FR2697409A1 - Removal of iodine@ from seaweed extracts, useful in mfr. of foodstuffs, dietetic prods., cosmetics etc. - by alcohol extraction of spray- or freeze-dried extract - Google Patents

Abstract

Selective removal of iodine from brown seaweed is effected by: (a) spray- or freeze-drying a liq. seaweed extract to obtain a dry extract; (b) subjecting the dry extract to at least one extn. with a primary aliphatic alcohol at elevated temp.; (c) sepg. the iodine-contg. alcohol fraction from the residue; and (d) drying the residue. Also claimed is a seaweed extract obtd. by the above process. USE/ADVANTAGE - The prods. are useful in the mfr. of foodstuffs, dietetic prods. and cosmetics, and in agriculture. Iodine is removed selectively, e.g. to meet requirements for food use or to avoid incompatibility problems in cosmetics, without excessive removal of other components, e.g. minerals and trace elements.

Description

PROCESS FOR SELECTIVE IODINE ELIMINATION IN ALGAE
BROWN AND ALGAE EXTRACT OBTAINED
The present invention relates to a process for the selective elimination of iodine from brown algae. It also relates to the algae extract obtained by the implementation of this process.

 Algae, in particular brown algae, are commonly used for the preparation of food, dietetic or cosmetic compositions. They are also used in agriculture.

 Examples of brown algae include Laminaria digitata, Fucus, Acophyllum and Himanthalia.

 However, the promotion of concentrated extracts of these algae faces several difficulties.

 Thus, first of all, iodine is a heavy metal and current legislation imposes concentration limits because its ingestion causes thyrotdian disorders.

 Secondly, the introduction of non-deioded algae extract is incompatible with conventional cosmetic formulations, since the chemical bonds of the preparations are broken.

 The present invention aims to overcome these drawbacks.

 To do this, it offers a process for the selective elimination of iodine from brown algae. This process is sufficiently selective to eliminate iodine or, at least, to reduce its rate to a value much lower than that fixed by the legislator, without really modifying the concentrations of the other components.

 Using this process, the composition of the product obtained is very close to that of the starting product, in particular as regards the concentrations of trace elements and mannitol.

 This process is economical and simple to implement.

It includes the following steps, which consist of
a) subjecting a liquid extract of algae to atomization or to lyophilization in order to obtain a dry extract
b) subject the dry extract from a) to at least one hot extraction with a primary aliphatic alcohol
c) separate the alcoholic fraction containing the iodine from the rest of the product
d) recover the latter after drying.

Furthermore, according to other advantageous but non-limiting characteristics
- the alga is chosen from the group consisting of Laminaria digitata, Fucus, Ascophyllum, Himanthalia
- said seaweed extract is a concentrated extract
- before step a), the extract is subjected to cold crystallization, the liquid phase then being subjected to atomization or lyophilization
- said alcohol consists of methanol
- the extraction is carried out at a temperature of about 70 to about 75 "C;
- said extraction is continued for approximately two hours
- At least two successive extractions are carried out, the solid fraction being each time dissolved in alcohol.

 The invention also relates to the algae extract obtained by implementing the method as described above.

 Other characteristics and advantages of the invention will appear from the description which will follow of certain preferred embodiments, made with reference to the appended drawing in which FIG. 1 is a diagram showing the different stages of the process of the invention.

 In Figure 1, the arrows in solid lines correspond to essential steps. On the contrary, the arrows in dotted lines relate to optional steps to which we will return later in the description.

 In a first step of the process, an aqueous extract of brown algae is subjected to atomization or to lyophilization in order to obtain a dry product.

 The extract is obtained by a method of known type, for example by soaking the thalli of algae in a water bath. In order to optimize the process of the invention, a concentrated extract of algae can be used.

 At this stage, the concentration of iodine in the extract is around 12 g / l of seaweed extract.

 When lyophilization is carried out, the liquid extract is placed in the condenser of a lyophilizer, at around -50 C. The product stabilizes and freeze-drying proceeds normally.

 As stated above, the algae extract can alternatively be subjected to atomization.

 Optionally, the extract can be subjected, before its dehydration by one of the two methods listed above, to cold crystallization.

 The extract is then placed for several days in a suitable container and stored at a temperature of 4-6 "C. Crystallization occurs and the crystals are separated from the liquid fraction by filtration on Büchner paper. Such an operation does not allows to recover only a small amount of iodine, of the order of 0.1 g / l. This low yield is explained by the fact that iodine is present in very low volatile form in algae.

 After drying by lyophilization or atomization, the dry extract is subjected to at least one hot extraction using a primary aliphatic alcohol. A preferred alcohol is ethanol. In the appended figure, the arrow 1 indicates that the extraction operation can be repeated several times.

 As will be seen in the examples below, this extraction treatment makes it possible to completely or almost completely rid the algae extract of the iodine contained at the start.

 We will see in the examples below the operating conditions of such an extraction.

 At the end of this operation, by drying in an oven or by atomization, a dry extract of algae is recovered, at least partially freed from the iodine contained at the start.

 In the following examples, "CLMO1" will be understood to mean an aqueous concentrated extract of Laminaria digitata.

Example 1
1158.9 g of CLAM01 are stored at 3-5 "C in aqueous form.

26.7 g of crystals are then recovered which titrate 0.06 g of iodine.

 1132.2 g of CLAM01 containing 6.20 g of iodine are recovered, which is subjected to atomization.

The 501.6 g of dry product are introduced into a
Soxhlet and are extracted with ethanol for 3 h 30 at 70-75 "C.

 99.9 g of an ethanolic extract titrating 6.06 g of iodine and 383.1 g of extraction residue containing 0.14 g of iodine are then recovered.

Example 2
A certain quantity of liquid CLAM01 is subjected to an atomization in order to obtain 100 g of dry CLAM01, which contains 1.347 g / l of iodine.

 The product obtained is extracted with 200 ml of ethanol for 45 min, in a bath at 70-75 C.

 After decanting the supernatant, 140 ml of an ethanolic extract are recovered, which is evaporated and then taken up in 50 ml of water. The corresponding product titers 0.9 g / l of iodine.

 The iodine is titrated by colorimetric dosing. This product is soluble in carbon tetrachloride and gives in its presence a purplish pink coloring.

 The remaining ethanolic phase is taken up in 200 ml of ethanol, under the same operating conditions as above. A product is then recovered, after evaporation and taken up in 50 ml of water, which titers 0.54 g / l of iodine.

 The operation is repeated under the same operating conditions. After filtration through Büchner, evaporation and recovery in 50 ml of water, the ethanolic phase titers 0.41 g / l.

 The residue from this treatment is dried in an oven and 83.1 g of dry algae concentrate containing 0.3 g / kg of iodine are recovered.

 The main characteristics of an extract CLAM01 subsequently subjected to a procedure as described above are given below.

Method of production: Cold aqueous extraction of Laminaria digitata, then concentration under vacuum at low temperature. Filtration at 5 microns, not separating proteins. To obtain 1 kg of Cl01, 18.6 kg of
Laminaria digitata fresh have been used.

 Presentation: Red brown liquid, completely natural, without additives or preservatives.

Physico-chemical parameters:
Density at 20 "C 1.25 to 1.28
pH 4.5 to 5.5
Conductivity 553 ms
Viscosity 15 cps
Refractive index 1.425 to 1.430
Total dry matter 42 to 46%
Chemical analysis:
Organic matter 16 to 20%
Proteins 16.5 to 17.5 g / l
Carbohydrates 14.5 to 15.5 g / l
Fat 1.5 to 2 g / l
Mannitol 10 to 20%
Alginates 0.17%
Cellulosic material 0.70%
Vitamin A 4.15 mg / l
Vitamin B2 0.6 to 0.7 mg / l
Vitamin B6 0.16 mg / l
Vitamin B12 0.01 mg / l
Vitamin C 217 mg / l
Vitamin E 1.15 mg / l
Mineral 23 to 38%
Potassium 72.50 g / l
Phosphorus 72.50 g / l
Sodium 37.50 g / l
Iodine 7.5 to 8.5 g / l
Magnesium 6.0 to 7.0 g / l
Calcium 2.0 to 3.0 g / l
Silicon 32 mg / l
Iron 10 mg / l
Zinc 9.50 mg / l
Manganese 2.5 to 3.5 mg / l
Copper 0.8 to 1.2 mg / l
Amino acids 1.5 to 2%
Glue 0.51% Ile 0.03%
Ala 0.38% Lys 0.03%
Asp 0.1% Arg 0.03%
Pro 0.1% Trp 0.03%
Gly 0.08% Phe 0.02%
Val 0.07% Orn 0.01%
Ser 0.07% His 0.01%
Thr 0.06% Met 0.01%
Leu 0.04% Tyr 0.007%
In the tables below, the concentrations of a few ions measured in extracts depleted in iodine are given.

Results on aqueous solution with a concentration of 2.528 g / l of extract
dry: Total weight of the sample:: 28.35 g ion dosed conc (ppm) conc in the extract quantity of ion (g)
dry (g / kg)
(1) (2) (3)
Fluorides 1.8 0.71 0.02
Chlorides 644.2 254.8 7.22
Sulfates 51.2 20.25 0.57-8
Bromides 7.10 2.81 0.08
Nitrates 12.2 4.83 0.14
Phosphates 18.4 7.28 0.21 (1) = Concentration in ppm in the aqueous solution (2) = Concentration of the ion in the dry extract in g / kg (3) = Quantity of ions in the sample in g.
Results on aqueous solution of concentration 1,936 g / l of dry extract:
Total weight of the sample: 28.35 g ion dosed conc (ppm) conc in the extract quantity of ion (g)
dry (g / kg)
(1) (2) (3)
Sodium 200.0 103.3 2.93
Ammonium
Potassium 257.0 132.75 3.76
Magnesium 22.6 11.67 0.33
Calcium 13.7 7.1 0.2 (1) = Concentration in ppm in the aqueous solution (2) = Concentration of the ion in the dry extract in g / kg (3) = Quantity of ions in the sample in g.

Concentration calculations were performed on several
samples. The results are as follows:
Determination of mineral salts present in a concentrated extract
iodine-depleted Laminaria digitata
The mineral salts of interest are present in large quantities in the product depleted in iodine
- sodium 103 to 110 g / kg
- potassium 132 to 135 g / kg
- magnesium 11 to 17 g / kg
- calcium 7 to 9.5 g / kg
- Fluoride 0.7 to 0.9 g / kg
- Chlorine 254 to 263 g / kg
- Sulfates 2.8 to 3.2 g / kg
- Phosphates 7 to 9 g / kg
Determination of trace elements present in an algae extract
Laminaria digitata iodine depleted
- Iron 48.83 to 50.10 mg / kg
- Copper 0.66 to 0.72 mg / kg
- Zinc 7.33 to 8.1 mg / kg
- Manganese 4.33 to 4.92 mg / kg
Total mineral matter = 36%.

Example 3
1000 g of atomized CLAM01 are subjected to a reflux extraction for two hours with 1700 ml of ethanol, at a temperature of 70-75 "C.

 After rapid decantation, the 600 ml of ethanolic ethanolic extract are subjected to evaporation and to recovery in 100 ml of water.

 The operation is repeated on the residue three times in succession under the same conditions, however using 1000 ml of ethanol each time.

 After drying in an oven at 50 ° C., 975.4 g of dry product containing 1.5 g of iodine per kilogram is obtained in the end.

 The above examples show that the process is effective; iodine only exists in trace amounts. This process is applicable under industrial conditions.

 This process is selective, the mineral salts and trace elements naturally present in large quantities in such extracts are preserved and completely bioavailable.

 The product obtained is stable, soluble in water and can be stored without additives (preservatives, etc.). It can therefore be used for any food, dietetic and agricultural use.

On the other hand, the use of such an extract is compatible with all cosmetic formulations and provides the properties directly linked to the presence of mineral elements and trace elements. By way of example, it can be introduced into the following preparations
- anti-aging product
- care products for sensitized and dull skin
- cell regeneration product
- solar products
- care products for the scalp and hair.

 Finally, the dry algae extract, rich in trace elements is stable at any pH (2 to 10) and at all temperatures (cold and hot).

 The process can be adapted, without significant modification, to brown algae other than Laminaria digitata.

 Primary aliphatic alcohols other than ethanol can be used in the process of the present invention.

Ethanol is however preferred when the algae extract is intended for use in the food industry.

Claims (9)

 1. A method of selective elimination of iodine in brown algae, characterized in that it comprises the following stages, consisting in:  a) subjecting a liquid extract of algae to atomization or to lyophilization in order to obtain a dry extract  b) subject the dry extract from a) to at least one hot extraction with a primary aliphatic alcohol  c) separate the alcoholic fraction containing the iodine from the rest of the product  d) recover the latter after drying.  2. Method according to claim 1, characterized in that the alga is chosen from the group consisting of: Laminaria digitata, Fucus, Ascophyllum, Himanthalia.  3. Method according to one of claims I and 2, characterized in that said algae extract is a concentrated extract.  4. Method according to one of claims 1 to 3, characterized in that prior to step a), the extract is subjected to cold crystallization, the liquid phase then being subjected to atomization or lyophilization .  5. Method according to one of claims 1 to 4, characterized in that said alcohol consists of ethanol.  6. Method according to one of claims 1 to 5, characterized in that the extraction is carried out at a temperature of about 70 to about 75 "C.  7. Method according to one of claims 1 to 5, characterized in that said extraction is continued for about two hours.  8. Method according to one of claims 1 to 6, characterized in that one proceeds to at least two successive extractions, the solid fraction being each time dissolved in alcohol.  9. Algae extract obtained by implementing the method according to one of claims 1 to 8.