IJCRR - 5(20), October, 2013
Pages: 59-65
Date of Publication: 02-Nov-2013
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SAFETY AND QUALITY ASPECTS OF REDUCING SALT CONTENT IN FOODS
Author: Ismail Balarabe Bilyaminu
Category: Healthcare
Abstract:Salt has been used since ancient times as an additive with many benefits such as preservative and antimicrobial agent and for impacting desirable sensory attributes in foods. Reports from various organisations shows that its consumption in recent times has been above the recommended daily intake and this has been linked with the rising cases of high blood pressure leading to cardiovascular diseases. Salt reduction strategies have been developed by various organisations and governments to ensure significant salt reduction while not compromising the safety and quality purposes of its use in foods.
Keywords: recommended daily allowance, safety, salt reduction
Full Text:
INTRODUCTION Salt is defined as a pure white crystalline dietary mineral use as a condiment on the dining table (Jacobson, 2005). Salt is the most popular seasoning found in many foods occurring either naturally or added during food processing to give the desirable taste and texture (Shee et al., 2010). Nutritionally, salt is a regulator of extracellular volume, maintain acid-base balance, neural transmission, renal functions, cardiac output and mycotoxic contractions (Dotsch et al., 2009). Chloride and sodium ions form the two major constituents of salt and are needed by living creatures in trace amounts for regulating fluid equilibrium of the body and sodium itself is useful in the nervous system for electrical signalling (Caldwell et al., 2000).
The use of salt for food preservation was an empirically developed practice dating back thousands of years (Stringer and Pin 2005). Salt acts as a food preservative which inhibits growth pathogenic and spoilage microorganisms allowing the nutritional value of foods such as meat, fish and vegetables to be prolonged from times of abundance to times of shortage [Stringer and Pin 2005; Centre for Disease Control and Prevention of United States (CDC) 2009]. However, the consumption of salt has been on the increase in this modern time and concerns have risen over the years on the health risks associated with its high intake which includes increase in blood pressure to the consuming individuals. Some health authorities such as American Heart Association (AHA) (2010) looking at the increasing trend in salt intake have recommended a reduction of dietary salt to avoid the aforementioned health risks. The United States Department of Health and Human Services (USDHHS) (2010) recommends a daily intake of not higher than 3750-5750mg of salt (1500-2300mg of Sodium) while in the UK it is targeted at not more than 6g/day [Scientific Advisory Committee on Nutrition (SACN) 2003].
The reduction of salt content in foods has been a topic of extreme international interest discussed under various platforms by the world health organisations to review its link with the health related issues (WHO, 2007; Dolye and Glass, 2010). The aim of these strategies was to make sure that member countries are aware of the
prospects and constraints of the use of salt in foods and to take measures which will alleviate the perceived negative effects. It is very crucial however to understand that all efforts aiming at reducing salt content in foods must be balanced with novel purpose of salting in many foods.
The purpose of this review is to critically overview the effects of salt reduction on food safety and quality with a view of finding suitable approach to follow to achieve the desired objectives. It will also look at various policies and strategies formulated by governments and stakeholders to ensure that the perceived health effects of high salt intake in foods has been minimised while not compromising the safety and quality of foods.
Effects of salt reduction in foods to human health
There has been a renewal of interest in recent times in the reduction of salt in foods driven by convincing evidence that its excessive intake is a major cause of high blood pressure (Karppanen and Mervaala 2005; Dickinson and Havas, 2007; He and MacGregor, 2008) and by decreasing intake of salt in the diet, hypertension which lead to cardiovascular disease could be prevented (Cutler and Roccella, 2006; Cook et al., 2007; Liem et al., 2011)
It has been estimated that, 62% of Cardiovascular Disease and 49% Schaemic Heart Disease was reported to be caused by high blood pressure (WHO, 2006; He and MacGregor, 2010). High salt consumption has also been connected with other health effects like gastric cancer (Tsugane et al., 2004); decrease of bone mineral concentration (Devine et al., 1995) and certainly obesity (He and MacGregor, 2008).
Asaria et al., (2007) estimated that 8.5 million cardiovascular- related death incidences could be prevented globally with 15% decrease in population salt consumption for ten years. Additionally, analysis conducted by the World Health Organisation concluded that salt intake reduction is the most cost effective method of preventing cardiovascular disease world-wide (WHO, 2006; WHO, 2007).
Effects of salt reduction from the food safety point of view
The prevention and control of foodborne disease causing pathogens is mandatory especially for higher risk people such as the young and elderly, pregnant women and immunocompromised. Over 5000 deaths were estimated to occur annually due to foodborne illness (Mead et al., 1999).
Taormina (2010) reported that the microbiological food safety and quality effects of salt reduction in foods obtain little attention in both peer-reviewed literature and media in comparison to that dedicated to cardiovascular health potential impacts. His claim was that food safety could be weakened accidentally as a result of salt reduction in foods which in turn decrease a key barrier against foodborne pathogens. The removal or reduction of salt could have effects that will not be present till after the system is applied (Taormina, 2010).
Antimicrobial function of salt in foods
In addition to flavour and other sensory quality improvement, salt plays a vital role in regulating microbial growth especially in refrigerated “ready-to-eat” (RTE) foods. The shelf-life stability of RTE foods is due to salt and moisture content (Taormina, 2010).The antimicrobial function of salt helps in shelf-life extension of foods by exerting drying effects and as a result water is drawn out of the cells of both microbes and food by the process of osmosis (Doyle and Glass 2010). The amount of salt required for the antimicrobial functions varies with species with Campylobacter being highly sensitive (Dolye and Roman, 1982). The minimum aw for growth of foodborne pathogens and the effect of salt in aw as before reduction in comparison with the other humectants is presented in Tables I and II, respectively.
Effect of salt reduction on food quality
Although high salt intake has been linked to hypertension leading to cardiovascular diseases, there have been deliberations on the effects of salt reduction on the quality attributes of food products. These attributes include taste, texture and consumer acceptability of the products; other quality parameters include moisture, fat and pH; and also processing conditions would be affected (Dotsch et al., 2009).
Salt plays a vital role in the food manufacturing process as an additive which enhances flavours, increases consumer acceptability and performs desirable functions in foods (Kilcast and den Ridder, 2007). These desirable functions can be dough formation in bread production, preservation and binding of water in meats and primarily for sensory improvement in some foods (Hutton, 2002).
In addition, in bread production, salt minimises yeast growth and allow for gluten development and therefore its reduction could lead to increase in yeast growth and negatively affects the texture of bread. However, by changing the mixing and mechanical operations as well as reduction in yeast used, these effects could be reduced to some extent (Cauvain, 2007). Analysis of rheological effects of salt reduction on dough and baking quality or organoleptic attributes showed no significant change at reduced salt concentrations (Cauvain, 2007), but complete removal may result in bad flavours and reduce dough and baking qualities (Lynch et al., 2009). All these facts must therefore be taken into consideration before significant reduction of salt to a safer level becomes possible.
Current improvements in salt reduction and proposed substitute methods
Various governments and other stakeholders in the food industry are highly concerned about salt reduction and these resulted in modelling of various innovative approaches for significant reduction of salt intake by consumers and the development of substitute methods which pose no health risks. These include initiatives on using ingredients such as different mineral salts like potassium chloride, extract from yeast and flavour improvers which give similar organoleptic attributes (Wallis and Chapman, 2012).
Many methods of salt reduction have been developed which may include gradual reduction of salt in foods over a period of time “reduction by stealth”, changing the matrix of food or emulsions and introduction of aroma that give an identical salty taste to consumers (Kilcast and denRidder, 2007; Wallis and Chapman, 2012). The strategy for salt reduction by stealth has recorded achievements with significant reduction of salt in processed foods been successful in the past three years by 20-30% and more is expected to meet the target of 6g/day by 2012 (He and MacGregor, 2008). It is also generally effective as no attitudinal change is needed from consumers and this has led to a more significant reduction by approximately 1g/day in the UK population (Kilcast and denRidder, 2007).
Various achievements in salt reduction have been recorded in the UK. This is presented in Table III.
FDF- Food and Drink Federation; BCCC- British Chocolate, Cake and Confectionery; SNACMA- Snacks Nuts and Crisps Manufacturers Association; ACMF-Association of Cereal Foods Manufacturers; N/A: Information not available. Sources: [European Commission (2008) and Food Standards Agency (2010)] CONCLUSION Salt is an essential nutrient and important ingredient for the production of safe foods with an acceptable organoleptic attributes and extended shelf life. However, analysis has indicated that its consumption in recent times has been above the recommended amount and therefore reduction is essential to reduce the occurrence of health related diseases (Dolye and Glass, 2010). Salt preserves foods by reducing water activity and inhibiting the growth of microorganisms and therefore its reduction in foods may have adverse results on food safety. It is therefore essential to reformulate foods, adjust processing and storage conditions and reduce shelf-life of food products to ensure the safety (Stringer and Pin 2005). The use of substitutes to replace salt has also been established to be an effective approach to reducing salt in foods. Example is the use of potassium chloride which acts like salt giving the desirable attributes and inhibits the growth of microorganisms such as Listeria monocytogenes and Staphylococcus aureus in a similar way to salt (Guardia et al. 2006). The importance of salt in ensuring safety and quality of foods is an essential factor to be considered. Hence this review recommends the following:
I.Need for research to identify the real implication of reducing salt in preparation and serving of foods on its shelf life and microbial safety.
II. Determine the efficiency of the proposed substitutes and cost implications on the overall food processing and supply chain. This will give a clear direction to follow without
compromising any of the effects of salt reduction on the quality and safety of foods.
References:
- American Heart Association (2010) Dietary Guidelines. Available from:http://www.cnpp.usda.gov/publications/DietaryGuidelines/meeting2/commentAttachement/AHA-220.pdf (accessed 20 February 2013).
- Asaria P, Chishlom D, Mathers C, Ezzati M, Beaglehole R. Chronic disease prevention: health effects and financial cost of strategies to reduce salt intake and control tobacco use.The Lancet 2007; 370: 2044-2053.
- Caldwell JH, Scaller KL, Lasher RS, Peles E, Levinson SR. Sodium channel Nav1.6 is localized at nodes of Ranvier, dendrites and synapse. Proceedings of the National Academy of Sciences of the United States of America 2000; 97: 5616-5620.
- Cauvain SP. Reduced salt in bread and other baked products. In Kilcast D, Angus F, editors. Reducing Salt in Foods. USA: CRC Press; 2007. p. 283-295.
- Centre for Disease Control and Prevention (2009) Application of lower sodium intake recommendations to adults-United States, 1999-2006. Morbidity and Mortality Weekly Reports 2009; 58:281-3.
- Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM, Kumanyika SM, Appel LJ, et al. Long-terms effects of dietary sodium reductions on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention. British Medical Journal 2007; 334:885-892.
- Cutler JA, Rocella EJ. Salt reduction for preventing hypertension and cardiovascular disease: a population approach should include children. Journal of Hypertension 2006; 48:818-19.
- Devine A, Criddle R, Dick I, Kerr D, Prince R. A longitudinal study of sodium and calcium intake on regional bone intensity in post-menopausal women. American Journal of Clinical Nutrition 1995; 62:740-5.
- Dolye ME, Glass KA. Sodium reduction and its effect on food safety, food quality and human health.Comprehensive Review in Food Science and Food Safety 2010; 9: 44-56.
- Dolye MP, and Roman D. Response of Campylobacter jejuni to sodium chloride. Journal of Applied Environmental Microbiology 1982; 43:561-5.
- Dotsch M, Busch J, Batenburg M, Liem G, Tareilus E, Mueller R, et al. Strategies to reduce sodium consumption: a food industry perspective. Critical Review in Food Science and Nutrition 2009; 49: 841-51.
- European Commission (2008) Draft: Collated Information on Salt Reduction in the EU. Available from: http://www.ec.europa.eu/health/ph_determinants/life_style/nutrition/documents/compilation_salt_en.pdf (accessed 5 March 2013).
- Food Standards Agency (2010) Industry Activity. London: FSA; Available from: http://www.food.gov.uk/healthiereating/salt/industry (accessed 5 March 2013).
- Guardia MD, Guerrero L, Gelabert J, Gou P, Arnau J. Consumer attitude towards sodium reduction in meat products and acceptability of fermented sausages with reduced sodium content. Journal of Meat Science 2006; 73:484-90.
- He, F. MacGregor GA. A comprehensive review on salt and health and current experience of world-wide salt reduction programmes. Journal of Human Hypertension 2008; 23:1-22.
- He F, MacGregor, GA. Reducing population salt intake world-wide: from evidence to implementation. Progress on Cardiovascular Disease 2010; 52:363-82.
- Hutton T. Sodium technological functions of salt in the manufacture of food and drink products. British Food Journal 2002; 104:126-52.
- Jacobson M. Sodium content of processed foods: 1983-2004.American Journal of Clinical Nutrition 2005; 81: 941-2.
- Kilcast D, danRidder C. Sensory issues in reducing salt in food products. In Kilcast D, Angus F. Reducing Salt in Foods- Practical Strategies. Cambridge, UK: Woodhead Publishing; 2007. p. 201-20,
- Liem DG, Miremadi F, Keast RSJ. Reducing salt in foods: the effect on flavour. Journal of Nutrients 2011; 3: 694-711.
- Lynch EJ, Dal Bello F, Sheehan EM, Cashman KD, Arendt EK. Fundamental studies on the reduction of salt on dough and bread characteristics. Journal of International Food Research 2009; 42:885-91.
- Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, et al. Food-related illness and death in the United States. Journal of Emerging Infectious Diseases 1999; 5:607-25.
- Scientific Advisory Committee on Nutrition (2003) Salt and Health. Available form: http://www.sacn.gov.uk/pdfs/sacn_salt_final.pdf (accessed 29 July 2013).
- Shee AK, Raja RB, Selhi, D, Kunhambu A, Arunachalm KD. Studies on the antibacterial activity potential of commonly used food preservatives. International Journal of Engineering Science and Technology 2010; 2: 264-9.
- Sperber WH. Influence of water activity on foodborne bacteria: a review. Journal of Food Protection 1983; 46:142-50.
- Stringer SC, Pin C. Microbial risks associated with salt reduction in certain foods and alternative options for preservation. Technical Report. Norwich: Institute of Food Research; 2004. Available from: http://www.food.gov.uk/multimedia/pdfs/acm740a.pdf (accessed 5 March 2013).
- Taormina PJ. Implication of salt and sodium reduction on microbial food safety. Critical Review in Food Science and Nutrition 2010; 50:209-27.
- Tsugane S, Sasazuki S, Kobayashi M, Sasaki S. Salt and salted food intake and subsequent risk of gastric cancer among middle-aged Japanese men and women. British Journal of Cancer 2004; 90: 128–34.
- United States Department of Health and Human Services (2010) Dietary Guidelines for Americans. Available from:http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/PolicyDoc/PolicyDoc.pdf (accessed 20 February 2013).
- Wallis, K. and Chapman, S. (June 2012) Current innovations in reducing salt in food products. Food Health Innovation Services. Available from:http://www.foodhealthinnovation.com/media/4072/salt_reduction_2012.pdf (accessed 20 February 2013).
- World Health Organisation (2006) Reducing salt intake in population: report of a WHO forum and technical meeting. Available from:http://www.who.int/dietphysicalactivity/reducingsaltintake.EN.pdf (accessed 22 February 2013).
- World Health Organisation (2007) Reducing salt intake in population. WHO document production services. Available from: http://www.who.int/dietphysicalactivity/salt_Report_VC_april07.pdf (accessed 22 February 2013).
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