Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B9/00—Essential oils; Perfumes
  • C11B9/02—Recovery or refining of essential oils from raw materials
  • C11B9/022—Refining

Definitions

• the present invention relates to a process for removing terpenes from essential oils in a three-step process.
• Essential oils are important aroma carriers in the food industry. For example, cold-pressed oils from citrus fruits are widely used for the production of essences for the beverage industry and for the flavoring of baked goods. These essential oils often contain terpene hydrocarbons from the mono- and sesquiterpene series, which have only limited storage stability and are thermolabile and, moreover, have a lower flavor intensity than the actual flavoring substances, which are predominantly derived from volatile oxygen-containing compounds such as aldehydes, ketones, esters, acids, phenols, alcohols and Put lactones together. For these reasons, the removal of the terpenes is an important step to improve the storage stability and to increase the aroma intensity of essential oils.
• a number of processes for the de-terpenization of essential oils which use differences in the vapor pressure, in the polarity or in the solubility of the terpene components in comparison with the oxygen-containing compounds to separate the terpenes. All of these processes have certain disadvantages, which are reflected either in the product quality, in the process costs or in the yield. For example, it has been described to dissolve essential oils in aqueous alcohols, whereby separate the terpenes and then obtain the desired aroma fractions by salting out or liquid-liquid extraction. The separation effect and the yield in these processes are unsatisfactory. Depending on the type of extractant used, technical or environmental problems can also occur.
• US Pat. No. 4,647,466 discloses a process for extracting volatile oxygen-containing substances such as ethyl butyrate or hexanal from citrus oils with the aid of compressed gases, enriching limonene. Since citrus oils such as Orange oils, however, consist of up to 95% limonene, very large amounts of CO2 or long extraction times are required to carry out the process in order to remove a high proportion of limonene with the necessary selectivity from the aromatic oil.
• the present invention was therefore based on the object of developing a process for removing terpenes from essential oils which does not have the disadvantages of the prior art mentioned, but rather a selective enrichment of the essential oils with good yields with little technical effort and under gentle conditions enables.
• the method according to the present invention consists of at least three stages.
• a polar solid (adsorbent) a polar solid (adsorbent).
• all terpene-containing essential oils can be used in the context of the present invention.
• Citrus oils obtained from citrus fruits such as oranges, lemons, mandarins, limes, limes, grapefruit or cravos are particularly suitable.
• other aromatic oils such as hop, clove, laurel, ginger, peppermint or cedarwood oil can also be used.
• CO2 extracts or oleoresins can also be used.
• the essential oils have a terpene content of up to 95%.
• the adsorbent can be loaded with the essential oil by the known methods, e.g. simply by mixing.
• Common polar solids such as e.g. Silica gel, aluminum oxide, diatomaceous earth, cellulose, bentonite, magnesium silicates etc. can be used. Silica gel and aluminum oxide have proven to be particularly advantageous.
• the amount of polar adsorbent can be varied within wide limits, but preferably 10 to 60% by weight of polar adsorbent are used, based on the starting amount of essential oil. With this loading of the adsorbent according to stage a), the oxygen-containing aroma substances are largely adsorbed on the solid, while the terpenes largely remain in the liquid phase. Depending on the type of aroma oil used and the amount of adsorbent used, about 60 to 95% of the aroma substances are adsorbed.
• the adsorbent loaded with the aroma substances is then separated from the terpenes remaining in the liquid phase.
• the methods customary in technology for separating solids and liquids can be used here. Because of the quick and complete separation centrifugation is preferably used according to the invention. However, it is readily possible to use other separation processes such as filtration at this stage. In this way, the majority of the terpenes contained in the essential oils can usually be removed without noticeable losses in the valuable aroma substances.
• the adsorbent can be used several times for adsorption. It is possible to increase the yield of aromas during adsorption by first mixing and separating the adsorbent with the terpene fraction from a previous batch as described above. In this case, the mixture of terpene fraction and adsorbent can be poured into a column and the essential oil to be enriched can be passed through in a type of column chromatography.
• the adsorbent loaded with aroma component is subjected to a high pressure extraction with compressed CO2, the aroma substances being desorbed or extracted.
• the high pressure extraction should take place at pressures above 70 bar and temperatures from 10 to 80 ° C in order to achieve a complete extraction of the aroma substances.
• the preferred extraction conditions are pressures of> 100 bar, in particular from 200 to 300 bar and / or temperatures from 30 to 70 ° C., because the aroma substances are obtained particularly quickly and gently under these conditions. It is clear that in addition to the desired flavoring substances, this high-pressure extraction also extracts the rest of the terpenes, which was also adsorbed onto the polar adsorbent in the first stage.
• a pre-extraction is carried out in a preferred embodiment before the high-pressure extraction (step c) in order to obtain the flavorings performed, in which the remaining terpenes are first removed from the adsorbent.
• This pre-extraction is also carried out with compressed carbon dioxide, but in contrast to the process conditions of stage c) (main extraction) at pressures below 100 bar, preferably at 70 to 90 bar.
• the temperature range for the pre-extraction is 30 to 80 ° C, preferably 50 to 70 ° C.
• a largely selective extraction of the terpenes takes place under these process conditions, while the aroma substances remain on the adsorbent.
• the terpene hydrocarbon content of these pre-extracts is generally higher than the terpene content of the starting oil.
• This pre-extraction is followed, as already described, by the main extraction (stage c), in which the oxygen-containing aroma substances are then obtained under gentle conditions.
• the CO2 aroma extracts obtained in this way can then be completely removed from the CO2 by lowering the density by the usual methods.
• Example 2 5 kg of orange oil with a lime content of 95.7% were stirred according to Example 1 with 1 kg of silica gel at room temperature for 120 minutes.
• the loaded silica gel was then separated from the liquid phase by centrifugation and extracted in a high-pressure extraction system with 40 kg of CO2 at 280 bar and 35 ° C. 625 g of concentrate with a lime content of 89.6% were obtained as the extract.
• the specific CO2 consumption was 8 kg CO2 per kg of starting oil.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Fats And Perfumes (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Medicines Containing Plant Substances (AREA)
• Extraction Or Liquid Replacement (AREA)
• Lubricants (AREA)
• Gas Separation By Absorption (AREA)

Applications Claiming Priority (2)

Publications (3)

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Cited By (2)

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• 1988
  • 1988-10-14 DE DE3834988A patent/DE3834988A1/de not_active Withdrawn
• 1989
  • 1989-10-04 MX MX017824A patent/MX171557B/es unknown
  • 1989-10-11 US US07/419,643 patent/US5061502A/en not_active Expired - Lifetime
  • 1989-10-11 ZA ZA897691A patent/ZA897691B/xx unknown
  • 1989-10-12 ES ES89119001T patent/ES2070877T3/es not_active Expired - Lifetime
  • 1989-10-12 EP EP89119001A patent/EP0363971B1/fr not_active Expired - Lifetime
  • 1989-10-12 DE DE58909186T patent/DE58909186D1/de not_active Expired - Fee Related
  • 1989-10-12 AT AT89119001T patent/ATE121447T1/de not_active IP Right Cessation
  • 1989-10-13 JP JP1265356A patent/JP2541670B2/ja not_active Expired - Fee Related
  • 1989-10-13 RU SU894742229A patent/RU1769761C/ru active
• 1995
  • 1995-04-20 GR GR950400819T patent/GR3015902T3/el unknown

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