vital (1). Additionally, removing sodium without a replacement could negatively impact the product if salt plays a functional role such as microbiological, texture, water-retention etc.
Novel Ingredients
With increasing pressure on the food industry to reduce sodium, many novel ingredients have emerged with the pretense of offering a solution to salt replacement for either taste issues or functionality (or both). These novel ingredients include some water-binding proteins and fibers, zero sodium leavening agents, natural sweeteners and some brand-name salt replacers containing other novel ingredients. Although many of these new ingredients may aid in effective sodium reduction, caution must be used as most have not been approved for use in foods in Canada. Before using a novel ingredient, it is imperative to verify with Health Canada or the Canadian Food Inspection Agency that the ingredient is permitted.
Salt Structure
The principle behind this solution is that if the structure of salt is optimized, less salt will be needed as its form will allow for a more effective salt perception (14). The crystal size and shape of salt will affect how the salt taste is perceived. Traditionally, salt is consumed in its granular form. However, evidence exists that demonstrates that solid salt in a flaked form is more effective in terms of binding, increasing pH, increasing protein solubolisation and improving cooking yield (15). Furthermore, claims have been made pertaining to the taste bioavailability of fine flake salt. In other words, fine flake salt is claimed to taste saltier than regular granular salt in its solid form, allowing for less salt to be used in formulations (4). The main limitation to the use of structure-optimized salt is that it will not be useful in applications where the salt is dissolved in the product. This option would be best suited for “dry” products, such as cured meats, crackers, chips, and other salty snacks.
References
- Mitchell M, Brunton NP, Wilkinson MG (2011) Current salt reduction strategies and their effect on sensory acceptability: a study with reduced salt ready-meals. Eur Food Res Technol 232:529-539.
- Bidlas, E., & Lambert, R. J. W. (2008). Comparing the antimicrobial effectiveness of NaCl and KCl with a view to salt/sodium replacement. International Journal of Food Microbiology, 124, 98−102.
- Fitzgerald E, Buckley J (1985) Effect of total and partial substitution of sodium chloride on the quality of cheddar cheese. J Dairy Sci 68:3127–3134
- Desmond E (2006) Reducing salt: a challenge for the meat industry. Meat Sci 74(1):188–196
- Gelabert, J., Gou, P., Guerrero, L., & Arnau, J. (2003). Effect of sodium chloride replacement on some characteristics of fermented sausages. Meat Science, 65, 833−839.
- Gimeno, O., Astiasarán, I., & Bello, J. (1998). A mixture of potassium, magnesium, and calcium chlorides as a partial replacement of sodium chloride in dry fermented sausages. Journal of Agricultural and Food Chemistry, 46, 4372−4375
- Gou, P., Guerrero, L., Gelabert, J., & Arnau, J. (1996). Potassium chloride, potassium
lactate and glycine as sodium chloride substitutes in fermented sausages and in dry- cured pork loin. Meat Science, 42(1), 37−48.
- United States Institute of Medicine. (2004) Dietary reference intakes for water, potassium, sodium, chloride and sulphate. Panel on dietary reference intakes for electrolytes and water, Standing committee on the scientific evaluation of dietary reference intakes. http://www.nap.edu/execsumm_pdf/10925.pdf)
- Ray KK, Dorman S, Watson RDS. 1999. Severe hyperkalemia due to the concomitant use of salt substitutes and ACE inhibitors in hypertension: A potentially life threatening interaction. J Hum Hypertens 13:717–720.
- Hay E, Derazon H, Bukish N, Katz L, Kruglyakov I, Armoni M. 2002. Fatal hyperkalemia related to combined therapy with a cox-2 inhibitor, ace inhibitor and potassium rich diet. J Emerg Med 22:349–352.
- Greenfield H, McCullum D, Wills RB. 1984. Sodium and potassium contents of salts, salt substitutes, and other seasonings. Med J Aust 140(8):460-2.
- Dunkel A, Koster J, Hofmann T (2007) Molecular and sensory characterization of c-glutamyl peptides as key contributors to the kokumi taste of edible beans (Phaseolus vulgaris L.). J Agric Food Chem 55:6712–6719
(14) Angus, F., Phelps, T., Clegg, S., Narain, C. den Ridder, C., & Kilcast, D., (2005). Salt in processed foods: Collaborative Research Project. Leatherhead Food International.
(15) Campbell, J. F. (1979). Binding properties of meat blends, effects of salt type, blending time and post-blending storage. Ph.D. Thesis, Michigan State University.
