RU2696308C1 - Method for extraction of essential oil from fennel fruits - Google Patents

Abstract

FIELD: essential oils industry.

SUBSTANCE: invention relates to the essential oil industry. Method involves milling fennel fruits, extraction of ground raw material with an organic solvent in a Soxhlet apparatus and evaporation of the solvent. Organic solvent used is an easily boiling liquid – perfluorobutane methyl ether with a feed/solvent ratio of 1:4.5–9.0 wt/wt, extraction of raw material is carried out for 1–5 hours, obtained extract is evaporated to obtain an oil extract, which is treated with ethanol 96 % vol/vol, with ratio of oil extract/ethanol 1:2, then mixture of oil extract and ethanol is centrifuged for separation of solution of essential oil in ethanol, which is evaporated under vacuum at 40 °C to produce purified essential fennel oil.

EFFECT: invention allows to develop effective ecologically clean method for extraction of essential oil from fennel fruits, which does not require specialized and complex equipment.

1 cl, 1 dwg, 3 tbl, 3 ex

Description

The invention relates to the essential oil, food and chemical pharmaceutical industries and can be used to isolate the essential oil from the fruits of ordinary fennel (Foeniculum vulgare Mill.), Family celery (umbrella) - Apiaceae (Umbelliferae).

At present, the literature describes several different methods for the isolation of essential oils from this plant material: hydrodistillation - the allocation of essential oils using water vapor; microwave distillation and extraction with organic solvents and liquefied gases [Damayanti A., Setyawan E. Essential oil extraction of fennel seed (Foeniculum vulgare) using steam distillation. Int. J. Sci. Eng., 2012. Vol. 3 (2). P.12-14,

Al-Hilphy A.R.S., Al-fekaiki D.F., Hussein R.A. Extraction of essential oils from some types of Umbelifera family using microwave-assisted water distillation. Journal of biology, agriculture and healthcare. 2015. Vol.5, No.22. - P.16-28.,

Benmoussa H., Farhat A., Romdhane M., Bouajila J. Enhanced solvent-free microwave extraction of Foeniculum vulgare Mill. Essential oil seeds using double walled reactor. Arabian Journal of Chemistry. 2016. In Press. https://doi.org/10.1016/j.arabjc.2016.02.02.010.,

Zorca M., Gainar I., Bala D. Influence of the process parameters on supercritical CO2 extraction of Fennel essential oil. Analele Universitatii din Bucuresti - Chimie, Anul XV (serie noua), 2006. vol. I, pag. 107-111.

Gainar I., Vilcu R., Mocan M. Supercritical fluid extraction and fractional separation of essential oils. Analele Universitatii din Bucuresti - Chimie, Anul XI (serie noua), 2002. vol. I, pag. 63-67.].

Closest to the claimed technical solution for the technical nature and the technical result achieved is the technology of separation using liquefied freon 134a described in [Girova, T., V. Gochev. I. Stoiliva, K. Dobreva, N. Nenov, V. Stanchev, and A. Stoyanova. (2001). Low temperature extracton of essential oil bearing plants by liquificate gases: Fruits from sweet fennel (Foeniculum officinale Mill.). International Scientific Conference eRA-6, Greece, 1-6.]. This method involves grinding and then extracting the fruits of ordinary fennel in a special installation using liquefied freon 134a at a pressure of 0.5 MPa, a temperature of 18-20 ° C, for 60 minutes and a particle size of the raw material of 0.15-0.25 mm. With these parameters, the yield of essential oil was 3.8% (vol / mass), and according to gas chromatography, the percentage of anethole was more than 68.3%, calculated on the peak area among other volatile components of the essential oil.

However, this method requires special equipment that must operate at an overpressure of 0.50 MPa. Another significant drawback of this method is the need for energy consumption for the operation of evaporation of the extract and the operation of condensation of solvent vapor in the refrigeration unit. The described method is adopted as a prototype of the invention.

An object of the invention is the development of a more efficient environmentally friendly method for the isolation of essential oil from the fruits of ordinary fennel, simple in execution, which does not require special and complex equipment.

The problem is solved using the proposed method for the isolation of essential oil from the fruits of ordinary fennel (Foeniculum vulgare Mill.), Including grinding anise fruits, extracting the crushed raw materials with an organic solvent in a Soxhlet apparatus, evaporating the solvent, moreover, an easily boiling liquid is used as an organic solvent - perfluorobutane methyl ester at a ratio of raw materials / solvent 1: 4.5-9.0 mass / mass, the extraction of raw materials is carried out for 1-5 hours, the resulting extract is evaporated with cond by sensing the extractant to obtain an oil extract to obtain an oil extract, which is treated with 96% v / v ethanol, with an oil extract / ethanol ratio of 1: 2 v / v, then the mixture of oil extract and ethanol is centrifuged to separate a solution of essential oil in ethanol, which is evaporated under vacuum at 40 ° C until a purified essential oil is obtained.

The resulting essential oil can be used in the medical, food or perfume and cosmetic industries.

The range of the ratio of raw materials / solvent 1: 4.5-9.0 wt./mass., Provides an effective extraction of the components of the essential oil from plant materials and is economically feasible. The lower limit value of 1: 4.5 mass / mass, due to the fact that this amount of extractant allows you to cover the bulk volume of plant material in the extractor with a small excess of extractant necessary for the possibility of the process of its circulation in the extraction apparatus. An increase in the ratio of raw material / solvent to more than 1: 9.0 mass / mass does not lead to an increase in the yield of components of the essential oil and requires unreasonably high energy costs and extractant.

The claimed extraction time interval of 1-5 hours provides an exhaustive extraction of the components of the essential oil from the raw material. Reducing the extraction time leads to a significant under-extraction of the essential oil. Increasing the extraction time is not advisable from an economic point of view, as well as energy consumption, since it does not lead to a significant increase in the yield of essential oil.

It was experimentally determined that an effective concentration of ethanol to clean the primary oil extract from the components of the fatty oil is ethanol 96% v / v with an oil extract / ethanol ratio of 1: 2 v / v. Under these conditions, there is a maximum dissolution of the essential oil in alcohol and its separation from the components of the fatty oil, which are separated by centrifugation for 30 minutes at 3000 rpm from the alcohol solution of the essential oil.

Quantitative analysis of trans-anethole in the extracts was performed using reverse phase high performance liquid chromatography (HPLC) using an Agilent Technologies chromatograph, Agilent 1200 Infinity series, manufactured in the USA, under the following conditions: mobile phase (A) - 1% an aqueous solution of formic acid, the mobile phase (B) is ethanol in a linear gradient feed mode; chromatographic column - Supelco Ascentis express C18, column dimensions 100 mm × 4.6 mm, particle size 2.7 μm; the speed of the mobile phase is 0.5 ml / min; chromatographic column temperature + 35 ° C; sample volume - 1 μl. Before quantitative analysis, an exact weighed portion of the primary extract was mixed with finely weighed ethanol of 70% vol., And centrifuged at 13000 rpm for 5 minutes. The ethanol solution was drained and analyzed.

A qualitative analysis of the extracts was carried out using gas-liquid chromatography using the method of internal normalization by the sum of the areas. GLC analysis was performed on a GCMS-QP2010 Ultra model chromatograph-mass spectrometer manufactured by Shimadzu, Japan. The separation was carried out on a column: Zebron ZB-5MS 30 mL × 0.25 mm ID × 0.25μdf; liquid phase: 5% -polysilarylene-95polydimethylsiloxane; temperature limits: from 70 ° C to 325/350 ° C. Chromatography conditions: carrier gas - helium with a constant flow - 3.0 ml / min; the analysis was carried out in isothermal mode. Column temperature - 70 ° C (isotherm 2 min) - 200 ° C (isotherm 5 min), temperature rise rate 5 deg / min. Evaporator temperature - 210 ° C; ion source temperature - 250 ° C; interface temperature - 250 ° C; sample injection mode - without dividing the flow - 1 min; detector voltage - 0.84 kV; emission stream - 60 μA; the volume of the injected sample is 1 μl. Detection was carried out in the full ion current (SCAN) mode in the m / z range of 30–500 Da, with a scanning speed of 1000 and a resulting time of 0.5 sec. Before analysis, the primary extract was dissolved in n-hexane and, if necessary, filtered through a filter with a pore size of 0.45 μm.

Example 1

A portion of crushed fruits of ordinary fennel weighing 5.01 g (particle fraction 0.1-0.5 mm) is placed in a Soxhlet circulation extractor. The raw material is poured with extractant 1: 7.5 mass / mass, 37.5 g (25.0 ml) and the extraction process is started within 2 hours. The resulting extract was evaporated in vacuo to an oily product, and the extractant was condensed.

The obtained primary oily extract for the isolation of trans-anethole from it is extracted with ethanol 96% v / v, in a ratio of 1: 2 v / v, centrifuged at 3000 r / min for 30 minutes and evaporated in vacuo at 40 ° C to obtain purified ether oils enriched with trans-anethole.

The raw materials are not removed from the extractor, heated to 65 ° C, purged with air until complete removal and condensation of the extractant. The regenerated extractant is combined with the bulk of the extractant and reused for extraction of a new batch of raw materials.

Some physico-chemical, environmental and toxic indicators of Freon 134a and Novec 7100 fluid for comparison are shown in Table 1.

Table 1. The main physico-chemical, environmental and toxic indicators of Freon 134a and Novec 7100 fluid

As can be seen from the data in Table 1, the Novec 7100 low-boiling liquid has a number of advantages, ceteris paribus, as compared to similar indicators of Freon 134a, namely, the Novec 7100 boiling point is 61 ° C, i.e. under normal conditions, it is a liquid with a heat of vaporization of almost half as compared with Freon 134a (112 <217 kJ / kg), heat capacity is 17% less than Freon 134a (1183 <1425 kJ / (kg · K)), the global warming potential 4 times less than Freon 134a (320 <1300 GWP).

The comparison results for the main features of the prototype and new technology are given in table.2.

Table 2. Comparison results for the main features of the prototype and new technology

As can be seen from the data table. 2, the results of comparing the new technology over the technology of the prototype demonstrate its advantages, namely: the absence of special equipment operating under high pressure, there are no electricity costs for condensing the extractant vapor, the working pressure is 1 atm., While the yield of purified trans-anethole is reached at 78 ± 3 °%.

The loss of extractant is 1.5 ± 0.2 g (1.0 ± 0.1 ml), which is equivalent to 4% of its original amount.

The composition of the volatile fraction of the primary extract obtained using Novec 7100 is shown in FIG. 1 (Chromatogram of the primary extract obtained using Novec 7100) and table. 3.

Table 3. The composition of the volatile fraction of the extract obtained using Novec 7100

Example 2

A portion of the crushed fruits of ordinary fennel weighing 5.03 g, is placed in a Soxhlet circulating extractor. The raw material is poured with extractant 1: 4.5 mass / mass, 22.5 g (14.9 ml) and the extraction process is started within 60 minutes. The resulting extract was evaporated in vacuo to an oily product, and the extractant was condensed.

The obtained primary oily extract for the isolation of carvone from it is extracted with 96% v / v ethanol in a ratio of 1: 2 v / v, centrifuged at 3000 r / min for 30 minutes and evaporated in vacuo at 40 ° C until a purified anethol enriched essential oil is obtained.

The yield of lipophilic substances with respect to the weight of LRS is 3.2 ± 0.2%.

The yield of purified anethole in relation to the weight of LRS is 1.58 ± 0.05%.

The yield of purified anethole is 67 ± 3%.

Example 3

A portion of crushed fruits of ordinary fennel weighing 5.01 g, is placed in a Soxhlet circulating extractor. The raw material is poured with extractant 1: 9.0 mass / mass 44.8 g (29.7 ml) and the extraction process is started within 300 minutes. The resulting extract was evaporated in vacuo to an oily product, and the extractant was condensed.

The obtained primary oily extract for the isolation of carvone from it is extracted with 96% v / v ethanol in a ratio of 1: 2 v / v, centrifuged at 3000 r / min for 30 minutes and evaporated in vacuo at 40 ° C until a purified anethol enriched essential oil is obtained.

The output of lipophilic substances in relation to the weight of the LRS is 3.6 ± 0.3%.

The yield of purified anethole in relation to the weight of LRS is 1.95 ± 0.05%.

The yield of purified anethole is 83 ± 4%.

The technical result is an effective and environmentally friendly method for the isolation of essential oil enriched with trans-anethole from the fruits of ordinary fennel simple to perform under normal conditions, without special and complex equipment.

EFFECT: invention makes it possible to isolate essential oil, which is enriched with trans-anethole from common fennel fruits using perfluorobutane methyl ester (Novec 7100) with minimal energy consumption, normal pressure using standard equipment typical for chemical-pharmaceutical and / or essential oil plants.

Claims (1)

The method of extracting essential oil from ordinary fennel fruits, including grinding fennel fruits, extracting the crushed raw materials with an organic solvent in a Soxhlet apparatus, evaporating the solvent, characterized in that an easily boiling liquid is used as an organic solvent - perfluorobutane methyl ester with a feed / solvent ratio of 1 : 4.5-9.0 wt./wt., The extraction of raw materials is carried out for 1-5 hours, the resulting extract is evaporated to obtain an oil extract, which is treated with ethano om 96% v / v, at a ratio of oil extract / ethanol 1:.. 2, then a mixture of the oil extract and ethanol, centrifuged for the separation of the essential oil ethanolic solution which is evaporated under vacuum at 40 ° C, to obtain a purified essential oil of fennel.

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