Roasted coffee

Abstract

The invention relates to a method for roasting coffee, in particular roasting extracted raw coffee at elevated pressure followed by roasting at lower pressure. Other aspects of the invention are roasted coffee and a container for use in a beverage preparation device, the container containing the roasted coffee.

Description

Technical Field

[0001] The present invention relates to a method for roasting coffee, in particular to roasting extracted green coffee at an elevated pressure and then at a lower pressure. Other aspects of the present invention are roasted coffee and a container for use in a beverage preparation device, the container containing the roasted coffee. Background Art

[0002] Coffee beans develop the characteristic aroma and taste of coffee during the roasting process. Lighter roasts are generally associated with a perceived higher acidity and more fruity and winey notes, while darker roasts produce a more intense and more roasted aroma.

[0003] Coffee drinkers do not have the same preferences in terms of coffee aroma and taste. In fact, many coffee drinkers are aware of the various sensory experiences that coffee can offer, in which different coffee bean types, origins, blends, and roasting processes all play a role.

[0004] When commercially roasting coffee, it is desirable to be able to adjust the taste and aroma of the coffee. This can create new sensory characteristics or maintain the constant sensory characteristics of the coffee product over time, thereby compensating for variations in the seasonal supply of different coffee beans.

[0005] Therefore, there has been a continuing need in the industry to find improved solutions for roasting coffee.

[0006] Any reference in this specification to prior art documents should not be construed as an admission that such prior art is well-known art or forms part of the common general knowledge in the field. As used in this specification, the words "comprising", "including" and similar words should not be construed as having an exclusive or exhaustive meaning. In other words, they are intended to mean "including, but not limited to". Summary of the Invention

[0007] The object of the present invention is to improve the existing technical situation. The object of the present invention is achieved by the subject matter of the independent claims. The dependent claims further develop the concept of the present invention.

[0008] Accordingly, in a first aspect, the present invention provides a method for roasting coffee, the method comprising:

[0009] a. roasting the extracted green coffee for a period between 20 seconds and 900 seconds at a pressure greater than 2 bar, wherein, prior to roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee; and

[0010] b. roasting the roasted extracted coffee of step a for a period between 20 seconds and 1200 seconds at a pressure between 0.5 bar and 1.5 bar and at a coffee temperature between 180°C and 260°C.

[0011] In a second aspect, the present invention provides roasted coffee having a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4.

[0012] A third aspect of the invention relates to a container for use in a beverage preparation device, the container containing the roasted coffee of the invention.

[0013] Surprisingly, the inventors have found that roasting the extracted coffee in two stages; a first roasting stage at an elevated pressure and a second roasting stage at a lower pressure such as atmospheric pressure, provides an enhanced ability to modulate the coffee into different flavor regions, resulting in enhanced roasted cereal notes, increased freshly roasted characteristics, and reduced earthy and medicinal notes, such as those typically associated with Robusta coffee. Specifically, the resulting roasted coffee has a high level of flavor compounds associated with the desired roasted cereal, bread - like notes, such as dimethyl disulfide, and a low level of flavor compounds associated with earthy notes, such as pyrazines characteristic of deeply roasted Robusta coffee. This effect occurs in both Robusta and Arabica coffee beans. Detailed Description

[0014] Accordingly, the present invention in part relates to a method for roasting coffee, the method comprising: a) roasting the extracted green coffee (e.g., extracted green coffee beans) for a period between 20 seconds and 900 seconds at a pressure greater than 2 bar, wherein prior to roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee; and b) roasting the roasted extracted coffee of step a for a period between 20 seconds and 1200 seconds at a pressure between 0.5 bar and 1.5 bar and a coffee temperature between 180 °C and 260 °C.

[0015] The present inventors have surprisingly found that roasting the extracted green coffee according to steps a) and b) provides the coffee with pleasant sensory characteristics and an enhanced toasted cereal note. The resulting coffee can for example have a weight ratio of dimethyldisulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4. In addition, the resulting coffee exhibits a reduction in earthy and medicinal notes, which attributes are typically unfavorably associated with Robusta coffee. The coffee exhibits a related strong reduction in guaiacol, for example it can have a weight ratio of guaiacol to dimethyldisulfide less than 30. Surprisingly, the method of the present invention is able to generate the desired flavor characteristics from extracted green coffee that has had a large proportion of its water - soluble coffee flavor precursor molecules, such as monosaccharides, disaccharides, amino acids, chlorogenic acids and trigonelline, removed. The green coffee extract can provide valuable by - streams, for example as a source of caffeine (a cognitive enhancer that increases alertness and attention), chlorogenic acids (antioxidants) and trigonelline (a beneficial nutrient factor).

[0016] Roasting the extracted green coffee at a pressure greater than 2 bar can be achieved for example by roasting the extracted green coffee in a gas pressurized to a pressure greater than 2 bar.

[0017] Green coffee is the term for unroasted coffee. Extracted green coffee is green coffee that has had some of its components extracted, for example by aqueous extraction of green coffee beans. Sucrose is the most abundant sugar in green coffee, being about 8 wt% in Arabica coffee beans and about 3 wt% - 6 wt% in Robusta coffee beans. The extracted green coffee according to the present invention has been extracted such that it contains less than 80% of the amount of sucrose in the unextracted sample of the same coffee. For example, Robusta coffee beans that contain 6 wt% sucrose in their natural state will contain less than 4.8 wt% sucrose as extracted green coffee beans. In one embodiment, before roasting, the extracted green coffee contains less than 60%, 40%, 30%, 20% or 15% of the amount of sucrose in the unextracted sample of the same coffee. In one embodiment, the extracted green coffee contains less than 3 wt% sucrose. These values of sucrose weight percentage are expressed as a percentage of the dry weight of the coffee.

[0018] In one embodiment, roasting the extracted green coffee according to step a) is carried out in a porous rotatable drum in a pressurizable chamber.

[0019] In step b), the roasted extracted coffee is roasted at a pressure of about atmospheric pressure. For example, the extracted coffee can be roasted at a pressure between 0.8 bar and 1.2 bar, such as between 0.9 bar and 1.1 bar.

[0020] The roasting of the extracted coffee roasted in step a according to step b can be carried out in a suitable roasting device, such as a drum roaster, a fluidized bed roaster or a paddle roaster. The roasting according to step b can be carried out in a device separate from the device used for roasting the extracted green coffee in step a. In one embodiment, the roasting according to step b is carried out in a fluidized bed roaster or a paddle roaster. The roasting according to step b can be carried out under an inert atmosphere such as nitrogen.

[0021] Many consumers expect the coffee they drink to contain no ingredients other than coffee beans. In one embodiment, the extracted green coffee is roasted in step a in the absence of any non-coffee ingredients, such as added sugar. In one embodiment, the roasting of step b is carried out in the absence of any non-coffee ingredients, such as added sugar. In another embodiment, all roasting steps in the method for roasting coffee are carried out in the absence of non-coffee ingredients, such as added sugar.

[0022] In one embodiment, the extracted green coffee is roasted in step a in the absence of any non-coffee bean ingredients, such as other components of the coffee cherry. In one embodiment, the roasting of step b is carried out in the absence of any non-coffee bean ingredients, such as other components of the coffee cherry. In another embodiment, all roasting steps in the method for roasting coffee are carried out in the absence of any non-coffee bean ingredients, such as other components of the coffee cherry.

[0023] In one embodiment, the extracted green coffee is obtained by extracting green coffee (e.g., green coffee beans) with an aqueous liquid and then separating the extracted green coffee from the extract. The extraction of the green coffee can be carried out for between 10 minutes and 6 hours, such as between 30 minutes and 3 hours, and further such as between 50 minutes and 90 minutes. The extraction can be a countercurrent extraction. The aqueous liquid can be water. During the extraction process, the temperature of the aqueous liquid can be between 20°C and 100°C, such as between 75°C and 95°C, and such as between 60°C and 90°C. The weight ratio of water to coffee can be between 2:1 and 5:1, such as between 2.5:1 and 4.5:1. At least 20% by weight of the soluble carbohydrates present in the unextracted green coffee can be extracted into the aqueous liquid, such as at least 30% by weight, 40% by weight, 50% by weight or 60% by weight. The soluble carbohydrates remaining in the green coffee after extraction can be less than 5% by weight on a dry weight basis, such as less than 4% by weight, 3% by weight or 2% by weight on a dry weight basis. The separation of the extracted green coffee from the liquid can be achieved by any suitable means, such as filtration, centrifugation and / or decantation. The extracted green coffee can be dried before further roasting, such as to a moisture content between 8% and 15%, such as between 8% and 13%, and further such as between 9% and 12%.

[0024] In the context of the present invention, green coffee is coffee (e.g., coffee beans) that has not been subjected to a temperature high enough to initiate roasting. In one embodiment, the green coffee has not been heated to a temperature above 110°C before extraction, such as the green coffee has not been heated to a temperature above 100°C, 90°C or 80°C before extraction. In another embodiment, the green coffee has not been heated to a temperature above 110°C during extraction, such as the green coffee has not been heated to a temperature above 100°C or 90°C during extraction.

[0025] In one embodiment, prior to baking in step b, the roasted extracted coffee of step a is combined with an aqueous green coffee extract. The green coffee extract is rich in water-soluble compounds such as monosaccharides, disaccharides, amino acids, chlorogenic acids, and trigonelline. These are all important precursors for flavor generation, especially monosaccharides, disaccharides, and amino acids. Without wishing to be bound by theory, the inventors believe that roasting the extracted green coffee under elevated pressure results in reduced levels of pyrazines (earthy flavor notes) and guaiacol (phenolic, medicinal, smoky, dusty flavor notes), thereby providing a reduction in unwanted Robusta characteristics. However, the green coffee extract is protected from these relatively harsh conditions and then re-incorporated at near ambient pressure for a second baking step, where the flavor precursors in the green coffee extract are allowed to react to form the desired flavors. The coffee may, for example, have a weight ratio of dimethyl trisulfide to 2,3-diethyl-5-methylpyrazine greater than 0.6.

[0026] In one embodiment, the aqueous green coffee extract is concentrated, for example to between 20% and 35% total solids, prior to combination with the roasted extracted coffee of step a and baking according to step b.

[0027] The aqueous green coffee extract may have had most or all of the caffeine removed, such that when the roasted extracted coffee of step a is combined with the aqueous green coffee extract and baked in step b, decaffeinated coffee is obtained. The caffeine may be removed by methods known in the art, such as contacting with activated carbon pre-loaded with coffee extract material such that the caffeine is selectively removed. The aqueous green coffee extract may contain less than 0.1 wt% caffeine, for example less than 0.05 wt% caffeine.

[0028] The roasted extracted coffee can be combined with the aqueous green coffee extract in a mixer (such as a stirred jacket mixer). Before and / or during the combination with the aqueous green coffee extract, the roasted extracted coffee can be kept under a slight vacuum, for example between 0.65 bar and 0.95 bar. This helps to incorporate the aqueous green coffee extract into the roasted extracted coffee to the maximum extent. Any aqueous green coffee extract not absorbed by the beans is removed, for example by sieving. In one embodiment, the roasted extracted coffee can be combined with the aqueous green coffee extract at a coffee to extract ratio (based on solids) between 2:1 and 10:1. This is the ratio of the roasted extracted coffee to the aqueous green coffee extract absorbed by the roasted extracted coffee. Preferably, the amount of the aqueous green coffee extract is selected such that it is completely absorbed by the roasted extracted coffee. However, if there is any remaining aqueous green coffee extract, it is removed by sieving or the like. For calculating the ratio of the roasted extracted coffee to the aqueous green coffee extract, any remaining aqueous green coffee extract is not included. The roasted extracted coffee can be rinsed with fresh water after combination with the aqueous green coffee extract. The roasted extracted coffee can be dried after combination with the aqueous green coffee extract and before roasting in step b. For example, it can be dried to a moisture content between 8 wt% and 15 wt%, such as between 8 wt% and 13 wt%, and further such as between 9 wt% and 12 wt%.

[0029] In one embodiment, the aqueous green coffee extract is obtained by extracting green coffee (e.g., green coffee beans) with an aqueous liquid and then separating the extracted green coffee from the extract. The extraction of green coffee can be carried out for between 10 minutes and 6 hours, such as between 30 minutes and 3 hours, and further such as between 50 minutes and 90 minutes. The extraction can be a countercurrent extraction. The aqueous liquid can be water. During the extraction process, the temperature of the aqueous liquid can be between 20°C and 100°C, such as between 75°C and 95°C, and such as between 60°C and 90°C. The weight ratio of water:coffee can be between 2:1 and 5:1, such as between 2.5:1 and 4.5:1. The aqueous green coffee extract can contain sucrose, for example, at a level between 15% and 45% by dry weight, and further such as between 20% and 40% by dry weight. The aqueous green coffee can contain amino acids, for example, at a level between 0.8% and 4.0% by dry weight, and further such as between 1.0% and 3.8% by dry weight. The aqueous green coffee extract can contain free phenols, for example, at a level between 15% and 40% by dry weight, and further such as between 20% and 35% by dry weight. Examples of free phenols include caffeoylquinic acid, dicaffeoylquinic acid, and feruloylquinic acid. The aqueous green coffee extract can contain trigonelline, for example, at a level between 1.5% and 4.0% by dry weight, and further such as between 2.0% and 3.5% by dry weight. The aqueous green coffee extract can contain caffeine, for example, at a level between 3% and 15% by dry weight, and further such as between 4.5% and 10% by dry weight. The aqueous green coffee extract can be decaffeinated and can contain less than 0.5% by dry weight, such as less than 0.25% by dry weight. In one embodiment, the aqueous green coffee extract contains, by dry weight, sucrose at a level between 15% and 45%, amino acids at a level between 0.8% and 4.0%, and trigonelline at a level between 1.5% and 4.0%.

[0030] The aqueous green coffee extract can have a total solids level between 10% and 50%, such as between 20% and 30%. The separation of the aqueous green coffee extract from the extracted green coffee can be achieved by any suitable means, such as filtration, centrifugation, and / or decantation.

[0031] In one embodiment, in step a), the extracted green coffee is roasted at a pressure above 9.5 bar in the presence of superheated steam.

[0032] In one embodiment, the superheated steam has a pressure greater than 10 bar, such as greater than 11 bar, and further such as greater than 12 bar. The superheated steam may have a pressure of 9.5 bar to 20 bar, such as 10 bar to 19 bar, and further such as 12 bar to 18 bar.

[0033] The pressure given in units of "bar" herein refers to absolute pressure, sometimes written as bara or bar(a). 1 bar is equal to 100 kPa.

[0034] The temperature of the steam must be such that the steam is in a superheated state at the steam pressure and the steam supply is sufficient to maintain a superheated steam atmosphere. Pressure-enthalpy diagrams of steam are widely available. When in a superheated state, the steam temperature can be 180 °C to 330 °C, such as 220 °C to 320 °C, and further such as 250 °C to 310 °C. For example, the superheated steam can be at a pressure of 13 bar and a temperature of 300 °C.

[0035] Coffee is generally not roasted in steam because the resulting coffee tends to be acidic. However, the roasting conditions used in the method of the present invention unexpectedly avoid this sourness, leaving the desired delicate acidity without unpleasant sourness.

[0036] In one embodiment, the extracted green coffee in step a) can be roasted in the presence of superheated steam to a final temperature (such as the final bean temperature) between 180 °C and 320 °C, such as 190 °C to 300 °C, and further such as 200 °C to 280 °C.

[0037] In one embodiment, the moisture content of the roasted coffee (such as coffee beans) in the presence of superheated steam is lower than that of the unroasted beans. Superheated steam is "dry" in the sense that it does not contain water in the liquid phase. Merely steaming the coffee with saturated steam before roasting does not provide the desired flavor modulation. In fact, a high moisture content in the coffee (such as the moisture in the beans being greater than or equal to 20% by weight) (such as may be the result of steaming in wet steam) causes the beans to have undesired sensory properties when subjected to roasting temperatures, such as undesired sourness and the formation of sensorially undesired compounds.

[0038] In one embodiment, the roasted coffee has a titratable acidity of less than 20 mmol of sodium hydroxide equivalent / 100 g of roasted coffee, such as less than 15 mmol of sodium hydroxide equivalent / 100 g of roasted coffee, and further such as less than 5 mmol of sodium hydroxide equivalent / 100 g of roasted coffee. The titratable acidity can be measured, for example, by suspending 10 g of roasted and ground coffee in 200 mL of water and boiling it. After boiling for 5 min with stirring and cooling, the evaporation loss is compensated by adding water. The suspension is filtered, and 50 mL of the filtrate is titrated to pH 6.60 with a 0.1 M aqueous sodium hydroxide solution.

[0039] Surprisingly, the coffee obtained by roasting the extracted coffee in the presence of superheated steam at a pressure above 9.5 bar in step a) and then combining it with an aqueous green coffee extract before roasting in step b) exhibits an increase in the sensory "coffeeness" characteristic. Thus, the coffee can have, for example, a weight ratio of dimethyl disulfide to methanethiol greater than 1.5.

[0040] In one embodiment, in step b), the roasted extracted coffee is roasted in the absence of steam. "Roasting in the absence of steam" means that no steam is introduced into the coffee during the roasting process; some steam may be inherently generated from the moisture in or on the coffee when the coffee is heated.

[0041] In one embodiment, a method for roasting coffee comprises roasting the extracted green coffee in the presence of superheated steam at a pressure above 12 bar for a period between 80 seconds and 150 seconds, wherein before roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee; and then roasting for a period between 200 seconds and 220 seconds without steam at a pressure between 0.8 and 1.2 bar and a coffee temperature between 180 °C and 220 °C.

[0042] Advantageously, the method of the present invention is capable of producing a flavor and aroma of the style typically associated with lightly roasted Arabica coffee from Robusta coffee. However, the coffee according to the present invention can be Arabica coffee (Coffea arabica), Robusta coffee (Coffea canephora), or a combination of these coffees. The coffee can be in the form of coffee beans (seeds of the coffee plant) that are substantially whole beans, cracked beans, ground beans, or a combination of these.

[0043] In one embodiment, the extracted green coffee is roasted in the presence of an inert gas in step a). The pressure during roasting can be achieved by introducing the inert gas into the roaster under pressure. In which at least 98% of the gas atmosphere of the roasted beans can be an inert gas, for example, the partial pressure of the inert gas can be 98% of the total pressure. The inert gas can be nitrogen.

[0044] In one embodiment, the roasted coffee can be ground, for example, the coffee can be ground after step b).

[0045] A beverage preparation device (e.g., a beverage maker) that accommodates extractable portioned ingredients provides a convenient way to prepare beverages. Such portioned ingredients are typically packaged in a container that is configured, for example, as a pod, pad, bag, sachet, capsule, etc. In one embodiment, roasted coffee (e.g., roasted and ground coffee beans) is filled into the container that is used to prepare a beverage when inserted into the beverage preparation device. The container can be, for example, a beverage capsule, among other configurations.

[0046] To best optimize the sensory characteristics of the coffee, the roasting of a certain proportion of the beans applied to the final blend can be different from the roasting of other beans applied to the blend. For example, in a blend of beans from different sources and / or different types, the beans of different sources / types can be roasted separately under conditions to optimize the final flavor and aroma. In one embodiment, the beans roasted in step b) are blended with additional coffee beans that have been roasted under different conditions.

[0047] In one embodiment, a method for roasting coffee includes: roasting a first type of extracted green coffee for a period between 20 seconds and 900 seconds in the presence of superheated steam at a pressure above 9.5 bar, wherein prior to roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee; and in another roasting step, roasting the coffee roasted in the presence of superheated steam for a period between 20 seconds and 1200 seconds at a coffee temperature between 180°C and 260°C and a pressure between 0.8 bar and 1.2 bar without steam; and roasting a second type of green coffee separately; and blending the roasted first type and second type of roasted coffee.

[0048] In one embodiment, the first type of extracted green coffee is from a different source and / or different coffee variety than the second type of green coffee. The first type of extracted green coffee can have a lower quality grade than the second type of coffee beans. The first type of extracted green coffee can be, for example, dry-processed Robusta or dry-processed Brazilian Arabica beans. The second type of green coffee from a different source and / or different coffee variety than the first type of coffee beans can be high-quality beans with inherent fruity / floral aromas and good acidity. The so-called "different sources" means that the coffee beans are grown in different geographical regions or countries. Colombia, Kenya, Costa Rica, Nicaragua, and Brazil are examples of sources. The second type of green coffee can be selected from the group consisting of: Colombian Arabica, Kenyan Arabica, Central American Arabica (e.g., Costa Rica or Nicaragua), high-quality Brazilian Arabica, highest-quality Robusta, and combinations thereof.

[0049] The two roasting phases of the method of the present invention do not have to be carried out at the same physical location. Roasters capable of roasting under elevated pressure or in the presence of superheated steam are generally more expensive than conventional roasters. It may be economically viable to have a central facility that roasts the extracted coffee under elevated pressure (optionally in the presence of superheated steam) and then transports this pressurized roasted spent coffee to a number of other locations (such as locations near the point of sale) for the roasting of step b. At these locations, the roasted extracted coffee is combined with an aqueous green coffee extract, which may also be carried out at a central location. The roasting of step b can be carried out, for example, at home or at a retail establishment, thus broadening the range of coffees with attractive aromas that can be offered. The coffee will generally be packaged into containers for transportation. In one embodiment, before roasting according to step b, the roasted extracted coffee of step a is packaged into containers and transported to at least one other location.

[0050] One aspect of the present invention provides a method for roasting coffee, the method comprising roasting the extracted green coffee for a period between 20 seconds and 900 seconds at a pressure greater than 2 bar, wherein before roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee, and then packaging it into a container. For example, the extracted green coffee can be roasted to a color with a CTN greater than 100 and then packaged into a container.

[0051] Another aspect of the present invention is the use of roasted extracted green coffee for subsequent roasting at home or at a retail establishment, wherein the roasted extracted coffee has been subjected to roasting for a period between 20 seconds and 900 seconds at a pressure greater than 2 bar, and wherein before roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee.

[0052] The inventors have surprisingly found that the roasted coffee according to the present invention has improved sensory properties confirmed by aroma chemistry, which is different from the type of coffee beans roasted only by conventional thermal roasting. The balance of aroma compounds associated with roasted cereal notes (such as dimethyl disulfide) and aroma compounds associated with earthy notes (such as alkylpyrazines characteristic of deeply roasted Robusta coffee) is much higher in the roasted coffee.

[0053] One aspect of the present invention provides a roasted coffee having a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4 (such as greater than 4.5, 5, 6, 7, 8, 9, 10 or 15). In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine between 4.5 and 40. 2,3 - diethyl - 5 - methylpyrazine is an aroma molecule that provides an earthy note.

[0054] Roasted coffee is a material obtained by roasting coffee beans, which can be, for example, roasted coffee beans or roasted ground coffee beans.

[0055] After suspending roasted and ground coffee in water, the weight of flavor compounds in roasted coffee for calculating the weight ratio can be quantified using isotope-labeled standards in combination with solid-phase microextraction and gas chromatography-mass spectrometry. This isotope dilution analysis (also known as stable isotope dilution analysis) is a method for volatile analysis that provides an accurate measurement of the compound content in roasted coffee. By incorporating the labeled standard at the earliest possible stage of sample preparation, such as directly in the roasted and ground coffee suspension, all physicochemical phenomena occurring between the standard addition and the instrument acquisition are fully compensated.

[0056] For example, quantification can be carried out as follows: Place 5 g of roasted and ground coffee in a screw-cap flask, suspend it with 100 mL of boiling water, and after closing, stir for 10 min, then cool on ice, and mix the obtained slurry with a limited amount of the labeled isotope of the analyte. Then, transfer an aliquot of the sample to a silanized glass vial, seal the vial and equilibrate at room temperature for 60 minutes, then extract the flavor compounds from the headspace by solid-phase microextraction at 40 °C for 10 minutes and quantify by gas chromatography-mass spectrometry.

[0057] In one embodiment, the roasted coffee of the present invention has a weight ratio of guaiacol to dimethyldisulfide of less than 30, such as less than 20, 15, 12, 11, 10, or 9. In one embodiment, the roasted coffee of the present invention has a weight ratio of guaiacol to dimethyldisulfide between 2 and 20, such as between 2.5 and 10, and further such as between 3 and 9. Guaiacol is a flavor molecule associated with phenolic, medicinal, and smoky odor notes, which are usually associated with the characteristics of Robusta coffee and are generally considered undesirable.

[0058] In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 0.6, such as greater than 0.65, 0.7, or 0.75. In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine between 0.6 and 5, such as between 0.7 and 4, and further such as between 0.75 and 3. An increase in the ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine is associated with a decreasing earthy odor note.

[0059] In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to methanethiol greater than 1.5, such as greater than 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 3.0, 3.5, 4.0 or 4.5. The roasted coffee of the present invention may have a weight ratio of dimethyl disulfide to methanethiol between 1.5 and 15.0, such as between 2.0 and 6.0, and further such as between 2.5 and 5.0. From a sensory perspective, a higher ratio of dimethyl disulfide to methanethiol is associated with a greater "coffeiness". The method of the present invention is particularly effective in increasing "coffeiness" when the extracted green coffee is roasted in the presence of superheated steam at a pressure greater than 9.5 in step a and then combined with an aqueous green coffee extract before roasting in step b. Particularly surprisingly and advantageously, the method of the present invention is capable of increasing the "coffeiness" of Robusta coffee. The roasted coffee of the present invention can be Robusta coffee and has a weight ratio of dimethyl disulfide to methanethiol greater than 1.5, such as greater than 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 3.0, 3.5, 4.0 or 4.5. The roasted coffee of the present invention can be Robusta coffee and has a weight ratio of dimethyl disulfide to methanethiol between 1.5 and 15.0, such as between 2.0 and 6.0, and further such as between 2.5 and 5.0.

[0060] In one embodiment, the roasted coffee of the present invention has a weight ratio of furfural to guaiacol greater than 3, such as greater than 4, 5, 6 or 7. In one embodiment, the roasted coffee of the present invention has a weight ratio of furfural to guaiacol between 3 and 20. In one embodiment, the roasted coffee of the present invention is Robusta coffee and has a weight ratio of furfural to guaiacol greater than 3, such as greater than 4 or 5. In one embodiment, the roasted coffee of the present invention has a weight ratio of furfural to guaiacol between 3 and 10. An increase in furfural is associated with enhanced toasty, toasted, and sweet notes. A decrease in guaiacol is associated with a reduction in phenolic, medicinal, and smoky notes, which are typically associated with the characteristics of Robusta coffee and are generally considered undesirable.

[0061] In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4 and a weight ratio of guaiacol to dimethyl disulfide less than 30. In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4 and a weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 0.6. In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4, a weight ratio of guaiacol to dimethyl disulfide less than 30, and a weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 0.6. In one embodiment, the roasted coffee of the present invention has a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4, a weight ratio of guaiacol to dimethyl disulfide less than 30, a weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 0.6, and a weight ratio of dimethyl disulfide to methanethiol greater than 1.5.

[0062] The color of roasted coffee beans can be expressed in CTN units. The CTN roast color can vary between 0 and 200 and is determined by measuring the intensity of infrared (IR) light (904 nm) backscattered by the sample when measured using a spectrophotometer such as the ColorTest of Neuhaus Neotec. The spectrophotometer irradiates the surface of the ground sample with monochromatic IR light of wavelength 904 nm from a semiconductor source. A calibrated light receiver measures the amount of light reflected by the sample. The average of a series of measurements is calculated and displayed by an electronic circuit. The color of the coffee beans changes depending on their degree of roasting. For example, green coffee beans typically have a CTN above 200, very lightly roasted coffee beans typically have a CTN of about 150, lightly roasted coffee beans typically have a CTN of about 100, and medium - dark coffee beans typically have a CTN of about 70. Very darkly roasted coffee beans typically have a CTN of about 45. The method of the present invention allows for the preparation of coffee having an appealing aroma typically associated with light roasting, such as light - roasted Arabica coffee. Unexpectedly, these aromas are retained at a relatively high degree of roasting. In one embodiment, the roasted coffee has a roast color between 30 CTN and 100 CTN, for example between 40 CTN and 90 CTN. In one embodiment, the roasted coffee is accommodated in a container that is used to prepare a beverage when inserted into a beverage preparation device. The container can be, for example, a beverage capsule, among other configurations.

[0063]

[0064] ​In one embodiment, the roasted coffee is encapsulated roasted (e.g., partially roasted) coffee for further roasting. The encapsulated roasted coffee can be packaged in a bulk container, e.g., for transfer between factories. The encapsulated roasted coffee can be packaged in a semi-bulk package for further roasting at home or in a retail store, such as a coffee shop.

[0065] One embodiment of the present invention is encapsulated roasted coffee for further roasting, wherein the weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine is greater than 4 and the weight ratio of guaiacol to dimethyl disulfide is less than 30, e.g., less than 20, 15, 12, 11, 10 or 9.

[0066] In one embodiment, the encapsulated roasted coffee (e.g., partially roasted coffee) for further roasting has a roast color between 75 CTN and 160 CTN, e.g., between 100 CTN and 150 CTN.

[0067] One aspect of the present invention is a container for use in a beverage preparation device, the container containing the roasted coffee of the present invention.

[0068] Those skilled in the art will understand that they can freely combine all the features of the present invention disclosed herein. Specifically, the features described for the methods of the present invention can be combined with the products of the present invention and vice versa. Additionally, the features described for different embodiments of the present invention can be combined. If there are known equivalents for specific features, such equivalents are incorporated as if they were explicitly mentioned in this specification.

[0069] Other advantages and features of the present invention will be apparent from the non - limiting examples.

[0070] Examples

[0071] Example 1: Green coffee extraction

[0072] The green coffee beans are pre - wetted to a moisture content of 50% - 60%, then extracted with water at 80°C - 90°C for 60 min, with a weight ratio of water to beans of 3.5:1, to provide extracted coffee beans and green coffee extract. The extracted coffee beans are dried to a moisture content of 12% by weight. The sucrose content of the extracted coffee beans is approximately 10% of the sucrose level in the beans before extraction. The aqueous green coffee extract from each coffee type is concentrated to 25% total solids by evaporation.

[0073] Example 2: Two-step roasting, pressurized with steam, no extract added

[0074] Roasting with steam under pressure: Weigh 500 grams of the extracted coffee beans and manually feed them into a perforated rotatable drum in a pressurizable chamber. The pressurizable chamber is isolated from the environment by a ball valve. The coffee is moved by rotating the drum. Meter superheated steam at 13 bar and 300 °C into the pressurizable chamber. Select the pressure to obtain a dark to medium-dark roasted color after two roasting steps without burning the beans. After 300 s, stop the steam flow to the pressurizable chamber and quickly reduce the pressure to atmospheric pressure. The rotatable drum reverses direction and the coffee is metered to the outlet of the pressurizable chamber. Then collect the processed coffee through the valve assembly at the bottom of the pressurizable chamber.

[0075] Roasting without steam at atmospheric pressure: Load 350 grams of the coffee roasted with steam as described above into a perforated drawer that can withstand a hot air flow at the required temperature. Measure the temperature of the coffee beans with a temperature probe. After 300 s at 210 °C, transfer the roasted coffee to a cooling chamber and expose it to an ambient temperature air flow to stop the roasting process. Then collect the samples from the cooling chamber. The Arabica samples are designated SA and the Robusta samples are designated SB.

[0076] Example 3: Two-step roasting, pressurized with steam, extract added

[0077] Roasting with steam under pressure: Weigh 500 grams of the extracted coffee beans and manually feed them into a perforated rotatable drum in a pressurizable chamber. The pressurizable chamber is isolated from the environment by a ball valve. The coffee is moved by rotating the drum. Meter superheated steam at 13 bar and 300 °C into the pressurizable chamber. Select the pressure to obtain a dark to medium-dark roasted color after two roasting steps without burning the beans. After 300 s, stop the steam flow to the pressurizable chamber and quickly reduce the pressure to atmospheric pressure. The rotatable drum reverses direction and the coffee is metered to the outlet of the pressurizable chamber. Then collect the processed coffee through the valve assembly at the bottom of the pressurizable chamber.

[0078] Incorporating the extract into the roasted extracted beans: Combine 2.85 kg of the extracted beans roasted with steam under pressure as described above with 2.2 kg of the coffee extract from Example 1 (combine the Arabica extract with the roasted extracted Arabica beans and the Robusta extract with the roasted extracted Robusta beans). The extract has a total solids content of 25%. Gently mix the beans and the extract in a double-jacketed Stephan mixer with a rotating arm at 50 °C for 24 hours. The beans absorb all of the extract. After mixing, rinse the beans with fresh water and dry them to a moisture content of 12%.

[0079] Steam-free roasting at atmospheric pressure: 350 g of the roasted and extracted beans incorporated with the extract (as described above) are loaded into a perforated drawer that can withstand a hot air stream at the required temperature. The temperature of the coffee beans is measured by a temperature probe. After 300 s at 210 °C, the roasted coffee is transferred to a cooling chamber and brought into contact with an ambient temperature air stream to stop the roasting process. Then samples are collected from the cooling chamber. The Arabica samples are designated as SEA and the Robusta samples are designated as SEB.

[0080] Example 4: Two-step roasting, pressurized with nitrogen, extract added

[0081] Roasting with nitrogen under pressure: 500 g of the extracted coffee beans are weighed and manually fed into a porous rotating drum in a pressurizable chamber. The pressurizable chamber is isolated from the environment by a ball valve. The coffee is agitated by rotating the drum. Nitrogen at 18 bar and 300 °C is metered into the pressurizable chamber. The pressure is selected to obtain a dark to medium-dark roasted color after two roasting steps without burning the beans. After 300 s, the nitrogen gas flow to the pressurizable chamber is stopped and the pressure is rapidly reduced to atmospheric pressure. The rotating drum is reversed and the coffee is metered to the outlet of the pressurizable chamber. Then the processed coffee is collected through a valve assembly at the bottom of the pressurizable chamber.

[0082] Incorporating the extract into the roasted and extracted beans: 2.85 kg of the extracted beans roasted with nitrogen under pressure as described above are combined with 2.2 kg of the coffee extract from Example 1 (the Arabica extract is combined with the roasted and extracted Arabica beans, and the Robusta extract is combined with the roasted and extracted Robusta beans). The extract has a total solids content of 25%. The beans and the extract are gently mixed in a double-jacketed Stephan mixer with a rotating arm at 50 °C for 24 hours. The beans absorb all of the extract. After mixing, the beans are rinsed with fresh water and dried to a moisture content of 12%.

[0083] Roasting at atmospheric pressure: 350 g of the roasted and extracted beans incorporated with the extract (as described above) are loaded into a perforated drawer that can withstand a hot air stream at the required temperature. The temperature of the coffee beans is measured by a temperature probe. After 300 s at 210 °C, the roasted coffee is transferred to a cooling chamber and brought into contact with an ambient temperature air stream to stop the roasting process. Then samples are collected from the cooling chamber. The Arabica samples are designated as NEA and the Robusta samples are designated as NEB.

[0084] Example 5: Comparative example

[0085] Roasting with steam under pressure: Weigh 500 grams of unextracted coffee beans and manually feed them into a porous rotatable drum in a pressurizable chamber. The pressurizable chamber is isolated from the environment by a ball valve. The coffee is moved by rotating the drum. Meter superheated steam at 16 bar and 300 °C into the pressurizable chamber. Select the pressure to obtain a dark to medium-dark roasted color after two roasting steps without burning the beans. After 300 s, stop the steam flow to the pressurizable chamber and quickly reduce the pressure to atmospheric pressure. The rotating drum reverses direction and the coffee is metered to the outlet of the pressurizable chamber. Then collect the processed coffee through the valve assembly at the bottom of the pressurizable chamber.

[0086] Load 350 grams of coffee roasted with steam as described above into a perforated drawer that can withstand a hot air stream at the required temperature. Measure the temperature of the coffee beans with a temperature probe. After 300 s at 210 °C, transfer the roasted coffee to a cooling chamber and expose it to an ambient temperature air stream to stop the roasting process. Then collect samples from the cooling chamber. The resulting coffee is called SRefA (Arabica) and SRefB (Robusta).

[0087] Roasting with nitrogen under pressure: Weigh 500 grams of unextracted coffee beans and manually feed them into a porous rotatable drum in a pressurizable chamber. The pressurizable chamber is isolated from the environment by a ball valve. The coffee is moved by rotating the drum. Meter nitrogen at 16 bar and 300 °C into the pressurizable chamber. Select the pressure to obtain a dark to medium-dark roasted color after two roasting steps without burning the beans. After 300 s, stop the nitrogen flow to the pressurizable chamber and quickly reduce the pressure to atmospheric pressure. The rotating drum reverses direction and the coffee is metered to the outlet of the pressurizable chamber. Then collect the processed coffee through the valve assembly at the bottom of the pressurizable chamber.

[0088] Load 350 grams of beans roasted with nitrogen under pressure into a perforated drawer that can withstand a hot air stream at the required temperature. Measure the temperature of the coffee beans with a temperature probe. After 300 s at 210 °C, transfer the roasted coffee to a cooling chamber and expose it to an ambient temperature air stream to stop the roasting process. Then collect samples from the cooling chamber. The resulting coffee is called NRefA (Arabica) and NRefB (Robusta).

[0089] Roasted in a single step at atmospheric pressure: Additional reference samples were prepared as follows. 350 grams of unextracted coffee were loaded into a perforated drawer that could withstand the hot air stream at the required temperature. The temperature of the coffee beans was measured by a temperature probe. The roasting times for the Arabica and Robusta samples were adjusted to obtain a similar roasting color; Arabica at 220 °C for 360 s and Robusta at 220 °C for 600 s. The roasted coffee was transferred to a cooling chamber and brought into contact with ambient temperature air stream to stop the roasting process. Then the samples were collected from the cooling chamber. The Arabica sample was designated as CRefA and the Robusta sample was designated as CRefB.

[0090] Example 6: Professional tasting :

[0091] Roasted coffee for tasting was prepared using a filter coffee machine. 50 g of coffee was extracted with 1000 ml of water at a temperature of 100 °C. Professional tasting was carried out by 6 people. Each person recorded their comments on the taste and aroma of each sample. Samples according to the present invention (SA, SB, SEA, SEB, NEA and NEB) all had comments regarding cereal notes, while the comparative examples did not have comments regarding cereal notes. Compared with the comparative Robusta samples, the Robusta samples roasted according to the present invention were less frequently mentioned with rubbery earthy aroma notes. Specifically, SEB was described as having medium roasting characteristics and exhibiting a balanced "coffeiness" characteristic, which is uncommon for Robusta coffee.

[0092] Example 7: Aroma analysis

[0093] Using isotope-labeled standards, combined with solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS / MS) analysis, the absolute content (mg / kg roasted coffee) of target aroma compounds in roasted and ground coffee (R&G) after suspension in water was quantified. This isotope dilution analysis (also known as stable isotope dilution analysis) is a volatile analysis method that provides an accurate measurement of the compound content in roasted coffee. By incorporating labeled standards at the earliest possible stage of sample preparation, here directly in the roasted and ground coffee suspension, all physicochemical phenomena occurring between the standard addition and the instrument acquisition are fully compensated.

[0094] Sample preparation

[0095] 5 g of roasted and ground coffee sample was placed in a screw-cap flask, suspended with 100 mL of boiling water, and stirred for 10 min after closing. After cooling on ice, the obtained slurry was doped with the labeled isotope of the analyte in a determined amount, and an aliquot (7 ml) of the sample was transferred to a sealed silanized glass vial (standard 20 mL vial for headspace / SPME analysis).

[0096] Extraction of aroma

[0097] The sample was equilibrated for 60 minutes at room temperature. Then, flavor compounds were extracted from the headspace by solid-phase microextraction (SPME) at 40 °C for 10 minutes (2 cm fiber, 50 / 30 μm StableFlex, coated with PDMS / DVB / Carboxen; Supelco, Buchs, Switzerland), and thermally desorbed into a split-splitless injector (split mode; 2 splits) heated at 240 °C for 10 min. GC-MS / MS analysis of the compounds of interest

[0098] Separation was performed using an Agilent 7890B gas chromatograph (Agilent, Basel, Switzerland) on a 60 m × 0.25 mm × 0.25 μm polar DB-624UI column (Agilent, Basel, Switzerland). Helium was used as the carrier gas with a constant flow rate of 1.2 mL / min. An oven program was then applied: the initial temperature of 40 °C was held for 6 minutes, then increased to 240 °C at 6 °C / min, and the final temperature was held for 10 minutes. Mass spectrometry was performed on an Agilent 7010 Triple Quad mass spectrometer (Agilent, Basel, Switzerland). Chromatograms were processed using Agilent MassHunter software.

[0099] Aroma results

[0100] Absolute content (mg / kg roasted coffee) and ratio of target aroma compounds

[0101]

[0102]

[0103] Samples according to the invention (SA, SB, SEA, SEB, NEA and NEB) all have a higher ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine compared to comparative samples. Dimethyl disulfide is associated with a roasted cereal note, while alkylpyrazines such as 2,3 - diethyl - 5 - methylpyrazine are associated with earthy notes, which are characteristic of deeply roasted Robusta coffee. Thus, higher levels of dimethyl disulfide result in an enhanced cereal note. All samples according to the invention have lower levels of 2,3 - diethyl - 5 - methylpyrazine than conventional roasted coffees CRefA and CRefB. Specifically, when the extracted green coffee is combined with an aqueous green coffee extract prior to roasting in step b after being pressure - roasted with nitrogen in step a (samples NEA and NEB), the roasted coffee has lower levels of 2,3 - diethyl - 5 - methylpyrazine compared to comparative examples NRefA and NRefB.

[0104] Samples according to the invention (SA, SB, SEA, SEB, NEA and NEB) all have a lower ratio of guaiacol to dimethyl disulfide compared to comparative examples. Guaiacol is a flavor molecule associated with phenolic, medicinal, smoky notes, which are generally associated with the characteristics of Robusta coffee and are generally considered undesirable. Specifically, for Robusta coffee, it can be seen that when the extracted green coffee is combined with an aqueous green coffee extract prior to roasting in step b after being pressure - roasted with nitrogen or superheated steam in step a (samples SEB and NEB), the roasted coffee has much lower levels of guaiacol compared to comparative examples SRefB, NRefB and CRefB.

[0105] It can be seen that when the extracted green coffee is combined with an aqueous green coffee extract prior to roasting in step b after being pressure - roasted with superheated steam in step a (samples SEA and SEB), the roasted coffee has a much higher ratio of dimethyl disulfide to methanethiol compared to comparative two - step roasted samples SRefA and SRefB or conventional roasted samples CRefA and CRefB. This is particularly evident for Robusta sample SEB, which has a ratio of dimethyl disulfide to methanethiol three times that of reference SRefB. A higher ratio of dimethyl disulfide to methanethiol is associated with a greater "coffeiness" characteristic.

[0106] The Arabica samples (SA, SEA, and NEA) according to the present invention all have a higher furfural to guaiacol ratio compared to the comparative Arabica samples (SRefA, NRefA, and CRefA). The Robusta samples (SB, SEB, and NEB) according to the present invention all have a higher furfural to guaiacol ratio compared to the comparative Arabica samples (SRefB, NRefB, and CRefB). Guaiacol is an aroma molecule associated with phenolic, medicinal, and smoky fragrance notes, which are typically associated with the characteristics of Robusta coffee and are generally considered undesirable. The increase in furfural is positively correlated with toasty, roasted, and sweet fragrance notes.

[0107] Example 8: Roast color

[0108] Roast color: The roast color is determined by measuring the intensity of infrared (IR) light (904 nm) backscattered by the sample using a Neuhaus Neotec’s ColorTest spectrophotometer when measuring 。

[0109] Sample name SA SB SEA SEB NEA NEB Roast color (CTN) 75 73 63 64 85 80

[0110] Sample name SRefA SRefB NRefA NRefB CRefA CRefB Roast color (CTN) 37 61 74 111 62 61

Claims

1. A method for roasting coffee, the method comprising a. roasting the extracted green coffee for a period between 20 seconds and 900 seconds at a pressure greater than 2 bar, wherein prior to roasting, the extracted green coffee contains less than 80% of the amount of sucrose in an unextracted sample of the same coffee; and b. roasting the roasted extracted coffee of step a for a period between 20 seconds and 1200 seconds at a pressure between 0.5 bar and 1.5 bar and at a coffee temperature between 180 °C and 260 °C.

2. The method according to claim 1, wherein the extracted green coffee is obtained by extracting green coffee with an aqueous liquid and then separating the extracted green coffee from the extract.

3. The method according to claim 2, wherein prior to extraction, the green coffee has not been heated to a temperature higher than 110 °C.

4. The method according to any one of claims 1 to 3, wherein prior to roasting in step b, the roasted extracted coffee of step a is combined with an aqueous green coffee extract.

5. The method according to claim 4, wherein the aqueous green coffee extract is obtained by extracting green coffee with an aqueous liquid and then separating the extracted green coffee from the extract.

6. The method according to any one of claims 1 to 5, wherein in step a), the extracted green coffee is roasted in the presence of superheated steam at a pressure higher than 9.5 bar.

7. The method according to any one of claims 1 to 5, wherein in step a), the extracted green coffee is roasted in the presence of an inert gas.

8. Roasted coffee having a weight ratio of dimethyl disulfide to 2,3 - diethyl - 5 - methylpyrazine greater than 4.

9. The roasted coffee according to claim 8, wherein the weight ratio of guaiacol to dimethyl disulfide is less than 30.

10. The roasted coffee according to claim 8 or claim 9, wherein the weight ratio of dimethyl trisulfide to 2,3 - diethyl - 5 - methylpyrazine is greater than 0.

6.

11. The roasted coffee according to any one of claims 8 to 10, wherein the weight ratio of dimethyl disulfide to methanethiol is greater than 1.

5.

12. The roasted coffee according to any one of claims 8 to 11, the roasted coffee having a roast color between 30 CTN and 100 CTN.

13. The roasted coffee according to claim 8 or claim 9, the roasted coffee being encapsulated roasted coffee for further roasting.

14. The roasted coffee according to claim 13, wherein the coffee has a roast color between 75 CTN and 160 CTN.

15. A container for use in a beverage preparation device, the container containing the roasted coffee according to any one of claims 8 to 12.

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