She has taught science courses at the high school, college, and graduate levels. Facebook Facebook Twitter Twitter. Updated September 08, Featured Video. Cite this Article Format. Helmenstine, Anne Marie, Ph. How Does Salt Preserve Food? How to Preserve a Halloween Jack-o'-Lantern.
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Learn About Amoeba Anatomy and Reproduction. Your Privacy Rights. To change or withdraw your consent choices for ThoughtCo. Salt favours lipid oxidation, accelerating rancidity and consequently affecting colour and flavour [ 47 ]. Salting is a process used in the preservation of several fish products, such as salted cod, sea bream, chub mackerel and smoked salmon, among others [ 48 ].
Cod Gadus morhua L. Different salting methods may be used for cod salting, giving the final product distinct characteristics [ 49 ]. Traditionally ripened herring is a protected product in Denmark. Beheaded herrings are put in plastic barrels with salt, sugar and some spices and kept for 36 months under refrigeration.
In the preparation of smoked fish products, such as smoked salmon, salt also plays an important role, since it decreases a W [ 51 ].
The major five dietary sources of sodium in the USA are ready-to-eat RTE foods, namely, bread and rolls, meat products, pizza, poultry and soups [ 52 ]. Flavour enhancement is one of the primary functions of salt in processed and ready-to-eat foods. Moreover, salt is one of the tools used for preservation to control microbial growth.
Salt plays a role in the flavour of cereals and other snack foods [ 53 ] and provides a texture and flavour enhancing function in crackers. In sauces, such as mayonnaise, and dressings, salt is used for preservation purposes but also as a texturing and emulsifying agent [ 54 ]. Ready-to-eat shrimp, due to its processing, cooking in salted water, is also an RTE food with a high-salt, high-sodium content.
Despite all the health problems associated to salt consumption, its excessive use is constantly growing.
Many changes are necessary to reduce salt intake and achieve the necessary reduction in high blood pressure. In fact, hypertension, which constitutes one of the risk factors for cardiovascular disease, particularly coronary heart disease and stroke, is highly correlated with the excessive consumption of salt in the human diet [ 57 ]. On the other hand, hypertension has been associated with high intakes of sodium through the sodium chloride NaCl used in food.
Still, sodium is important for distinct physiological functions and is essential for cellular homeostasis [ 58 ]. The WHO recommends that adults consume less than 5 g just under a teaspoon of salt per day [ 56 ].
This mineral is essential for human health to maintain plasma volume, regulating body water content and electrolyte balance, transmission of nerve impulses and normal cell function; however, its excess in human diet leads to high blood pressure. This problem is often correlated with high consumption of sugar and fat, besides salt.
However, a decrease in potassium intake and an unhealthy lifestyle are responsible for the increased numbers of noncommunicable diseases NCDs. NCDs, also known as chronic diseases, result from a combination of genetic, physiological, environmental and behavioural factors and are generally prolonged in duration [ 12 , 59 ]. The main types of NCDs are cardiovascular diseases like heart attacks and strokes , cancers, chronic respiratory diseases such as chronic obstructive pulmonary disease and asthma and type 2 diabetes [ 59 ].
According to the WHO , NCDs are the cause of 41 million deaths of people each year, being cardiovascular diseases the first cause of death. Cardiovascular disease is the leading cause of death in the USA [ 60 ]. The trials that studied the role of salt in the blood pressure begun with the studies in rats of Goldblatt [ 61 ].
Some years later, Kempner [ 62 ] stated for the first time that high salt could induce hypertension and low salt could lower blood pressure. This was followed by a huge number of clinical studies about sodium restriction to control blood pressure. The result of numerous trials along the years pointed out the importance of a diet with low income of salt to decrease blood pressure.
Sacks et al. However, nowadays, some researchers criticise these evidences referring that most trials evaluated high blood pressure, malnourished and mainly aged patients [ 64 ].
So, according to McCarron et al. Another aspect to be considered in human health is the necessity to evaluate jointly low sodium and high potassium intake, because high potassium consumption has a beneficial effect in preventing hypertension [ 67 ].
Potassium is present mainly in fruits, vegetables and unrefined foods and is essential for regulating fluid balance and controlling the electrical activity of the heart and other muscles and maintains normal cell function. Increased potassium intake reduced blood pressure, and it can mitigate the negative effects of elevated sodium consumption on blood pressure [ 68 ].
The food reformulation, concerning modification in food composition with the development of healthier products, and at the same time consumer acceptance, is one strategy to achieve sodium reduction and a better intake of potassium in the human diet.
Some countries, in Europe, published legislation for food reformulation by setting maximum levels for certain food components or by defining health targets. The National Salt Reduction Initiatives, developed in , has the goal of reaching the maximum recommended intake of 5 g salt all over Europe. Some recent findings indicate that human sodium intake is controlled by physiology and cannot be modified by public health policies [ 65 ].
Nevertheless, the reduction of the dietary salt intake remains a global public health priority [ 14 ]. If the consumption of high levels of sodium table salt contains It is not the salt as such, which is the culprit, but the sodium in the salt. Therefore, when discussing salt reduction, one must consider all sources of sodium.
Strategies on how to reduce salt content in food products without depreciating their quality have been proposed by several institutional and health-related organisations that recommend cooking with little or no added salt, valorising the natural taste of foods.
The strategies may include, among others, seasoning with aromatic herbs, spices, lemon juice, wine and vinegar; use of marinades and garlic vines to season foods the day before; combining tasteless foods with foods of more intense flavour, such as onion, garlic, pepper and tomato; cooking with low amounts of water, to concentrate aroma and flavours; no addition of salt if the meal contains preprepared sauces, sausages or canned food; avoiding adding more salt while cooking; and not putting the salt shaker on the table.
Plain salt reduction studies are shown in Table 1. Salt reduction can further be achieved in three main ways: replacement of sodium chloride by potassium chloride, addition of a flavour enhancer that enhances the salty taste even with lower salt contents and changing the physical structure of sodium chloride so that its crystals dissolve faster in the mouth, tasting saltier [ 47 ].
Potassium chloride KCl has been used as the main alternative to NaCl in salt replacement experiments, mostly because its antimicrobial effectiveness has been reported to be similar to that of NaCl [ 80 ].
The effect on consumer acceptance or consumer perception of low-salt foods has been evaluated, and these studies should precede the development of new products by the food industry [ 81 ]. Table 2 summarises some recent studies on salt replacement, considering different food products.
As it can be seen from Table 2 , there are numerous salt replacement studies on bread and meat products, whereas only a few on other foods. Regarding bread and other bakery products, potassium chloride has a lower inhibiting effect on the yeast. Furthermore, proofing and mixing times are shorter. Moreover, potassium chloride is more difficult to dissolve in water than sodium chloride.
The undissolved grains will cause dark brown spots on the crust of the product. Still, KCl showed characteristics similar to NaCl in baked products. However, other salt replacers, such as magnesium chloride, ammonium chloride, magnesium sulphate or calcium chloride, have limited application due to their more unpleasant flavour [ 97 ]. Aromatic and medicinal plants AMP can also be used as flavouring agents, giving a tastier flavour to foods and thus enabling salt reduction [ 98 ].
Herbs or AMP, namely, oregano, basil, marjoram, thyme and bay leaf, added to fresh soups, reduced the need for salt intake when the perceived herb flavour increased [ 87 ]. Spices have also been added to dried fish goldstripe sardinella Sardinella gibbosa to reduce the amount of added salt [ 78 ].
Salicornia sp. Several studies have reported the reduction of salt content in meat products and its partial replacement with other salts, such as potassium chloride KCl , magnesium chloride MgCl , lithium chloride LiCl , calcium chloride CaCl 2 and phosphates [ ]. However, concerning dry-cured meat sausages, it is more difficult to develop low-salt traditional products.
Sodium chloride has a determinant effect both in flavour as in the microbiological stability of sausages. Gou et al. A significant reduction in the sodium content of Spanish sausages was achieved by the partial replacement of NaCl by different percentages of calcium ascorbate [ 86 ].
However, these sausages showed worse results for colour and texture when compared with control sausages. Regarding microbiological parameters, no unwanted changes were noticed with the replacements of NaCl by other salts, in all the above-mentioned studies. From a sensory point of view, the major advantage of these sausages seems to be the insufficient salty flavour. Microbiological analyses of traditional Portuguese dry-fermented sausages Painho de Portalegre with low-salt content.
These results seem to indicate that the natural microbiota of these sausages is characteristically halotolerant. This is even more evident for yeasts. Considering that these microbiological groups are associated with the hygiene conditions of the manufacturing process, the bacteriostatic role of salt was beneficial.
As for the technological microbiota [ , ], the lactic acid bacteria, still present in high numbers in the final product, which is characteristic in this kind of sausage, almost do not vary with the sodium chloride concentration. The counts of all other microbial groups did not vary with salt content. The results obtained for these two last attributes may be because salt stimulates salivation and potentiates the flavour of foods. Concerning global appreciation, there was a slight preference for the sausages with less salt.
Sensory analysis of traditional Portuguese dry-fermented sausages Painho de Portalegre with low-salt content. Generally, the microbiota of these sausages did not vary with salt content.
Furthermore, concerning sensory analysis, no significant differences were observed for any of the studied attributes. Furthermore, the rheological analysis showed no influence of salt content in the studied attributes.
Furthermore, the production of Painho de Portalegre is characterised by a different formulation regarding salt content. These may significantly influence the qualitative and quantitative formation of biogenic amines, since they modulate the microbiota throughout the manufacturing process.
Thus, regarding the profile in biogenic amines, differences were detected between the two salt concentrations. In another study with Painho de Portalegre , the effect of salt in the profile of biogenic amines was evaluated.
Several other studies on traditional Portuguese sausages have shown the neutral or positive effect of salt reduction on these products. Salt reduction does not negatively affect the quality and acceptability of sausages [ ]. Low-salt sausages were clearly preferred by panellists [ 69 ].
Coutron-Gambotti et al. Regarding rheological analysis, salt content did not significantly influence the textural characteristics of the sausages, namely, hardness, cohesiveness, elasticity, gumminess, chewiness and shear force.
Bread is a major contributor to sodium intake. Salt sodium chloride has been used as a food preservative for centuries. The value of salt in preserving foods was so highly prized by the Ancient Romans that it was used as a form of currency. Salt remained the most used form of food preservation until much more recent times when modern food preservation methods were developed such as refrigeration, freezing and canning foods.
Salt acts as a preservative by inhibiting microbial growth. Salt acts by drawing water out of the cells of foods and bacteria through a process known as osmosis. Reducing the amount of water available to bacteria inhibits or slows bacterial growth and reproduction.
High concentrations of salt can also rupture bacterial cells due to differences in pressure between the outside and inside of the microorganism. Salt is also effective in protecting foods against moulds and yeast- it prevents the fermentation of yeast and the growth of moulds by reducing water supply.
Vegetables are generally preserved by pickling them in a salt and water solution brine , while meat may be rubbed with salt and dry cured or may be injected with a salt solution.
Most often foods must be preserved in much lower salt concentrations to retain the desirable qualities of the food.
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