JP6528231B2 - Coffee bean processing method, coffee bean manufacturing method and coffee bean processing system - Google Patents

Description

  The present invention relates to a coffee bean processing method, a coffee bean manufacturing method and a coffee bean processing system.

  Coffee is mainly grown in the tropics. Generally, harvested coffee seeds are stripped of seed coat and pulp in the production area. The coffee beans (raw beans) from which the seed coat and pulp have been removed (refined) are transported to the place of consumption.

  There are two methods for refining coffee beans: natural drying and washing. In the natural drying method, harvested coffee seeds are sun-dried and then threshed to peel seed coat and flesh. After that, it is further sieved to obtain green beans. In this method, silver skin (astringent skin), parchment (inner skin), flesh etc. are not sufficiently separated and removed. Also, because it takes two to three weeks to dry it on concrete, bricklaying or dirt-hardened non-paved roads, it can not be said that hygiene management is sufficient and it is easy to get dirty when it dries. For this reason, coffee beans (unwashed coffee) transported from Brazil or other production areas that adopt the natural drying method are contaminated with dirt, dust, and further, such as stones and wood fragments, in addition to seed coat and pulp. It is known that it is extremely dirty. Even in the case of the water-washing type purification adopted in a production area such as Colombia, the green beans after water-washing are dried outdoors until the water content becomes about 15% or less. For this reason, the dirt at the time of drying can not be avoided.

  Coffee beans are generally transported by sea. For this reason, in addition to postharvest pesticides and hemp fibers mixed during transportation, a fermented odor or mold odor in a high temperature ship hold is attached to coffee beans. For this reason, the coffee beans transported and imported to the vicinity of the consumption area are contaminated by a large amount of contaminants even if they are raw beans of high quality regardless of the purification method in the production area The fact is that it has an offensive odor such as odor and mold odor.

  Coffee beans are used as raw beans as raw materials for extracting ingredients such as caffeine, or after roasting and for drinking. The taste, aroma and other flavors of coffee used for roasting vary greatly depending on the roasting conditions as well as differences in the place of production and variety. Also, green bean stains affect the taste, aroma and other qualities of coffee after roasting. In particular, natural dried refined green beans have a high residual content of parchment which tends to cause incomplete roasting, seed coats that cause astringency and turbidity of extracted coffee, especially silver skin, and also contaminations In addition, the quality is unstable, and after roasting a muddy odor remains.

  However, as for the cleaning of coffee beans, it is only practiced to blow the green beans to be roasted and to disperse hemp fibers and the like. However, green coffee beans have stains on not only visible stains but also on the center cut portion, which can not be completely removed by a blower or the like.

  Water washing is avoided because coffee beans are susceptible to loss of flavor due to the presence of moisture and can not be stored. Moreover, since roasting of coffee beans is performed at a high temperature of about 200 to 250 ° C., it is considered that there is no problem even if there is a certain amount of contaminants during roasting. The need for dry beans in the roaster is another reason to avoid water washing.

  Patent Document 1 describes a method of washing uncooked dried green coffee beans with water and centrifugally dewatering.

Patent 3022885 gazette

  Soaking the green coffee beans in water for a long time is undesirable for maintaining the quality of the coffee beans, as can be seen from the fact that water washing has conventionally been avoided.

  Then, this invention aims at removing stain | pollution | contamination from a coffee green bean, suppressing deterioration of quality.

To achieve the above object, the present invention provides a coffee bean processing method, to disengage the fine powder was transferred in air adheres to the green coffee beans to collide the dried green coffee beans unroasted each other The removal process of sucking out and removing the fine powder together with air, the water washing process of washing the green coffee beans with stirring after the removal process, the water washing process of stirring the green coffee beans, and dewatering the green coffee beans after the water washing process And a drying step of reducing the total amount of internal water content and surface water to 20% by weight or less.

In the method for producing roasted coffee beans according to the present invention, the uncooked dried green coffee beans are transferred by air so as to collide with each other to release the fine powder adhering to the green coffee beans and the fine powder together with the air is released. The removal step of sucking out and removing the powder, and the washing step of washing the green coffee beans with stirring after the removal step, and the water washing step of washing the green beans after the washing step; The method further comprises the steps of: drying the total amount of surface moisture to 20% by weight or less; and roasting the green coffee beans to obtain roasted coffee beans after the drying step.

In the present invention, in the coffee bean processing system, the uncooked dried green coffee beans are transferred by air so as to collide with each other, the fine powder adhering to the green coffee beans is detached, and the fine powder is mixed with air. A powder removing device for sucking out and removing it, a water washing device for washing the green coffee beans from which fine powder is removed by the powder removing device while stirring and washing, and the green coffee beans washed with the water washing device And a drying device for reducing the total amount of the internal water content and the surface water to 20% by weight or less.

  ADVANTAGE OF THE INVENTION According to this invention, stain | pollution | contamination can be removed from a coffee green bean, suppressing the fall of quality.

It is a systematic diagram of the coffee bean processing system in one embodiment of the coffee bean processing method concerning the present invention. It is a flowchart in one embodiment of the coffee bean processing method concerning the present invention.

  One embodiment of a coffee bean processing method according to the present invention will be described with reference to the drawings. Note that this embodiment is merely an example, and the present invention is not limited to this. The same or similar configurations will be denoted by the same reference symbols, and overlapping descriptions will be omitted.

  FIG. 1 is a system diagram of the coffee bean processing system of the present embodiment.

  The coffee bean processing system comprises a powder removal device 10, a washing device 20 and a drying device 30.

  The powder removing apparatus 10 has a receiving tank 11, a valve 12, a green bean transfer pipe 13, a receiver tank 14, a rotary valve 15, a green bean transfer blower 16, a dust collection pipe 17, a filter 18 and a dust collection blower 19 There is. The receiving tank 11 comprises, for example, a cylindrical portion opened at the top and a funnel-shaped portion provided below the cylindrical portion.

  The green bean transfer piping 13 is connected to the lower end of the receiving tank 11 via a valve 12. An air gap is formed in the connecting portion between the green bean conveying pipe 13 and the receiving tank 11 so that the secondary air flows from the outside. The green bean transfer piping 13 extends vertically downward from the connection portion with the receiving tank 11 and then extends once horizontally, then extends vertically upward, is bent horizontally, and is connected to the side surface of the receiver tank 14. A pipe extending horizontally from the green bean transfer blower 16 is connected to a portion that extends downward from the connection portion of the green bean transfer pipe 13 with the receiving tank 11 and bends horizontally.

  The receiver tank 14 is formed, for example, in a cylindrical shape. The lower end of the receiver tank 14 is connected to the rotary valve 15. A dust collection pipe 17 is connected to the upper end of the receiver tank 14. The lower end of the receiver tank 14 is connected to the cleaning device 20 via a rotary valve 15. The rotary valve 15 has two outlets, the other outlet being connected to the receiving tank 11.

  The dust collection pipe 17 is connected to the dust collection blower 19 via the filter 18.

  The cleaning apparatus 20 includes a cleaning tank 21, an agitator 22, a valve 23, and a pipe 24. The cleaning tank 21 is formed in, for example, a cylindrical shape whose upper side is opened. A piping 24 is connected to the lower end of the cleaning tank 21 via a valve 23. The stirrer 22 stirs the water stored in the washing tank 21. The other end of the pipe 24 connected to the washing tank 21 extends to the drying device 30. The drying device 30 is, for example, a centrifugal dewatering device.

  A sorting machine 40 is connected to the drying device 30. A roasting machine 50 is connected to the sorting machine 40.

  FIG. 2 is a flowchart of the coffee bean processing method of the present embodiment.

  This coffee bean processing method has a removal step (S1), a water washing step (S2), a drying step (S3), a sorting step (S4) and a roasting step (S5). In the removing step (S1), first, uncooked dried green coffee beans 90 are put into the receiving tank 11 (S1). The green coffee beans 90 are, for example, coffee beans produced at a production area and transported to a treatment site. This coffee green bean 90 is a wash that is transported from Colombia or the like, or an Ann Washed green bean that is transported from Brazil or the like. Fine powder such as dirt may be attached to the green coffee beans 90.

  Next, in a state where the rotary valve 15 is switched to the receiving tank 11 side, air is blown out from the green bean conveying blower 16. The air blown out from the green bean transfer blower 16 sends out the green coffee beans falling from the green bean transfer piping 13 toward the receiver tank 14. The green coffee beans sent to the receiver tank 14 fall to the rotary valve 15 side by gravity. Thus, by transferring the green coffee beans, the green coffee beans collide with each other, and the fine powder such as dirt attached to the surface of the green coffee beans is released from the green coffee beans.

  At this time, by sucking the air from the receiver tank 14 by the dust collection blower 19, dirt lighter than green coffee beans is sent to the filter 18 side through the dust collection pipe 17. As a result, the fine powder adhering to the green coffee beans is removed and captured by the filter 18. Thus, in the removal step (S1), the fine powder adhering to the unroasted dried green coffee beans is removed.

  In the washing step (S2), first, with the valve 23 closed, the rotary valve 15 is switched to the washing device 20 side, and the green coffee beans from which fine powder has been removed in the removal step (S1) is charged into the washing device 20 Do. Thereafter, while the valve 23 is closed, water is injected into the washing device 20, and the water in the washing device 20 is stirred by the stirrer 22. Thus, the green coffee beans are washed with water while being stirred. The water may be replaced and the water washing step (S2) may be performed multiple times.

  It is preferable to forcibly agitate the water in the washing device 20 with a device equipped with a stirring blade, since the dirt on the silver skin and the center cut portion is difficult to remove by water flow stirring. The amount of water to be added to the green beans may be any amount that can sufficiently contact the green beans and produce a water flow, and specifically, it is preferably about the same as that of the green beans to about 1.5 times. The water used for washing is desirably at room temperature or less, specifically at 20 ° C. or less, preferably at 10 ° C. or less, more preferably at 5 ° C. or less. Generally, when cleaning dirt, using warm water has better cleaning efficiency than using low-temperature water, but it is better to use a water below room temperature to clean the dirt by stirring rather than using warm water. Preferred from the quality aspect of coffee beans. The green beans of the coffee after washing usually have a wash water turbidity (measured according to JIS K 0101) of 10 or less.

  In the drying step (S3), first, the valve 23 is opened, and the green coffee beans after washing with water are introduced from the washing device 20 into the drying device 30. The transfer of green coffee beans from the washing device 20 to the drying device 30 can use, for example, dropping by gravity or delivery by compressed air. Thereafter, the drying device 30 is operated, water is attached to the surface by water washing, and the green coffee beans in which the water has penetrated are dried. It is preferable that the total content of the internal moisture content and surface moisture of the green coffee beans after drying be 20% by weight or less.

  The drying device 30 is, for example, a combination of a centrifugal dewatering device and a blower drying device. It is preferable to carry out centrifugal dehydration at a rotational speed of 1000 rpm or more for 5 minutes or more. The total water content of the green coffee beans after centrifugal dewatering is preferably 19% or less. It is preferable to dry the green coffee beans after centrifugal dewatering under forced air.

  In the sorting step (S4), the dried coffee green beans are sorted by the sorter 40. For example, while shooting green coffee beans to be transported with a camera, the color, pattern, size, etc. are measured by data processing of an optical image to remove green coffee beans of poor quality. In the roasting step (S5), the green coffee beans which have been dried and selected to be only good products are roasted by the roasting machine 50.

  In the present embodiment, since the fine powder is removed from the green coffee beans in a dry state in the removal step (S1), the soil of the green coffee beans can be sufficiently removed even if the water washing time is short. That is, since the time for immersing the green coffee beans in water is shortened, the deterioration of the green coffee beans quality is suppressed. Moreover, since the stains are removed from the green coffee beans in the removal step (S1) and the water washing step (S2), the quality of the green coffee beans is easily visible. For this reason, it is possible to sort only non-defective coffee green beans by the sorting step (S4).

  There are no particular limitations on the type of coffee, the production area, etc. to be subjected to this treatment. The cultivar may be any of Arabica (Bourbon), Robusta and Riberica. The unrefined coffee green beans refined (dried) in the production area may be used, and the purification method in the production area may be either a water washing method or a natural drying method. The moisture content of such green coffee beans is usually about 11 to 13% for the natural drying type (for example, Brazil) and about 14 to 15% for the water washing type (for example, Indonesia).

DESCRIPTION OF SYMBOLS 10 ... Powder removal apparatus, 11 ... Receiving tank, 13 ... Raw bean conveyance piping, 14 ... Receiver tank, 15 ... Rotary valve, 16 ... Raw bean conveyance blower, 17 ... Dust collection piping, 18 ... Filter, 19 ... Dust collection blower 20: Washing device, 21: Washing tank, 22: Stirrer, 23: Valve, 24: Piping, 30: Drying device, 40: Sorting device, 50: Roasting device

Claims (5)

A removal step of transferring the uncooked undried roasted green coffee with air so as to collide with each other , separating the fine powder adhering to the green coffee, and sucking out and removing the fine powder with the air ;
After the removing step, a washing step of washing the green coffee beans with stirring while washing;
A drying step of dewatering the green coffee beans to make the water content 20% by weight or less in total of the internal water content and the surface water after the water washing step;
A method of processing coffee beans, comprising:   The coffee bean processing method according to claim 1, further comprising a sorting step of sorting the green coffee beans after the drying step.   The coffee bean processing method according to claim 2, wherein the sorting step uses an optical image of the green coffee beans. A removal step of transferring the uncooked undried roasted green coffee with air so as to collide with each other , separating the fine powder adhering to the green coffee, and sucking out and removing the fine powder with the air ;
After the removing step, a washing step of washing the green coffee beans with stirring while washing;
A drying step of dewatering the green coffee beans to make the water content 20% by weight or less in total of the internal water content and the surface water after the water washing step;
A roasting step of roasting the green coffee beans to obtain roasted coffee beans after the drying step;
A method for producing roasted coffee beans, comprising: A powder removing device for transferring the unroasted dried green coffee with air so as to collide with each other to release the fine powder adhering to the green coffee and sucking out the fine powder with air to remove the fine powder ;
A water washing apparatus for washing the green coffee beans from which fine powder has been removed by the powder removing apparatus while stirring and stirring;
A drying device for dewatering the green coffee beans washed by the water washing device to make the water content 20% by weight or less in total of the internal water content and the surface water;
A coffee bean processing system characterized by having.

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