DK150601B - Method for preparation of a physiological acceptable mineral salt mixture - Google Patents

Description

150601

The present invention relates to a process for preparing a physiologically acceptable mineral salt mixture suitable as table salt or household salt, whereby seawater, preferably ocean water containing 3 -4% mineral salts, is evaporated during precipitation of mineral salt fractions.

The seawater in the large oceans contains a wide spectrum of mineral salts, of which sodium chloride is the main constituent. The composition of the water in the different oceans is approximately the same. A typical analysis is the following (see Sandoz Bulletin # 51 of 1979):

Ions mg per liter 15 Chloride 19 300

Sodium 10,700

Sulfate (S0 ~ 2) 2 700

Magnesium 1 300

Hydrogen carbonate (HCO3) 700 Calcium 400

Potassium 385

Borate (B0 ~ 3) 124

Bromide 65

Strontium 8 '25 Other ions 18

Total 35 700

Among "other ions" are all the essential trace minerals as well as some heavy metals, such as lead, cadmium and mercury, which are considered to be toxic in high concentrations, but they are found in seawater in such low quantities that they can hardly cause any health risk. However, the composition may vary somewhat depending on the water depth.

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Ever since ancient times, it has been common to extract so-called "sea salt" by evaporation of seawater, so that more or less pure sodium chloride crystallizes. The evaporation took place and still takes place in large basins, which are dug at the shore. Seawater is passed through trenches from the sea into the basins, where the water, under the influence of solar radiation, gradually evaporates, and a significant part of the sodium chloride content crystallizes.

The remaining mother liquor has always been discarded, partly because it was not possible to obtain a satisfactory crystalline product under the evaporation conditions, and partly because the mother liquor has been in open basins for weeks and months and thus has been exposed to strong pollution. It has also been thought that the concentration of heavy metals has been increased so that the product is not physiologically acceptable.

French Patent No. 1,583,412 relates to a process for producing a "total sea salt" with high biological nutritional value. In the patent specification, it is carefully explained how by stepwise evaporation the mineral salts contained in the seawater can be separated into numerous salt fractions of varying composition. However, the patent does not indicate how a homogeneous mineral salt mixture can be prepared with reduced sodium chloride content.

25 It is known that the content of all seawater dissolved ions corresponds very closely to the composition of the tissue fluids of the animal and human organism, except that the sodium chloride content is relatively substantially higher in seawater than in the organism. This is consistent with the fact that human ancestors have lived in seawater at an early stage and adapted their enzyme system to this environment. The content of some important atoms in seawater and the human organism, respectively, is shown in the following table, given in exponent of ten: - 3 - 150601

Concentration of ions in

Atom seawater human cell ions / nl ions / cell

Boron 1.3 E12 1.2 E7

Fluorine 4 E10 2.6 E8

Sodium 2.8 E14 2.8 E10

Magnesium 3.2 E13 8.7 E9

Aluminum 6 E7 2.2 E7

Silicon 6 E10 3.0 E8

Phosphorus 1 E9 1.4 Eli

Sulfur 1.7 E13 3.3 E10

Chlorine 3.3 E14 1.8 E10

Potassium 6.0 E12 2.2 E10

Calcium 6.0 E12 1.6 Eli

Titanium 3 E7 1.3 E6

Vanadium 4 E6 2.4 E5

Chromium 6 E6 6.0 E5

Manganese 2.5 E7 2.2 E6

Iron 4 E7 4.4 E8

Cobalt 2 E6 3.0 E5

Nickel 6 E6 1.0 E6

Copper 6 E7 1.0 E7

Zinc 6 E7 2.2 E8

Arsenic 1.1 E6

Selenium 4 E7 1.5 E6

Rubidium 1 E9 7.9 E7

Strontium 5 E10 1.0 E7

Zirconium 2.0 E7

Niob 7.0 E6

Molybdenum 5 E7 3.2 E5 Silver 4 E6

Cadmium 2.5 E5 1.6 E6

Tin 1.5 E7 1.5 E6

Antimony 3.5 E6 solder 2 E8 1.5 E6

Barium 6 E7 7.3 E5

Lead 1 E7 2.3 E6 150601 - 4 -

From the specification of French Patent No. 2,082,097, an aqueous saline solution which is saturated with sodium chloride and made by evaporation of seawater is known to a volume of 1 / 8.9 of the original. The concentrate thus prepared is stated to be particularly suitable as human and animal food and as a therapeutic diet. The concentrate has a density of approx. 1.21 and is stated to contain 272.4 g / l NaCl, 63 g / l MgCl2.6H2O, 46 g / l MgSO4.7H2O, 4.7 g / l KCl and most of the elements in ionic form, preferably at low concentrations . It has been mentioned that the concentrate has an improved nutritional value compared to the pure sodium chloride normally used as table salt, partly because of the reduced content of NaCl and partly because of the content of essential trace minerals. However, no description is given in the specification of converting the concentrate to a dry mineral salt mixture, except that it is known to evaporate seawater altogether. It is stated that such total evaporation cannot occur in the usual solar evaporation basins.

In the patent no instructions are found to reduce the content of NaCl in relation to the normal composition of the seawater.

The use of trace minerals as dietary supplements is known, for example, from DK patentans. No 507/73, in particular the importance of scandium and antimony is emphasized. A preferred composition described herein has a ratio of Na: Ca: K: Mg of approx.

7-17: 33: 68-86: 5-15 and contains scandium and antimony in amounts of 0.1 - 0.0001%.

More recently, it has been found that many people, when salting the food, are given a much greater amount of sodium than the natural need for the organism, and that this poses a health risk. Excess salt must be excreted by the organism through the kidneys, which can be overloaded. In addition, an excessive salt content in the diet can offset the organism's natural electrolyte balance.

35 A frequent consequence is elevated blood pressure and circulatory disorders, such as atherosclerosis, cerebral haemorrhage and blood clots.

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The present invention has for its object to prepare a table salt or household salt containing all the ions present in seawater in approximately unchanged proportions, except for a reduced sodium content.

Another object of the invention is to provide a method whereby a salt preparation of the kind specified can be provided in the form of a homogeneous mineral salt mixture in which all the trace elements are uniformly distributed and having a texture suitable for a table salt.

The process according to the invention is characterized in that the seawater is evaporated until part of the sodium chloride and calcium carbonate is separated, after which the concentrated mother liquor liberated from the separated mineral salts is subjected to a single drying in a single step under conditions where the mineral salts dissolved in the precipitate are precipitated as a dry and homogeneous mineral salt mixture.

Surprisingly, a mineral salt mixture with such properties and composition can be prepared in such a simple way that the traditional solar evaporation basins used to produce sea salt on a technical scale cannot be used to prepare such compositions.

The degree of evaporation in the first step depends on the properties of the finished salt preparation. It has proved appropriate to evaporate to between 1/15 and 1/30 25 of the original volume. At a lower degree of evaporation, the sodium chloride content will be higher than desirable for most purposes, while evaporation to less than 1/30 of the original lead to products whose high potassium and magnesium content gives some flavor, different from pure sodium chloride.

The best taste properties are obtained by evaporation - 6 - 150601 to approx. 1/20 of the original volume. A mineral salt mixture prepared in this way will contain Na: K: Mg: Ca in the relative ratio 90: 6: 21.2: 0.30. This mixture will have about the same taste as pure sodium chloride.

5 More powerful evaporation, for example up to 1/30 volume or less, provides mineral salt mixtures which are suitable in the household for salting the food during cooking.

The final drying should be done in a way that no fractional crystallization occurs, as it would give an inhomogeneous product. Suitable drying methods are spray drying and drum drying. Particularly preferred is the latter, obtaining coarse shell-like flakes which are easily crushed to any desired degree of fineness. Spray drying gives a very fine-grained powder, which is not very suitable as table salt, but can be used as a household salt for cooking.

The process according to the invention will be illustrated in the following by means of some exemplary embodiments.

Example 1

Seawater from the waters between Iceland and Greenland is collected and filtered. It is evaporated in a covered vessel fitted with vapor coils and exhaust pipes for water vapor, first to the saturation point and then to a volume of 1/15 of the original. During the evaporation, some calcium carbonate is first excreted and then a substantial amount of sodium chloride.

The remaining mother liquor is spray-dried to obtain a fine powder of the following composition:

Sodium 28%

Potassium 1.5%

Magnesium 5.3% Lead below 4 ppm - 7 - 150601

Cadmium 0.4 ppm

Mercury "0.02 ppm

The powder produced has a typically strong salt taste which is indistinguishable from the taste of pure sodium chloride. The product is suitable for salting food products.

Example 2

Seawater of the kind set forth in Example 1 is evaporated in a closed crystallization vessel to 1/20 of the original volume. After separation of crystallized sodium chloride, a mother liquor of the following composition is obtained:

Sodium 90 g / liter

Potassium 6

Magnesium 21.2 -

Calcium 0.31 - 15 This solution is dried in a drum dryer to form coarse flakes of relatively low room weight. The product is then ground in a rotary mill to a particle size suitable for litter boxes. The taste is very satisfying, much like pure sodium chloride, but with a slight 20 spicy hue.

Example 3

The procedure described in Example 2 is repeated with the change that the seawater is evaporated to 1/30 of the original volume. The evaporated solution has the composition: 25 Sodium 88 g / liter

Potassium 7.6 g / liter

Magnesium 26

Calcium 0.5 - 8 - 150601

The finished product has an acceptable taste, although some bitterness can be felt due to a right potassium and magnesium content. The product is suitable for salting food in the household.

Example 4

To 1 liter of deionized water is added 500 mg of the mineral salt mixture prepared according to Example 3. The solution is saturated with carbon dioxide. The mixture is an excellent and tasty mineral water.