Extraction of coffee oil from coffee-based feedstocks using a new environmentally friendly and scalable process

Abstract

The present invention relates to a process for extracting coffee oil from a coffee-based feedstock using an extraction solvent, comprising holding a mixture of the coffee-based feedstock and the extraction solvent under mechanical or magnetic agitation for at least 30 minutes, followed by separating a liquid phase comprising the extraction solvent and removing the extraction solvent from the liquid phase to obtain coffee oil, wherein the extraction solvent is an ester solvent, and to the coffee oil obtained by said process.

Description

[Technical field]

[0001] The present invention relates to a process for extracting coffee oil from a coffee-based feedstock, and to the coffee oil extracted using said process.

[0002] Coffee is one of the most popular beverages worldwide and therefore the coffee industry and its consumption result in large amounts of residues. There is growing interest in finding new valuable products from the so-called "residues" and "coffee oil" has been identified as a product that can be used in the cosmetic industry, the food industry or biodiesel production, and potentially in the pharmaceutical industry.

[0003] Coffee oil contains mainly triglycerides, fatty acids, sterols, melanoidins and phospholipids. It is obtained by extraction from various parts of the Arabica coffee plant, green or roasted coffee beans, Arabica coffee spent grounds, etc. There is a demand for large amounts of coffee oil for industrial use, and therefore, a high-yield industrial process for the extraction of coffee oil is required. The commonly reported quality parameters for natural oils, including Arabica coffee oil, are acid value, fatty acid composition, iodine value, peroxide value and saponification value. [Background technology]

[0004] A widely known method for extracting Arabica coffee oil from spent grounds is by using supercritical fluid extraction. This method typically uses high temperatures and pressures to extract the coffee oil with liquefied gas. One of the most common supercritical fluids is CO2. When using CO2, the temperatures and pressures required are lower than with other supercritical fluids, but there are still explosive hazards associated with scaling up the use of supercritical fluids. The accumulation of CO2 in enclosed spaces also poses a suffocation risk to humans.

[0005] Another common method of obtaining Arabica coffee oil from spent grounds utilizes Soxhlet extraction. This extraction method requires boiling an organic solvent. The condensing steam then extracts the coffee oil from the coffee grounds. The organic solvent needs to be heated and refluxed throughout the process, increasing costs and reducing the energy efficiency of the process.

[0006] Further developments have evaluated the efficiency of various extraction solvents for coffee extraction and shown that hexane provides the best yields (Non-Patent Document 1). Although it provides high yields, hexane is toxic and poses environmental concerns, especially when used on an industrial scale where large quantities are required.

[0007] Solvents to replace toxic hexane are disclosed in Patent Document 1, for example, solvents including chloroform, acetone, diethyl ether, ethyl acetate, petroleum ether and ethanol are used in the ultrasonic extraction process. The ultrasonic frequency is 30-70KHZ, and the ultrasonic treatment time is 5-40 minutes. The ultrasonic extraction principle is based on the working principle of acoustic or ultrasonic cavitation. However, such a process requires special equipment for the generation of ultrasonic waves, which is not found in normal industrial facilities and is expensive. In addition, the quality of coffee oil may be affected by ultrasonic treatment, which may damage the triglycerides in coffee oil. For example, decomposition of the backbone of triglycerides in coffee oil may be observed, resulting in more free fatty acids that may affect the long-term stability of the oil. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] China Patent Application Publication No. 105925364 [Non-patent literature]

[0009] [Non-Patent Document 1] K. Somnuk, P. Eawlex, G. Prateepchaikul; Agriculture and Natural Resources; Vol 51 (2017); 181-189 Summary of the Invention [Problem to be solved by the invention]

[0010] It is therefore an object of the present invention to provide a high yield process for extracting high quality coffee oil, which process can be easily applied on an industrial scale using simple and standard industrial equipment, and which is simple, cost effective, energy efficient and environmentally friendly. The resulting oil can be further refined using a simple, cost effective and scalable process to isolate a coffee oil with a low content of undesirable components. [Means for solving the problem]

[0011] In a first aspect, the present invention relates to a process for extracting coffee oil from a coffee-based feedstock by using an extraction solvent, where a mixture of the coffee-based feedstock and the extraction solvent is held under mechanical or magnetic stirring for at least 30 minutes, after which a liquid phase containing the extraction solvent and the extracted coffee oil is separated. Further, the extraction solvent is removed from the liquid phase to obtain the coffee oil. According to the present invention, the extraction solvent is an ester solvent. Surprisingly, it has been found that when using an ester solvent, good yields are obtained for the extraction process without the need to heat the solvent. This allows for an efficient extraction process that is scalable, easy to use, and results in coffee oil that avoids undesirable components, thus requiring fewer processing and purification steps.

[0012] The process can be carried out using standard scale-up equipment and steps such as, for example, large jacketed reactors, mechanical or magnetic stirring, and Nutsche filtration. The developed process does not require toxic solvents such as hexane, but instead uses low-toxicity ester solvents that are sustainable and easily scalable.

[0013] In a preferred embodiment, the process is carried out at ambient temperature (about 15-25° C.).

[0014] In another preferred embodiment, which can be freely combined with the above, the process is carried out for at least 1 hour.

[0015] In a further preferred embodiment, which can be freely combined with the above, the process is carried out at atmospheric pressure.

[0016] In a further preferred embodiment, which can be freely combined with the above, the process is carried out under a standard oxygen-rich or inert atmosphere (nitrogen, argon or CO2).

[0017] Preferably, the ester solvent is selected from the group of aliphatic and aromatic, linear and branched acetates, propionates and butyrates.

[0018] In a most preferred embodiment, the ester solvent is ethyl acetate.

[0019] In a further embodiment, optionally in combination with the foregoing, the coffee-based feedstock is selected from roasted coffee beans and spent coffee grounds.

[0020] In a further embodiment, which can be freely combined with the above, the coffee oil is further subjected to a refining process (bleaching and deodorizing) to remove undesirable components and obtain a pale yellow to colorless oil. Due to the low content of undesirable components, the refining process is very simple, cost-effective and easy to scale up.

[0021] In a further preferred embodiment, which can be freely combined with the above, the purification process comprises the following steps: - dissolving the oil in a suitable solvent, adding activated charcoal to the solution, and maintaining the solution under mechanical or magnetic stirring for at least 3 hours; - filtering the resulting slurry and separating the liquid phase containing the coffee oil; removing the solvent, preferably in vacuum, to isolate the refined coffee oil.

[0022] A suitable solvent is, for example, a non-polar organic solvent, preferably heptane.

[0023] Additionally, the process may include washing the cake with a solvent and combining the resulting wash with the filtrate prior to removing the solvent.

[0024] In a second aspect, the present invention relates to a coffee oil comprising triglycerides, fatty acids, sterols, melanoidins and phospholipids, the fatty acid and triglyceride composition being as follows: Palmitic acid 21-87% peak area Stearic acid 4-21% peak area% Oleic acid 4-15% peak area% Linoleic acid ≦50% peak area% Linolenic acid ≦2% peak area% Arachidic acid 1-8% peak area% Behenic acid ≦3% peak area%.

[0025] According to a preferred embodiment, the oil obtained has: optionally, an acid number of less than or equal to 4 mg KOH / g oil, and / or optionally, an iodine value between 13 and 138 g / 100 g, and / or Optionally, a SAP value between 132 and 192, and / or Optionally, a peroxide value of less than 5 mEq oxygen / Kg, and / or - optionally a caffeine content of less than or equal to 1.5% by weight, based on the total weight of the coffee oil; and / or optionally a tocopherol content of less than or equal to 2% by weight, based on the total weight of the coffee oil, and / or Optionally, a density between 0 and 1 g / mL.

[0026] The analytical method is described below.

[0027] Different aspects and embodiments of the invention are explained in more detail in the following description of exemplary embodiments and in the drawings. [Brief description of the drawings]

[0028] [Figure 1] Diagram showing an overview of the extraction process to obtain coffee oil from discarded used grounds. [Diagram 2] Calibration curve obtained from standard solutions of α-tocopherol in coffee oil samples according to the present invention [Diagram 3] Calibration curve obtained for the calculation of peroxide value in coffee oil samples according to the present invention [Figure 4] HPLC chromatograms of standard solutions for determining the caffeine content in coffee oil samples according to the present invention [Diagram 5] HPLC chromatograms of coffee oil samples according to the invention for determining caffeine content [Figure 6] GC chromatogram of blank sample for identifying fatty acid composition in coffee oil sample according to the present invention [Figure 7] GC chromatogram of methyl linoleate marker for identifying fatty acid composition in coffee oil samples according to the present invention [Figure 8] GC chromatogram of fatty acid methyl ester USP reference standard mixture for identifying fatty acid composition in coffee oil samples according to the present invention [Figure 9] GC chromatogram of coffee oil sample according to the present invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] <Coffee-based feedstocks> According to the present invention, a coffee-based feedstock is used as the input material from which coffee oil is extracted. In preferred examples, the coffee-based feedstock comprises roasted coffee beans and Arabica coffee spent grounds, or any other commonly used type of coffee that is commonly available. Roasted coffee beans are obtained from green coffee beans that are subjected to a heating process (roasting process). In a preferred embodiment, coffee spent grounds are used, which is a by-product of the existing coffee industry as a residue obtained during the extraction process, providing a cost-effective and environmentally friendly alternative to the extraction process.

[0030] The input material to the developed process preferably has a moisture content of 10% by mass or less. If the moisture exceeds 10%, microorganisms such as Botrytis cinerea (a common grey mould found on rotting fruit / vegs) can start to grow, for example, on the spent flour, which can result in organisms producing lipase enzymes and breaking down triglycerides. Therefore, careful drying needs to be carried out to kill the organisms. A moisture meter using IR heating can be used to gravimetrically measure the moisture content in the input material, for example by following the mass loss as a function of heating. Alternatively, the same approach may be used, using a drying tunnel with an IR probe as well as IR drying.

[0031] <Extraction solvent> Coffee oil extraction is a solid-liquid extraction process in which a solid input material as described above is mixed with a liquid solvent under mechanical agitation to form an extraction mixture. During the process, coffee oil is leached from the solid input material with the aid of the liquid solvent, also called the extraction solvent. It has been found that a sustainable, scalable and cost-effective extraction process is implemented when an ester solvent is used as the extraction solvent.

[0032] Ester solvents represent compounds in which at least the hydroxyl group of the carboxylic acid RCOOH is replaced by an alkoxy group, for example from an alcohol R'-OH. According to the invention, ester solvents appear in formula (I): [ka] In the formula, R and R' independently represent a substituted or unsubstituted aliphatic or aromatic group. Preferably, R is an aliphatic group having 1 to 12 carbon atoms.

[0033] More preferably, R is a linear or branched C1-C4 alkyl group. Even more preferably, R is a linear or branched C2-C4 alkyl group. Exemplary R are C1-C4 alkyl groups, including, without limiting the scope of the invention, methyl, ethyl, propyl, and butyl. Such solvents are non-toxic and provide an environmentally friendly alternative for the extraction process.

[0034] Preferably, R' is a straight or branched chain alkyl group. More preferably, R' is a C1-C6 alkyl group. Exemplary aromatic groups, without limiting the scope of the invention, are phenyl and benzyl groups. Exemplary C1-C6 alkyl groups, without limiting the scope of the invention, are methyl, ethyl, propyl, butyl, pentyl and hexyl. Even more preferably, R' is ethyl.

[0035] Preferred examples of compounds having formula (I) include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, t-butyl acetate, benzyl acetate, isoamyl acetate, ethyl phenylacetate, ethyl propionate or ethyl butyrate.

[0036] <Mixing> The extraction process according to the present invention is carried out under mechanical and / or magnetic stirring, which means a process in which the solid input material is suspended in a liquid extraction solvent and the mixture remains uniformly suspended by using mechanical and / or magnetic stirring. Mechanical stirring is obtained by using a mechanical stirrer that converts mechanical power into fluid circulation or stirring. Exemplary stirrers include, but are not limited to, turbine stirrers, paddle stirrers, anchor stirrers, propeller stirrers, helical stirrers, etc. Magnetic stirring is achieved by using a magnetized stir bar (elliptical, oval or cross-shaped) and an electric current to move the stir bar and stir the suspension. Baffles built into the reactor improve stirring, whether magnetic or mechanical. It is therefore understood that sonication of the extraction mixture is not carried out under stirring according to the present invention.

[0037] <Mixing time> According to the present invention, the extraction mixture formed from the coffee-based feedstock and the extraction solvent is kept under mechanical or magnetic stirring for at least 30 minutes. If the process is carried out for less than 30 minutes, a significant decrease in yield is observed.

[0038] Preferably, the extraction mixture is kept under mechanical and / or magnetic stirring for at least 30 minutes and up to 24 hours, even more preferably at least 1 hour and up to 16 hours. If the process is carried out for more than 24 hours, the process efficiency decreases as less material can be processed in a given time.

[0039] <Reaction temperature> Preferably, the extraction process is carried out at ambient temperature, which is understood to be a temperature between 15 and 25° C., 59 and 77° F. or 288.15 and 298.15 K. Heating above this temperature is less energy efficient and may result in transesterification of triglycerides with ester solvents (e.g., conversion of fatty acids to ethyl esters (EEFA)) or thermal decomposition of the oil.

[0040] If the process is carried out at temperatures below 15° C., a decrease in oil yield may be observed since solvent capacity may decrease with temperature. At the same time, cooling requires the expenditure of energy and is therefore less energy efficient than maintaining the reaction temperature at ambient temperature.

[0041] <Reaction pressure> Preferably, the extraction process is carried out at atmospheric pressure. The term "atmospheric pressure" is defined as 1.01325 bar, 101325 Pa, 1013.25 hPa, 1013.25 mbar, 760 mmHg, 29.9212 inches Hg or 14.696 psi. If higher pressure is used in the process, it will require the consumption of energy and therefore will be less energy efficient. Also, higher pressure may lead to deterioration of the oil.

[0042] <Inert atmosphere> The extraction can be carried out on a small scale under a standard oxygen-rich atmosphere. In scale-up facilities, it is preferred to carry out the process under an inert atmosphere to reduce the risk due to the flash point of the extraction solvent. Flash point is understood to be the lowest temperature at which the extraction solvent can vaporize and form an ignitable mixture in air. An inert atmosphere is obtained, for example, by an inert gas such as nitrogen or argon. On a larger scale, the extraction is preferably carried out in a suitable jacketed reactor. Reactor materials include, but are not limited to, stainless steel, Hastelloy, plastic, mild steel and glass. The jacket provides the ability to control the internal temperature regardless of the temperature outside the reactor.

[0043] <Separation of oil from extraction solvent> The extraction solvent can be removed from the coffee oil by any method known to those skilled in the art. For example, the extraction solvent can be removed from the coffee oil under reduced pressure using a rotary evaporator or wiped film evaporator with minimal heating to about 60° C.

[0044] <Calculation of the yield of coffee oil obtained> The yield of the obtained coffee oil is calculated based on the following formula 1:

number

[0045] <Refining process> The coffee oil according to the invention may be used as is or may be subjected to a further refining process. Refining may be carried out, for example, to obtain decolorization and / or deodorization of the oil or to remove undesirable components. In a preferred application, the undesirable components removed are melanoidins. Melanoidins are brown, high molecular weight heterogeneous polymers formed when sugars and amino acids combine (via the Maillard reaction). Melanoidins are responsible for the brown color of the oil. During the roasting process of the coffee beans, melanoidins are further produced, so that in some applications the content of melanoidins in the coffee oil may be too high for the desired application. The melanoidins precipitate in the oil, resulting in a two-phase product that is difficult to handle in subsequent applications (e.g., the reproducibility of the sampling is reduced).

[0046] The purification process includes the following steps: - dissolving the oil in a suitable solvent, adding activated carbon to the solution, and maintaining the solution under mechanical or magnetic stirring for at least 3 hours; - filtering the resulting slurry and separating the liquid phase containing the Arabica coffee oil; removing the solvent, preferably in vacuum, to isolate the refined arabica coffee oil.

[0047] A suitable solvent is, for example, a non-polar organic solvent, preferably heptane.

[0048] Optionally, the process includes washing the cake with a solvent and combining the resulting wash with the filtrate before removing the solvent. Preferably, the wash is performed twice.

[0049] The refining process can be carried out on the obtained coffee oil, filtered or unfiltered. For unfiltered coffee oil, the oil first undergoes a process to remove any solid particles present in the oil. Preferably, the filtration process is carried out under vacuum. As a non-limiting example, during the filtration process, the oil is passed through a frit 3 sintered funnel under vacuum.

[0050] <Calculation of the content of undesirable components in the obtained coffee oil> The content of undesirable components (e.g., melanoidins) is calculated based on the following formula 2:

number

[0051] <Coffee oil composition> According to the present invention, by using the above-mentioned extraction process, coffee oil with improved properties can be obtained.

[0052] Coffee oil or arabica coffee seed oil refers to a lipid oil that contains primarily triglycerides, fatty acids, sterols, melanoidins and phospholipids. Arabica coffee seed oil may contain up to 95% triglycerides by NMR.

[0053] In a preferred embodiment, the fatty acid composition comprises: Palmitic acid 21-87% peak area Stearic acid 4-21% peak area% Oleic acid 4-15% peak area% Linoleic acid ≦50% peak area% Linolenic acid ≦2% peak area% Arachidic acid 1-8% peak area% Behenic acid ≦3% peak area%.

[0054] The method for determining peak area % is described in the United States Pharmacopeia, USP 43-NF38 p.6676 <401> This is done by cGMP analysis as disclosed in Fixed Fats and Oils. For example, according to the USP, the formula for calculating the amount of each fatty acid is as follows:

number

[0055] Examples of analytical and computational methods are described below in this patent application.

[0056] The term fatty acid composition, as used herein, refers to the amount of different fatty acids present in the product of coffee oil hydrolysis, including both free and bound fatty acids in triglycerides, all present in coffee oil. Fatty acid composition is reported as a percentage of the peak area obtained from the integrated signal in a chromatogram generated from gas chromatography.

[0057] According to a preferred embodiment of the present invention, it is possible to obtain a coffee oil having a peroxide value of less than or equal to 5 mEq oxygen / g. The term peroxide value refers to a measure of the oxidation present in the oil. If this value is high, it is an indication of radical decomposition / oxidation.

[0058] According to another preferred embodiment, which can be freely combined with the above, a coffee oil can be obtained having an iodine value of less than or equal to 130 g / 100 g oil. The term iodine value refers to a measure of the unsaturation of the oil and is measured as grams of iodine consumed per 100 g of oil (g / 100 g).

[0059] According to yet another preferred embodiment, freely combinable with any of the above embodiments, a coffee oil having an acid value of 3 mg KOH / g or less can be obtained. The term acid value (or free fatty acid) refers to the amount of potassium hydroxide required to neutralize the free fatty acids present in the oil. Free fatty acids or acid value is measured in milligrams of potassium hydroxide per gram of oil (mg / g). Acid value indicates the level of unbound fatty acids present in the oil, with different levels potentially affecting the pH and quality of the oil.

[0060] According to yet another preferred embodiment, freely combinable with any of the above embodiments, a coffee oil can be obtained having a saponification value of ≧140 mg / g and ≦185 mg / g. The term saponification value refers to the amount of potassium hydroxide required to neutralize the free fatty acids present in the oil and to saponify the esters in 1 g of oil. The saponification value is measured in milligrams of potassium hydroxide per gram of oil (mg / g). The saponification value indicates the amount of total fatty acids bound as esters in triglycerides and free fatty acids not bound present in the oil.

[0061] According to yet another preferred embodiment, which can be freely combined with any of the above embodiments, a coffee oil is obtained having a caffeine content of less than or equal to 1.5% by weight, based on the total weight of the coffee oil.

[0062] According to yet another preferred embodiment, which can be freely combined with any of the above embodiments, a coffee oil is obtained having a tocopherol content of less than or equal to 2% by weight, based on the total weight of the coffee oil.

[0063] According to yet another preferred embodiment, which can be freely combined with any of the above embodiments, a coffee oil can be obtained having a density less than or equal to 0.861 g / mL and more than or equal to 0.989 g / mL, the term density referring to the mass per unit volume of the oil and indicating the lipophilicity of the oil since oil is less dense than water. EXAMPLES

[0064] In the following, an exemplary embodiment of the extraction process for obtaining coffee oil from discarded used grounds will be described in detail with reference to the drawings. Figure 1 shows an overview of the extraction process for obtaining coffee oil from discarded used grounds that would otherwise be sent to a landfill. The process may be equally applicable to any other type of input material, be it of coffee-based feedstock as described in the present invention. First, the discarded coffee grounds are dried until the moisture content is equal to or less than 10% by weight. The dried used coffee grounds are mixed with an extraction solvent according to the present invention at ambient temperature and atmospheric pressure and kept under mechanical and / or magnetic stirring for at least 30 minutes. The coffee grounds are filtered off and the filtrate is concentrated in vacuum to obtain a brown Arabica coffee oil.

[0065] Starting materials were provided by various local coffee shops.

[0066] The used coffee grounds used for all brews are a mixture of waste coffee grounds from different cafes. Each batch was mixed before use to ensure a homogenous content.

[0067] Virgin beans (dark roast) were collected from one of these cafes. The beans were ground using a "UUOUU Mini Grinder" and passed through a sieve to remove unground beans. The sieved product was used in the extraction process for direct comparison with the extraction of spent coffee grounds.

[0068] <Process of extracting coffee oil using various solvents - laboratory scale experiment> Examples 1-11, 21-24 and Comparative Example 1 were performed using the same batch of spent coffee grounds obtained from a local cafe.

[0069] Example 1 Spent coffee grounds (Limiting Reagent; LR, 10.07 g) were stirred with methyl acetate (50 mL; 5 vol) in a 100 mL round bottom flask at ambient temperature and atmospheric pressure for 16 hours. The coffee grounds were filtered and the cake was washed twice with methyl acetate (10.07 mL; 1 vol). The filtrate was concentrated in vacuo to give 1.31 g of brown Arabica coffee oil (13.1% yield).

[0070] The yield calculation is based on Equation 1:

number

[0071] Example 2 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with ethyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown Arabica coffee oil (yield 14.1%).

[0072] Example 3 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with n-propyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 14.3%).

[0073] Example 4 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with isopropyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 14.4%).

[0074] Example 5 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with tert-butyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 16.4%).

[0075] Example 6 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with n-butyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 14.2%).

[0076] Example 7 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with isoamyl acetate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 13.1%).

[0077] Example 8 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with ethyl propionate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 13.1%).

[0078] Example 9 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with ethyl butyrate (5 vol) at ambient temperature and atmospheric pressure for 16 hours to obtain brown arabica coffee oil (yield 13.2%).

[0079] Example 10 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with benzyl acetate (5 vol) in a 100 mL round bottom flask at ambient temperature and atmospheric pressure for 16 hours. The coffee grounds were filtered and the cake was washed twice with benzyl acetate (1 vol). A brown solution was obtained, which was similar in color to the oils in all previous examples. Due to the low volatility of the organic solvents used, it was not possible to isolate the oil. The solution was analyzed for fatty acid composition, with the results being similar to the previous examples.

[0080] Example 11 As in Example 1, spent coffee grounds (limiting reagent; LR) were stirred with ethyl phenylacetate (5 vol) in a 100 mL round bottom flask at ambient temperature and atmospheric pressure for 16 hours. The coffee grounds were filtered and the cake was washed twice with ethyl phenylacetate (1 vol). A brown solution was obtained, which was similar in color to the oils in all previous examples. Due to the low volatility of the organic solvents used, it was not possible to isolate the oil. The solution was analyzed for fatty acid composition, with the results being similar to the previous examples.

[0081] Comparative Example 1 Spent coffee grounds (Limiting Reagent; LR, 10.02 g) were stirred with hexane (50 mL; 5 vol) in a 100 mL round bottom flask at ambient temperature and atmospheric pressure for 16 h. The coffee grounds were filtered and the cake was washed twice with hexane (10 mL; 1 vol). The filtrate was concentrated in vacuo to give 1.23 g of brown Arabica coffee oil (12.3% yield).

[0082] The yield calculation is based on Equation 1:

number

[0083] The results from these examples are summarized in Table 1. [Table 1]

[0084] From Table 1 it can be observed that the use of hexane as an extraction solvent is not environmentally friendly, is less efficient and results in a clearly lower yield than that obtained by using the extraction solvent according to the present invention.

[0085] <Coffee oil extraction process; yield evaluation over time> The evolution of the yield over time is then observed when extracting coffee oil from dried spent coffee grounds at ambient temperature and atmospheric pressure using ethyl acetate as the extraction solvent. The results are summarized in Table 2.

[0086] Example 21 Spent coffee grounds (60.87 g; limiting reagent; LR) were stirred with ethyl acetate (300 ml; 5 vol) in a 500 ml round bottom flask at ambient temperature and atmospheric pressure for 30 minutes. The coffee grounds were filtered and the cake was washed twice with ethyl acetate (60 ml; 1 vol). The filtrate was concentrated in vacuum to give brown arabica coffee oil (13.4% yield).

[0087] Example 22 Spent coffee grounds were stirred with ethyl acetate as in Example 21, except at ambient temperature and pressure for 1 hour, to give brown arabica coffee oil (13.0% yield).

[0088] Example 23 Spent coffee grounds were stirred with ethyl acetate as in Example 21, except at ambient temperature and pressure for 6 hours, to produce brown arabica coffee oil (13.6% yield).

[0089] Example 24 Spent coffee grounds were stirred with ethyl acetate as in Example 21, except at ambient temperature and pressure for 48 hours, to give brown arabica coffee oil (14.0% yield).

[0090] The results are summarized in Table 2. [Table 2]

[0091] From Table 2, it can be observed that the yields after 16 hours remain at similar values. Since the yields from 16 to 48 hours are similar, the energy required to keep the process running for the additional hours is not justified and the process becomes inefficient.

[0092] <The process of re-extracting coffee oil from defatted used coffee grounds> Example 31 As in Example 22, the spent coffee grounds extracted with ethyl acetate were then dried to 10% or less and re-extracted with ethyl acetate. The dried defatted spent coffee grounds (60.42 g; LR) were stirred with ethyl acetate (300 mL; 5 vol) in a 500 mL round-bottom flask at ambient temperature and atmospheric pressure for 16 hours. The coffee grounds were filtered and the cake was washed twice with ethyl acetate (60 mL; 1 vol). The filtrate was concentrated in vacuum to obtain brown Arabica coffee oil (1.17 g; 1.9% yield). As can be seen, the amount of coffee oil recovered after re-extraction is very low, which means that an efficient process is carried out in the first extraction according to the invention.

[0093] <Scale-up experiment> Examples 41-42 were carried out using a separate batch of spent coffee grounds obtained from a local cafe. A 20 L glass jacketed reactor was used for the extraction process.

[0094] Example 41 Spent coffee grounds (2 kg; limiting reagent; LR) were stirred in ethyl acetate (10 L; 5 vol) in a 20 L glass jacketed reactor at ambient temperature and atmospheric pressure for 1 hour. The coffee grounds were filtered through a sintered funnel (frit 3). The reactor and cake were washed with ethyl acetate (2 L; 1 vol). The cake was washed with further ethyl acetate (2 L; 1 vol). The solvent was removed by distillation from the reactor at atmospheric pressure and elevated temperature. Final concentration was completed in vacuum on a rotary evaporator to give a brown natural Arabica coffee oil (235 g; 11.8%).

[0095] Example 42 Spent coffee grounds (2 kg; limiting reagent; LR) were stirred in ethyl acetate (10 L; 5 vol) in a 20 L glass jacketed reactor at ambient temperature and atmospheric pressure for 2 hours. The coffee grounds were filtered through a sintered funnel (frit 3). The reactor and cake were washed with ethyl acetate (2 L; 1 vol). The cake was washed with further ethyl acetate (2 L; 1 vol). The solvent was removed by distillation from the reactor at atmospheric pressure and elevated temperature. Final concentration was completed in vacuum on a rotary evaporator to give a brown output Arabica coffee oil (226 g; 12.7%).

[0096] <Content of undesirable ingredients (e.g., melanoidin)> Spent coffee grounds from the same batch were extracted with ethyl acetate at ambient temperature and pressure for 1 hour and at reflux for 1 hour. The resulting coffee oil was used in the following experiments.

[0097] Example 51 Arabica coffee oil (16.34 g; LR), obtained by extraction with ethyl acetate at ambient temperature and atmospheric pressure for 1 hour, was dissolved in heptane (65 mL; 4 vol). The solution of coffee oil in heptane was added to a 500 mL flask containing activated charcoal (12.35 g; 75% by weight). The flask was rinsed with heptane (16 mL; 1 vol) and the washings were added to the flask containing the charcoal, heptane and oil. The slurry was stirred at ambient temperature and atmospheric pressure for 3 hours. The slurry was filtered. The flask and cake were washed twice with heptane (16 mL; 1 vol). The cake only was washed two more times with heptane (16 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo to give a yellow decolorized and deodorized Arabica coffee oil (13.99 g; 85.6%). The mass loss during decolorization of ambient extracted output Arabica coffee oil is 2.35 g (14.4%).

[0098] Example 52 Arabica coffee oil (17.88 g; LR), obtained by extraction with ethyl acetate under reflux for 1 h, was dissolved in heptane (71 mL; 4 vol). The solution of coffee oil in heptane was added to a 500 mL flask containing activated charcoal (13.43 g; 75% by weight). The flask was rinsed with heptane (18 mL; 1 vol) and the washings were added to the flask containing the charcoal, heptane, and oil. The slurry was stirred at ambient temperature and pressure for 3 h. The slurry was filtered. The flask and cake were washed twice with heptane (18 mL; 1 vol). The cake only was washed two more times with heptane (18 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo to give a yellow bleached and deodorized arabica coffee oil (14.64 g; 81.9%). The mass loss during bleaching of the ambient extracted output arabica coffee oil is 3.24 g (18.1%).

[0099] The results show that coffee oil obtained by extraction with ethyl acetate under reflux has a higher melanoidin content than coffee oil obtained by extraction with ethyl acetate at ambient temperature and atmospheric pressure.

[0100] <Extraction using various esters> The following examples were carried out using spent coffee grounds from the same batch.

[0101] Example 61 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and methyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with methyl acetate (10 mL; 1 vol). The cake only was washed with further methyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The product isolated was a dark orange oil (1.37 g; 13.6% yield).

[0102] Example 62 To a 100 mL round bottom flask was added spent coffee grounds (10.06 g; LR) and methyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with methyl acetate (10 mL; 1 vol). The cake only was washed with further methyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange oil (1.02 g; 10.1% yield).

[0103] Comparative Example 2 To a 100mL round bottom flask was added spent coffee grounds (10.04g; LR) and methyl acetate (50mL; 5vol). The slurry was stirred under reflux for 1 hour. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with methyl acetate (10mL; 1vol). The cake only was washed with further methyl acetate (10mL; 1vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The product isolated was a brown oil with a dark brown / black solid precipitate present (1.05g; 10.5% yield).

[0104] Example 63 To a 100 mL round bottom flask was added spent coffee grounds (10.02 g; LR) and n-propyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-propyl acetate (10 mL; 1 vol). The cake only was washed with further n-propyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The isolated product was a dark orange oil (1.23 g; 12.3% yield).

[0105] Example 64 To a 100 mL round bottom flask was added spent coffee grounds (10.04 g; LR) and n-propyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-propyl acetate (10 mL; 1 vol). The cake only was washed with further n-propyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange oil (1.03 g; 10.3% yield).

[0106] Comparative Example 3 To a 100 mL round bottom flask was added spent coffee grounds (10.08 g; LR) and n-propyl acetate (50 mL; 5 vol). The slurry was stirred at reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-propyl acetate (10 mL; 1 vol). The cake only was washed with further n-propyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a brown oil with a brown solid precipitate present (1.23 g; 12.2% yield).

[0107] Example 65 To a 100 mL round bottom flask was added spent coffee grounds (10.08 g; LR) and isopropyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isopropyl acetate (10 mL; 1 vol). The cake only was washed with further isopropyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The isolated product was a dark orange oil (1.29 g; 12.8% yield).

[0108] Example 66 To a 100 mL round bottom flask was added spent coffee grounds (10.05 g; LR) and isopropyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isopropyl acetate (10 mL; 1 vol). The cake only was washed with further isopropyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange oil (1.11 g; 11.0% yield).

[0109] Comparative Example 4 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and isopropyl acetate (50 mL; 5 vol). The slurry was stirred under reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isopropyl acetate (10 mL; 1 vol). The cake only was washed with further isopropyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a brown oil with a dark brown / black solid precipitate present (1.22 g; 12.1% yield).

[0110] Example 67 To a 100 mL round bottom flask was added spent coffee grounds (10.05 g; LR) and n-butyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-butyl acetate (10 mL; 1 vol). The cake only was washed with further n-butyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange-brown oil (1.25 g; 12.4% yield).

[0111] Example 68 To a 100 mL round bottom flask was added spent coffee grounds (10.00 g; LR) and n-butyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-butyl acetate (10 ml; 1 vol). The cake only was washed with further n-butyl acetate (10 ml; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The isolated product was a dark orange oil (1.02 g; 10.2% yield).

[0112] Comparative Example 5 To a 100 mL round bottom flask was added spent coffee grounds (10.04 g; LR) and n-butyl acetate (50 mL; 5 vol). The slurry was stirred at reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with n-butyl acetate (10 mL; 1 vol). The cake only was washed with further n-butyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a brown oil with a solid precipitate present (1.25 g; 12.5% ​​yield).

[0113] Example 69 To a 100 mL round bottom flask was added spent coffee grounds (10.04 g; LR) and t-butyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with t-butyl acetate (10 mL; 1 vol). The cake only was washed with further t-butyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The isolated product was a dark orange oil (1.14 g; 11.4% yield).

[0114] Example 70 To a 100 mL round bottom flask was added spent coffee grounds (10.03 g; LR) and t-butyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with t-butyl acetate (10 mL; 1 vol). The cake only was washed with further t-butyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange oil (1.00 g; 10.0% yield).

[0115] Comparative Example 6 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and t-butyl acetate (50 mL; 5 vol). The slurry was stirred at reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with t-butyl acetate (10 mL; 1 vol). The cake only was washed with further t-butyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a brown oil with a brown-black precipitate (1.17 g; 11.6% yield).

[0116] Example 71 To a 100 mL round bottom flask was added spent coffee grounds (10.06 g; LR) and benzyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with benzyl acetate (10 mL; 1 vol). The cake only was washed with further benzyl acetate (10 mL; 1 vol). Due to the low volatility of the solvent the product could not be isolated but the resulting solution was analysed for appearance. The resulting solution was a clear solution with a light brown-yellow colour.

[0117] Example 72 To a 100 mL round bottom flask was added spent coffee grounds (10.05 g; LR) and benzyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 hour. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with benzyl acetate (10 mL; 1 vol). The cake only was washed with further benzyl acetate (10 mL; 1 vol). Due to the low volatility of the solvent the product could not be isolated but the resulting solution was analysed for appearance. The resulting solution was a clear solution with a light brown-yellow colour.

[0118] Comparative Example 7 To a 100 mL round bottom flask was added spent coffee grounds (10.08 g; LR) and benzyl acetate (50 mL; 5 vol). The slurry was stirred under reflux for 1 hour. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with benzyl acetate (10 mL; 1 vol). The cake only was washed with further benzyl acetate (10 mL; 1 vol). Due to the low volatility of the solvent it was not possible to isolate the product but the resulting solution was analysed for appearance. The resulting solution was a clear solution with a dark brown colour.

[0119] Example 73 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50°C. The isolated product was a dark orange-brown oil (1.19 g; 11.8% yield).

[0120] Example 74 To a 100 mL round bottom flask was added spent coffee grounds (10.05 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange-brown oil (1.04 g; 10.3% yield).

[0121] Comparative Example 8 To a 100 mL round bottom flask was added spent coffee grounds (10.09 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a dark brown oil with a solid precipitate present (1.13 g; 11.2% yield).

[0122] Example 75 To a 100 mL round bottom flask was added spent coffee grounds (10.01 g; LR) and ethyl phenylacetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl phenylacetate (10 mL; 1 vol). The cake only was washed with further ethyl phenylacetate (10 mL; 1 vol). Due to the low volatility of the solvent the product could not be isolated but the resulting solution was analysed for appearance. The resulting solution was a clear solution of light brown-yellow colour.

[0123] Example 76 To a 100 mL round bottom flask was added spent coffee grounds (10.03 g; LR) and ethyl phenylacetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 hour. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl phenylacetate (10 mL; 1 vol). The cake only was washed with further ethyl phenylacetate (10 mL; 1 vol). Due to the low volatility of the solvent it was not possible to isolate the product but the resulting solution was analysed for appearance. The resulting solution was a clear solution with a light brown-yellow colour.

[0124] Comparative Example 9 To a 100 mL round bottom flask was added spent coffee grounds (10.03 g; LR) and ethyl phenylacetate (50 mL; 5 vol). The slurry was stirred under reflux for 1 hour. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl phenylacetate (10 mL; 1 vol). The cake only was washed with further ethyl phenylacetate (10 mL; 1 vol). Due to the low volatility of the solvent the product could not be isolated but the resulting solution was analysed for appearance. The resulting solution was a clear solution with a dark brown colour.

[0125] Example 77 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and isoamyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isoamyl acetate (10 mL; 1 vol). The cake only was washed with further isoamyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 70-75 °C. Residual isoamyl acetate was removed from the product using azeotropic distillation with ethyl acetate during the final concentration of the oil. The isolated product was a dark orange-brown oil (1.37 g; 13.6% yield).

[0126] Example 78 To a 100 mL round bottom flask was added spent coffee grounds (10.08 g; LR) and isoamyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isoamyl acetate (10 mL; 1 vol). The cake only was washed with further isoamyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 70-75 °C. Residual isoamyl acetate was removed from the product using azeotropic distillation with ethyl acetate during the final concentration of the oil. The isolated product was a dark orange-brown oil (1.32 g; 13.1% yield).

[0127] Comparative Example 10 To a 100 mL round bottom flask was added spent coffee grounds (10.09 g; LR) and isoamyl acetate (50 mL; 5 vol). The slurry was stirred under reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with isoamyl acetate (10 mL; 1 vol). The cake only was washed with further isoamyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 70-75 °C. Residual isoamyl acetate was removed from the product using azeotropic distillation with ethyl acetate during the final concentration of the oil. The isolated product was a brown oil with a dark brown / black solid precipitate present (1.32 g; 13.1% yield).

[0128] Example 79 To a 100 mL round bottom flask was added spent coffee grounds (10.06 g; LR) and ethyl propionate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl propionate (10 mL; 1 vol). The cake only was washed with further ethyl propionate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60°C. The isolated product was a dark orange-brown oil (1.25 g; 12.4% yield).

[0129] Example 80 To a 100 mL round bottom flask was added spent coffee grounds (10.01 g; LR) and ethyl propionate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl propionate (10 mL; 1 vol). The cake only was washed with further ethyl propionate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60 °C. The product isolated was a dark orange-brown oil (1.04 g; 10.4% yield).

[0130] Comparative Example 11 To a 100 mL round bottom flask was added spent coffee grounds (10.04 g; LR) and ethyl propionate (50 mL; 5 vol). The slurry was stirred under reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl propionate (10 mL; 1 vol). The cake only was washed with further ethyl propionate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60 °C. The product isolated was a brown oil with a dark brown / black solid precipitate present (1.26 g; 12.5% ​​yield).

[0131] Example 81 To a 100 mL round bottom flask was added spent coffee grounds (10.01 g; LR) and ethyl butyrate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl butyrate (10 mL; 1 vol). The cake only was washed with a further amount of ethyl butyrate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60°C. The isolated product was a dark orange-brown oil (1.25 g; 12.5% ​​yield).

[0132] Example 82 To a 100 mL round bottom flask was added spent coffee grounds (10.02 g; LR) and ethyl butyrate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl butyrate (10 mL; 1 vol). The cake only was washed with a further amount of ethyl butyrate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60°C. The isolated product was a dark orange-brown oil (1.15 g; 11.5% yield).

[0133] Comparative Example 12 To a 100 mL round bottom flask was added spent coffee grounds (10.07 g; LR) and ethyl butyrate (50 mL; 5 vol). The slurry was stirred under reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl butyrate (10 mL; 1 vol). The cake only was washed with a further amount of ethyl butyrate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 55-60 °C. The product isolated was a brown oil with a dark brown / black solid precipitate present (1.45 g; 14.4% yield).

[0134] The results of Examples 61-82 showed that extraction at ambient temperature and atmospheric pressure has similar efficiency to reflux extraction, especially when the process is carried out for at least 16 hours. Moreover, the oil obtained by extraction at ambient temperature and atmospheric pressure has improved sensory properties compared to the oil obtained by extraction at reflux.

[0135] <Effect of extraction temperature> Spent coffee grounds from the same batch as experiments 61-73 were used for the following experiments.

[0136] Example 91 To a 100 mL round bottom flask was added ethyl acetate (50 mL; 5 vol). The solvent was heated to 50 ± 2.5 °C. To the hot solvent was added spent coffee grounds (10.05 g; LR). The slurry was stirred at 50 ± 2.5 °C for 1 hour. The slurry was cooled to ambient temperature (22.8 °C). The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a dark orange-brown oil with no solids present (1.10 g; 10.9% yield).

[0137] Increasing the extraction temperature from ambient to 50° C. showed only a slight improvement in terms of yield compared to ambient temperature. Thus, increasing the temperature does not have a significant effect on yield as expected.

[0138] <Extraction of unused roasted coffee powder> Example 101 To a 100 mL round bottom flask was added virgin roasted coffee grounds (10.01 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 16 hours. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a brown oil with a brown-black precipitate (1.54 g; 15.4% yield) present.

[0139] Example 102 To a 100 mL round bottom flask was added virgin roasted coffee grounds (10.08 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at ambient temperature and pressure for 1 h. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The product isolated was a brown oil with a black-brown precipitate present (1.32 g; 13.1% yield).

[0140] Example 103 To a 100 mL round bottom flask was added virgin roasted coffee grounds (10.04 g; LR) and ethyl acetate (50 mL; 5 vol). The slurry was stirred at reflux for 1 h. The contents were cooled to ambient temperature. The slurry was filtered through a sintered funnel (frit 3). The flask and cake were washed with ethyl acetate (10 mL; 1 vol). The cake only was washed with further ethyl acetate (10 mL; 1 vol). The filtrate and washings were combined and concentrated in vacuo at 45-50 °C. The isolated product was a brown oil with a black-brown precipitate present (1.53 g; 15.2% yield).

[0141] <Qualitative analysis> An example of the analytical method is described below in relation to Example 22. However, the same method can be used to characterize any coffee oil composition according to the present invention.

[0142] <Acid value> Acid value is USP 43-NF38 p.6676 <401> Identified as described in Fixed Fats and Oils.

[0143] As data was collected for each example, the data was trended and an acceptable range was obtained for each value. For a data set, the number of data points and the value of each were known. From this, an average value was calculated according to Equation 2:

number

[0144] To obtain the upper and lower limits of the acceptable range, the upper control limit (UCL) and the lower control limit (LCL) were calculated. Each formula is explained below together with the formula used to calculate the standard deviation (Formula 3):

number

[0145] The following data shown in Table 3 were obtained for Example 22:

Table 3

[0146]

Number

[0147] The numerical values are rounded to include the calculated UCL and LCL. For this dataset, the range was rounded to the nearest mg. The acid value of the extracted coffee oil was 4 mg / g or less.

[0148] <Density> The mass was recorded using an OHAUS Navigator™ NV422 balance. The volume was measured using an Eppendorf single-channel pipette (1 - 10 mL).

[0149] 1 mL of coffee oil from Example 22 was accurately measured and weighed (0.97 g). The density was calculated using Equation 4:

Number

[0150] Calculation example of coffee oil using Equation 4:

Number

[0151] <SAP value> SAP value is USP 43-NF38 p.6676 <401> Fixed Fats and Oils were identified as described in. Potassium hydroxide pellets (≥85%) were obtained from Scientific Laboratory Supplies. Methanol (99%) was obtained from Alfa Acer. Phenolphthalein solution (Indicator; Reag. Ph.Eur.; 1% in ethanol) and 0.5N hydrochloric acid (Volumetric; Reag. Ph.Eur., 0.5M; 0.5N) were obtained from Honeywell Fluka. Masses were recorded on an OHAUS Navigator™ NV422 balance. Glass volumeters used were class A analytical grade. Smaller volumes were measured using Eppendorf single channel pipettes (1-10 mL).

[0152] The procedure was as follows: 1.49 g of coffee oil from Example 22 was weighed into a 500 mL round bottom flask. To this, 25 mL of 0.5 N alcoholic potassium hydroxide was added. The contents were refluxed for 90 minutes. The contents were cooled. To this, 1 mL of phenolphthalein TS was added. The solution was titrated with 0.25 N hydrochloric acid VS until the pink color was removed and the initial color was observed. The volume of 0.25 N hydrochloric acid VS required was 21.8 mL. A blank titration was performed with 25 mL of 0.5 N potassium hydroxide solution containing 1 mL of phenolphthalein. The blank titer was 45.0 mL.

[0153] The saponification number was calculated according to Equation 5:

number

[0154] For Example 22, the SAP value according to Equation 5 is:

number

[0155] <Free fatty acid value> Free fatty acid values ​​are USP 43-NF38 p.6676 <401> Determined as described in Fixed Fats and Oils. Methanol (HPLC grade, 99.9%) and 1N potassium hydroxide solution were obtained from Fisher, and diethyl ether (purity, >99.5%) was obtained from Honeywell. The glass volumeters used were Class A analytical grade. Masses were recorded on an OHAUS Navigator™ NV422 balance. The procedure is as follows: 1.02 g of coffee oil from Example 22 was dissolved in 50 mL of a 1:1 mixture of diethyl ether and methanol. This mixture was titrated with 0.01 N potassium hydroxide solution for at least 30 seconds until a precipitate formed (titer = 1.8 mL potassium hydroxide, 0.01 N).

[0156] Using the titer of 0.01N potassium hydroxide, the free fatty acid (FFA) value of a sample can be determined using Equation 6:

number

[0157] The following calculations are applicable to Example 22: FFA = (56.11 × 1.8) × (0.01 / 1.02) FFA=0.99 mg / g.

[0158] <Iodine value> Iodine value is USP 43-NF38 p.6676 <401> Fixed Fats and Oils are identified as described. Iodine monobromide (98%), potassium iodide (99%) and starch indicator solution (1%, Acculute Standard Volumetric Solution) were obtained from Alfa Acer, acetic acid, glacial acetic acid (99%) were obtained from Fisher and 0.1N sodium thiosulfate solution was obtained from Honeywell. Glass volumeters used were Class A analytical grade. Smaller volumes were measured using Eppendorf single channel pipettes (1-10 mL). Mass was recorded on an OHAUS Navigator™ NV422 balance. The procedure was as follows: Iodobromide Test Solution (TS) - 2.03 g of iodobromide was dissolved in 100 mL of glacial acetic acid and stored in a light-proof glass container.Potassium Iodide Test Solution (TS) - 16.49 g of potassium iodide was dissolved in 100 mL of deionized water and stored in a light-proof glass container.

[0159] Sample Titration: 0.20 g of coffee oil from Example 22 was dissolved in 25 mL of dichloromethane. To this was added 25 mL of Iodobromide TS. The solution was allowed to stand for 30 minutes, protected from light, with mixing every 10 minutes. To this was added 30 mL of Potassium Iodide TS and 100 mL of deionized water. The solution was titrated with 0.1 N sodium thiosulfate solution until the iodine color faded, at which point 3 ml of starch indicator solution was added. The titration of 0.1 N sodium thiosulfate was continued until the iodine color in the aqueous phase was completely gone. The titer was recorded as 36.8 mL.

[0160] Blank Titration: 25 mL of dichloromethane was added to the vessel, to which was added 25 mL of Iodobromide TS. The solution was allowed to stand for 30 minutes, protected from light, with mixing every 10 minutes. To this was added 30 mL of Potassium Iodide TS and 100 mL of deionized water. The solution was titrated with 0.1 N Sodium Thiosulfate solution until the iodine color faded. At this point, 3 ml of Starch Indicator Solution was added. The titration of 0.1 N Sodium Thiosulfate was continued until the iodine color in the aqueous phase was completely gone. The titer was recorded as 46.4 mL.

[0161] Using the sample titer and the blank titer, the iodine number, which represents the degree of unsaturation in the oil, can be calculated using Equation 7:

number

[0162] The following calculations are applicable to Example 22: Iodine value = [126.90 x (46.4 - 36.8) x 0.1] / (10 x 0.2) Iodine value = 60.9 g I2 / 100 g.

[0163] <Tocopherol content> All UV-visible spectrophotometric measurements were performed on a Jenway 7205 spectrophotometer. α-Tocopherol (95%; synthetic) was obtained from ACROS Organics. Isopropanol was obtained from ReAgent. Masses were recorded on an OHAUS Navigator™ NV422 balance. Glass volumeters used were class A analytical grade. Smaller volumes were measured using Eppendorf single channel pipettes (1-10 mL).

[0164] Tocopherol standard solution: 0.10 g of α-tocopherol was weighed into a 100 mL volumetric flask. This was diluted to volume with isopropanol. The mixture was shaken until complete dissolution of α-tocopherol was observed. This solution (A-1000 μg / mL) was used to make 11 additional standard solutions ranging from 1 to 100 μg / mL (B-L).

[0165] Sample solution: 0.97 g of sample taken from Example 22 was weighed into a vial. To this, 10 mL of isopropanol was added. This solution (sample solution 1) was shaken until the sample was completely dissolved. To a 100 mL volumetric flask, 1 mL of sample solution 1 was added. This was diluted by volume with isopropanol and shaken until completely mixed (sample solution 2). To a 100 mL volumetric flask, 1 mL of sample solution 2 was added. This was diluted by volume with isopropanol and shaken until completely mixed (sample solution 3).

[0166] UV-Vis Analysis: Sample solutions A-L from Table 4 were analyzed by UV-Vis at 290 nm. A blank consisting of isopropanol only was also analyzed at 290 nm. A calibration curve was obtained from the standard solutions. Any values ​​in the range of 2.0-2.50 for absorbance were discarded as these saturated the detector. A best fit line was fitted to the graph and the tocopherol content in the samples was calculated using the equation: All sample solutions were analyzed by UV-Vis. The most centrally located value of the data points obtained from the standard solutions was used for the tocopherol calculation. Any obvious outliers to the best fit line for the standards were removed from the graph if at least eight data points remained on the graph. The equation from the best fit line is shown in Equation 8:

number

[0167] Therefore, the α-tocopherol concentration in a diluted sample measured by UV-Vis follows Equation 9:

number

[0168] The value of α-tocopherol / gram of coffee oil can be calculated from the concentration calculation above and the mass of coffee oil in the original sample.

[0169] The following calculations are applicable to Example 22: [Table 4]

[0170] Figure 2 shows the calibration curve obtained from the standard solutions of α-tocopherol. The equation obtained for the best fit line is:

number

[0171] The absorbance of sample solution 3 was 0.423. The amount of α-tocopherol in the sample can be calculated as follows:

number

[0172] <Peroxide value> All UV-visible spectrophotometric measurements were performed on a Jenway 7205 spectrophotometer. Hydrogen peroxide (30% in water) was obtained from Fisher, Pierce™ Quantitative Peroxide Assay: Lipid compatible formulations were obtained from Thermo Scientific.

[0173] Working Reagent Preparation - 100 μL of Reagent A (Pierce™ Quantitative Peroxide Assay: Lipid Compatible Formulation) was added to 10 mL of Reagent C (Pierce™ Quantitative Peroxide Assay: Lipid Compatible Formulation).

[0174] A 30% (9.8 M) stock solution of hydrogen peroxide was serially diluted to obtain seven standard solutions ranging from 10 to 100 µM.

[0175] 90 μL of each standard solution was added to 900 μL of working reagent, followed by the addition of 10 μL of methanol. After each solution was allowed to stand for 20 minutes, the absorbance of each solution was measured at 560 nm to prepare a calibration curve.

[0176] 90 μL of coffee oil from Example 22 was added to 900 μL of working reagent, followed by 10 μL of methanol. The solution was allowed to stand for 20 minutes, after which the absorbance was measured at 560 nm. The absorbance values ​​of the samples were compared to the standard curve to calculate the peroxide value of the coffee oil.

[0177] Sample solutions 1-7 were analyzed by UV-Vis at 560 nm. Blanks consisting of water and working reagent only were also analyzed at 560 nm. A calibration curve was obtained from the standard solutions. Any values ​​in the range of 2.0-2.50 for absorbance were discarded as these saturated the detector. A best fit line was fitted to the graph and the peroxide value of the samples was calculated using the equation: All sample solutions were analyzed by UV-Vis. The most centered value of the data points obtained from the standard solutions was used to calculate the peroxide value. The equation from the best fit line is as follows according to equation 10:

number

[0178] Therefore, the peroxide value of the sample measured by UV-Vis is calculated by Equation 11:

number

[0179] The mmol value of coffee oil can be generated from a concentration calculation.

[0180] Peroxide value is defined as the amount of peroxide oxygen per kilogram of fat or oil and is expressed in milliequivalents. (Note: 1 milliequivalent = 0.5 millimole; 1 mEq of O2 = 1 mmol / 2 = 0.5 mmol of O2, where 2 is the valence.

[0181] The following calculations are applicable to Example 22: [Table 5]

[0182] Figure 3 shows the calibration curve obtained from the data in Table 5 for the calculation of the peroxide value. The equation obtained for the best fit line is: y=0.0108x+-0.144

[0183] The absorbance of the coffee oil sample was 0.754 and the concentration of peroxide value was calculated as follows: X=(y+0.144) / 0.0108=(0.754+0.144) / 0.0108=83μM =(83 / 1000)×2×0.97=0.161mEqO2 / kg.

[0184] <Caffeine content> Caffeine content is determined by HPLC chromatography as described in USP29-NF24 Page 338.

[0185] Tetrahydrofuran (HPLC grade, 99.8%), acetonitrile (HPLC grade, 99.8%) and glacial acetic acid (99%) were supplied by Fisher Scientific. Caffeine (99.7%) and anhydrous sodium acetate (99%) were supplied by Alfa Acer. Theophylline (99+%) was supplied by Acros Organics.

[0186] The steps are as follows − In preparing the mobile phase, 1.64 g of anhydrous sodium acetate was dissolved in 2 L of deionized water. The solution was filtered through a 0.2 micron filter. 1910 mL of this solution was taken and transferred to another container. To this, 50 mL of acetonitrile and 40 mL of tetrahydrofuran were added. The solution was carefully mixed and the pH was adjusted to about 4.5 using glacial acetic acid.

[0187] For System Suitability Preparation Solution 1 - 0.10 g of theophylline was measured into a 100 mL volumetric flask. To this was added approximately 80 mL of mobile phase and the solution was heated to 45° C. until all solids were completely dissolved. The solution was diluted to volume with mobile phase and shaken to mix.

[0188] For System Suitability Prepared Solution 2 - Accurately measure 2 mL of System Suitability Solution 1 into a 100 mL volumetric flask. Dilute the solution to volume with mobile phase and shake to mix.

[0189] For Standard Preparation Solution 3 - 0.10 g of caffeine was accurately measured into a 100 mL volumetric flask and approximately 50 mL of mobile phase was added. The solution was shaken until the solids were completely dissolved. The solution was diluted to volume with mobile phase. The mixture was shaken to combine.

[0190] For Standard Preparation Solution 4 - 20 mL of Standard Solution 3 was measured into a 100 mL volumetric flask to which was added 20 mL of System Suitability Solution 2 and 20 mL of mobile phase. The mixture was shaken to combine and mobile phase was added to volume.

[0191] Sample preparation - 0.2 g of coffee oil from Example 22 was weighed and diluted with 10 mL of mobile phase. The solution was stirred overnight. The sample was passed through a 0.22 μm filter before injection.

[0192] HPLC assays were performed and analyzed by a high performance liquid chromatograph (HPLC; Agilent 1100) equipped with a diode array detector (G1315B diode array detector). 18 The column (Thermo, 4.6 mm x 150 mm) was used at 25 °C. The injection volume was 10 μL. Compounds were eluted with an isocratic mobile phase consisting of 10 mM sodium acetate buffer pH 4.5 / acetonitrile / tetrahydrofuran (955:25:20 v / v / v). The separated compounds were monitored at 275 nm and the flow rate was set at 1 mL / min.

[0193] Standard solution 4 and the samples were chromatographed and the peak responses were recorded. The relative retention times for caffeine and theophylline were 1.0 and 0.70, respectively, which conformed to the USP specifications for the caffeine assay as set forth in USP29-NF24, p.338.

[0194] The following calculations are applicable to Example 22: FIG. 4 shows the HPLC chromatogram of standard solution 4, which has two peak responses as shown in Table 6. [Table 6]

[0195] FIG. 5 shows the HPLC chromatogram of the coffee oil sample for determining caffeine content, with one peak response corresponding to caffeine as shown in Table 7: [Table 7]

[0196] As dictated by the United States Pharmacopeia monographs (USP29-NF24 Page 338), the relative retention times for caffeine and theophylline should be approximately 1.0 and 0.69, respectively. To calculate the relative retention times of peak X versus peak Y, Equation 12 is applied:

number

[0197] About this example: RRT(1)=3.337 / 4.616 RRT(1) = 0.72.

[0198] Using the peak response of caffeine in standard solution 4 and / or assay, determine the C8H in the assay sample. 10 The amount of N4O2 in mg can be calculated using Equation 13:

number

[0199] r u and r s are the peak responses of caffeine obtained from the sample preparation and the four standard preparations, respectively.

[0200] Calculation example: Mass=50×0.2×(151.026 / 727.476) Mass=2.08mg / 200mg Mass=1.04mg / 100mg.

[0201] <Fatty acid composition in coffee oil> The fatty acid composition of coffee oil is as per the United States Pharmacopoeia, USP 43-NF38 p.6676 <401> Identified by gas chromatography (GC) as described in Fixed Fats and Oils.

[0202] The following methods and calculations are applicable to Example 22.

[0203] Reagents: Potassium hydroxide pellets (≥85%) were obtained from Scientific Laboratory Supplies. Methanol (99%) was obtained from Alfa Acer. Methanolic boron trifluoride (12%; 1.5M) and n-heptane (HPLC grade; 99%) were obtained from ACROS Organics. Sodium sulfate (anhydrous; 99%) was obtained from Alfa Acer. Methyl linoleate (99%) was obtained from ACROS Organics. Fatty acid methyl ester mixture (USP reference standard; FAME standard mixture; 100 mg; 25 FAME's) was obtained from Scientific Laboratory supplies. The gas chromatography system used was a G1530A Agilent 6890 GC. The GC column was purchased from Agilent (DB-Wax; part number 122-7032; 30 m x 0.25 mm; 0.25 μm; 7 inches; fused silica). The GC method was based on Agilent Technologies; Column Selection for the Analysis of Fatty Acid Methyl Esters; Application; Food Analysis; Page 4-5; Method 1.

[0204] Standard solution: 100 mg of methyl linoleate was dissolved in 10 mL of n-heptane (10 mg / mL). A 1 mg / mL methyl linoleate solution was made by diluting 1 mL of the 10 mg / mL methyl linoleate solution with 9 mL of n-heptane. Both the reference standard mixture and the 1 mg / mL methyl linoleate standard used as a marker were analyzed by gas chromatography. Other standard solutions of methyl palmitate, methyl stearate, methyl oleate, methyl linolenate, methyl arachidate, and methyl behenate were similarly prepared and analyzed by gas chromatography to obtain retention time markers.

[0205] Sample digestion: A 0.1 g sample of coffee oil from Example 22 was weighed into a round bottom flask. To this, 2 mL of 20 g / L methanolic potassium hydroxide was added. The contents were refluxed for 30 minutes. To this, 2 mL of methanolic boron trifluoride solution was added through the condenser. The contents were refluxed for 30 minutes. To this, 4 mL of n-heptane was added through the condenser. The contents were refluxed for 5 minutes. The contents were cooled for 30-60 minutes. To the cooled mixture, 15 mL of saturated sodium chloride solution was added. The mixture was transferred to a separatory funnel. The aqueous phase was discarded. The organic phase was washed with 10 mL of deionized water. The aqueous phase was discarded. The organic phase was dried over anhydrous sodium sulfate. The dried organic phase was filtered through a cotton plugged pipette. The resulting solution was analyzed by gas chromatography. Details of the equipment and experimental conditions are provided in Table 8 below. [Table 8]

[0206] The peak areas of all fatty acid ester signals are integrated. The peak areas can then be used to calculate the peak area % of each signal. After all signals are integrated, any signals with a % peak area <0.05% are removed. Each signal is identified by comparing the retention time with the retention time observed in a standard fatty acid ester mixture. Equation 14 is used to calculate the peak area % as follows:

number

[0207] The results of this example are shown in Table 12.

[0208] According to this example, the following GC chromatograms and data were obtained: - The GC chromatogram of the blank sample is shown in Figure 6 and the corresponding data is shown in Table 9 below. -The GC chromatogram of the methyl linoleate marker is shown in Figure 7, and the corresponding data is shown in Table 10 below. - the GC chromatogram of the reference standard mixture is shown in Figure 8 and the corresponding data are shown in Table 11 below; and -The GC chromatogram of the coffee oil sample is shown in Figure 9, and the corresponding data and peak area calculations are shown in Table 12 below.

[0209] [Table 9]

[0210] [Table 10]

[0211] [Table 11-1] [Table 11-2]

[0212] [Table 12-1] [Table 12-2]

Claims

1. 1. A method for extracting coffee oil from a coffee-based feedstock using an extraction solvent, comprising: holding a mixture of the coffee-based feedstock and the extraction solvent under mechanical or magnetic agitation for at least 30 minutes, followed by separating a liquid phase comprising the extraction solvent; and removing the extraction solvent from the liquid phase to obtain coffee oil, wherein the extraction solvent is an ester solvent represented by formula (I): 【Chemical 1】 wherein R and R′ independently represent a substituted or unsubstituted aliphatic or aromatic group. A method characterized by:

2. 2. The method according to claim 1, characterized in that the method is carried out at a temperature of 15 to 25°C.

3. 3. The method according to claim 1 or 2, characterized in that the method is carried out for at least 30 minutes.

4. 10. The method of claim 1, wherein the method is carried out at atmospheric pressure.

5. 10. The method of claim 1, wherein the method is carried out in a standard oxygen-rich or inert atmosphere.

6. The method according to claim 1, wherein in formula (I), R is an aliphatic group having 1 to 12 carbon atoms or 1 to 6 carbon atoms.

7. The method according to claim 6, wherein in formula (I), R is a linear or branched C1 to C4 alkyl group.

8. 2. The method according to claim 1, wherein in formula (I), R' is a linear or branched alkyl group.

9. 9. The method of claim 8, wherein the compound having formula (I) is ethyl acetate.

10. 10. The method of claim 1, wherein the coffee-based feedstock is selected from roasted coffee beans and spent coffee grounds.

11. The coffee oil is prepared by the following steps: - dissolving the obtained coffee oil in a refining solvent, adding activated carbon and maintaining under mechanical or magnetic stirring for at least 3 hours to obtain a slurry; - filtering the resulting slurry to separate the liquid phase containing the coffee oil; - removing the refining solvent from the liquid phase to isolate refined Arabica coffee oil.

10. The method of claim 1, further comprising a purification process comprising:

12. 12. The method of claim 11, wherein the purification solvent is heptane.

13. 12. The method of claim 10 or 11, wherein the refining process further comprises filtering the resulting slurry to separate a liquid phase containing coffee oil, and removing the refining solvent to isolate the refined coffee oil.

14. Coffee oil comprising triglycerides, fatty acids, sterols, melanoidins and phospholipids, wherein the fatty acids and triglycerides have a composition of: Palmitic acid 21 to 87 peak area% Stearic acid 4-21% peak area% Oleic acid 4-15% peak area% Linoleic acid ≦50% peak area% Linolenic acid ≦2% peak area% Arachidic acid 1-8% peak area % Behenic acid ≦3% peak area% Coffee oil characterized by:

15. Acid value of less than -4 mg KOH / g oil Iodine value of -13 to 138 g / 100 g SAP values ​​between -132 and 192 Peroxide value of less than -5mEq oxygen / kg - Caffeine content not exceeding 1.5% by weight based on the total weight of the coffee oil - A tocopherol content of not more than 2% by weight based on the total weight of the coffee oil - Density of 0 to 1 g / mL Coffee oil according to claim 14, characterized in that it has

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