IL29786A - Process for decolorizing algae and a food composition containing the product obtained thereby - Google Patents

Description

Process for decolorizing algae and a food composition containing the product obtained thereby pDian ixian m nV'aan jiTa nanym nisR n^mn^ T» nn This invention relates to a new food composition basically containing non-toxic algae of "the "blue algae" (cyanophyta) division.

More particularly, this invention relates to a food composition containing glucides, lipides and protides, said proti-des consisting at least partly of the above-defined algae.

According .to a preferred embodiment, this food composition also contains vitamins and mineral salts a part of vhich may! provide oligoelements .

The algae are introduced into the food product in such amounts that the resulting 'composition contains most usually from 10 to 80% of algae and from 20 to 90% of additional food elements, as defined hereafter, said percentages being given by weight.

According to another feature, the food composition contain in % of calories with respect to the total number of calories, from to 85% and preferably 55 to 75% of glucides, from 2 to 4-0% and preferably 15 to 30% of lipides and from 5 to 4-0% and preferably 10 to 20% of protides. Expressed by weight, the global amount of mineral salts, vitamins and oligoelements is preferably between 0.5 and 15%.

The algae which may be used in this invention belong to claw tne "blue algae" diyaciLon, preferaoly to the oscillatoriaceae family. By way of examples of algae of this family, the following may be named :. the Spirulina species, and particularly Spirulina maxima, Spirulina platensis, Spirulina maior, , Spirulina sucalsa, Spirulina subrevis, Spirulina princeps, as well as the Oscillatoria species, for example Oscillatoria agardhii . Algae of one type as well as mixtures of algae of the same amily or of different families may be used in th -food composition.

Food products may thus he obtained, whereof the protldic constituent consists of the above algae for 10 to S of the total number of calories present.

The resulting food ma be advantageously used for feeding humans as well as grown or growing animals, such as poultry (fo example chickens and laying hens), sheep, oxen, cows, horses, pigs, rabbits, guinea pigs, rats or mice, the composition of the ood obviously varying according to the species to be fed, e.g. a) humans - age, sex, occupation b) poultry age and whether being reared for egg- laying, or fo broiler purposes; c) large animals - age, whether being reared for meat production, for breedin purposes, as work animals and so on; d) small animals - age, whether being reared as pets, or for vivisection and so on.

These algae are of outstanding interest for feedin people as well as for feeding animals.

In fact, up to now the proteins of animal origin were preferred to the proteins of vegetal origin since the former had a bette balance of essential amlnoacids. It has how been discovered that the proteins provided by the algae are advantageous substitutes for the animal proteins, as shown in the following table wherein a comparison is. made with an ideal composition given by the Food and Agricultura Organization (F.A.O.).

Aminoacids (weight in grams for Spirulina P.A.O. tOOg of proteins) alga composition isoleuclne 6 4.2 leucine 8 4.6 lysine 4.6 4.2 phenylalanine 5 2.8 tyrosine 4 2.8 sulfur-containing aminoacids( total) 1,8 4.2 threonine < .6' 2.8 tryptophane 1. 1.4 valine 6.5 4.2 From this comparison there results that the only insufficiency of this alga is an Insufficiency of some sulfur-containing aminoacids, whereas, for example, the beef meat. is also deficient in tryptophane *: it is thus evident that these algae exhibit a ood value which is unexpected for such a vegetal. They also exhibit amexcellent digestibility being ., for the most part attributable to the fact that they contain low amounts of cellulose (less than 6j by weight).

It must also be mentioned that they constitute both an outstanding source of vitamins such as those of the B group (particularly Β^2 which may be used as a restorative, the C vitamin, carotene and also an outstanding source of minerals necessary to life, particularly sodium, calcium, phosphorus, iron and copper.

" The algae may be eaten in the fresh state or stored when they are in a dry state. It is indeed possible to dry the fresh algae by many procedures such as lyophllisatlon or atomlzation which do not alter their properties. It is also possible to shape them to powders, cakes, granules or any The dry product is a very rich nutrient ( it contains 65 to 7Q¾ of proteins., 2 to> 3$ of lipides, 18 to 20 of glucides, as well as vitamins, and minerals), and although it may he consumed as such, it may also be utilized, if desired, in admixture with various other products, for example as described hereinafter* For example it may he admixed with: - products which are poorer in proteins and richer in glucides (starch and sugars) such as, for example, cereal, flour, rice, com, manioc, sorghum, potatoes, saccharose. It may also he introduced into shaped aliments (pastes, bread, biscuits and so on)* - products which are relatively rich in proteins such as leguminous plants (20 to 21$ of proteins), the deficiency of which in some aminoacids, however, must be compensated by an external source* The algae, in that case, act as a complement* - sulfur-containing aminoacids either in the pure form (for xample methionine which is made industrially) or in the form of compounds which contain the latter (for example sorghum) these sulfur-containing aminoacids compensating for the deficiency of the algae and thus allowing to obtain a balanced proteinic food* - some complements such as fats, vitamins and salts which are necessary in some particular foods* - flavourings andor dyes which are used to give to the algae and to the mixtures of these algae with the various above-defined compounds, the taste and aspect of foods which are well-known and easily accepted by humans or various animals* By the combination of all of these additives bringing to the obtained food either the equilibrium of the constituents or a better aspect, it is possible to obtain various types of aliments fit for all types of human and animal nutrition.

The composition of this food by quality and quantity will obviously vary according to the required objective and the types of people or animals to be fed..

The various examples of composition and use given by way of illustration do not limit in any way the use of the algae to these cases it may be said, however, that in most of the cases, the resulting food consists of 10 to 8Q¾ of algae and 20 to 90?o of additional food (these percentages relating to the weight of the dry material), the algae providing 10 to 95$ of the protidlc calories of the food.

As to human nutrition, the obtained aliments may be used for example ae: - Food of high nutritive value for ill people, teenagers, old people, by virtue of the numerous vitamins and particularly the B^g vitamins* - Pood or people who have stomach diseases or for gastrectomized people, by virtue of the high digestibility and the low volume to be absorbed: since a human being must absorb one thousandth of his weight Of proteins, and since I00g of algae provide about 65g of proteins, a man of 65 kg weight may thtiis be fed with only 100 g of these dry algae per day.

Food for people who make intense efforts (sportsmen) by virtue of the high calorific value· - Baby food and food for young children.

- Dietetic food : due to their low content of fats, these algae may be used for those on a slimming diet.

In fact, for each gram of protein, the alga provides 0.04 g of lipides whereas meat provides 0.7 g, milk or eggs 0.9 g and cheese 1.2 g of the same.

Pood, for starved people} this product of vegetal origin exhibits a high content of proteins (these people suffer a high deficiency of proteins) at a low price.

In some cases, the food compositions exhibits a strong coloration which is attributable to the strong coloratio of some algae. Such food, for this reason, may be unsuitable for feeding humans (due to their inbred reluctance to consume such strongly coloured food) or some animals (for example calves usually .drink only whitje "milks"). It may ■ . . ■ f be convenient to use for the manufacture of the food product, algae which have been previously decolorised according to a process which is one object of this invention.

This process for treating colored algae exhibits the double advantage of making these algae more easily acceptable to humans and animals and providing natural pigments of. good quality.

Though this process is particularly convenient for oscillatoriaceae, it may also be applied to most of blue algae which, as a rule, contain the same pigments, however in different proportions according to the species This process consists in treating said algae with a solvent consisting of a mixture of water and an alcohol, and comprising optionally a ketone, in order to extract at least in part the pigments which are present in the. algae and the extraction may be carried out in one or several steps.

Alcohols generally used are aliphatic alcohols of 1 to 8 carbon atoms, such as methanol, ethanol, propanoic butanol, isobutanol or hexariol and < of,1-20 the ketones optionally used are /carbon atoms, such as butanone, methyl* ethyl-ketone, diethyl-ketone or propyl-ethyl-ketone. The amount of water may range from 5 to 95$ (preferably 20 to 6($ and the amount of aliphatic alcohol from 5 to 95$ (preferably 40 to 80$) of the total volume of the mixture, the amount of organic auxiliary solvent (the ketone) varying from 0 to 3$ (preferably 10 to 20 ) with respect to the total volume* It has been found that those mixtures of alcohols and water give better results in the decolonization of the algae than do, for example, a single alcohol, or mixtures of alcohols with solvents other than water which have been tried (e.g. chloroform) and that the addition of a ketone to an alcohol-water mixture^more desirable than the addition of other organic solvents which have also been tried (e.g. petroleum ether). A preferred composition contains water and an alcohol in a volumetric ratio of about 1. Alcohols particularly preferred are ethanol and butanol and the preferred ketone is acetone.

This treatment may be carriedout on fresh algae which have been separated recently from the culture medium by any known means, for example filtration or centrifugatin. Since they have been grown in media of high salt concentration, these algae are degontegrated when they are placed in the separation medipm and they lose their pigments which dissolve into the solvents used.

This treatment may also be carried out on algae which have been dried by any known process, such as atomlzation, pulverisation or drying, and are in the form of powders. It is usually sufficient, in that case, in order to extract the pigments, to have the algae suspended in the solvent used.

While the aecoloriaatlon treatment may be carried out by mere stirring of the fresh or .dried algae i the solvent, it is of course1.also possible t6 uee any known process or apparatus, for example a eoxhlet apparatus.

The amount of solvent is usually between 0·1 and 1 000 liters and preferably between 1 and 200 liters per kilogram of dried algae; The extraction time is dependent upon the algae or solvents used. It takes usually from some minutes to several hours, most often 15 minutes to 7 hours, the temperature being preferably between 20 and 150°C.

During this treatment, the pigments pass Into the solvent which tends to be progressively colored whereas the algae are progressively decolorised and may, for example* turn to green, orange-green, green-brown or white greyish. Once the decolorisation operation has come to an end, it is possible to recover the pigments from their solutions in the used solvents by any known means such as : evaporation, lyophillsation and the like, it is also possible to reextract some of these pigments by selective solvents.

The decolorised algae may be used as food for the same purposes as described above and give decolorised food products with about the same nutritive value. However since this treatment sometimes goes together with a slight decrease of the protides content (about %), it · may be necessary to introduce the decolorised algae into the food in a slightly higher amount so as to compensate for this loss of calories* The 'following examples are given by way o illustration, not of limitation.' - ! The . conditions under which the algae have been grown are those described in the French patent No. 1I+58O61, filed August ΐ6, 1963 by the same applicants Example 1 The following materials are admixed in the following proportions : b weight Algae of the spirullna type com wheat fat additional aminoacids minerals and vitamins The resulting mixture i milled and constitutes a food product which has been used to rear chickens* The chickens fed with such a food have shown no noticeable deficiencies in weight* or other characteristics· Example 2 There are admixed* in the given proportions, the following materials: by weight Algae of the spirullna type 19 cerealB 75 lucerne flour 5 vitamins and minerals 1 The resulting powdered mixture constitutes a food composition which has been used to feed growing pigs of 20 to 50 kg.

··-""" Example 3 in this example, there are used algae of the Oscillatorla agardhll type which have been cultivated In a culture basin, in the absence of algae of other types.

The ollowing materials are admixed : dry algae (6¾¾ by weight of proteins) wheat fat fish meal (65$ by weight of proteins) vitamins and minerals The mixture is crushed and there is obtained a food containing 2i$ of proteins with which growing chickens have been fek. Outstanding results have been obtained. The chickens fed with such a ood have shown no noticeable deficiencies in weight, or other characteristics.

Exampl h The same- algae as in example 3 have been used to manufacture the following mixture : algae ( oscillatoria agardhli) wheat com fish meal vitamins and minerals fat This food has been used with outstanding results to feed laying hens.

Example 5 In this example there is used a mixture of Oscillatoria agardhii algae with Spirullna platensis (maxima) algae, which had been cultivated together in the same culture basin. This culture has given a mixture comprising about 50$ by weight of algae of eachf type with which the following mixture has been made: 9¾ by weight alga of the splrulina type 10 algae of the oscillatoria type 10 lucerne flour 8 cereals 70 fat ■·■ minerals and vitamine 1 The resulting mixture is milled and the obtained food contains 17^ of proteins* It is well adapted to the feeding of young pigs, with which quite a satisfactory growth has been observed. .

Example 6 There are used in this example algae of the same type as in example 5> with which the following mixture has been made: % by weight splrulina algae 10 oscillatoria algae 10 barley and corn (in equal amounts) 50 boiled potatoes 20 fat 5 minerals , . 5 This food has been used to feed young pigs. The outstanding results are attributable mostly to the high content of 2 vitamin of the algae said vitamin being necessary to growing pigs. For the latter the necessary vitamins are B^* B2» B6> B 2 elnd ΡΡ· All of them are present in the used algae* Example 7 There are used fresh algae of the splrulina type which have been collected in a culture pool, and then filtered© ■ 1 I · ■ . · . ' ■ · '· . ' and washed on a rotative filter to eliminate the excess of After filtering, a cake is obtained which contains about 82$ by weight of water. 55 of this cake (lOg dry weight) are placed in a soxhlet. There is added 1 liter of a solvent consisting of Water and ethanol in equal volumes, and the heating is carried out to reflux.

After 10 minutes, the solvent turns to blue-green, then to yellow after a further 10 minutes, whereas the algae have progressively lost their color to give a greyish white product. The resulting decolorised product is milled and there is finally obtained a powder containing 6% of proteins, which may be used for the same purposes as in the previous examples.

Example 8 There are used decolorised algae of the splrulina type, as obtained according to the process of example: 7» in order to prepare the following mixture : <& by weight (dry material) ^decolorised algae powdered whey fat starch minerals The resulting food mixture may be used to prepare an artificial milk substitute which has given excellent results on growing calves.

The comparative teste hereunder recited show that such mixtures lead to a decolorizing efficiency hotter than that obtained by using either single solvents or other mixtures of solvents* COMPARATIVE' TES I 3 g of dry algae of the Splrullna type was placed In a 250 ml Soxhlet* There was added thereto 150 ml of ethanol and the whole was heated to reflux* The amount of solvent was renewed ever 10 minutes, and the extraction was conducted during 12 hours* At the end of the operation! the algae still had a dark greenish oheatnuti-oolour· COMPARATIVE TES II , Comparative test I was repeated* under the same conditions except that the solvent used was a mixture of 20 % chloroform and 80 ethanol (by volume) · The colou o algae turned from blue-green to grey-green after 12 hours* COMPARATIVE TES III The test was Carried out under the same conditions as in Comparative Test 1, except that the solvent used was. a mixture of 80 ethanol} 10 % petroleum ether and \Q water (by volume}* At the end of the operation, the algae still had a dark grey colour* Example 9 This process was carried out under the same conditions aa in Comparative Test 1» but the solvent used was a mixture of 80 % ethano » iO % acetone and 0 water (by volume)* After 5 hours, the solvent did not extract any more pigment and remained colourless* At the end of the i2«*our operation, the algae had only a very pale yellow colour* Example 10 Example 9 wae repeated, hut the extraction wae interrupted after only 5 hours. The algae also had a very pale yellow colour*

Claims (1)

1. 297Q6/k ■4 Claims ; 1 · A process for decolorizing algae of the class Oyanophyceae, said process comprising extracting the pigments contained in said algae by means of a mixture comprising 5 to 9¾S by volume of water and 5 to 3% by j&l^oh ll volume of an aliphatlcTcontaining t-8 carbon atoms. 2* Process according to claim 1 , wherein the extraction is oarried out by means of a mixture of 5 to 3% by volume of water, 5-9¾S by volume of such aliphatic alcohol further containing up to 30$ by volume of a ketone containing up to 20 carbon atoms* 3. Process according to claim 1 or 2, wherein the alcohol is ethanol. U. Process according to claim 2, wherein the ketone is acetone. 5. Process according to> claim , wherein the amount of the mixture is. from 0*1 to 1,000 litres per kilogram of dry algae. 6* Process according to claim 1 , wherein the decolor-isatlon is oarried out on fresh algae. 7· Process according to claim 1, wherein the docolor-isatlon is carried out on dry algae* 6. The decolorised algae as obtained according to> the process of any one of claims 1 to 7. 9. A food composition for feeding humane or animals, whic comprises from 10 to 80$ by weight of decolorised algae according to claim 8 and from 20 to 9Q¾ by weight of an additional food. 10. Pigments, whenever obtained aooordlng to the process of any one of' claims 1 to 7*