ES2668951T3 - Procedure for artificial aging of Iris rhizomes for accelerated formation of ironic isomers - Google Patents

Abstract

Procedure to accelerate the aging of lily rhizomes, which comprises the storage of lily rhizomes in an atmosphere with oxygen content, which at 25ºC has an oxygen partial pressure of 50 kPa (0.5 bar) or more, and a temperature of 25ºC or more.

Description

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DESCRIPTION

Procedure for artificial aging of Iris rhizomes for accelerated formation of ironic isomers Technical field

The present invention relates to a method for accelerating the aging of lily rhizomes (Iris) and for the preparation of Iris butter from aged rhizomes.

State of the art

The rhizomes of the iris classes Germanic Iris, Iris pallida and some of their hybrids, such as Iris Barbata, contain terpenoid compounds, the so-called iridian compounds, from which valuable aromatic substances, the so-called irones, can be formed, by division oxidative The aging process is currently produced by storing dried rhizomes for a period of at least three to four years [F.-J. Marner, Current Organic Chemistry, 1997, 1, 153-186]. The irons are obtained by steam distillation of the rhizomes aged in the essential oil, the so-called Iris butter, which has many outlets in the perfumery, cosmetics and food industry.

For the acceleration of the aging process some experiments were carried out. Thus, wet chemical oxidation methods were developed with potassium permanganate or nitrite salts [F.-J. Marner, W. Krick, B. Gellrich, L. Jaenicke, W. Winter, J. Org. Chem., 1982, 47, 2531-2536; W. Krick, F.-J. Marner, L. Jaenicke, Z. Naturforsch., 1983, 38c, 179; FR-2 620 702, 3/24/89; US Patent No. 6,224,874B1], microbiological and enzymatic biotransformation procedures were tested [EP 0443 925; EP 0353 683; U.S. Patent No. 4,963,480; EP 0443 926; US Patent No. 5,100,790] or ionizing radiation was used for the treatment of fresh rhizomes [FR-2 653 637], to accelerate the formation of irons.

However, in practice the mentioned methods for accelerated formation of irones are not implemented, because they are not desired by the consumer as it is a chemical pretreatment of natural products [B. Roger, X. Fernandez, V. Jeannot, J. Chahboun, Phytochem. Anal., 2010, 21, 483-488] or cannot be implemented economically.

WO 2009/004517 describes a procedure for the ripening of Iris roots. In this regard, firstly, the rhizomes are briefly heated in water to eliminate the pathogens, but without deactivating the enzymes for subsequent fermentation. The roots are then crushed and fermented. The procedure is performed with fresh rhizomes that do not dry out. Information is also provided on the study of fermentation with externally added enzymes and without oxygen. In this regard it was found that without oxygen the formation of irons is clearly affected.

objective

The prolonged storage time of the Iris rhizomes in the traditional preparation method of at least three years is economically problematic, because it is necessary to have a storage space, the cash flow is interrupted and can considerable losses occur due to pest infestation. In addition, this reduces the motivation of farmers to put new Iris plantations. The known procedures for accelerating the aging of Iris rhizomes require a considerable use of reagents such as oxidizing agents or enzymes, or the use of microorganisms and there is a risk of low acceptance by consumers due to chemical pretreatment.

In view of this problem, the present invention is based on the objective of providing a method to accelerate the aging of the rhizomes and to obtain Iris butter, which allows a considerable shortening of the storage time and in this respect, can be carried out economically , without the need for prior treatment with chemicals or enzymes.

In order to achieve this objective according to the invention, lily rhizomes are stored in an atmosphere with oxygen content, an increased pressure and an increased temperature. In this regard it was surprisingly found that the amount of irones increases in a few days to weeks to an amount that is greater than in the case of rhizomes stored in a conventional manner for three years.

Summary of the invention

The present invention relates to a method for accelerating the aging of lily rhizomes, which comprises the storage of lily rhizomes in an oxygen-containing atmosphere, which at 25 ° C has a partial oxygen pressure of 100 kPa (1 bar) or more, and at a temperature of 25 ° C or more.

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In addition, the invention relates to a process for obtaining Iris butter from aged lily rhizomes, which after storage comprises performing a steam distillation or extraction.

Advantageous effects of the invention

The advantages achieved by the procedure consist in particular in that it is possible to shorten the storage time of dried iris rhizomes up to now at least three years (although in part also up to five years or more) up to only a few days to weeks. In this regard, no oxidizing chemicals such as potassium permanganate or nitrite salts or complex microbiological or enzymatic processes are used from the point of view of the process technique, but only mixtures of oxygen-containing gases, such as oxygen for industrial use , compressed air or synthetic air at increased pressure and increased temperature. In this way, a waste-free product is obtained, something important for customer acceptance in the cosmetic sector. In addition, the costs for storage and losses or the decrease in quality due to pest infestation disappear. Additionally, for the duration of the application of the procedure to dried iris rhizomes, the composition of the different ironic isomers can be influenced and with it the aroma of the Iris butter prepared therefrom and thus controlled. Another advantage is obtained by the added flexibility in the preparation for the now reduced waiting time.

Detailed description of the invention

The process according to the invention can be used in relation to all kinds of lilies suitable for obtaining irons. In this regard, they are in particular lilies of the Germanic Iris, Iris pallida, Iris pallida argéntea variegata, Iris pallida aurea variegata, Iris pallida alba, Iris neglecta, Iris spectabilis, Macedonian Iris, and / or other variations of Iris barbata.

Usually, before storage, the rhizomes of the lilies are peeled, crushed and then dried. For crushing, the rhizomes can be cut into pieces of 1-3 cm in size. It is also possible to grind them to further increase the surface and acceleration of the formation of irons.

Alternatively it is also possible to use untreated or just dried rhizomes, something preferred by some perfume manufacturers. However, then, during storage according to the invention, due to the smaller surface area, a decrease in the reaction rate with oxygen would have to be counted, so that if necessary it may be necessary to correspondingly increase the oxygen concentration, the temperature and / or storage time.

Drying can occur by simple storage at room temperature, or at an increased temperature of for example 30-40 ° C or more, in particular about 45-60 ° C. To further improve the drying efficiency, the pressure can be reduced or dried under vacuum. However, in such circumstances, due to the volatility of the terpenes, which constitute the starting material of the irones, the formation of irones can be reduced. Therefore, mild drying conditions are preferred.

Drying time is not especially limited. In general, drying ends when a constant weight has been reached. In case of vacuum drying or drying with hot air this can occur in a few hours, for example in 5 to 48 hours, in particular 10-24 hours. With a simple drying by storage may be necessary several days to weeks. The smaller the rhizomes are cut, the faster the drying will be.

The storage is then produced in a pressure-resistant container, which can be heated as an autoclave in an oxygen-containing atmosphere such as air, oxygen / inert gas mixtures or pure oxygen.

In this respect, it depends decisively on the concentration of oxygen, which in turn can be calculated using the equation po2V = no2RT from the temperature and the partial pressure of oxygen po2. At a fixed temperature, the concentration co2 = no2 / V is proportional to the partial pressure, it is applied that po2V = (no2 / V) * RT.

According to the invention, the concentration will be selected such that the partial pressure of oxygen at 25 ° C (298 K) is 50 kPa (0.5 bar) or more. Preferably the partial pressure of oxygen is 200 kPa (2 bar) or more, more preferably 500 kPa (5 bar) or more, even more preferably 2000 kPa (20 bar) or more. In this respect, an atmosphere of pure oxygen can be used; in this case the previous partial pressure data correspond to the total pressure at 25 ° C. The determination of the partial pressure of oxygen can occur when using pure oxygen simply because the reaction vessel is filled at 25 ° C and the pressure is measured. When filling occurs at another temperature, then the measured pressure should be recalculated if necessary using the above equation with the value at 25 ° C.

Alternatively, an inert oxygen-gas mixture or also air can be used, the total pressure must be increased depending on the oxygen content of the mixture correspondingly, so that the

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partial pressure of oxygen at the previous interval. The determination of the partial pressure of oxygen is also produced by measuring the pressure of the introduced gas, which however in this case must be multiplied by the oxygen content of the gas. When, for example, air is used, which has an oxygen content of approximately 21%, then a total pressure of approximately 250 kPa (2.5 bar) would be necessary to obtain the necessary partial oxygen pressure of at least 50 kPa (0 , 5 bars).

There is no special upper limit for partial oxygen pressure. However, the maximum pressure may be limited by the type of vessel used. In this regard, it should also be noted that due to heating the pressure continues to increase, as appropriate.

Storage occurs at a temperature of at least 25 ° C, preferably in the range of 30-80 ° C, in particular 40-60 ° C. An increased temperature accelerates the formation of irones, although at very high temperatures there is a risk that the formation of unwanted by-products is favored or that decomposition reactions may occur, so that the amount of irones formed may decrease again.

The duration of storage is not limited in a special way. Usually, the content in irones initially increases clearly with the storage time and then reaches a maximum, and with very long storage times it can decrease again due to decomposition reactions. Exact development over time may depend on oxygen concentration, pressure and temperature.

An adequate storage duration can be determined by measuring the development over time of the content in irons and for example it can be two days or more, preferably a week or more. Conversely, the duration of storage, in terms of the profitability of the procedure and the risk of decomposition of the irons, normally does not last more than 12 weeks. Thus a usual storage duration of 1-12 weeks, preferably 1-8 weeks, in particular preferably 1-4 weeks occurs.

Obtaining Iris butter with iron content from aged rhizomes is produced by usual procedures, for example, steam distillation or solvent extraction such as supercritical carbon dioxide.

Examples

Example 1:

Rhizomes of Germanic Iris of Moroccan origin are used. Fresh rhizomes are peeled and cut into pieces of approximately 2 cm. They undergo different drying methods. One part is dried in an adsorption dryer in air flow at 45 ° C, the other part in a vacuum chamber that can be heated at 50 ° C to constant weight (at approximately 30-40%). The pieces are then placed in stainless steel pressure pumps, which are filled with oxygen (2000-3000 kPa (20-30 bar) at 25 ° C) and placed tightly closed to the gases in an oil bath at 50 ° C. As a negative control, pieces of rhizome stored at ambient air of the same charge are used.

After 1, 2 and 4 weeks, samples from the negative control are taken and after 1, 2, 4, 6, 10 and 12 weeks, samples are taken from the pressure pumps and analyzed to obtain the content in irons. While the content in irons of the negative control for 4 weeks is at low values between 10-30 mg / kg, it increases considerably in the samples of the pressure pumps (see representations 1 and 2). In the rhizomes, dried in the adsorption dryer, after 2 weeks, a maximum in the total content of irones was processed, located at 496 mg / kg (representation 1). In rhizomes, dried in the vacuum drying chamber, the maximum was 358 mg / kg and reached after 4 weeks (representation 2). It should also be noted that as the rhizomes remained in the pressure pumps, the ratio of cis-a-irone isomers with respect to y-irona in favor of y-irona varied.

For the analysis of irones, 0.5 g of the rhizomes are finely crushed for each sample and mixed with 100 µl of a methanolic ionone solution with a concentration of 10 mg / ml as internal standard, which corresponds to a addition of 1 mg of ionone for each sample. The samples are then mixed with 5 ml of diethyl ether and subjected to extraction for 15 min in an ultrasonic bath. The excess is removed and the extraction is repeated with 3 ml of diethyl ether and 5 min in an ultrasonic bath. Leftovers from the respective sample are combined, concentrated in nitrogen flow and after filtration by syringe filter they serve as analysis solution. The samples are measured on a gas chromatograph with flame ionization detector. Quantification is produced by comparing the peak areas of the internal ionone standard with those of the ironic isomers. For the determination of a correction factor, the peak areas of the same amounts of ionone and an authentic mixture of the isomer of irons are compared.

Example 2:

Rhizomes of Iris germanica of Moroccan origin are used. Fresh rhizomes are peeled and cut into pieces of

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about 2 cm and dried in the drying chamber at 45 ° C. The dried rhizomes are then crushed to obtain powder (grain size of approximately 1 mm). The subsequent treatment is as described in example 1.

As a comparison, an extraction of a three-year-old Iris sample (naturally aged) was performed according to the same procedure as described in example 1 and also measured. The results are represented in representation 3. In the same way as in example 1, also in this case, by means of the method according to the invention of artificial aging, the content in irones increases considerably after 1, 2, 3, 4 and 5 weeks, while the content in ironas is still reduced in the case of rhizomes stored outdoors (control). Already after 1 week of artificial aging the content in irones of these rhizomes exceeds that of those stored for 3 years (representation 3).

Description of the representations

Figure 1: contents in irises of rhizomes of Iris (Germanic Iris) treated differently, freshly dried (adsorption drying). The contents of the ironic isomers of the three control groups (contr.) Were clearly lower after storage of 1, 2 or 4 weeks at ambient air than in the case of rhizomes, stored 1, 2, 4, 6, 10 and 12 weeks with oxygen atmosphere (2000-3000 kPa (20-30 bar) at 25 ° C) and increased temperature (50 ° C) (O2). In each case the sums of the irones are indicated in mg / kg.

Figure 2: contents in irises of rhizomes of Iris (Germanic Iris) treated differently, freshly dried (vacuum drying chamber). The contents of the ironic isomers of the three control groups (contr.) Were clearly lower after storage of 1, 2 or 4 weeks at ambient air than in the case of rhizomes, stored 1, 2, 4, 6, 10 and 12 weeks with oxygen atmosphere (2000-3000 kPa (20-30 bar) at 25 ° C) and increased temperature (50 ° C) (O2). However, in this trial the maximum content in irones was reached after 4 weeks. In each case the sums of the irones are indicated in mg / kg.

Figure 3: contents in irises of rhizomes of Iris (Germanic Iris) treated differently, freshly dried (drying chamber, air circulation). Iris rhizomes were sprayed after drying. The contents of the ironic isomers of the five control groups (contr.) Were clearly lower after storage of 1, 2, 3, 4 or 5 weeks at ambient air than in the case of rhizomes, stored 1, 2, 3, 4 and 5 weeks with oxygen atmosphere (2000-3000 kPa (20-30 bar) at 25 ° C) and increased temperature (50 ° C) (O2). In each case the sums of the irones are indicated in mg / kg.

Claims (8)

 one.

 Procedure for accelerating the aging of lily rhizomes, which includes the storage of lily rhizomes in an oxygen-containing atmosphere, which at 25 ° C has a partial pressure of

 5

 oxygen of 50 kPa (0.5 bar) or more, and a temperature of 25 ° C or more.

 2.

 Method according to claim 1, in which lilies of the Germanic Iris, Iris pallida, Iris pallida argéntea variegata, Iris pallida aurea variegata, Iris pallida alba, Iris neglecta, Iris spectabilis, Macedonian iris and / or other varieties of Iris are used bearded

 10 3.

 Method according to claim 1 or 2, in which peeled and / or unpeeled rhizomes, cut and / or powdered and / or whole are used.

 4. 15

 Process according to at least one of claims 1 to 3, which before storage comprises drying the rhizomes.

 5.

 Process according to at least one of claims 1 to 4, wherein the atmosphere at a temperature of 25 ° C has a partial oxygen pressure of 200 kPa (2 bar) or more, preferably 500 kPa (5 bar) or more.

 20 6.

 Process according to at least one of claims 1 to 5, wherein an atmosphere of pure oxygen is used.

 LO CM

 Process according to at least one of claims 1 to 6, wherein the temperature during storage is 25-80 ° C.

 8.

 Method according to at least one of claims 1 to 7, wherein the storage duration is at least two days, preferably at least one week.

 30 9.

 Method according to at least one of claims 1 to 8, wherein the storage is carried out in an autoclave.

 10.

 Method for obtaining Iris butter from iris rhizomes, which comprises carrying out the process according to one of claims 1 to 9 as well as after storage, carrying

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 perform an extraction or distillation by steam or hydrodestilation.