MXPA97008439A - Procedure for the isomerization of lutein to zeaxanthin, and the product obtained with me - Google Patents

Abstract

An isomerization process of Lutein to Zeaxanthin is described which includes a saponification or concalcali treatment step of a plant extract containing Lutein, followed by a stabilization step. In the process of the present invention, saponification and stabilization are carried out in the presence of a catalyst for the isomerization of Lutein to Zeaxanthin at a temperature of about 60 to 140 ° C, obtaining an approximate yield of 70% to 96% of conversion of Lutein contained in veget extract

Description

"PROCEDURE FOR THE ISOMERIZATION OF LUTEIN TO ZEAXANTINE AND THE PRODUCT OBTAINED WITH THE SAME" FIELD OF THE INVENTION The present invention relates to obtaining natural pigments of vegetable origin for food for human and animal consumption, and more particularly, it is related to a process of saponification and isomerization of Lutein to obtain Zeaxanthin.

BACKGROUND OF THE INVENTION Natural pigments of vegetable origin have become increasingly important as the world awakens awareness of the potential danger that synthetic pigments, previously used in human and animal consumption foods, have shown. The extraction of dyes from flowers has been carried out for a long time. In the book Colorantes Naturales de México, published by Industrias Resistol SA in 1988, methods of extracting "flower dyes" are described, which include steps such as grinding the petals of flowers, or boiling them, and adding substances such as industrial alcohol. 96 degrees, solutions of alum and vinegar, in addition to mentioning an infinity of applications of various dyes. Within these applications, and in particular in the poultry industry, the yellow color of the yolk of the egg and the skin of the chicken is originated by the pigments contained in the food that these birds ingest. The importance of pigmentation is related to the health and quality of the breeding conditions of these birds, and has become a key factor in the marketing of chicken and eggs. The main compounds associated with pigmentation in birds (and also in other species such as fish and crustaceans) are called carotenoids, which are related in their chemical structure to Carotene. The main carotenoids involved in the pigmentation industry are generically called Xantofilas (from the Greek Xantós = yellow, and edges = lover, friend), which have the characteristic of being insoluble compounds in water and slightly soluble in ethyl alcohol and ether. These carotenoids are generally found as an integral part of natural products such as alfalfa, corn gluten, cempasúchil flower and chili, among others. The traditional sources of carotenoids involved in poultry pigmentation have been alfalfa and corn gluten, in which the carotenoids are found in their free form. The demands of the market were forcing poultry farmers to increase the levels of pigmentation in their products, and with it, to the natural pigment industry in search of alternative sources of carotenoids. The flower of cempasúchil (Tagetes erecta) has become a viable alternative for this purpose due to its high content of Xanthophylls, although these are found in esterified form in it. The yellow pigments of the cempasúchil flower and other vegetable sources, are currently marketed saponified and formulated in various solid or liquid vehicles, and have been used for almost four decades as additives in animal feed, mainly to color the skin of broiler chicken and egg yolks in laying hens. The saponification of said yellow pigments is necessary to facilitate the assimilation of these in the organism of the birds, since the pigments that are in esterified form are free or hydrolysed after the saponification, in such a way that they can be absorbed by the organism of the birds more quickly and efficiently. In volume 65 of the journal "Poultry Science" pages 1708 to 1714 of the year 1986, an article by D. L. Fletcher, et. al., in which the saponification effect of the extracts of the cempasuchil flower is analyzed in its capacity to color egg yolks and chicken skin. At the industrial level, the extraction of pigments from the cempasúchil flower, and other vegetables, is traditionally carried out by means of solvents of various types to form extracts containing the carotenoids, in the form of oleoresins, mainly. To achieve greater pigmentation capacity, extracts containing Xanthophylls are subsequently treated so that the Xanthophylls that are in esterified form, are hydrolyzed, generally by means of saponification processes. There are various methods to hydrolyze the Xanthophylls, such as the one described in US Pat. No. 3,783,099, granted the lo. January 1974, in which it is mixed with the plant material that contains Xantofilas, an enzyme such as cellulase and a chelating agent such as ethylene diamine tetra-acetic acid (EDTA), which hydrolyze the esters to conditions of constant pH and extract Xanthophylls, and therefore, avoid the need for saponification after extraction. The most common hydrolysis procedure, as already mentioned, is saponification or alkali treatment of the plant extracts. A large number of saponification processes of the pigments obtained from carotenoids in esterified form exist in the current art. U.S. Patent No. 3,523,138 issued August 4, 1970, describes various processes for treating cempasuchil flower extracts by means of aqueous solutions of alkali metal hydroxides in the presence of low molecular weight alkane alcohols, in which use temperatures ranging from 0 ° C to 150 ° C with reaction times between 1 minute and 8 hours, depending on the temperature used, since with the increase in temperature, the reaction time is reduced. In this patent it is established that to achieve an optimal treatment at 90 ° C, a time of 3 hours must be used. The Mexican Certificate of Invention No. 1697, granted on May 4, 1978, describes a procedure to obtain a powdered pigment concentrate with enhanced activity from oils containing Xanthophylls, in which the Xanthophylls contained in the cempasuchil flower are extracted by means of solvents such as chloroform or acetone, which are then removed, obtaining a pasty mass containing Xanthophylls, fats, resins and waxes that were entrained by the solvent. Once the Xanthophylls have been extracted, they are emulsified by means of a surfactant, for example a detergent, in order to dissolve the pasty mass in water and saponify by incorporating an alkali such as ammonium hydroxide, potassium hydroxide or sodium hydroxide, a a temperature between 50 and 90 ° C for 15 to 60 minutes, after which an antioxidant and fixative of Xanthophylls is added to fats such as Lecithin, and a substance that adheres to Xanthophylls such as carboxymethyl cellulose, Grenetin and palmitates. The solution is neutralized with a precipitant such as phosphoric acid, silicic acid or magnesium chloride to entrain Xanthophylls and finally subjected to filtration, washing, drying and milling steps to obtain the final pigment powder. In the prior art of said invention certificate, it is established that until that moment, no procedure had been conceived to obtain powdered pigment concentrates from oils containing Xanthophylls enhancing their activity. Mexican Invention Certificate No. 6010, granted on September 24, 1984, describes a procedure for obtaining a stable pigment concentrate of Xanthophylls from the cempasuchil flower comprising the steps of: extracting the oil from the cempasuchil flower by means of of solvents; saponify with an alkali the oily extract mixed with the solvent at temperatures between 55 ° C and 65 ° C at atmospheric pressure; extract the solvent to obtain a concentrate rich in Xanthophylls; and, stabilize the concentrate by means of an antioxidant selected from ethoxyquin and ascorbic acid. In the previous art chapter of Certificate of Invention No. 6010, several documents are cited, including the aforementioned Mexican Invention Certificate No. 1697, in which the development of investigations since 1915 on Xanthophylls and their pigmenting activity can be observed , as well as various forms of saponification of the Xanthophylls. It is important to mention that what was considered as novel in the process claimed in the Certificate of Invention No. 6010, was that it was a dry saponification procedure, and that it did not require a subsequent neutralization. Mexican Invention Certificate No. 6320, issued on April 1, 1985, describes an improved process for the preparation of stabilized fat-soluble extracts, from vegetable raw materials (such as the cempasúchil flower), in which the extract is saponified vegetable base at a temperature within the range of 60 to 90 ° C, with a concentrated solution of potassium or sodium hydroxide in the presence of an emulsifying thickener, such as carboxymethyl cellulose, grenetine or soluble starch, controlling moisture during the process of obtaining the extract and carrying out the saponification reaction at reduced pressure or vacuum conditions of between 0.1 and 0.05 atmospheres, considering an average reaction time of 3 hours to obtain a saponification yield of 95% to 100%. The previous art of the Certificate of Invention 6320, mentions that the problem of extracts Xantofilas dust is its instability due to surface contact with atmospheric oxygen and the containers that contain them, and claimed as a novelty a procedure in which they are used metallic precipitating agents and stabilizers to improve the properties of the powdered pigments, as well as the reaction in vacuum.

An additional aspect with respect to the hue of the final color of the yolk of the egg or the skin of the chicken, is that this tonality has importance according to the requirements of the different markets in which this type of additives are used, as such Thus, there are markets such as Orientals in which the preferences towards orange-reddish tones are very clear, which is why the producers of these coloring additives have been concerned with developing products and processes aimed at satisfying these requirements. Among the Xanthophylls that are usually extracted from the flower of cempasuchil in an esterified form, Lutein and Zeaxanthin are found, with Lutein being the highest proportion (80%). For this reason, Lutein is also known by the name Xantofila, since it is found in the greatest amount in nature. US Patent No. 3,569,386 issued November 10, 1970, discloses various compositions containing carotenoids, which when added to stall bird feeds, give different colors of the egg yolk, and Poultry Science magazine, in the volume 64 of 1985, page 925, published a study on the influence of various foods containing Xanthophylls from various sources. The traditional attempts to achieve reddish orange tones, have been oriented mainly to develop mixtures of yellow pigments of the flower of cempasúchil (Tagetes erecta) and red pigments of the pepper (Capsicum annum); however, it is known that products rich in Zeaxanthin, such as corn gluten alone or in addition to extracts of cempasuchil, achieve the same results in a satisfactory way from the commercial point of view. Abstracts of "Chemical Abstracts" No. 108473z of volume 73 of 1970 and No. 145772c of volume 89 of 1978, describe the use of pigments based on Xanthophylls in the combined foods for chickens, and more specifically, mixtures of Lutein and Zeaxanthin with other Xanthophylls to color egg yolk and chicken skin. The proportion between Lutein and Zeaxanthin are the ones that determine the tonality of the final color imparted by these pigments when used as additives. For the above reasons, research has been done on various carotenoids, in order to obtain those that provide greater pigmenting activity, and it has been found that a high content of Zeaxanthin in the pigments is desirable, so that processes for isomerize Lutein to Zeaxanthin. The isomerization reaction of Lutein to Zeaxanthin has been known for more than 40 years, as can be seen in references such as Karrer P, et. to the. of 1947 published in Helv. Chim. Acta 30, page 266, where said isomerization is reported and that of other carotenoids in the presence of Sodium Ethoxide. In the journal Acta Chem. Scand. B28 No.l, p. 137 of 1974, A. G. Andrewes describes the isomerization of Lutein to Zeaxanthin in the presence of polar solvents such as Potassium Methoxide with Methyl Alcohol and Methyl Sulfate. Evidence that the isomerization reactions of carotenoids can be catalyzed by means of heat can be found in US Patent No. 3,989,757 issued November 2, 1976, in which a carotenoid isomerization process consisting of submerging is described. said carotenoids in water, and heat them to temperatures between 50 and 120 degrees centigrade. The development of powerful analysis technologies, such as high pressure liquid chromatography. { HPLC by its acronym in English), has allowed to determine the percentage of Lutein and Zeaxanthin contained in the extracts of the flower of cempasuchil, as well as the percentage that is obtained by the saponification processes of the prior art. The documents related to the hydrolysis of carotenoids until now mentioned, they include a great amount of processes of saponification, or treatment with alkali, of oils of extracts of the flower of cempasúchil, which are carried out under the most diverse conditions of pressure, temperature, atmosphere, quantity and nature of alkaline substances, solvents, precipitants, etc. They also present evidence on several factors that can lead to the isomerization of carotenoids, such as temperature and a medium in which there is a base and / or an alcohol. For these reasons, it is not unexpected that it has been observed empirically that with the saponification processes of the prior art, the content of Zeaxanthin in the final product after saponification when the temperature is increased. Based on the foregoing and analyzing the prior art, it can be inferred that the improvements in pigmenting activity described in some of the documents related to obtaining Xanthophylls mentioned above were due, on the one hand, to the greater ease of assimilation in chickens of the obtained extract, and additionally, that within the saponification process, the isomerization of Lutein to Zeaxanthin is also carried out, which caused the content of Zeaxanthin in the final pigment to increase without the producer had evidence of this. For this reason, it could be considered that the traditional process of saponification is carried out in parallel with the isomerization of Lutein to Zeaxanthin, since the final content of Zeaxanthin increases with increasing temperature in the same saponification process. It has been observed that the contents of other carotenoids in the final pigment are also modified by using higher temperatures, which leaves evidence that other isomerizations are also carried out by means of the traditional saponification process, probably also due to the increase Of temperature. On the other hand, the instability of the carotenoids contained in the pigments, has always been a problem for the producers of the same, since the carotenoids are affected by the oxygen of the environment, temperature and light. For this reason, various methods of stabilizing compositions containing Xanthophylls exist in the prior art. Until now, it has not been possible to achieve total stability of the carotenoids contained in a plant extract, so that said stabilization procedures are only techniques for delaying the degradation of the total carotenoids contained in a composition, such as US Patent No. 3,523,138 mentioned above, which describes a method of stabilization by means of temperature with scale from 0 to 150 ° C. The aforementioned Mexican invention certificates describe stabilization methods by means of the addition of antioxidants and precipitating agents, and US Patent No. 3,535,426 issued October 20, 1970, describes a process for stabilizing cempasuchil flower concentrates. dried by means of antioxidants, fat and heat. The stabilization procedures of the aforementioned documents are intended to maintain for a certain time (at least 6 months), approximately the same content of total carotenoids in products that contain them and are used together with the saponification or hydrolysis processes traditional It has been observed that the yields of the isomerization of Lutein to Zeaxanthin which is carried out with the saponification and stabilization methods of the prior art, can become high under high temperature conditions; however, the content is still not sufficient for commercial applications, which is why producers in general maintain the traditional conditions, with which pigments are obtained with an initial content of Zeaxanthin of approximately 6% and most of Lutein, since It seems, the latter is more stable. The above is achieved by using various pressure conditions during saponification, and temperatures between 50 and 90 ° C. However, the market currently demands pigments with a high content of Zeaxanthin, which is why various processes have been developed to produce only Zeaxanthin, ranging from bacterial ones, such as the one published in the summary of "Chemical Abstracts" No. 16923v of volume 79 from 1973, to chemical synthesis, such as that described in US Pat. No. 3,558,712, but it has not yet been possible to develop a process that makes it possible to obtain Zeaxanthin in high concentration from plant extracts, and which at the same time maintains the stability of the total carotenoids for a long time. In North American Patent No. 5,523,494, a saponification process is described by which it is possible to obtain high yields of Zeaxanthin; however, it has been observed that the pigment obtained does not have the necessary stability in terms of total carotenoids for a prolonged time. As a consequence of the foregoing, it has been sought to eliminate the drawbacks of the current isomerization methods of Lutein to Zeaxanthin and to provide an improved procedure for the isomerization of Lutein to Zeaxanthin, which in addition to eliminating the disadvantages previously established, allows to obtain a stable product with a considerably higher Zeaxanthin content than that obtained with prior art processes.

OBJECTS OF THE INVENTION Taking into account the defects of the prior art, it is an object of the present invention, to provide a process for the isomerization of Lutein to Zeaxanthin, which allows obtaining products with high contents of Zeaxanthin. It is another object of the present invention to provide a process for the isomerization of Lutein to Zeaxanthin, which allows to decrease the time in which high yields can be obtained in the isomerization of Lutein to Zeaxanthin during the saponification and stabilization of plant extracts containing Lutein. It is a further object of the present invention to provide a process for the isomerization of Lutein to Zeaxanthin, which makes it possible to obtain a reaction product that can be subsequently treated, maintaining the stability of the total content of carotenoids in a formulation for a prolonged time.

DETAILED DESCRIPTION It has been found surprisingly to employ surfactants with a range of hydrophilic-lipophilic balance (HLB), from 1 to 40, during the isomerization of Lutein to Zeaxanthin, that said surfactants act as selective catalytic agents when used in the processes of saponification and stabilization of plant extracts containing lutein, such as those of the cempasúchil flower, alfalfa, chili or any plant variety extract containing carotenoids. Among the surfactants which are used as catalysts for the isomerization of Lutein to Zeaxanthin, the following substances may be mentioned, but are not limited to the following substances: propylene glycol, celtostearyl alcohol-20 POE (Poly-oxy-ethylene units) , ethylene glycol distearate, ammonium lauryl sulfate, sodium lauryl sulfate; triethanolamide lauryl sulfate, sodium alkylbenzenesulfonate, polyglycol fatty acid esters, nonyl phenol-30 POE, polyethylene glycol distearate, sorbitan-20 POE monostearate, sorbitan-20 POE mono-oleate, or mixtures thereof. As already mentioned in the previous art chapter, the isomerization procedure of Lutein to Zeaxanthin of the current technique is carried out by means of the traditional saponification process, obtaining low isomerization yields and with low stability with respect to the total carotenoids . It should be noted that in the traditional saponification process, thickeners such as carboxymethyl cellulose, grenetine or soluble starch are used to emulsify the vegetable extracts and to be able to carry out saponification in the aqueous phase; however, to date there is no evidence that the use of such surfactants results in an increase in the isomerization performance of Lutein to Zeaxanthin. The process of isomerization of Lutein to Zeaxanthin of the present invention, consists in adding the surfactant that works as a catalyst, during the treatment with alkali or saponification of a vegetable extract containing Lutein, and stabilizing the reaction mixture for an additional time to a temperature close to that of saponification, once it is finished. The complete procedure is carried out in a time of approximately 1 to 6 hours, depending on the saponification process, the catalyst, and the plant extract that are used, obtaining in this way an approximate yield of 70% to 96% of conversion of Lutein contained in the plant extract initially. The saponification of the vegetable extract containing Lutein, is preferably carried out by means of treatment with alkali solutions such as Sodium Hydroxide, Potassium Hydroxide or Calcium Hydroxide or its mixtures, either in aqueous medium or using alcohols such as methanol, Ethanol, iso-Propanol, or other low molecular weight alcohols; under conditions of temperature of approximately 60 to 140 ° C under conditions of reduced or positive pressure, preferably at atmospheric pressure; and, in an inert atmosphere, with controlled humidity or without control of the atmosphere. The surfactants that function as isomerization catalysts must be present in the saponification reaction in proportions of approximately 1 to 35% by weight with respect to the amount of oil extract of vegetable origin containing Lutein, preferably from about 5% up to Approximately 15%. In a specific embodiment of the present invention, in which extracts of the cempasúchil flower are subjected to the process, the saponification thereof is carried out in an aqueous solution of potassium hydroxide in a concentration at room temperature of approximately 20 to 70%, preferably a concentration of 50%, at a temperature comprised between approximately 110 and 120 ° C, at atmospheric pressure, and under an uncontrolled atmosphere, the catalyst proportions being preferably used between 5% and 15%, approximately. The stabilization, in this embodiment, is carried out at a temperature between 70 and 140 ° C, approximately, for a time of 60 to 90 minutes, approximately. The complete procedure, in this modality, is carried out in a time of approximately 2 to 3 hours. Once the process is complete, a reaction product with a Zeaxanthin content of about 40% to 70% of the total carotenoids is obtained. The final content of Zeaxanthin depends mainly on the vegetable extract that is saponified, on the saponification process used, on the catalyst used and on the stabilization time. The reaction product obtained can be subsequently purified or directly formulated in various presentations of extracts, either liquid or solid formulations, with high or low concentrations of Zeaxanthin, in addition to being able to use various excipients according to the final application. Starting from the vegetable extracts with high concentration of Zeaxanthin as those obtained by means of the present invention, it is possible to obtain products or compositions with a standard concentration of carotenoids and a specific proportion of Zeaxanthin that does not depend on process conditions, but rather by means of mixtures of said high-concentration plant extracts with other vegetable extracts and / or conventional commercial-type pigment compositions with low concentration of Zeaxanthin, such as Cromophyl-LR or Cromophyl-20R, a wide range of compositions can be obtained with Various concentrations and proportions of Zeaxanthin standardized in finished products, whether liquid or solid. The following examples are intended to illustrate the scope of the present invention in all its aspects and do not limit it.

EXAMPLES The examples presented below were carried out by the saponification process of the current technique, with saponification yields close to 100%, at a pressure atmosphere and at temperatures close to 115 ° C. The typical HPLC profile of an oil extract of cempasuchil which was used as raw material for the process is shown in Table I.

T B L A Seven tests were carried out to demonstrate the action of various catalytic agents, in which the content was obtained as a percentage of carotenoids of final pigment samples by means of high pressure liquid chromatography (HPLC), and the results are shown in Table II. The parameters of the tests were: T A A nd = Not Detected. The 7 tests indicated in Table II were carried out using similar conditions of reaction time. The Reference Test (E0) was carried out without any catalyst but using the same procedure.

Tests 1 to 6 (El a E6) were carried out in the presence of different catalytic agents, observing that in all cases, reaction products with Zeaxanthin content higher than the Reference Test (EO) were obtained. The catalyst agents used in tests 1 to 6 were added in a proportion close to 8% by weight of the oleoresin of cempasuchil flower, according to the following: propylene glycol for Test 1 (El); 20-POE sorbitan mono-oleate for Test 2 (E2); Nonyl phenol 30-POE for Test 3 (E3); Sodium alkyl benzene sulfonate for Test 4 (E4); Lauryl triethanol amide sulfate for Test 5 (E5); and, 10 POE Alcohol for Test 6 (E6). As can be seen, in the results of the previous tests the action of the catalytic agents is evident as regards the increase of the Zeaxanthin content in the final pigment, since in Test 1 (El), although it is presented a lower final content of Zeaxanthin with respect to the catalyzed examples, an increase of about 3 times is registered with respect to the content thereof of the Reference Test (EO). It should be noted that in the tests in which a surfactant agent was used as a catalyst (El a E6), a stable pigment was obtained in terms of total carotenoid content. In order to demonstrate the stability of the pigments that are obtained from the reaction product of the present invention, Tests 7 and 8, identified as E7 and E8, respectively, were carried out in Table III, which were taken to according to the following: TEST Propylene glycol Mono sorbitan oleate (%) * 20 POE (%) E7 0 0 E8 18 10 * Percentage by weight with respect to the amount of raw extract of the cempasúchil flower.

The conditions of agitation, time, pressure and temperature were the same for both tests. The reaction products obtained were formulated and analyzed before and after being subjected to conditions of challenge or accelerated degradation, heating them at 75 ° C for 72 hours, at the end of which their total carotenoid content was determined. The results obtained are shown in Table III. T A B L A I I I The results obtained show that in the case of Test 7 (E7), the degradation was 52.2%, more than double that observed in the pigment obtained by the method of the present invention, in which only 12% degradation was obtained, as shown in the results of Test 8 (E8). Although certain embodiments of the invention have been illustrated and described, it should be emphasized that numerous modifications to them are possible. The present invention, therefore, should not be considered as restricted, except for what is required by the prior art and by the spirit of the appended claims.

Claims (14)

NOVELTY OF THE INVENTION CLAIMS

1. - A procedure of isomerization of Lutein to Zeaxanthin of the type comprising saponification or alkali treatment of a plant extract containing Lutein, followed by a stabilization step, characterized in that saponification and stabilization are carried out in the presence of a catalyst for the isomerization of Lutein to Zeaxanthin at a temperature of 60 to 140 ° C, approximately, obtaining an approximate yield of 70% to 96% conversion of the Lutein contained in the vegetable extract.

2. - A process of isomerization of Lutein to Zeaxanthin, according to claim 1, further characterized in that the catalyst is a surface-active agent with a hydrophilic-lipophilic balance scale between ly 40.

3. - A process of isomerization of Lutein to Zeaxanthin, according to claim 2, further characterized in that the catalyst is selected from the group comprising: propylene glycol; keto-stearyl alcohol-20 POE; ethylene glycol distearate; ammonium lauryl sulfate, sodium lauryl sulfate; triethanol amide lauryl sulfate; sodium alkylbenzenesulfonate; polyglycol fatty acid esters; nonyl phenol-30 POE; polyethylene glycol distearate; sorbitan-20 POE monostearate; mono-oleate of sorbitan-20 POE; or, mixtures thereof

4. - A process of isomerization of Lutein to Zeaxanthin, according to claim 3, further characterized in that the surfactant must be present in a proportion of approximately 1 to 35% by weight of the plant extract that contains Lutein

5. - A process of isomerization of Lutein to Zeaxanthin, according to claim 4, further characterized in that the plant extract containing Lutein can be extract of flower of cempasuchil, alfalfa, chili, or any other plant variety containing carotenoids

6. - A process of isomerization of Lutein to Zeaxanthin, according to claim 5, further characterized in that, when the plant extract containing Lutein is cempasuchil flower, the amount of catalyst used is approximately 5% to 15%. % in weigh .

7. - A procedure of isomerization of Lutein to Zeaxanthin, according to claim 4, further characterized in that the saponification or treatment with alkali, is carried out by treating in an aqueous medium the plant extract containing Lutein with an alkali solution selected from Sodium Hydroxide, Potassium Hydroxide, Hydroxide of Calcium or mixtures thereof, at a temperature between approximately 60 and 140 ° C; and, the stabilization is carried out at a temperature between approximately 60 and 140 ° C.

8. - A process of isomerization of Lutein to Zeaxanthin, according to claim 4, further characterized in that saponification or treatment with alkali, is carried out by treating the plant extract containing Lutein with an alkali solution selected from sodium hydroxide , potassium hydroxide, calcium hydroxide or mixtures thereof, in the presence of a low molecular weight alcohol.

9. - A process of isomerization of Lutein to Zeaxanthin, according to claim 8, further characterized in that the low molecular weight alcohol is selected from methanol, ethanol, iso-propanol and mixtures thereof.

10. - A process of isomerization of Lutein to Zeaxanthin, according to claim 7, further characterized in that the saponification or treatment with alkali, when the plant extract containing Lutein is extract of cempasuchil flower, is carried out using a solution aqueous potassium hydroxide at a concentration of about 20 to 70%, preferably using a 50% concentration; at a temperature of 110 to 120 ° C, approximately and at atmospheric pressure; and, the stabilization is carried out at a temperature between about 70 and 140 ° C, for a time of about 60 to 90 minutes, obtaining a reaction product containing Zeaxanthin in up to about 80% of the total carotenoids.

11. - A reaction product with a high content of Zeaxanthin, characterized in that the reaction product has up to about 80% Zeaxanthin content with respect to the total carotenoids, and is obtained using the method claimed in claims 1 to 10.

12. - A reaction product with high content of Zeaxanthin, according to claim 11, further characterized in that the reaction product, due to its high content of Zeaxanthin, allows the preparation of liquid and / or solid formulations, which are stable with respect to the concentration of total carotenoids for a extended time .

13. - A reaction product with high content of Zeaxanthin, according to claim 12, further characterized in that the formulation is prepared by mixing the reaction product with commercial products such as Cromophyl-LR and Cromophyl-20.

14. A pigment composition, characterized by comprising a reaction product with a high content of Zeaxanthin as claimed in claims 11 to 13; and, a solid or liquid excipient.