Process for producing liquid coffee extract products

Abstract

The present invention relates to a process for producing a liquid coffee extract product, the process comprising the steps of a) subjecting roast and ground coffee to an extraction process to produce a high aromatic coffee extract and a low aromatic coffee extract, and b) combining the low aromatic coffee extract and the high aromatic coffee extract to obtain a liquid coffee extract product, the method further comprising the step of increasing the pH of the low aromatic coffee extract to a pH not exceeding 5.5, the low aromatic coffee extract being maintained at a temperature below 110° C. prior to step b).The present invention also relates to a liquid coffee extract product comprising 4-O-caffeoyl-muco-γ-quinide in an amount of at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or at least 30 mg per kg dry matter of coffee product after the coffee extract product has been stored under chilled conditions for 6 months.

Description

[Technical field]

[0001] The present invention relates to a process for producing a liquid coffee extract product having improved storage stability at chilled and ambient temperatures. [Background technology]

[0002] Liquid coffee extract products, such as liquid coffee concentrates, are increasingly in demand for commercial and / or industrial purposes. For the production and sale of liquid coffee extract products, such as liquid coffee concentrates for use in coffee vending machines, it is desirable to provide liquid coffee with sufficient shelf life. To date, such liquid coffee extract products are mostly stored in frozen form, sometimes refrigerated. Non-refrigerated storage can reduce supply chain costs. However, most products sold for non-refrigerated storage still have an undesirably short shelf life.

[0003] Generally speaking, liquid coffee extract products (such as concentrates or extracts) become unstable over time and become increasingly acidic at room temperature. As known to those skilled in the art, a decrease in pH can lead to microbial action as well as chemical reactions, such as the slow hydrolysis of some compounds such as esters and lactones, the oxidation of carbonyl-containing compounds or even the Maillard reaction occurring between polysaccharides and proteins. It is common knowledge throughout the literature that a pH of 4.8 is considered the lower limit of taste acceptance. Above that pH level, the extracted coffee becomes undrinkable. To overcome microbial acidification, liquid coffee is often treated with UHT (Ultra High Temperature). A particularly suitable UHT treatment is 120° C. for a few seconds.

[0004] A reference on the shelf life of liquid coffee is EP 1374690. In this reference, the extracted coffee is subjected to acidity correction essentially immediately after preparation by adding a base or anionic resin to raise the pH above 5.5. The resulting extract is pasteurized. Pasteurization is discussed in this reference with holding times and temperatures that do not affect the organoleptic properties of the extracted coffee. Typical temperature ranges are 100°C to 140°C with holding times of less than one minute. Again, this method fails to produce a product of sufficient shelf life and quality.

[0005] Another reference on stabilization of liquid coffee is EP 1182936. This reference appears to describe the formation of acids during storage or to reduce the formation of acids. This may be done by addition of alkali or ion exchange. Usually the pH is raised above 9. Even this method fails to produce a product with sufficient shelf life and quality.

[0006] It is an object of the present invention to provide a process which achieves improved preservation of the liquid coffee brew product together with improved flavor and quality.

[0007] It is also an object of the present invention to provide a liquid coffee extract product that can be stored under chilled and / or ambient conditions without significant loss of flavor or quality.

[0008] It is also an object of embodiments of the present invention to overcome at least one problem in the prior art, whether or not it is explicitly disclosed herein. Summary of the Invention [Problem to be solved by the invention]

[0009] According to a first aspect of the present invention there is provided a process for producing a liquid coffee extract product, the process comprising: a) subjecting roast and ground coffee to an extraction process to produce a high aromatic coffee extract and a low aromatic coffee extract; b) combining the low aromatic coffee extract with the high aromatic coffee extract to obtain a liquid coffee extract product, There is provided a process for producing a liquid coffee extract product, wherein the method further comprises the step of increasing the pH of the low-aromatic coffee extract to a pH not exceeding 5.5, wherein the low-aromatic coffee extract is maintained at a temperature below 110°C prior to step b).

[0010] Surprisingly, it has been found that increasing the pH of liquid coffee extract products prevents deterioration due to release of bound acids during storage under chilled and ambient conditions. The increase in pH causes or reduces the formation of acids during storage. Advantageously, this allows the liquid coffee extract products to have a shelf life of more than six months without significantly affecting aroma.

[0011] Moreover, it has been surprisingly found that increasing the pH of the liquid coffee extract product beyond 5.5 prevents the aroma profile from becoming unbalanced. Without being bound by theory, it is believed that there is some relationship between the pH of the coffee and the distribution of aroma compounds between the gas phase (the headspace above the cup) and the liquid phase (in the extract). For example, the inventors have found that increasing the pH of the coffee extract product beyond 5.5 reduces the concentration of 2-furfurylthiol (roast note) in the headspace, making the coffee aroma appear flatter. Meanwhile, aroma compounds such as pyridine (fishy odor) show the opposite effect. In other words, it has been observed that increasing the pH beyond 5.5 increases the concentration of pyridine in the headspace, resulting in the perception of off-flavors.

[0012] Thus, the inventors have surprisingly found that increasing the pH to no more than 5.5 reduces the imbalance in the aroma profile and results in better sensory qualities of the resulting product.

[0013] It has also been surprisingly found that by maintaining the temperature below 110°C prior to step b), the quality of the liquid coffee extract product is improved and costs and energy requirements in the manufacturing process are reduced.

[0014] Surprisingly, the inventors have found that the low aroma coffee extract product does not need to be heat treated at temperatures above 110° C. to release the bound acids, since the pH is increased to no more than 5.5 in the pH increasing step, which is observed to improve the taste and quality of the liquid coffee concentrate.

[0015] The process may further comprise concentrating the reduced aroma coffee extract to produce a reduced aroma coffee extract concentrate.

[0016] The step of concentrating the reduced aromatic coffee extract may be carried out after step a) and before step b).

[0017] In this embodiment, step b) comprises combining the low aroma coffee extract concentrate with the high aroma coffee extract to produce a liquid coffee extract product.

[0018] A concentrate is distinguished from an extract by having been subjected to a substantial water removal process, such as evaporation of the water. A low-aroma coffee concentrate generally has a dry matter solids content of at least 4% by weight, preferably 4-75% by weight, more preferably 10-60% by weight. In some embodiments of the invention, a low-aroma coffee concentrate may have a dry matter solids content of 15-40% by weight. In other embodiments of the invention, a low-aroma coffee concentrate may have a dry matter solids content of 50-60% by weight.

[0019] The process of the present invention may further comprise the step of combining a portion of the low-aromatic coffee extract with the high-aromatic coffee extract to form a mixture, and the further step of adding the mixture to the remainder of the low-aromatic coffee extract.

[0020] In embodiments where the process includes concentrating a low-aroma coffee extract, the process may further include the steps of combining a portion of the low-aroma coffee extract concentrate with the high-aroma coffee extract to form a mixture, and the further step of adding the mixture to the remainder of the low-aroma coffee extract concentrate.

[0021] The inventors have surprisingly discovered that by combining at least a portion of a low-aroma coffee extract or a low-aroma coffee extract concentrate with a high-aroma coffee extract to form a mixture, it is possible to store the high-aroma extract for longer periods without adversely affecting its quality.

[0022] Typically, in existing processes, the high aromatic extract is combined with the low aromatic coffee extract or low aromatic coffee extract concentrate without mixing with the low aromatic coffee extract or low aromatic coffee extract concentrate. Therefore, if the low aromatic coffee extract or low aromatic coffee extract concentrate is subjected to further processing steps such as centrifugation and / or pH treatment and the high aromatic coffee extract is stored for a long period of time, the high aromatic coffee extract may develop the negative properties observed in the coffee extract or coffee concentrate when the high aromatic extract is combined again with the low aromatic coffee extract or low aromatic coffee extract concentrate.

[0023] Furthermore, forming a mixture allows the high aromatic extract to be recombined with the low aromatic coffee extract or low aromatic coffee extract concentrate without compromising the concentration of the low aromatic coffee extract or low aromatic coffee extract concentrate. For example, by forming a mixture, the low aromatic coffee extract or low aromatic coffee extract concentrate is minimally diluted when the mixture is returned, since the mixture already contains a portion of the low aromatic coffee extract or low aromatic coffee extract concentrate.

[0024] In step c) at least 1%, 2%, 3%, 4%, 5%, 6% or 7% by weight of the low-aroma coffee extract or low-aroma coffee extract concentrate is combined with the high-aroma coffee extract to form a mixture. In some embodiments, no more than 40%, 35%, 30%, 25%, 20%, 15% or 10% by weight of the low-aroma coffee extract or low-aroma coffee extract concentrate may be combined with the high-aroma coffee extract to form a mixture.

[0025] Preferably 2-40% by weight, more preferably 5-40% by weight, more preferably 5-25% by weight, more preferably 5-15% by weight, most preferably 10% by weight of the low aromatic coffee extract or low aromatic coffee extract concentrate is combined with the high aromatic coffee extract to form a mixture.

[0026] The mixture may have a ratio between the low-aromatic coffee extract or low-aromatic coffee extract concentrate and the high-aromatic coffee extract of at least 0.2:1, 0.3:1, 0.35:1, 0.4:1, or 0.5:1. In some embodiments, the ratio of the low-aromatic coffee extract or low-aromatic coffee extract concentrate to the high-aromatic coffee extract may be no more than 1:1, 0.9:1, 0.8:1, 0.7:1, or 0.6:1.

[0027] Preferably, the mixture has a ratio of low-aromatic coffee extract or low-aromatic coffee extract concentrate to high-aromatic coffee extract of 0.35:1 to 0.7:1, more preferably 0.4:1 to 0.65:1, more preferably 0.5:1 to 0.6:1, most preferably 0.55:1.

[0028] The above ratio may be the mass ratio between coffee solids in the low-aromatic coffee extract or low-aromatic coffee extract concentrate and the high-aromatic coffee extract.

[0029] The aromatic coffee extract may be stored before and / or after formation of the mixture.

[0030] Typically, combining the remaining low-aromatic coffee extract or low-aromatic coffee extract concentrate with the mixture of low-aromatic coffee extract or low-aromatic coffee extract concentrate and high-aromatic coffee extract takes place in the factory before any further processing steps and packaging.

[0031] In the factory, after a temporary, preferably cooled, storage, preferably below 10° C., the mixture may be added directly to the low-aroma coffee extract or low-aroma coffee extract concentrate without further processing. For addition to the low-aroma coffee extract or low-aroma coffee extract concentrate, the mixture is preferably stored and cooled for as short a time as possible, these steps limiting aroma loss and multiple decomposition reactions of the aroma as much as possible.

[0032] The step of increasing the pH may increase the pH to a pH not greater than 5.4, 5.2, 5.3, 5.2, 5.1, 5.0, 4.9, 4.8, or 4.7. In some embodiments, the step of increasing the pH may increase the pH to at least 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0.

[0033] The step of increasing the pH may increase the pH to 4.5 to 5.5, 4.6 to 5.5, 4.7 to 5.5, 4.8 to 5.5, 4.9 to 5.5, or 5.0 to 5.5.

[0034] The pH of the reduced aroma coffee extract and / or reduced aroma coffee extract concentrate may be increased by at least 0.1, 0.2, 0.3, 0.4, 0.5, or 0.6. In some embodiments, the pH of the coffee extract and / or coffee extract concentrate may be increased by no more than 0.8, 0.7, 0.6, or 0.5.

[0035] The pH of the low-aroma coffee extract and / or low-aroma coffee extract concentrate may be increased by 0.1 to 0.8, 0.1 to 0.7, 0.1 to 0.6, 0.1 to 0.5, or 0.1 to 0.4 units higher than the pH at the start of the increase.

[0036] This increase is relative to the pH at the start of the increase, i.e. if the pH at the start of the increase is 4, then as the pH increases it will still be acidic, for example 5. However, the starting pH of the coffee stream is preferably between 4.5 and 5.5, more preferably between 4.8 and 5.5.

[0037] In the step of increasing the pH, the titratable acidity of the low-aroma coffee extract and / or low-aroma coffee concentrate may be increased by no more than 250 mmol / kg, 225 mmol / kg, 200 mmol / kg, 175 mmol / kg, 150 mmol / kg, 140 mmol / kg, 130 mmol / kg, 120 mmol / kg, 110 mmol / kg, 105 mmol / kg, 100 mmol / kg, 95 mmol / kg, 90 mmol / kg, or 85 mmol / kg. In some embodiments, the titratable acidity of the low-aroma coffee extract and / or low-aroma coffee concentrate may be increased by at least 40 mmol / kg, 50 mmol / kg, 60 mmol / kg, 65 mmol / kg, 70 mmol / kg, 75 mmol / kg, 80 mmol / kg, or 85 mmol / kg.

[0038] The titratable acidity may be increased by 40-250 mmol / kg, 40-225 mmol / kg, 40-200 mmol / kg, 40-175 mmol / kg, 40-150 mmol / kg, 40-140 mmol / kg, 40-130 mmol / kg, 40-120 mmol / kg, 40-110 mmol / kg, 50-110 mmol / kg, 60-110 mmol / kg, preferably 70-110 mmol / kg.

[0039] "Titratable acidity" is used herein to refer to the total acid concentration of the low-aroma coffee extract and / or low-aroma coffee concentrate, measured in mmol / kg of dry coffee material.

[0040] Surprisingly, the inventors have found that a lower degree of deacidification prevents the imbalance of the aroma profile.

[0041] The pH may be increased using any suitable procedure.

[0042] In one embodiment of the present invention, alkali may be added to the low-aroma coffee extract and / or low-aroma coffee extract concentrate to increase the pH.

[0043] The alkali may be selected from the group consisting of sodium hydroxide, calcium hydroxide, potassium hydroxide and sodium bicarbonate.

[0044] Alternatively, the pH increasing step is carried out without the addition of alkali.

[0045] Advantageously, avoiding the addition of various extraneous substances ensures that the product after processing remains "coffee" according to some applicable food laws in many jurisdictions, where the addition of substances other than those resulting from the extraction would result in a product that is not permitted to be represented as coffee, it being understood that such a product may be perceived differently by the consumer.

[0046] Preferably, the step of increasing the pH is carried out using an ion exchange process.

[0047] Advantageously, the use of an ion exchange process means that no additives are added to the low-aroma coffee extract and / or low-aroma coffee extract concentrate.

[0048] In such embodiments, preferably the pH increasing step is carried out without the addition of alkali.

[0049] The ion exchange process may be carried out by the addition of ion exchange resins and / or adsorbents.

[0050] The adsorbents may be carbon-, polyacrylate-, or polystyrene-based. Examples of commercially available adsorbents include Purolite® MN200, Purolite® MN202, and Lewatit® AF5.

[0051] The ion exchange resin may be a strongly basic or a weakly basic anion exchange resin. Preferably, the ion exchange resin is a weakly basic anion exchange resin.

[0052] The ion exchange resin may be based on polyacrylate or polystyrene.

[0053] Preferably, the ion exchange resin may be based on polyacrylate.

[0054] The ion exchange resin may have one or more amine functional groups. The amine functional groups may be primary, tertiary and quaternary amine groups, as well as polyamine groups. Preferably, the amine functional groups are tertiary amines.

[0055] Examples of commercially available ion exchange resins are listed in the table below.

[0056] [Table 1] At least 50%, 60%, 70%, 80%, or 90% by weight of the low-aroma coffee extract and / or low-aroma coffee concentrate may be subjected to the pH increasing step, in some embodiments up to 98%, 95%, 90%, 85%, or 80% by weight of the low-aroma coffee extract and / or low-aroma coffee concentrate may be subjected to the pH increasing step.

[0057] Preferably 60 to 98% by weight, more preferably 70 to 98% by weight, most preferably 85 to 95% by weight of the low-aromatic coffee extract and / or low-aromatic coffee concentrate may be subjected to the pH increasing step.

[0058] The coffee selected for extraction in step a) can be any type of roasted coffee. Choosing roasted coffee is well known to those skilled in the art. For example, the starting material can be normal coffee bean raw material for some industrial extraction processes, the coffee raw material being roasted in the normal way. In principle, a mixture of several different types of coffee raw material is used for that purpose. The roasted coffee beans are ground, the degree of grinding generally seeking a compromise between leaving as large a surface as possible and having the lowest possible pressure drop across the extraction cell. The ground beans can have an average size of 2.0 millimeters.

[0059] In order to better preserve the coffee aroma, the pH increasing step of the present invention is carried out on a low-aroma coffee extract and / or a low-aroma coffee extract concentrate by a) subjecting roast and ground coffee to one or more extraction steps with water to obtain a coffee extract, and separating the coffee extract (i.e. subjecting the coffee extract to separation) either by fractional distillation during one or more extraction steps in a) or by aroma recovery after step a) to obtain a high-aroma coffee extract and a low-aroma coffee extract.

[0060] Those skilled in the art will understand that separation by fractional distillation results in fractional collection of the extract, and that other separation methods, or combinations such as fractional collection of the extract and aroma recovery, can be used. Examples of aroma recovery after step a) include steam stripping, supercritical CO2 extraction and pervaporation.

[0061] Preferably, the coffee extract is fractionated during the extraction step a). The particular coffee aroma present in the resulting highly aromatic coffee extract has a more natural coffee character compared to the coffee aroma recovered by steam stripping from the complete extract after step a). A highly aromatic coffee extract and a low aromatic coffee extract are obtained. As known to those skilled in the art, the highly aromatic coffee extract distinguishes itself from the low aromatic coffee extract by having a relatively large amount of volatile flavor compounds compared to the semi-volatile flavor compounds. Such compounds are known, for example, from Clarke RJ and Vitzthum OG, Coffee Recent Developments, 2001 (ISBN 0-632-05553-7), p. 71, table 3.3. From this table (table 3.3), it is clear that, on the one hand, propanal, methylpropanal and 2,3 butanedione are measurable volatile flavor compounds. On the other hand, pyrazine compounds and guaiacol compounds are semi-volatile flavor compounds.

[0062] Taking 2,3-butanedione as an example of a volatile coffee flavor compound and guaiacol, 4 ethyl guaiacol and 2-acetylpyrazine as examples of semi-volatile coffee flavor compounds, respectively, the weight:weight ratio of volatile to semi-volatile coffee flavor compounds can be used to characterize high aroma and low aroma coffee extracts.

[0063] The weight:weight ratio of 2,3-butanedione to guaiacol in the low-aroma coffee extract may not exceed 1:1, 0.9:1, 0.8:1, 0.7:1, 0.6:1, 0.5:1, 0.4:1, or not exceed 0.3:1.

[0064] The weight:weight ratio of 2,3-butanedione to guaiacol in the low-aroma coffee extract may be from 0.06:1 to 0.3:1, from 0.07:1 to 0.29:1, from 0.08:1 to 0.28:1, from 0.09:1 to 0.27:1, from 0.10:1 to 0.26:1, or from 0.11:1 to 0.25:1.

[0065] The weight:weight ratio of 2,3-butanedione to guaiacol in the aromatic extract may be at least 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1.

[0066] The weight:weight ratio of 2,3-butanedione to guaiacol in the highly aromatic extract may be from 2.10:1 to 12.90:1, from 2.20:1 to 12.80:1, from 2.30:1 to 12.70:1, from 2.40:1 to 12.60:1, or from 2.44:1 to 12.59:1.

[0067] The weight:weight ratio of 2,3-butanedione to guaiacol in the mixture of low-aroma coffee extract and high-aroma extract may be at least 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, or at least 15:1.

[0068] The weight:weight ratio of 2,3-butanedione to guaiacol in the mixture of low-aromatic coffee extract and high-aromatic extract may be from 2.50:1 to 18.90:1, from 2.60:1 to 18.80:1, from 2.70:1 to 18.70:1, from 2.75:1 to 18.60:1, or from 2.76:1 to 18.60:1.

[0069] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the low-aroma coffee extract may be not more than 2:1, 1.9:1, 1.8:1, 1.7:1, 1.6:1, 1.5:1, 1.4:1, 1.3:1, 1.2:1, 1.1:1, 1:1, 0.9:1, 0.8:1, 0.7:1, 0.6:1, 0.5:1, 0.4:1 or not more than 0.3:1.

[0070] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the low-aroma coffee extract may be from 0.20:1 to 1.70:1, from 0.25:1 to 1.65:1, from 0.30:1 to 1.60:1, from 0.35:1 to 1.55:1, or from 0.37:1 to 1.51:1.

[0071] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the highly aromatic coffee extract may be at least 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1.

[0072] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the highly aromatic coffee extract may be from 2.30:1 to 28.0:1, from 2.40:1 to 27.95:1, from 2.50:1 to 27.90:1, from 2.60:1 to 27.85:1, or from 2.62:1 to 27.83:1.

[0073] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the mixture of low aroma coffee extract and high aroma extract may be at least 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, 30:1, 31:1, 32:1, 33:1, 34:1, 35:1, 36:1, 37:1, 38:1, 39:1, or at least 40:1.

[0074] The weight:weight ratio of 2,3-butanedione to 4-ethylguaiacol in the mixture of low-aroma coffee extract and high-aroma extract may be from 2.70:1 to 43.50:1, 2.75:1 to 43.40:1, 2.80:1 to 43.30:1, 2.85:1 to 43.20:1, 2.90:1 to 43.10:1, 2.95:1 to 43.05:1, or 2.97:1 to 43.04:1.

[0075] The weight:weight ratio of 2,3-butanedione to 2-acetylpyrazine in the low-aroma coffee extract may not exceed 1:1, 0.9:1, 0.8:1, 0.7:1, 0.6:1, 0.5:1, 0.4:1, or not exceed 0.3:1.

[0076] The weight:weight ratio of 2,3-butanedione to 2-acetylpyrazine in the low-aroma coffee may be from 0.1:1 to 0.7:1, from 0.15:1 to 0.65:1, from 0.20:1 to 0.60:1, or from 0.25:1 to 0.60:1.

[0077] The weight:weight ratio of 2,3-butanedione to 2-acetylpyrazine in the enhanced aromatic coffee extract may be at least 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, or at least 28:1.

[0078] The weight:weight ratio of 2,3-butanedione to 2-acetylpyrazine in the highly aromatic coffee extract may be 10:1-30:1, 11:1-30:1, 12:1-30:1, 12.1:1-29.9:1, 12.2:1-29.8:1, 12.3:1-29.7:1.

[0079] The weight:weight ratio of 2,3-butanedione to 2-acetylpyrazine in the mixture of low-aroma coffee extract and high-aroma extract may be from 17.00:1 to 35.70:1, 17.05:1 to 35.65:1, 17.10:1 to 35.60:1, 17.15:1 to 35.55:1, 17.20:1 to 35.50:1, 17.25:1 to 35.45:1, or 17.27:1 to 35.45:1.

[0080] The extraction process for producing the high-aromatic and low-aromatic coffee extracts may be any suitable method known to those skilled in the art. Multiple extraction processes for producing the high-aromatic and low-aromatic coffee extracts are well known in the coffee production field. The process may further include one or more pasteurization steps to reduce microbial growth in the liquid coffee extract product.

[0081] The pasteurization step may include a heat treatment.

[0082] The heat treatment may be carried out at a temperature of 60° C. to 120° C. and a holding time of 1 to 100 seconds. The heat treatment may be carried out at a temperature of 60° C. to 95° C. and a holding time of 20 to 70 seconds. The heat treatment may be carried out at a temperature of 100 to 120° C. and a holding time of 1 to 5 seconds.

[0083] The process may further comprise the step of chilling the liquid coffee extract product to a temperature below 6° C. Preferably, the step of chilling the liquid coffee concentrate reduces the temperature of the concentrate to between 4° C. and below 6° C.

[0084] Chilling the liquid coffee extract product may be carried out by any suitable refrigeration method known in the art.

[0085] Surprisingly, it has been observed that the liquid coffee extract product produced by the process of the present invention may be stored as a chilled product without negative quality effects. In this way, the process of the present invention is capable of providing a chilled liquid coffee extract product that may be stored for a period of time that is substantially indistinguishable when compared to existing frozen liquid coffee extract products stored for the same period. Advantageously, this means that the liquid coffee extract product produced by the process of the present invention is suitable for use in a chilled supply chain, thereby improving customer convenience.

[0086] The process may further include the addition of a conventional liquid or multiple dry filler components that may also be added. One filler component may be used to neutralize to some extent the pronounced flavor characteristics of the first primary extract. The filler is preferably a high yield coffee product. The filler may be added to the low aromatic coffee extract and / or low aromatic coffee extract concentrate before or after the pH increasing step.

[0087] According to a second aspect of the present invention there is provided a liquid coffee extract product having a pH not exceeding 5.5, as obtained by the process according to the first aspect of the present invention.

[0088] The liquid coffee extract product may be a liquid coffee concentrate.

[0089] Surprisingly, the inventors have found that the liquid coffee extract product as obtained by the process of the present invention has an improved shelf life and can be stored at ambient temperature (generally between 5°C and 25°C, preferably indicating a temperature not requiring refrigeration) for at least 6 months without spoilage.

[0090] The inventors have also discovered that the liquid coffee extract product as obtained by the process of the present invention has an improved shelf life and can be stored at refrigerated temperatures (generally referring to a temperature between 4°C and 6°C) for at least six months without spoilage.

[0091] The liquid coffee extract product has a shelf life of at least 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 months depending on ambient conditions.

[0092] The liquid coffee extract product has a shelf life of at least 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 months depending on the refrigerated conditions.

[0093] "Shelf life" refers to the period during which a liquid coffee extract product may be stored without significant adverse effects on the sensory profile. More specifically, the term "shelf life" may refer to the period during which a liquid coffee extract product may be stored without substantial oxidation.

[0094] The liquid coffee extract product may contain 4-O-caffeoyl-muco-γ-quinide.

[0095] In such embodiments, the coffee extract product may contain 4-O-caffeoyl-muco-γ-quinide in an amount of at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 6 months.

[0096] Chilled conditions means storage at a temperature of 2 to 8°C.

[0097] The coffee extract product may contain 4-O-caffeoyl-muco-γ-quinide in an amount of 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, or 30-68 mg per kg dry matter of the coffee product after storage under chilled conditions for 6 months.

[0098] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 9 months.

[0099] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, 30-68, 30-67, 30-66, 30-65, 30-64, 30-63, 30-62, 30-61, 30-60, 30-59, 30-58, 30-57, 30-56, 30-55, 30-54, 30-53, 30-52, or 30-51 mg per kg dry matter of the coffee product after storage for 9 months under chilled conditions.

[0100] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 12 months.

[0101] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, 30-68, 30-67, 30-66, 30-65, 30-64, 30-63, 30-62, 30-61, 30-60, 30-59, 30-58, 30-57, 30-56, 30-55, 30-54, 30-53, or 30-52 mg per kg dry matter of the coffee product after storage for 12 months under chilled conditions.

[0102] Surprisingly, the inventors have found that coffee products as obtained by the process of the present invention have much higher levels of 4-O-caffeoyl-muco-γ-quinide during storage. The inventors have found that the higher levels of 4-O-caffeoyl-muco-γ-quinide act as a bitter component, which preserves the required bitterness of the coffee product throughout storage and contributes to improving the shelf life of the coffee product.

[0103] The liquid coffee extract product may contain from 6% to 80% by weight of coffee solids (ie dry matter), preferably from 10% to 65%, more preferably from 15% to 50%.

[0104] The liquid coffee extract product may be suitable for storage at ambient conditions. In such embodiments, the liquid coffee extract product may be stored at a temperature between 5°C and 25°C.

[0105] In such embodiments, the liquid coffee extract product of the present invention may be stored at ambient conditions without a significant reduction in the sensory profile of the liquid coffee extract product.

[0106] The liquid coffee extract product may be suitable for storage under chilled conditions. In such an embodiment, the liquid coffee extract product may be stored at a temperature between 2°C and 8°C, preferably between 4°C and 6°C.

[0107] In such embodiments, the liquid coffee extract product of the present invention may be stored under refrigerated conditions without a significant reduction in the sensory profile of the liquid coffee extract product.

[0108] The liquid coffee extract product may be packaged in any suitable packaging, for example, a pouch, bag, carton, or bottle.

[0109] According to a further aspect of the present invention there is provided a liquid coffee extract product comprising 4-O-caffeoyl-muco-γ-quinide, wherein the amount of 4-O-caffeoyl-muco-γ-quinide in the coffee product is at least 20 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 6 months.

[0110] Chilled conditions means storage at a temperature of 2 to 8°C.

[0111] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee product may be at least 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least 30 mg per kg dry matter of the coffee product after 6 months storage under refrigerated conditions.

[0112] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, or 30-68 mg per kg dry matter of the coffee product after six months of storage under chilled conditions.

[0113] In yet a further aspect of the present invention there is provided a liquid coffee extract product comprising 4-O-caffeoyl-muco-γ-quinide, wherein the amount of 4-O-caffeoyl-muco-γ-quinide in the coffee product is at least 20 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 9 months.

[0114] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be at least 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mg per kg dry matter of the coffee product after 9 months storage under refrigerated conditions.

[0115] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, 30-68, 30-67, 30-66, 30-65, 30-64, 30-63, 30-62, 30-61, 30-60, 30-59, 30-58, 30-57, 30-56, 30-55, 30-54, 30-53, 30-52, or 30-51 mg per kg dry matter of the coffee product after storage for 9 months under chilled conditions.

[0116] In yet a further aspect of the present invention there is provided a liquid coffee extract product comprising 4-O-caffeoyl-muco-γ-quinide, wherein the amount of 4-O-caffeoyl-muco-γ-quinide in the coffee product is at least 20 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 12 months.

[0117] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mg per kg dry matter of the coffee product after storage under refrigerated conditions for 12 months.

[0118] The amount of 4-O-caffeoyl-muco-γ-quinide in the coffee extract product may be 30-80, 30-79, 30-78, 30-77, 30-76, 30-75, 30-74, 30-73, 30-72, 30-71, 30-70, 30-69, 30-68, 30-67, 30-66, 30-65, 30-64, 30-63, 30-62, 30-61, 30-60, 30-59, 30-58, 30-57, 30-56, 30-55, 30-54, 30-53, or 30-52 mg per kg dry matter of the coffee product after storage for 12 months under chilled conditions.

[0119] The inventors have found that coffee products containing high levels of 4-O-caffeoyl-muco-γ-quinide exhibit improved taste and have improved shelf life after storage for 6, 9 or 12 months.

[0120] According to a further aspect of the present invention there is provided a process for producing a liquid coffee concentrate, the process comprising: a) subjecting roast and ground coffee to an extraction process to produce a high aromatic coffee extract and a low aromatic coffee extract; b) concentrating the low-aroma coffee extract to produce a low-aroma coffee extract concentrate; c) combining a portion of the low aroma coffee extract concentrate with the high aroma coffee extract to form a mixture; d) adding the mixture to the remainder of the low aroma coffee extract concentrate, There is provided a process wherein the method further comprises the step of increasing the pH of the low-aroma coffee extract and / or low-aroma coffee extract concentrate to a pH not exceeding 5.5.

[0121] The temperature of the low-aroma coffee extract and / or the low-aroma coffee extract concentrate and / or the liquid coffee concentrate may be maintained at a temperature below 110°C throughout the process steps a), b), c) and d).

[0122] Further aspects of the invention may incorporate, where appropriate or suitable, any of the features of the other aspects of the invention described herein. [Brief description of the drawings]

[0123] In order that the invention may be more clearly understood, one or more embodiments thereof will now be described, by way of example only, with reference to certain examples and drawings which follow. [Figure 1] FIG. 1 illustrates a process scheme of a preferred embodiment of the present invention. [Diagram 2] 1 is a chart comparing the concentration of 4-O-caffeoyl-muco-γ-quinide (4-CmQ) contained in a product of the present invention and an existing product. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0124] One of the preferred embodiments of the present invention is illustrated in Figure 1. Roasted coffee is extracted and separated into a high-aroma coffee extract and a low-aroma coffee extract. The low-aroma extract is then evaporated to obtain a low-aroma coffee extract concentrate. The low-aroma coffee extract concentrate is then pH-adjusted (by anion exchange). The low-aroma coffee extract concentrate is then combined with the high-aroma extract to obtain the liquid coffee concentrate of the present invention.

[0125] Reference Example 1: extraction From a single batch of roast and ground coffee consisting of 100% Robusta coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0126] evaporation Using a mechanical vapour recompression (MVR) or thermal vapour recompression (TVR) evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solid content of 58%.

[0127] process The low aromatic coffee extract concentrate was then diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0128] Fragrance level (addback) The high aroma coffee extract was recombined with the low aroma coffee extract concentrate to produce a liquid coffee concentrate.

[0129] final product The pH of the resulting liquid coffee concentrate was 5.01.

[0130] No detectable off flavour was detected in the liquid coffee concentrate.

[0131] During a 12 month shelf life at a storage temperature of -20°C, the pH of the liquid coffee concentrate was 4.93.

[0132] After 3, 6, 9 and 12 months, the liquid coffee concentrate was not perceived as acidified by a team of sensory experts. This sample was used as a comparative sensory standard for Examples 2-4.

[0133] Example 2 extraction From a single batch of roast and ground coffee consisting of 100% Robusta coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0134] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 2.44:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 2.62:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 22.59:1.

[0135] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.11:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 0.37:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.58:1.

[0136] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0137] Formation of the mixture About 10% by weight of the low aromatic coffee extract concentrate is combined with the high aromatic extract to form a mixture in a ratio of low aromatic coffee extract concentrate to high aromatic coffee extract of 0.55:1.

[0138] process The low aromatic coffee extract concentrate was diluted to a dry matter solids content of 33% and subjected to separation.

[0139] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.99-5.27 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 72 mmol / kg.

[0140] Fragrance level (addback) After the pH has been treated, the mixture formed by combining the low-aromatic coffee extract concentrate and the high-aromatic coffee extract is recombined with the pH treated low-aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0141] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0142] final product The pH of the resulting liquid coffee concentrate was 5.20.

[0143] No detectable off flavour was detected in the liquid coffee concentrate.

[0144] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.84.

[0145] After 3, 6, 9 and 12 months, the liquid coffee concentrate was not considered to have a significant sensory difference by a team of sensory experts when compared to the frozen liquid coffee concentrate described in Reference Example 1. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0146] Example 3 extraction From a single batch of roast and ground coffee consisting of 100% Robusta coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0147] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 2.44:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 2.62:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 22.59:1.

[0148] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.11:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 0.37:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.58:1.

[0149] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0150] Formation of the mixture About 10% by weight of the low aromatic coffee extract concentrate is combined with the high aromatic extract to form a mixture having a low aromatic coffee concentrate to high aromatic coffee extract ratio of 0.55:1.

[0151] The mixture had a weight:weight ratio of 2,3-butanedione:guiacol of 2.76:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 2.97:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 28.53:1.

[0152] process The low aromatic coffee extract concentrate was diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0153] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.99-5.38 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 94 mmol / kg.

[0154] Fragrance level (addback) After the pH has been treated, the mixture formed by combining the low-aromatic coffee extract concentrate and the high-aromatic coffee extract is recombined with the pH treated low-aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0155] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0156] final product The pH of the resulting liquid coffee concentrate was 5.22.

[0157] No detectable off flavour was detected in the liquid coffee concentrate.

[0158] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.86.

[0159] After 3, 6, 9 and 12 months, the liquid coffee concentrate was deemed by a team of sensory experts to have no significant sensory differences when compared to the frozen liquid coffee concentrate described in Reference Example 1. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0160] Example 4 extraction From a single batch of roast and ground coffee consisting of 100% Robusta coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0161] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 2.44:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 2.62:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 22.59:1.

[0162] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.11:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 0.37:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.58:1.

[0163] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0164] Formation of the mixture About 10% by weight of the low aromatic coffee extract concentrate is combined with the high aromatic extract to form a mixture having a low aromatic coffee concentrate to high aromatic coffee extract ratio of 0.55:1.

[0165] The mixture had a weight:weight ratio of 2,3-butanedione:guiacol of 2.76:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 2.97:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 28.53:1.

[0166] process The low aromatic coffee extract concentrate was diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0167] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.99-5.49 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 116 mmol / kg.

[0168] Fragrance level (addback) After the pH has been treated, the mixture formed by combining the low-aromatic coffee extract concentrate and the high-aromatic coffee extract is recombined with the pH treated low-aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0169] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0170] final product The pH of the resulting liquid coffee concentrate was 5.28.

[0171] No detectable off flavour was detected in the liquid coffee concentrate.

[0172] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.88.

[0173] After 3, 6, 9 and 12 months, the liquid coffee concentrate was deemed by a team of sensory experts to have no significant sensory differences when compared to the frozen liquid coffee concentrate described in Reference Example 1. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0174] Reference Example 5: extraction From a single batch of roast and ground coffee consisting of 30% Arabica coffee beans and 70% Robusta coffee beans, high and low aromatic coffee extracts are obtained by packed bed column extraction.

[0175] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0176] process The low aromatic coffee extract concentrate was then diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0177] Fragrance level (addback) The high aromatic coffee extract was recombined with the low aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0178] final product The pH of the resulting liquid coffee concentrate was 4.96.

[0179] No detectable off flavour was detected in the liquid coffee concentrate.

[0180] During a 12 month shelf life at a storage temperature of -20°C, the pH of the liquid coffee concentrate was 4.81.

[0181] After 3, 6, 9 and 12 months, the liquid coffee concentrate was not perceived as acidified by a team of sensory experts. This sample was used as a comparative sensory standard for Example 6.

[0182] Example 6 extraction From a single batch of roast and ground coffee consisting of 30% Arabica coffee beans and 70% Robusta coffee beans, high and low aromatic coffee extracts are obtained by packed bed column extraction.

[0183] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 8.37:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 11.69:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 29.70:1.

[0184] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.15:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 0.60:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.58:1.

[0185] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0186] process The low aromatic coffee extract concentrate was then diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0187] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.88-5.10 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 70 mmol / kg.

[0188] Fragrance level (addback) After the pH has been treated, the high aromatic coffee extract is recombined with the pH treated low aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0189] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0190] final product The pH of the resulting liquid coffee concentrate was 5.06.

[0191] No detectable off flavour was detected in the liquid coffee concentrate.

[0192] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.81.

[0193] After 3, 6, 9 and 12 months, the liquid coffee concentrate was deemed by a team of sensory experts to have no significant sensory differences when compared to the frozen liquid coffee concentrate described in Reference Example 5. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0194] Reference Example 7 extraction From a single batch of roast and ground coffee consisting of 100% Arabica coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0195] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0196] process The low aromatic coffee extract concentrate was then diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0197] Fragrance level (addback) The high aromatic coffee extract was recombined with the low aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0198] final product The pH of the resulting liquid coffee concentrate was 4.80.

[0199] No detectable off flavour was detected in the liquid coffee concentrate.

[0200] During a 12 month shelf life at a storage temperature of -20°C, the pH of the liquid coffee concentrate was 4.68.

[0201] After 3, 6, 9 and 12 months, the liquid coffee concentrate was not perceived as acidified by a team of sensory experts. This sample was used as a comparative sensory standard for Examples 8 and 9.

[0202] Example 8 extraction From a single batch of roast and ground coffee consisting of 100% Arabica coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0203] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 12.59:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 27.83:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 12.34:1.

[0204] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.25:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 1.51:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.27:1.

[0205] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0206] process The low aromatic coffee extract concentrate was then diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0207] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.80-4.98 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 65 mmol / kg.

[0208] Fragrance level (addback) After the pH has been treated, the high aromatic coffee extract is recombined with the pH treated low aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0209] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0210] final product The pH of the resulting liquid coffee concentrate was 4.90.

[0211] No detectable off flavour was detected in the liquid coffee concentrate.

[0212] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.68.

[0213] After 3, 6, 9 and 12 months, the liquid coffee concentrate was deemed by a team of sensory experts to have no significant sensory differences when compared to the frozen liquid coffee concentrate described in Reference Example 7. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0214] Example 9 extraction From a single batch of roast and ground coffee consisting of 100% Arabica coffee beans, a high aromatic coffee extract and a low aromatic coffee extract are obtained by packed bed column extraction.

[0215] The highly aromatic coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 12.59:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 27.83:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 12.34:1.

[0216] The low aroma coffee extract had a weight:weight ratio of 2,3-butanedione:guaiacol of 0.25:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 1.51:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 0.27:1.

[0217] evaporation Using an MVR or TVR evaporator, the low aromatic coffee extract is concentrated by evaporation to a dry matter solids content of 58%.

[0218] Formation of the mixture About 10% by weight of the low aromatic coffee extract concentrate is combined with the high aromatic extract to form a mixture having a ratio of low aromatic coffee concentrate to high aromatic coffee extract of 0.55:1.

[0219] The mixture had a weight:weight ratio of 2,3-butanedione:guiacol of 18.60:1, a weight:weight ratio of 2,3-butanedione:4-ethylguaiacol of 43.04:1, and a weight:weight ratio of 2,3-butanedione:2-acetylpyrazine of 17.27:1.

[0220] process The low aromatic coffee extract concentrate was diluted to a dry matter solids content of 33% and subjected to centrifugation.

[0221] The pH of the low-aromatic coffee extract concentrate was then adjusted to 4.68-4.83 by passing the resulting low-aromatic coffee extract concentrate through an anion column (Lewatit® XA 945). The anion column contained a polyacrylate-based ion exchange resin. The titratable acidity of the low-aromatic coffee extract concentrate increased by 68 mmol / kg.

[0222] Fragrance level (addback) After the pH had been treated, the mixture formed by combining the low-aromatic coffee extract concentrate and the high-aromatic coffee extract was recombined with the pH treated low-aromatic coffee extract concentrate to form a liquid coffee concentrate.

[0223] The liquid coffee concentrate was then heat treated at 77°C for a holding time of 21 seconds for the removal of lactic acid bacteria.

[0224] final product The pH of the resulting liquid coffee concentrate was 4.77.

[0225] No detectable off flavour was detected in the liquid coffee concentrate.

[0226] During a 12 month shelf life at a storage temperature of 4-6°C, the pH of the liquid coffee concentrate was 4.66.

[0227] After 3 and 6 months, the liquid coffee concentrate was deemed by a team of sensory experts to have no significant sensory differences when compared to the frozen liquid coffee concentrate described in Reference Example 7. Furthermore, the liquid coffee concentrate was not perceived as acidified by the team of sensory experts.

[0228] It can be seen from Examples 2-4, 6 and 8-9 that the liquid coffee concentrate produced by the process of the present invention, when tested by a team of sensory experts, may be stored under refrigerated conditions without any significant difference in the sensory profile of the coffee. It can thus be seen that the present process provides a liquid coffee concentrate that may be stored under refrigerated conditions for extended periods of time without significant sensory deterioration.

[0229] In the above examples, the weight:weight ratios of volatile and semi-volatile compounds in the high aromatic extract, low aromatic extract and mixtures of low aromatic coffee extract and high aromatic extract were determined as follows:

[0230] 5 g of liquid coffee concentrate and 50 μl of internal standard solution (containing 1-methylindole, 1-phenylethanol, 2-ethylbutanal, 4-heptanone, diethyl disulfide, ethyl maltol, ethyl vanillin, linalool-d3, propionic-2,2-d2 acid, pyrazine-d4) were suspended in 5 ml of saturated salt solution of sodium sulfate (anhydrous) granules. Aroma isolation was achieved by liquid-liquid extraction of this suspension with 5 ml of methyl tertiary-butyl ether (MTBE).

[0231] The resulting solution was equilibrated in an ultrasonic bath at 40° C. for 30 minutes and then centrifuged at 3000 rpm for 15 minutes at 6° C. The supernatant was transferred to an Eppendorf vial, some dry sodium sulfate (fine) was added, mixed, and the mixture was allowed to settle for 15 minutes. The mixture was centrifuged at 100,000 rpm for 10 minutes at 6° C.

[0232] The extracted aroma compounds of interest were separated by capillary gas chromatography (Stabilwax DA column: 30 m, ID 0.25 mm, and 0.5 μm film (Restek Technologies), injection temperature 40° C., slow temperature ramp of 15° C. / min to 250° C.) and detected by mass spectrometry MS-MS in SRM mode. Quantification was achieved using the relative response to an internal standard.

[0233] As shown in FIG. 2, the coffee product obtained via the process of the present invention has a much higher concentration of 4-O-caffeoyl-muco-γ-quinide (4-CmQ) during storage when compared to existing products.

[0234] To generate the data in Figure 2, 5-caffeoylquinic acid (5-CQA) was obtained from Sigma-Aldrich and a working solution of approximately 2500 mg / L was obtained by dilution in 20% MeOH / MilliQ water (MQW). This working solution was further diluted with MQW to obtain calibration solutions of 250 and 500 mg / L.

[0235] The concentrated coffee products described below are then obtained by diluting the 0.1% dry matter solution with water.

[0236] 4-CmQ in coffee products was then analyzed by HPLC-UV at 35° C. using a Phenyl-Hexyl Luna, 250 mm x 4.6 mm, column and detected at 324 nm.

[0237] Separation was performed using the eluents MeOH (eluent A) and ammonium formate buffer (0.25 mol / l, pH 3.5) (eluent B) with the program shown in the table below.

[0238] [Table 2] As shown in FIG. 2 , the medium roast blend (MR) consisting of 30% Arabica coffee beans and 70% Robusta coffee beans prepared according to Example 6, the strong roast blend (SR) consisting of 100% Robusta coffee beans prepared according to Example 3, and the delicate roast blend (DR) consisting of 100% Arabica coffee beans prepared via the process according to Example 8 all had dry matter coffee solids of at least 30 mg per kg, even after storage of the products for 12 months under refrigerated conditions.

[0239] In contrast, existing products such as Aromat Cafe Extra direct, Aromat Cafe Gold direct and Aromat Cafe Organic direct from CAFEA Gruppe, along with the smooth roast blend from Jacobs Douwe Egberts, had much lower levels of 4-O-caffeoyl-muco-γ-quinide over the entire shelf life, resulting in perceptible differences in the taste profile over time within each product.

[0240] As a result, the products of the present invention exhibited improved shelf life and reduced perceptible differences in taste profile over time when compared to existing products.

[0241] One or more embodiments have been described above by way of example only - many variations are possible without departing from the scope of protection granted by the appended claims.

Claims

1. 1. A process for producing a liquid coffee extract product, said process comprising: a) subjecting roast and ground coffee to an extraction process to produce a high aromatic coffee extract and a low aromatic coffee extract; b) combining said low aromatic coffee extract with said high aromatic coffee extract to obtain a liquid coffee extract product, 2. A process for producing a liquid coffee extract product, wherein the method further comprises the step of increasing the pH of the low-aroma coffee extract to a pH not exceeding 5.5, and wherein the low-aroma coffee extract is maintained at a temperature below 110°C prior to step b).

2. 2. The process according to claim 1, wherein after step a) and before step b), the process further comprises the step of concentrating the low-aromatic coffee extract to produce a low-aromatic coffee extract concentrate, and step b) comprises combining the low-aromatic coffee extract concentrate with the high-aromatic coffee extract to obtain a liquid coffee extract product.

3. 3. The process according to claim 1 or claim 2, wherein after step a) and before step b), a part of the low aromatic coffee extract or low aromatic coffee extract concentrate is combined with the high aromatic coffee extract to form a mixture, and step b) comprises adding the mixture to the remainder of the low aromatic coffee extract or low aromatic coffee extract concentrate.

4. 4. The process according to claim 3, wherein at least 2% by weight of said low aromatic coffee extract or said low aromatic coffee extract concentrate is combined with said high aromatic coffee extract to form said mixture.

5. 5. The process according to claim 4, wherein 2-40% by weight of said low aromatic coffee extract or said low aromatic coffee extract concentrate is combined with said high aromatic coffee extract to form said mixture.

6. 6. The process according to claim 5, wherein 5-15% by weight of said low aromatic coffee extract or said low aromatic coffee extract concentrate is combined with said high aromatic coffee extract to form said mixture.

7. 7. The process according to any one of claims 3 to 6, wherein the mixture has a ratio between the low-aromatic coffee extract or low-aromatic coffee extract concentrate and the high-aromatic coffee extract of at least 0.2:

1.

8. 8. The process according to claim 7, wherein the mixture has a ratio between low-aromatic coffee extract or low-aromatic coffee extract concentrate and high-aromatic coffee extract of 0.35:1 to 0.7:

1.

9. 9. The process of any one of claims 1 to 8, wherein the step of increasing the pH may increase the pH to between 4.5 and 5.

5.

10. 10. The process of any one of claims 1 to 9, wherein the step of increasing the pH may increase the pH to between 4.8 and 5.

2.

11. 11. The process of any one of claims 1 to 10, wherein the step of increasing the pH may increase the pH by 0.1 to 0.

8.

12. 12. The process according to any one of claims 1 to 11, wherein the step of increasing the pH comprises increasing the titratable acidity of the low-aromatic coffee extract and / or low-aromatic coffee by an amount not exceeding 250 mmol / kg.

13. 13. A process according to claim 12, wherein the titratable acidity of the low-aromatic coffee extract and / or low-aromatic coffee concentrate may be increased by 40 to 340 mmol / kg.

14. 14. A process according to claim 13, wherein the titratable acidity of the low-aromatic coffee extract and / or low-aromatic coffee concentrate may be increased by 50 to 140 mmol / kg.

15. 15. A process according to claim 14, wherein the titratable acidity of the low-aromatic coffee extract and / or low-aromatic coffee concentrate may be increased by 70 to 110 mmol / kg.

16. 16. The process of any one of claims 1 to 15, wherein the step of increasing the pH is carried out using an ion exchange process.

17. 17. The process of claim 16, wherein the ion exchange process comprises the addition of an ion exchange resin and / or an adsorbent.

18. 18. The process of claim 17, wherein the ion exchange resin is polyacrylate or polystyrene based.

19. 19. A process according to any one of the preceding claims, wherein at least 50% by weight of the low-aroma coffee extract and / or low-aroma coffee extract concentrate is subjected to the pH increasing step.

20. 20. The process according to claim 19, wherein 70-98% by weight of said low-aroma coffee extract and / or low-aroma coffee extract concentrate is subjected to said pH increasing step.

21. 21. A liquid coffee extract product having a pH not exceeding 5.5 obtained by the process of any one of claims 1 to 20.

22. 22. The product of claim 21, wherein the liquid coffee extract product is a liquid coffee concentrate.

23. 23. The product of claim 21 or 22, wherein the coffee extract product comprises 4-O-caffeoyl-muco-γ-quinide in an amount of at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least 30 mg per kg dry matter of the coffee product after storage under chilled conditions for 6 months.

24. 1. A liquid coffee extract product comprising 4-O-caffeoyl-muco-γ-quinide, wherein the amount of 4-O-caffeoyl-muco-γ-quinide in said coffee product is at least 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or at least 30 mg per kg dry matter of said coffee product after six months of storage under refrigerated conditions.

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