JP2756993B2 - Method and apparatus for evaluating the quality of coffee beans - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for evaluating the quality of coffee beans.

[Conventional technology and its problems]

Generally, commercially available coffee beans are those obtained by drying, threshing, and carefully filtering the fruits of ripe coffee beans, feeding the green beans into a roaster, and imparting flavor and aroma in a roasting process. In other words, the roasting of coffee beans causes the components of the green beans to undergo chemical changes to produce volatile fragrances, caramel colors, etc., and that the coffee taste of sourness, bitterness, sweetness, and aroma depends on the roasting conditions. Has been known.

By the way, the conventional method for judging the quality of coffee beans is based on a so-called sensory test, in which the coffee beans roasted in the roasting step are pulverized and tasted by adding and extracting boiling hot water. It takes a lot of people and a long time to be fair.
Moreover, the judgment is made based on the taste of human being greatly influenced by human factors, and cannot be an objective and universal judgment, and therefore requires a skilled person.

From the above, it goes without saying that the development of a method and an apparatus for determining coffee beans that can be objectively and simply performed without being influenced by human factors has been desired.

[Object of the invention]

Table 1 shows the chemical components of raw beans and those of roasted beans chemically measured and analyzed.

According to Table 1, it can be understood that the components significantly reduced after roasting are protein, sucrose and chlorogenic acid, and that these three components are the main components that produce taste and flavor by a thermal reaction during roasting. It is considered.

The present invention seeks to measure the absorbance of a target coffee bean by near-infrared spectroscopy in a short time, thereby obtaining an objective coffee bean quality evaluation value.

[Means for solving the problem]

According to the present invention, a measured absorbance obtained from a certain amount of coffee beans by near-infrared spectroscopy, and a quality evaluation value including acidity, bitterness, sweetness, and aroma obtained by a sensory test of known coffee beans and a known value A method for solving the above-mentioned problem is provided by a coffee bean quality evaluation method in which a quality evaluation value is calculated based on a predetermined quality evaluation coefficient based on a measured absorbance value of coffee beans.

In addition, a comprehensive evaluation is made based on the absorbance measurement value obtained from a certain amount of coffee beans by near-infrared spectroscopy and the quality evaluation value including sourness, bitterness, sweetness, and aroma obtained by a sensory test of known coffee beans. A means for solving the above-mentioned problem is provided by a coffee bean quality evaluation method in which a comprehensive evaluation value is calculated based on an evaluation value and a quality evaluation coefficient predetermined based on a known absorbance value of coffee beans.

Further, according to the apparatus of the present invention, an irradiating means for irradiating a coffee bean sample with near-infrared light in a plurality of wavelength bands, a light-receiving means for receiving near-infrared light after irradiating the coffee beans, A near-infrared light spectrometer equipped with signal processing means for converting the near-infrared light received by the means into absorbance and outputting the absorbance, and a quality evaluation value obtained by a sensory test of a known coffee bean. A storage device in which a quality evaluation coefficient determined by the known absorbance of the coffee beans output by the signal processing unit is set; and an absorbance of the measurement target coffee beans output by the signal processing unit and the quality evaluation coefficient Solving the problem by providing a coffee bean quality evaluation device comprising: a calculation device for calculating a quality evaluation value including sourness, bitterness, sweetness, and aroma of the coffee beans to be measured. It was because of means.

An irradiating unit that irradiates the coffee bean sample with near-infrared light in a plurality of wavelength bands; a light-receiving unit that receives the near-infrared light after irradiating the coffee bean; A near-infrared spectrophotometer equipped with signal processing means for converting infrared light into absorbance and outputting the absorbance, and comprehensive evaluation determined comprehensively from quality evaluation values obtained by a sensory test of known coffee beans A storage device in which a quality evaluation coefficient determined by a value and a known absorbance of coffee beans output by the signal processing unit is set; and an absorbance of the coffee beans to be measured output from the signal processing unit and the quality evaluation. A computing device for calculating a comprehensive evaluation value that is comprehensively determined by a coefficient and a quality evaluation value including the sourness, bitterness, sweetness, and aroma of the coffee beans to be measured; And a means for solving the above problems by providing a valence device.

(Operation)

A narrow bandpass filter that crushes coffee beans and passes only specific wavelengths suitable for components related to the taste and flavor of coffee, such as proteins, lipids, sucrose, and chlorogenic acid, which are the main elements that create the taste and flavor of coffee. The absorbance of the sample bean is measured by using the detected value, and a quality evaluation coefficient for calculating a quality evaluation value previously determined by a multiple regression analysis method based on the detected value and the evaluation value of the sensory test, sourness, bitterness, and sweetness. -To calculate the quality evaluation value of fragrance etc.

Alternatively, a total evaluation value is calculated from a total evaluation value comprehensively determined based on quality evaluation values such as sourness, bitterness, sweetness, and aroma, and a predetermined quality evaluation coefficient.

In addition, pulverize the sample beans, especially with high-speed
The use of powder particles having a particle size of 0 μm or less can eliminate the influence on the absorbance measurement by the near-infrared spectroscopy due to the pulverized particle size, and can more accurately measure the absorbance by the near-infrared spectroscopy.

Furthermore, in order to change the incident angle of the incident optical axis with respect to the optical filter surface disposed between the light source and the measurement unit disposed between the light source and the measurement unit, the inclination angle of the optical filter surface is changed, and By continuously scanning the wavelength band in the wavelength range of 1100 to 2500 nm, it becomes possible to select an optimum filter in the absorbance analysis and obtain a continuous absorbance curve of the sample.

Next, installing a heating device inside the measurement device, or installing a temperature detector in or near the sample container of the measurement device and correcting the circuit of the control device means that the near-infrared rays originally irradiated on the sample are absorbed by the sample. This is a phenomenon that occurs when a chain of atoms constituting a molecule vibrates due to thermal energy.Since the natural vibration differs depending on the type of atom and the chain state, the molecular structure depends on the initial thermal energy of the sample. Due to the inaccurate measurement of the absorption due to the difference in temperature, the initial thermal energy of this sample is compared with the reference temperature and corrected, and the change in outside air temperature to the absorbance measurement value of near infrared spectroscopy Therefore, it is not necessary to consider the influence.

Further, the moisture content of the sample bean is calculated from the measured absorbance value, and the moisture content is calculated during the quality evaluation value calculation to obtain a quality evaluation value. By correctly correcting the measured absorbance value of the spectroscopic analysis, it is possible to obtain a more accurate quality evaluation value or comprehensive evaluation value of the sample beans.

〔Example〕

Hereinafter, a first embodiment of a coffee bean quality evaluation apparatus according to the present invention will be described with reference to the accompanying drawings FIG. 1 to FIG.

FIG. 1 is a schematic view of a coffee bean quality evaluation apparatus 1 according to the present invention when viewed from the front. Inside the cabinet 2, a near-infrared spectroscopic analyzer 3 and a controller 4 whose detailed configuration will be described with reference to FIG.
On the front panel of the cabinet 2, a sample container mounting box 5 for mounting a sample container (sample placement unit) for storing the coffee beans to be measured, a light emitting diode or a CRT type for visually displaying operation procedures and calculation results of the apparatus. A display device 6, an operation push button 7, and a printer 8 that enables a hard copy of a calculation result are provided. The control device 4 is connected to a light source, a detector, a display device 6, an operation push button 7, a printer 8 and the like of the near-infrared spectroscopy device 3, and an input / output signal processing device 4a for processing various signals. Specific coefficients individually set for each main component of coffee beans for calculating the evaluation value, bean prices for each brand or grade input through the input device (keyboard) 9, various corrections and various controls A storage device 4b for storing procedures and the like, and a calculation device 4c for calculating a quality evaluation value or the like of coffee beans based on the measured value obtained by the near-infrared spectroscopic analyzer 3 and the specific coefficient. In addition, a specific coefficient and a necessary correction value that are individually set for each main component of the coffee beans are stored in a read-only memory (hereinafter, referred to as a ROM) in the storage device 4b in advance. Further, the printer 8 is not limited to the built-in type, but may be an external connection type.

By the way, the near-infrared rays irradiated to the sample are absorbed by the sample because the chain of atoms that make up the molecule vibrates due to thermal energy, and the natural frequency differs depending on the type of atom and the state of the chain. In addition, the magnitude of the vibration changes in the near-infrared wavelength region, causing heat absorption. In addition, when the sample initially has a small amount of thermal energy (when the temperature is low), the amount of absorption due to the difference in molecular structure is not accurately measured due to the small vibration, so that it is necessary to correct the temperature. Normally, no correction is required above 20 ° C.

The temperature setting device 77 adjusts the temperature of the near-infrared spectroscopic analyzer 1 to a constant temperature. When the temperature is low, the heating device 78 is operated to set the temperature to 25 ° C. normally. This has the purpose of preventing the sample temperature from changing and eliminating errors due to the temperature of the electric circuit.

FIG. 2 is a cross-sectional view of a main part of an embodiment of the near-infrared spectroscopic analyzer 3 disposed inside the cabinet 2. The illustrated near-infrared spectrometer 3 is of a reflection type, and includes, as main components, a light source 31, a reflector 32, a narrow band-pass filter 33, an integrating sphere 34, and detectors 35a and 35b. Light source 3
The light emitted from 1 and converted into parallel rays through an appropriate optical system (not shown) is converted into near-infrared light of a specific wavelength by passing through a narrow band pass filter 33, and then the inclination angle is changed. The direction can be changed toward a lighting window 36 provided by opening the upper part of the integrating sphere 34 by the reflecting mirror 32 configured to be freely changeable. Light is reflected by the reflector 32 and the lighting window of the integrating sphere 34
The near-infrared light entering the integrating sphere 34 via the
The light is irradiated to the measuring section 37 provided with the bottom of the sample container 34 opened, that is, the coffee beans 55 in the sample container 52 mounted at a predetermined position behind the sample container mounting box 5 are irradiated from directly above. The diffusely reflected light from the coffee beans 55, while being reflected inside the integrating sphere 34, ultimately reaches a pair of detectors 35a and 35b disposed at target positions around the measurement unit 37, Thereby, the intensity of the reflected light is measured. Note that a sensor 79 for measuring the temperature of the sample container is provided in the sample container mounting box 5 below the sample container 52, and the analysis value is corrected by the sample temperature as described in detail for the temperature setting device 77. Further, in the illustration omitted, a pair of detectors, that is, two detectors indicated by reference numerals 35a and 35b are provided to correct the optical symmetry and efficiently receive the reflected light from the coffee beans 55. But,
The number is not limited to two and may be one or three or more detectors.

Here, the light source 31 is provided between the light source 31 and the reflecting mirror 32.
The configuration of the narrow band-pass filter 33 which becomes near-infrared light of a specific wavelength when light emitted from the filter passes therethrough, and physical characteristics required for the filter will be described. The narrow band-pass filter 33 includes an arbitrary number of filters (for example, six filters 33a to 33a) each having a different dominant wavelength pass characteristic.
3f), these are mounted on a rotating disk and rotated by an appropriate angle so that the filter can be sequentially selected and exchanged so that a desired filter is located on a line connecting the light source 31 and the reflecting mirror 32. The dominant wavelength in the transmission characteristics of the filter refers to the maximum transmission wavelength of near infrared rays that are transmitted when the incident optical axis is perpendicular to the surface of the filter. As another specific configuration example of the narrow band transmission filter 33, a prismatic reflecting mirror 32 is located inside, and a plurality of filters 33a to 33f are respectively located at positions facing each surface of the reflecting mirror. There is also a configuration in which it is formed in a prism shape and can be rotated. When the narrow band-pass filter 33 is a disk-shaped filter, if the inclination angle of the rotating surface with respect to the incident optical axis can be finely and continuously adjusted by a motor or the like, each filter can be adjusted. Near-infrared light of a different wavelength shifted from the main wavelength of the transmission characteristic of the NIR can be continuously produced. This is a well-known phenomenon.When the angle of the incident optical axis with respect to the filter surface is changed from 90 °, the maximum transmission wavelength shifts in the range of several tens of nm according to the angle change. It depends on the phenomenon.

Next, physical characteristics required for the narrow band pass filter 33 will be described with reference to FIG. FIG. 3 is a graph (absorbance curve) showing the relationship between the irradiation wavelength and the absorbance when different coffee beans are irradiated with near-infrared light whose wavelength changes continuously. The absorbance logIo / I is the common logarithm of the reciprocal of the ratio of the reflected light amount I from the sample beans to the reference irradiation light amount (total irradiation light amount) Io. It can be easily understood that the content of each of the components is remarkably expressed as a difference in absorbance. Since the present invention measures the absorbance of coffee beans at an arbitrary wavelength using this phenomenon, as a wavelength of near-infrared light irradiated on coffee beans for measurement,
In the wavelength range of 1100 to 2500 nm, a specific peak is observed on the absorbance curve due to the components of coffee beans (In this example, An
m, Bnm ... Fnm) The absorbance is measured in the wavelength band. Therefore, each filter 33a provided in the narrow band-pass filter 33
33f are required to have each wavelength as a specific transmission characteristic, that is, a main wavelength, in order to generate near-infrared light of each wavelength suitable for calculation of a quality evaluation value contained in coffee beans.

Next, a specific operation of the coffee bean quality evaluation device of the present invention having the above configuration will be described. First, the light source 31 is turned on by operating the operation push button 7, and until the near-infrared light of a specific wavelength reaching the measuring unit 37 based on the light emitted from the light source 31 is stabilized, the near-infrared spectroscopic analyzer 3 Is preheated by a heating device 78 or the like. After a lapse of a predetermined time for preheating, the sample container mounting box 5 is once pulled out of the cabinet 2 of the apparatus, and the sample container 52 filled with the crushed coffee bean sample 55 is placed at a predetermined position. To complete the measurement preparation. At this time, the temperature sensor 79 of the sample container device box 5 measures the temperature of the sample container 52. Note that the coffee beans 55 are desirably pulverized to have a particle size of about 50 microns or less in order to prevent an error in the measured value, but it is not necessary to pulverize the particles. Also, in order to reduce light loss due to diffuse reflection, ground coffee beans 55
It is preferable that the sample is filled in the sample container 52 in such a manner that the surface becomes a flat surface, and that the surface is covered with a transparent glass plate while applying some pressure.

When the measurement preparation work is completed, first, a filter 33A having Anm as a main wavelength is selected to be on a line connecting the light source 31 and the reflecting mirror 32, and near-infrared light having a wavelength of Anm is converted into coffee beans 55. The measurement of the reflection absorbance when irradiating is started. The work of measuring the reflection absorbance is 55
Measurement of the total irradiation amount, that is, the reference light amount,
Measurement of the amount of reflected light actually reflected by the coffee beans 55 when the reference irradiation light amount is applied to the coffee beans 55
Consists of two measurements. Although one of the two measurements may be performed first for one filter, the following description will be made on the assumption that the measurement of the reference irradiation light amount is performed first. The measurement of the reference irradiation light amount is performed by setting the tilt angle of the reflecting mirror 32 having a variable tilt angle to an angle at which the reflected light from the mirror 32 directly hits the inner wall of the integrating sphere 34.
It is carried out in a state changed by rotating means (not shown) using a motor or the like. By doing so, the light from the reflecting mirror 32 directly applied to the inner wall of the integrating sphere 34 reaches the detectors 35a and 35b finally while diffusely reflecting the inner wall in multiple directions,
It is detected as a reference irradiation light amount. On the other hand, the measurement of the amount of reflected light from the coffee beans 55 is performed according to the above-described principle after the inclination angle of the reflecting mirror 32 is returned to the original position shown in FIG. In addition, selection of the first filter after completion of measurement preparation,
It goes without saying that the execution of each of the measurement of the reference irradiation light quantity and the measurement of the reflected light quantity can be performed automatically by storing a procedure program in the ROM in the storage device 4b of the control device 4 and following the program. Further, it is also useful to increase the measurement accuracy by performing each of the above-described measurement of the reference irradiation light amount and the reflected light amount for one filter a plurality of times, and taking an average of the measured values.
Each measurement value based on the reference irradiation light amount detected by the detectors 35a and 35b and the reflection light amount from the coffee beans 55 is communicated to the control device 4 and written in a memory (hereinafter, referred to as a RAM) in the storage device 4b. Is stored once.

When the measurement of the absorbance at the irradiation wavelength Anm is completed, the flow shifts to the measurement of the absorbance at the next irradiation wavelength, that is, at Bnm in this embodiment. Here, the measurement of the reference irradiation light amount and the measurement of the reflected light amount are performed by the same method and procedure as in the case of Anm. Each measurement value is communicated to the control device 4 as actual measurement data as in the previous time, and is temporarily stored in the RAM in the storage device 4b. Similarly, the remaining absorbance measurements, that is, absorbance measurements at the wavelengths Cnm, Dnm, Enm, and Fnm, are sequentially performed, and the measured values are communicated to the control device 4 as actual measurement data, and are stored in the RAM.
Is stored. It should be noted that the operation of exchanging and selecting each of the filters 33a to 33f of the narrow band pass filter 33 accompanying the transition to the absorbance measurement at a specific wavelength after the absorbance measurement at a specific wavelength is completed is usually performed by a storage device of the control device 4. It is automatically performed according to the procedure program pre-written in the ROM in 4b, but even in the case of this embodiment, it is not always necessary to perform the absorbance measurement for all the six wavelengths.
The wavelength to be measured can be arbitrarily selected in consideration of the accuracy required for the required quality evaluation value or the time required for measurement, and the selection can be made by selecting the measurement wavelength in the operation push button 7. This can be done with a button.

The measurement of the absorbance described so far is performed simply by sequentially exchanging the six filters 33a to 33f set in the narrow band pass filter 33, thereby measuring the spot-like absorbance at each main wavelength of each of the filters 33a to 33f. Although it was a method, as described above, if the incident angle of the incident light with respect to the surface of the filter is changed from the reference 90 °, the phenomenon that the maximum transmission wavelength shifts in the range of several tens nm from the main wavelength is used. , Wavelength region where the difference in component content is noticeable in the absorbance difference
Continuous absorbance measurement at 1100 nm to 2500 nm is also possible.
In the case of the first embodiment shown in the figure, the angle of the optical axis incident on the narrow band-pass filter 33 formed in a disc shape is adjusted appropriately by a motor or the like based on a command signal from the controller 4 (not shown). This is possible by finer and continuous changes.

Next, the arithmetic unit 4c of the control device 4 is connected to the RAM of the storage device 4b.
A large number of actually measured data obtained by the absorbance measurement stored in, for example, the measured values of the reference irradiation light amount and the reflected light amount at each measurement wavelength, and for calculating the quality evaluation value stored in advance in the ROM of the storage device 4b. A quality evaluation value of the coffee beans is calculated based on the quality evaluation coefficient value. The RO of the storage device 4b
This quality evaluation coefficient value written in advance in M is based on a quality evaluation value obtained by, for example, a sensory test for a large number of coffee beans, and performs signal processing on an absorbance measurement value from a detector,
It is a constant determined by multiple regression analysis.

Here, an example of a multiple regression analysis for obtaining a quality evaluation coefficient will be described. For example, six filters P ₁ nm, P ₂ nm, P ₃ nm, P ₄ n
Using m, P ₅ nm and P ₆ nm, it is assumed that the following linear relationship is established from the measured value of absorbance from the detector for the quality evaluation value A (for example, sourness) of coffee beans.

_{A 1 = F 0 a + F} 1 a · X 11 + F 2 a · X 21 + ... + F 6 a · X 61 + ε 1 this time An: quality evaluation value by such functional tests of the coffee beans.

F ₀ a~F ₆ a: quality evaluation coefficient values by multiple regression analysis.

X ₁ ~X _6: P ₁ ~P filter corresponding absorbance ₆ (log value).

εn: error.

It is.

Substituting into n multiple regression equation performs absorbance distribution for the samples in the same _{way, A 1 = F 0 a +} F 1 a · X 11 + F 2 a · X 21 + ...... + F 6 a · X 61 + ε 1 A 2 = F ₀ a + F ₁ a X ₁₂ + F ₂ a X ₂₂ + ... + F ₆ a X ₆₂ + ε ₂ An = F ₀ a + F ₁ a X ₁ n + F ₂ a X ₂ n + ... + F ₆ a X ₆ n + εn, and a multiple regression analysis is performed using the above n multiple regression equations, and F ₀
to F ₆ obtains the quality evaluation coefficient values a when _{A = F 0 a + F 1} a · X 1 + F 2 a · X 2 + ... + F 6 a · X 6 next. The relational expression between the quality evaluation value of coffee beans and the measured absorbance value is established.

by the way. Filter the filter P ₁ to P ₆ are one and shows the embodiment, the optimum filter selection of the to ensure accuracy, the wavelength range subdividing the regression analysis in the wavelength range of 1100nm~2500nm For example, all are combined and found in a matrix using the absorbances obtained at 2 nm intervals.

Next, the absorbance of n samples is measured by a detector for other quality evaluation values B (for example, bitterness) of coffee beans using the six filters, and the following equation is established similarly to the quality evaluation values.

B = seeking F ₀ b + F ₁ in _{b · X 1 + F 2 b} · X 2 + ... + F 6 b · X 6 or more as the component performs multiple regression analysis quality assessment factors, absorbance detector quality evaluation value Determine by measurement.

By the way, since it is clear that the moisture contained in the sample beans affects the pulverized particle size at the time of pulverization or the absorbance at the time of near-infrared spectroscopic analysis, when calculating the measured absorbance of the target coffee beans and the quality evaluation coefficient, The calculation is performed with the moisture value of the target coffee beans as a correction value.

This moisture value can also be determined from the above-mentioned measured absorbance. In other words, the natural frequency is clear from the molecular formula of water, and the wavelength is set to 1940 nm. Based on the absorbance measurement value obtained in this wavelength range, the water value is calculated by calculating the water conversion coefficient of the storage device. Things. This moisture conversion coefficient can also be determined more simply than the above-mentioned quality evaluation coefficient from the relational expression between the measured absorbance value and the measured moisture value by chemical analysis or the like.

The obtained quality evaluation coefficient and the quality evaluation value calculated by the calculation formula of the absorbance measurement are visually displayed on the display device 6 at the same time when the calculation in the arithmetic device 4c is completed, and are automatically or automatically operated. 7 is fed out from the printer 8 as a hard copy based on a command to the printer 7. Further, the moisture and the like obtained in the process of obtaining the quality evaluation value may be simultaneously displayed on the display device 6 together with the quality evaluation value.

A total evaluation value for comprehensively evaluating coffee beans can be obtained based on the quality evaluation values obtained as described above, for example, acidity, bitterness, sweetness, aroma, and the like.

For example, the evaluation method of each quality evaluation value is evaluated on a scale of 10 points, and the total score of each quality evaluation value is regarded as an overall evaluation value, or the degree of involvement of each quality evaluation value in the overall evaluation is changed and finer. There are various forms that can be evaluated according to preference and various forms are considered. Finally, it is possible to calculate an evaluation value such as belonging to this rank as a comprehensive evaluation of this coffee bean. According to the present invention, the above-mentioned quality evaluation value can be a fair judgment of coffee beans in a short time and not influenced by human factors.

The quality evaluation value of each coffee bean calculated by the present quality evaluation device can be stored as data in an external storage device using a magnetic medium such as a floppy disk. When calculating the ratio, etc., the data from the external storage device
It is also possible to read into the RAM of 4b and perform necessary calculations based on this.

In the above description, coffee beans are crushed. However, the coffee beans need not always be crushed.
However, in this case, it goes without saying that the accuracy of the obtained quality evaluation value is reduced to some extent.

In the analysis of coffee beans by the quality evaluation device, the coffee beans are crushed and analyzed. For the crushing of the coffee beans, a so-called centrifugal sample crusher that rotates at high speed in a wire mesh or includes crushing blades. Is used. This will be described below.

The sample pulverizing device 117 includes a quantitative supply unit 118, a pulverizing unit 119, and a separation unit 120, and will be described below in order from the quantitative supply unit 118. The fixed amount supply unit 118 of the present embodiment is composed of a so-called vibration supply device, that is, the one end of the supply gutter 122 having one end opened as the discharge unit 121 is close to the falling port 124 at the lower end of the input hopper 123, and Provided horizontally, the other end is supported by leaf springs 125A, 125B and vibrator 1
It is formed so as to be vibrated by 26.

Next, as for the pulverizing section 119, a supply hopper 127 having a lower end as a supply port 128 is provided below the discharge section 121 of the supply gutter 122. Below the supply hopper 127, a crusher 129 having an almost circular upper surface is provided, and in the center of the lower surface of the crusher 129,
Shaft of commutator motor 130 arranged below crusher 129
A boss 132 into which 131 is inserted is formed. Meanwhile, crusher 129
A number of crushing blades 133 are erected at equal intervals on the circumferential surface of the upper surface (12 in this embodiment).
By the drive of 30, it rotates at high speed together with the crusher 129. 131a
Is a screw portion for fixing the crusher 129 to the shaft 131.

Around the crusher 129, a cylindrical perforated ring 134 is provided through a crushing blade 133 and a slight gap.
A number of holes 134a are formed in 34. The size of the hole 134a is selected depending on the desired size of the sample, but is set to 50 μ in the present embodiment. Further, an outer peripheral ring 135 is provided around the perforated ring 134, and the outer peripheral ring 135 and the perforated ring 134 are provided.
Is formed in the dust collecting path 136.

Next, the separating unit 120 will be described. The separation unit 120 mainly includes a cyclone separator 137. That is, the dust collecting path 136 and the cyclone separator 137 are tangentially connected to each other by the communication air path 138, and the lower end of the cyclone separator 137 faces the sample bottle 139 in an airtight manner. The sample bottle 139 is set on a bottle mounting table 140 which can be lowered by a spring 141.

In the vicinity of the cyclone separator 137, a tubular filter 142 made of cloth or the like is mounted in a state of being suspended between the upper ring 143 and the lower ring 144, and the inner cylinder 145 and the upper ring 143 of the cyclone separator 137 have a U shape. They are connected by a letter-shaped connecting pipe 146. Further, it is connected to the lower end of the lower ring 144 to be connected to a dust collector 147.
Are detachably and airtightly provided.

When using this sample crusher 117, the sample crusher 1
When the 17 vibrator 126 is operated and the coarsely pulverized bean powder is introduced into the charging hopper 123, the bean powder in the vicinity of the dropping port 124 is appropriately and fixedly supplied through the supply gutter 122 vibrated by the vibrator 126. The toner is conveyed by the amount to the discharge unit 121 side, sequentially falls into the supply hopper 127 from the discharge unit 121, and is supplied to the pulverizer 129 via the supply port 128.

The crusher 129 rotates at a high speed (1
The rice grains supplied onto the crusher 129 are repelled to the perforated ring 134 side by centrifugal force, and are beaten by the impact / shear blade of the crushing wing 133 rotating at high speed, and shattered. Crushed. Thus,
The pulverized beans smaller than the hole 134a of the perforated ring 134 leak into the dust collecting path 136 from the hole 134a.

By the way, wind is generated by the crushing blades 133 rotating at a high speed, and the crushed bean powder causes the perforated ring 134 to be generated.
Leaks through the holes 134a,
Communicating the bean powder in 36, the air separator 138 and the cycle separator 1
Transport to 37.

The wind mixed with the bean powder conveyed into the cyclone separator 137 flows down the conical portion in a spiral shape, causing the stalled rice powder to fall into the sample bottle 139 from the lower end thereof. On the other hand, finer bean flour (for example, about 20 μm or less) and dust finer than these bean flours pass through the inner cylinder 145, the connecting pipe 146, and the upper ring 143 to the filter 142 together with the airflow, and are filtered by the filter 142. Only the airflow flows out of the filter 142, causing ultrafine bean powder and dust unsuitable for the desired sample to fall from the lower ring 144 into the dust collector 147.
The air that has flowed out of the filter 142 is exhausted to the outside of the device via a squirrel or the like (not shown).

In this way, the sample soybean powder adjusted to a certain width is filled in the sample container 33, inserted into the measuring unit 11 from the external supply unit, and starts measuring the absorbance.

In the quality evaluation device of the above-described embodiment, the absorbance when the coffee beans are irradiated with near-infrared light having a specific wavelength is measured by measuring the intensity of light reflected from the coffee beans. Although the apparatus was used, a transmission-type near-infrared spectroscopic analyzer that measures the intensity of transmitted light transmitted through coffee beans can also be used, and furthermore, the absorbance based on both reflected light and transmitted light can be used. A more accurate near-infrared spectroscopic analyzer for measuring the above-mentioned can be used.

〔The invention's effect〕

As described in detail above, according to the coffee bean quality evaluation device according to the present invention, anyone can use a sensory test based on taste with individual differences, or a method that requires time and requires skill, such as chemical quantitative analysis. Can obtain an accurate coffee bean quality evaluation value easily and in a short time.

Further, when the quality evaluation device according to the present invention includes the sample supply device, the content of a predetermined component of the coffee beans is measured, and the quality evaluation value of the coffee beans is obtained based on the measured content. The work of pulverizing the particles and the work of filling the sample container are all automated, and the measurement becomes simpler and more reliable.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a coffee bean quality evaluation device according to an embodiment of the present invention, FIG. 2 is a side sectional view of a main part of a near-infrared spectroscopic analyzer used in the quality evaluation device of FIG. The figure shows a graph (absorbance curve) showing the relationship between the near-infrared irradiation wavelength and the absorbance of coffee beans of different brands, FIG. 4 is a partially cutaway front view of a sample grinding device, and FIG. 5 is the sample grinding of FIG. FIG. 6 is a partially cutaway right side view of the device. In the figure, 1... Coffee bean quality evaluation device, 2.
Cabinet, 3 ... NIR spectrometer, 4 ... Control device, 4a ... Input / output signal processing device, 4b ... Storage device (RO
M, RAM), 4c: arithmetic unit, 5: sample container mounting box, 6
...... Display device, 7 ... Operation push button, 8 ... Printer, 9 ... Input device (keyboard), 31 ... Light source, 32 ... Reflector, 33 ... Narrow band pass filter, 33a
~ 33f ... Filter, 34 ... Integrating sphere, 35a, 35b ... Detector, 36 ... Lighting window, 37 ... Measurement unit, 52 ... Sample container, 55
…… Sample (coffee beans), 77 …… Temperature setting device, 78 …… Heating device, 79 …… Temperature sensor, 117 …… Sample crusher, 1
18: fixed quantity supply unit, 119: crushing unit, 120: separation unit, 12
1 ... discharge section, 122 ... supply gutter, 123 ... input hopper, 1
24… falling port, 125A, 125B, 125C… leaf spring, 126… vibrator, 127… supply hopper, 128… supply port,
129 …… Pulverizer, 130 …… Sized particle motor, 131 …… Shaft, 132 …… Boss, 133 …… Pulverized wings, 134 …… Perforated ring, 135 …… Peripheral ring, 136 …… Pulverizer, 137 … Cyclone separator, 138… Contact air path, 139… Sample bottle, 140… Bottle mount, 141… Spring, 142… Filter, 143… Upper ring, 144… Stock ring, 145…
... inner cylinder, 146 ... connecting pipe, 147 ... dust collector.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-167243 (JP, A) JP-A-62-291546 (JP, A) JP-A-63-33644 (JP, A) 299743 (JP, A) JP-A-62-186951 (JP, A) JP-A-63-188743 (JP, A)

Claims (11)

(57) [Claims] 1. An absorbance measurement value obtained from a certain amount of coffee beans by near-infrared spectroscopy, a quality evaluation value including sourness, bitterness, sweetness and aroma obtained by a sensory test of a known coffee bean and a known value. A quality evaluation method for a coffee bean, wherein a quality evaluation value is calculated based on a quality evaluation coefficient predetermined based on a measured absorbance value of a coffee bean. 2. The water content of a known coffee bean, which is determined by measuring the water content contained in a certain amount of coffee beans by near-infrared spectroscopy and by chemical analysis for calculating the water content. Of the known coffee beans and a moisture conversion coefficient determined in advance by measuring the absorbance of the known coffee beans by the near-infrared spectroscopy, and correcting the quality evaluation value obtained by calculating the measured absorbance value of the coffee beans and the quality evaluation coefficient. The method for evaluating the quality of coffee beans according to claim 1, wherein the value is a value. 3. Comprehensive judgment based on absorbance measured from a certain amount of coffee beans by near-infrared spectroscopy and quality evaluation values including sourness, bitterness, sweetness and aroma obtained by a sensory test of known coffee beans. A quality evaluation method for a coffee bean, wherein a total evaluation value is calculated based on a total evaluation value determined based on a total evaluation value to be obtained and a measured value of absorbance of a known coffee bean. 4. The water content of a known coffee bean, which is determined by measuring the water content contained in a certain amount of coffee beans by a near-infrared spectrophotometry and a chemical analysis for calculating the water content. Ratio and a moisture conversion coefficient determined in advance by measuring the absorbance of the known coffee beans by the near-infrared spectroscopy, and correcting the overall evaluation value obtained by calculating the measured absorbance value of the coffee beans and the quality evaluation coefficient. The method for evaluating the quality of coffee beans according to claim 3, wherein the value is a value. 5. Irradiation means for irradiating near-infrared light in a plurality of wavelength bands to a coffee bean sample, light-receiving means for receiving near-infrared light after irradiating the coffee beans, and light-receiving by the light-receiving means A near-infrared light spectrometer equipped with signal processing means for converting the obtained near-infrared light into absorbance and outputting the absorbance, a quality evaluation value obtained by a known sensory test of coffee beans, and the signal processing A storage device in which a quality evaluation coefficient determined by the known absorbance of coffee beans output by the means is set, and the absorbance of the measurement target coffee beans output from the signal processing unit and the quality evaluation coefficient, An arithmetic unit for calculating a quality evaluation value including sourness, bitterness, sweetness and aroma of the coffee beans to be measured, and a quality evaluation device for coffee beans. 6. The storage device stores a water conversion coefficient obtained from a water content measured by a chemical component analysis of a known coffee bean and an absorbance of the known coffee bean outputted by a signal processing means. In the arithmetic unit, the quality including the sourness / bitterness, sweetness / aroma of the measurement target coffee beans is calculated based on the absorbance of the measurement target coffee beans output from the signal processing unit and the quality evaluation coefficient and the moisture conversion coefficient. The apparatus for evaluating the quality of coffee beans according to claim 5, wherein the evaluation value is calculated. 7. Irradiation means for irradiating near-infrared light in a plurality of wavelength bands to a coffee bean sample, light-receiving means for receiving near-infrared light after irradiating the coffee beans, and light-receiving by the light-receiving means The near-infrared light spectroscopy device provided with signal processing means for converting the near-infrared light into absorbance and outputting the absorbance, and a quality evaluation value obtained by a sensory test of a known coffee bean. A storage device in which a quality evaluation coefficient determined by the overall evaluation value and the known absorbance of coffee beans output by the signal processing unit is set; and the absorbance of the coffee beans to be measured output from the signal processing unit. An arithmetic unit that calculates an overall evaluation value that is comprehensively determined by the quality evaluation coefficient and the quality evaluation value including the sourness, bitterness, sweetness, and aroma of the coffee beans to be measured. Quality evaluation device of coffee beans to be. 8. The storage device stores a moisture conversion coefficient obtained from a water content measured by a chemical component analysis or the like of a known coffee bean and an absorbance of the known coffee bean output by a signal processing means. In the arithmetic unit, the quality including the sourness, bitterness, sweetness, and aroma of the coffee beans to be measured is determined based on the absorbance of the coffee beans to be measured output from the signal processing means and the quality evaluation coefficient and the moisture conversion coefficient. The apparatus for evaluating the quality of coffee beans according to claim 7, wherein the apparatus calculates a comprehensive evaluation value comprehensively determined based on the evaluation value. 9. The apparatus for evaluating the quality of coffee beans according to claim 5, wherein the plurality of wavelength bands continuously scan a wavelength range of 1100 nm to 2500 nm. 10. The coffee bean quality evaluation device according to claim 5, wherein a heating device and a temperature setting device for measuring the measurement device at a constant temperature are provided inside the measurement device. . 11. A coffee bean according to claim 5, wherein a temperature detector is provided at or near the sample container in order to correct the circuit of said control device according to the temperature or air temperature of said coffee bean. Quality evaluation device.