JPH02154137A - Method and device for evaluating quantity of coffee bean - Google Patents

Abstract

PURPOSE:To evaluate the quality of coffee beans objectively without being affected by artificial factors by using a reflection type near infrared spectral analyzing instrument which measures the intensity of reflected light from the coffee beans. CONSTITUTION:The coffee beans are ground and the near infrared spectral analyzing instrument measures the content of protein, lipid, cane sugar, etc., as principal elements in the sample beams which affect the taste and flavor of coffee. Namely, the light absorptivity of the sample beams is measured by using a narrow-band-pass filter 33 which passes only specific wavelength suitable to the content measurement of the components to be measured and the content of each component is found from the detected values and component evaluation coefficients for content calculation which are found previously by a multiple regression analysis method; and a quality evaluated value is calculated from said value and a quality evaluation coefficient for quality evaluation which is obtained according to the correlation to the evaluated value of a functional test. Consequently, the quality of the coffee beams is evaluated objectively without being affected by artificial factors.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for evaluating the quality of coffee beans, particularly roasted beans.

[Conventional technology and its problems] Commercially available coffee beans are made by drying fully ripened coffee beans, m grains, and! The four selected raw beans are put into a roasting machine and given flavor and aroma in the roasting process. In other words, roasting causes chemical changes in the components of green coffee beans, producing volatile aromas and caramel colors, and the taste of coffee, including sourness, bitterness, sweetness, and aroma, is influenced by the roasting conditions. has become known.

By the way, the conventional method for determining the quality of these coffee beans is
This is a so-called sensory test in which the coffee beans roasted in the roasting process are crushed, heated to boiling temperature, and the extracted product is actually tasted. This requires the following. Moreover, the judgment is made based on human taste, which is greatly influenced by human factors, and cannot be objectively and universally determined, and therefore requires a skilled person.

From the above, it goes without saying that there is a desire for the development of a coffee bean determination device that can objectively and easily perform coffee bean determination without being influenced by human factors.

[Object of the Invention] Table 1 shows chemical measurements and analyzes of the chemical components of green beans and those of roasted beans.

Table 1 (%) According to Table 1, it can be seen that the components that significantly decreased after roasting were protein, sucrose, and chlorogenic acid.
These three components are thought to be the main elements that create taste and flavor through thermal reactions during roasting.

Therefore, the present invention aims to measure the content of each component contained in roasted coffee beans in a short time, and thereby obtain an objective quality evaluation value of coffee beans.

Furthermore, in the present invention, a method and apparatus for determining the quality evaluation value of roasted coffee beans will be described in detail, but this is because the taste of coffee is caused by changes in the chemical components of coffee beans during roasting, resulting in a unique taste. Due to the physical properties of green coffee beans, even if roasted under the same conditions, the physical properties and component content after roasting will not be uniform. The objective is to obtain a quality evaluation value.

[Means for solving problems]

According to the present invention, the content of components contained in a certain amount of roasted coffee beans is determined by measuring the absorbance using near-infrared spectroscopy and the known chemical component analysis of coffee beans in order to calculate the content. The content is determined by a component conversion factor predetermined based on the content and the absorbance measurement value of the known coffee beans by the near-infrared spectroscopy method. The problem was solved by a coffee bean quality evaluation method that calculates a quality evaluation value based on a quality evaluation value obtained by a sensory test or the like and a quality evaluation coefficient predetermined based on the known ingredient content of the coffee beans.

Further, according to the present invention, there is provided an irradiation means for irradiating a roasted coffee bean sample with near-infrared rays in a plurality of wavelength bands, a light-receiving means for receiving the near-infrared rays after the coffee beans have been irradiated, and a method for receiving light by the light-receiving means. A signal processing means of a near-infrared spectrometer is electrically connected to a control device, and the signal processing means of the near-infrared spectrometer is electrically connected to a control device. a storage device in which a component conversion coefficient calculated and determined from the component content measured by chemical component analysis of the beans and the known absorbance of the coffee beans outputted by the signal processing means; and an output from the signal processing means a calculation device that calculates the component content of the coffee beans by applying the absorbance of the coffee beans to be measured and the component conversion coefficient; A quality evaluation coefficient calculated and determined by the known quality evaluation value of the coffee beans evaluated by is also set, and the component content of the coffee beans calculated by the calculation device and the quality evaluation coefficient are operated. A coffee bean quality evaluation device that calculates quality evaluation values was used as a means of solving the problem.

[For production]

Coffee beans are ground, and the content of proteins, lipids, sucrose, chlorogenic acid, etc., which are the main elements that create the taste and flavor of coffee, contained in the sample beans is measured using near-infrared spectroscopy. That is, the absorbance of the sample bean is measured using a narrow band pass filter that passes only a specific wavelength suitable for measuring the content of the component to be measured, and this detected value is used to calculate the content calculated in advance by multiple regression analysis. The content of each component is determined using the component evaluation coefficient, and the quality evaluation value is calculated based on this value and the quality evaluation coefficient for quality evaluation obtained in advance based on the correlation with the evaluation value of the sensory test. It is something.

〔Example〕

Hereinafter, a first embodiment of the coffee bean quality evaluation apparatus according to the present invention will be described with reference to the accompanying drawings 1 to 3.

FIG. 1 is a schematic diagram of a coffee bean quality evaluation apparatus 1 according to the present invention viewed from the front. Inside the cabinet 2, a near-infrared spectrometer 3 and a control device 4, the detailed configuration of which will be explained with reference to FIG. 2 below, are disposed. The front panel of the Ki A vignette 2 includes a sample container mounting box 5 for mounting a sample container (sample placement section) containing coffee beans to be measured, and a light emitting diode or light emitting diode for visually displaying the operating procedure of the device, calculation results, etc. A CRT-type display device 6, operating buttons 7, and a printer 8 capable of making a hard copy of calculation results are provided. The control device 4 includes an input/output signal processing device 4a that is connected to the light source, detector, display device 6, operating button 7, printer 8, etc. of the near-infrared spectrometer 3 and processes various signals; Component conversion coefficient values for calculating the content of each component, specific coefficients individually set for each main component of coffee beans for calculating quality evaluation values, input using the input device (keyboard) 9. A storage device 4b for storing bean prices for each brand or grade, various corrections, various control procedures, etc., and a storage device 4b for storing coffee bean prices for each brand or grade, various corrections, various control procedures, etc. It consists of a calculation device 4C for calculating quality evaluation values and the like. In addition, the specific coefficients and necessary correction values that are set individually for each main component of coffee beans are
Read-only memory in the storage device 4b, ROM
) is stored in advance. Further, the printer 8 is not limited to a built-in type, and may be an externally connected type.

By the way, near-infrared rays irradiated onto a 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 atoms and the chain state. In addition, the magnitude of vibration changes in the near-infrared wavelength region, causing heat absorption. Furthermore, if the sample initially has little thermal energy (low temperature), the amount of absorption due to differences in molecular structure cannot be measured accurately because the vibrations are small, so it is necessary to correct the temperature. Normally, no correction is required when the temperature is 20°C or higher.

The temperature setting device 77 adjusts the near-infrared spectrometer 1 to a constant temperature, and when the temperature is low, it operates the heating device 78 and normally
Set to ℃. This has the purpose of preventing changes in the sample temperature and eliminating errors due to the temperature of the electric circuit.

FIG. 2 is a sectional view of a main part of an embodiment of the near-infrared spectrometer 3 disposed inside the cabinet 2. As shown in FIG. The illustrated near-infrared spectrometer 3 is of a reflective type, and its main components include a light source 31, a reflecting mirror 32, a narrow band pass filter 33, an integrating sphere 34, and detectors 35a and 35b.
has. The light emitted from the light source 31 passes through an appropriate optical system (not shown) and becomes parallel light. After passing through the narrow band pass filter 33, the light becomes near-infrared light of a specific wavelength. A reflecting mirror 32 configured to freely change the direction of the integrating sphere 34 can be used to change the direction toward a lighting window 36 provided by opening the top of the integrating sphere 34. Against! ) The near-infrared light reflected by the I mirror 32 and entering the interior of the integrating sphere 34 through the lighting window 36 of the integrating sphere 34 is transmitted to the measuring section 37 provided by opening the bottom of the integrating sphere 34, and thus to the sample. Container mounting box 5
The coffee beans 55 in the sample container 52 located at a predetermined rear position are irradiated from directly above. The diffusely reflected light from the coffee beans 55 is reflected inside the integrating sphere 34, and finally reaches a pair of detectors 35a and 35b arranged at symmetrical positions with the measurement unit 37 as the center. This measures the intensity of the reflected light. The sample container mounting box 5 below the sample container 52 is provided with a sensor 79 for measuring the temperature of the sample container, and as described in detail regarding the temperature setting device 77, the analysis value is corrected based on the sample temperature. In addition, in the illustrated embodiment, the optical symmetry is modified and the coffee beans 55
In order to efficiently receive the reflected light from the
That is, although two detectors indicated by reference numbers 35a and 35b are provided, the number is not limited to two, and may be - or three or more detectors.

Here, the configuration of the narrow band pass filter 33, which is provided between the light source 31 and the reflecting mirror 32, and through which the light emitted from the light source 31 becomes near-infrared light of a specific wavelength, and the requirements for this filter are explained. Explain the physical characteristics etc. The narrow band pass filter 33 is composed of a plurality of arbitrary filters (for example, six filters 33a to 33[) each having a different dominant wavelength pass characteristic, and these are attached to a rotating disk and rotated by an appropriate angle. By this, light source 3
The configuration is such that a desired filter can be sequentially selected and replaced so that it is located on the line connecting the reflector 1 and the reflecting mirror 32. Note that in the transmission characteristics of a filter, the dominant wavelength refers to the maximum transmission wavelength of near-infrared rays that are transmitted when the incident optical axis is perpendicular to the filter surface. Another specific example of the structure of the narrowband transmission filter 33 is to place a prismatic reflecting mirror 32 inside and place a plurality of filters 33a to 33f at positions facing each surface of the reflecting mirror. There is also a configuration in which it is configured in a prismatic shape and is rotatable. In addition, when the narrow band pass filter 33 is disc-shaped, if the inclination angle of its rotating surface with respect to the incident optical axis can be finely and continuously adjusted by means such as an electric motor, each filter can be adjusted finely and continuously. It is possible to continuously produce near-infrared light of different wavelengths shifted from the main wavelength of the transmission characteristic possessed by This is a generally well-known phenomenon, but
This is due to the phenomenon that when the angle of the incident optical axis with respect to the surface of the filter is changed from 90'', the maximum transmission wavelength shifts within a range of several tens of nanometers in response to the change in angle.

Next, the physical characteristics required of the narrow band pass filter 33 will be explained based on FIG. 3. Figure 3 is a graph showing the relationship between irradiation wavelength and absorbance when different coffee beans are irradiated with near-infrared light whose wavelength changes continuously (
absorbance curve). The absorbance 1oalo/I is the common logarithm of the reciprocal of the ratio of the reflected light ff1l from the sample rice to the reference irradiation source (total irradiation light flit) Io. It can be easily understood that the amount of content of each of the above components is clearly expressed as a difference in absorbance. Since the present invention utilizes this phenomenon to measure the content of a predetermined component contained in coffee beans, the wavelength of near-infrared light irradiated onto coffee beans for measurement is in the wavelength range 1100. ~2500nm
Among them, specific peaks can be seen on the absorbance curve for each component (in this example, Anm, [3nm...Fnm
). Therefore, each of the filters 33a to 3] included in the narrow band pass filter 33 generates near-infrared light of each wavelength suitable for measuring each component contained in coffee beans.
It is required that each of the wavelengths have a specific pass characteristic, that is, as a dominant wavelength.

Next, the specific operation of the coffee bean quality evaluation apparatus of the present invention having the above configuration will be explained. First, the light source 31 is turned on by operating the operating button 7, and the near-infrared spectrometer 3 is preheated using a heating device 78 or the like. After the predetermined time for preheating has elapsed, the sample container mounting box 5 is placed in the cabinet 2 of the device.
After the sample container 52 filled with the ground coffee bean sample 55 is placed in a predetermined position, the sample container 52 is inserted into the cabinet 2 to complete the premature ejaculation measurement.

The temperature sensor 79 of the sample container device box 5 measures the temperature of the sample container 52. The coffee beans 55 are preferably ground to a particle size of approximately 50 microns or less in order to avoid errors in the measured values, but this is not necessarily the case. In addition, in order to reduce light loss due to diffused reflection, the ground coffee beans 55 are filled into the sample container 52 with the surface thereof being flat, and some pressure is applied using a transparent glass plate. It is preferable to cover the surface while adding it.

When the measurement preparation work is completed, the filter 33A having the main wavelength of Anm is first selected so as to be on the line connecting the light source 31 and the reflecting mirror 32, and the wavelength, A, n
Next, we begin measuring the reflected absorbance when the coffee beans 55 are irradiated with near-infrared light of m. The measurement work of reflection absorbance involves measuring the total amount of irradiation irradiated onto the coffee beans 55, that is, the reference amount of light, and the measurement of the amount of light actually reflected by the coffee beans 55 when the reference amount of irradiation light is irradiated onto the coffee beans 55. It consists of two measurements: the measurement of the amount of reflected light. Although it is possible to carry out either of the two measurements on one filter first, in the following explanation, it is assumed that the measurement of the reference irradiation light weight is carried out first. The reference irradiation light weight is measured using a reflector 32 whose inclination angle is variable.
The angle of inclination of the sphere 34 is adjusted to such an angle that the reflected light directly hits the inner wall of the integrating sphere 34 using a rotating means (such as a motor).
(not shown). By doing this, the reflecting mirror 3 directly applied to the inner wall of the integrating sphere 34
The light from 2 finally reaches the detectors 35a and 35b while diffusing and refracting the inner wall in many directions, and is detected as a reference irradiation light beam. On the other hand, the measurement of the amount of reflection from the coffee beans 55 is carried out 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, each execution of the first filter selection after the measurement preparation is completed, the measurement of the reference irradiation light amount, and the measurement of the reflected light interval is performed by storing a procedure program in the ROM in the storage device 4b of the control device 4.
Needless to say, it can be done automatically according to the program. Furthermore, it is also useful to increase measurement accuracy by performing each of the above-mentioned reference irradiation light amount and reflected light measurements for one filter multiple times, and taking the average of these measurements as the measured value. Detector 35a
, 35b and the reflected light from the coffee beans 55 are controlled as actual measurement data for calculating the respective contents of protein, lipid, water, etc. contained in the coffee beans. The information is communicated to the device 4 and is temporarily stored in a writable memory (hereinafter referred to as RAM) in the storage device 4b.

After completing the measurement of absorbance at the irradiation wavelength Anln,
The process moves on to measurement of absorbance at the next irradiation wavelength, that is, 3 nm in this example. Here again, the measurement of the reference irradiation light amount and the measurement of the reflected light amount are performed using the same method and procedure as in the case of the above-mentioned Anm.

As in the previous case, each measurement value is communicated to the control device 4 as actual measurement data for calculating the content rate of each component, and is sent to the storage device 4.
It is temporarily stored in RAM in b. Similarly, each of the remaining absorbance measurements, i.e. wavelength cnm, Dnm, Enm,
Absorbance measurements of Fnmt' were performed sequentially, and each measurement value was
This is communicated to the control device 4 as actual measurement data and stored in the RAM. Note that the operation of replacing and selecting each of the filters 33a to 33f of the narrow band pass filter 33 when the absorbance measurement at a specific wavelength is completed and the transition to the absorbance measurement at the next specific wavelength is normally performed by the storage device of the control device 4. R in ff4b
This is automatically performed according to the procedure program written in advance in the OM, but even in the case of this embodiment, the above 6.
It is not necessary to perform absorbance measurement for all wavelengths, and the wavelengths to be measured can be arbitrarily selected in consideration of the accuracy required for the desired quality evaluation value, the time required for measurement, etc. The selection can be made using the measurement wavelength selection button in the operating button 7.

The absorbance measurement described so far is performed simply by using the six filters 33a to 33 set in the narrow band pass filter 33.
By sequentially exchanging f, each of the tiles 33a to 3
3 was a method of measuring spot absorbance at each dominant wavelength, but as mentioned above, when the angle of incidence of the incident light on the filter surface is changed from the standard 90', the maximum transmission wavelength changes from the dominant wavelength. By utilizing the development that shifts in the range of several tens of nanometers, it is also possible to continuously measure the absorbance in the wavelength range from 1100 nm to 2500 nm, where the difference in the content of the components is noticeable in the absorbance difference. In this case, the angle of the optical axis of incidence on the narrow band pass filter 33 configured in a disc shape is finely and continuously controlled by an appropriate adjusting means (not shown) such as an electric motor based on a command signal from the control device 4. This is possible by changing .

Next, the arithmetic unit 4C of the control device 4 executes R of the storage device 4b.
A large amount of actual measurement data obtained by absorbance measurement stored in the AM, that is, measurement values between the reference irradiation light amount and reflected light at each measurement wavelength, and the content rate of each component stored in advance in the ROM of the storage device 4b. Based on the component conversion coefficient values for calculation, each content rate of protein, lipid, water, etc., which are important components in evaluating the quality of coffee beans, is calculated. Note that the component conversion coefficient value stored in advance in the ROM of the storage device 4b for each component is based on the content rate of each component measured using, for example, a chemical quantitative analysis method for a large number of coffee beans. Signal processing the absorbance measurement value from the detector,
This is a constant determined by multiple regression analysis.

Here, an example of multiple regression analysis for determining component conversion coefficients will be shown. For example 6 filters P+ nm, P2
nm, P3 nm, P4 nm, Ps nm,
It is assumed that when the absorbance of one component A of coffee beans is measured with a detector using P6 nm, the following linear relationship holds true.

A+ =Foa +F+a -Xn+F2a
Lu X2++-+Fea -XS I+ε+ In this case, 80: Content percentage of coffee bean component A as measured by atomic absorption spectrometry.

Foa-Faa: Component conversion coefficient value obtained by multiple regression analysis.

×1 to Xe: Absorbance (I O (1 value)) corresponding to filters P+ to P6, respectively.

εn: Error.

It is.

Similarly, when absorbance analysis is performed on n samples and substituted into the multiple regression equation, AI=FOa +FIa -XII+F2a ''X21
−＋−−−−−−−+F6a Medium Xe + +5! A2
=FOa 10FIa 'XI2+F2a ``X22+
−−−・−+ F s a 11X a 2+ε2A
n =FQa +FIa -Xln +F2a -X2
n + · + Fea - Xa.The relational expression for measuring the absorbance of component A with a detector is established.

by the way. The filters P1 to P6 are:
This shows one example, and to ensure accuracy, the optimal filter was selected by performing the regression analysis at 1100 nm to 1100 nm.
A wavelength range subdivided in the wavelength range of 2500 nm, for example 2
It was found by combining everything matrix-wise using 19 absorbances at nm intervals.

Next, using six filters, the absorbance of n samples of coffee beans, component B, is measured with a detector, and the following formula holds true for the component.

B=Fob +F+b -X+ +F2b -X2-1
-10F6b-x6 As described above, multiple regression analysis was performed on each component to determine the component conversion coefficient for each component. The content of each component is determined by absorbance measurement using a detector.

Next, the arithmetic unit 4C calculates a quality evaluation value using a formula based on each content rate of protein, lipid, water, etc. determined as described above.

Here, components A and B are components that determine the taste of coffee beans. Each of these components is calculated using the component conversion coefficient determined by the multiple regression analysis described above. Next, an example of regression analysis for obtaining a quality evaluation coefficient to obtain a quality evaluation value will be described.

The quality evaluation value (T) is T=a (Axdrunk)+b Assume that it can be found by a, b, x above.

Similarly to components A and B, if y is determined by the least squares method using the evaluation values of n coffee beans through sensory tests and the components A and B of n coffee beans determined by the detector, then this a , b, x, and y are quality evaluation coefficients.

The quality evaluation value calculated using the above-mentioned watered-down quality evaluation coefficient and quality evaluation calculation formula is visually displayed on the display device 6 at the same time as the completion of the total c7 in the disturbance device 4C, and is automatically or operated. Based on the command to the pushbutton 7, the printer 8 prints out a hard copy. Further, the contents of each component such as protein, lipid, water, etc. determined during the process of determining the quality evaluation value may be visually displayed on the display device 6 at the same time as the quality evaluation value.

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

In the above description, ground coffee beans were used, but the coffee beans do not necessarily have to be ground. However, in this case, it goes without saying that the accuracy of the obtained quality evaluation value decreases to some extent.

Now, in order to analyze coffee beans using the above-mentioned quality evaluation device, the coffee beans are ground and analyzed, and for grinding the coffee beans, a so-called centrifugal sample grinding device is used, which consists of grinding blades that rotate at high speed within a wire mesh. used. This will be explained below.

The sample crushing device 117 includes a quantitative supply section 118 and a crushing section 119.
and a separation section 120, hereinafter referred to as the quantitative supply section 11.
The explanation will be given in order starting from 8. The quantitative supply section 118 of this embodiment is a so-called photographic supply device, that is, one end is used as the discharge section 121, and the bottom of the other end of the supply gutter 122, which is rolled up, is close to the drop port 124 at the lower end of the input hopper 123. , and are provided horizontally, and the other end portions are plate springs 125A, 125B.
It is formed so that it is supported by a vibrator 126 and is sensed by a vibrator 126.

Next, regarding the crushing section 119, the discharge section 1 of the supply gutter 122
A supply hopper 127 is provided below 21 and has a supply port 128 at its lower end. A crusher 129 whose upper surface is approximately circular is provided below the supply hopper 127.
At the center of the lower surface of 29 is a boss 13 into which a shaft 131 of a commutator motor 130 disposed below the crusher 129 is fitted.
2 is formed. On the other hand, a large number of crushing blades 133 are erected at equal intervals on the circumference of the upper surface of the crushing plate 129 (in this embodiment, one
2), these crushing blades 133... are driven by the front power distribution motor 130 to rotate at high speed together with the crushing blade 5J129. 13
Reference numeral 1a denotes a threaded portion that fixes the crushing plate 129 to the shaft 131.

A cylindrical perforated ring 134 is provided around the crushing plate 129 with a slight gap between the crushing blades 133 and the perforated ring 134, and a large number of holes 134a are formed in the perforated ring 134. Hole 1
The size of 34a is selected depending on the desired size of the sample, but in this example it is 50μ. Further, an outer ring 135 is provided around the perforated ring 134, and a dye path 136 is provided between the outer ring 135 and the perforated ring 134.
to form.

Next, the separation section 120 will be explained. The separation section 120 mainly consists of a Nifron separator 137. That is, the powder collection path 136 and the cyclone separator 137
are tangentially connected to each other by a connecting air passage 138,
The lower end of the cyclone separator 137 faces the sample bottle 139 in an airtight manner. The sample bottle 139 is connected to the spring 14
1, it is set on a lowerable bottle mounting stand 140.

A tube-shaped filter 142 made of cloth or the like is installed near the upper ring 14 near the Neutron separator 137.
The inner cylinder 145 of the cyclone separator 137 and the upper ring 143 are connected by a 0-shaped connecting pipe 146. Further, a dust collector 147 connected to the lower end of the lower ring 144 is detachably and airtightly provided.

When using this sample crushing device 117, when the vibrator 126 of the sample crushing device 117 is activated and the bean flour coarsely crushed by the coarse crushing roller is introduced into the input hopper 123, the bean flour near the drop port 124 is Vibrator-1
26, a certain amount of the powder is conveyed through the vibrating supply gutter 122 to the discharge section 121 side, and sequentially falls from the discharge section 121 into the supply hopper 127, and is supplied onto the crushing plate 129 through the supply port 128. Ru.

The crusher 129 rotates at high speed (
10,00 Orpm or more), and the rice grains fed onto the grinding plate 129 are repelled by centrifugal force toward the perforated ring 134, and are also passed through the grinding blades 133, which rotate at high speed.
・It is crushed and crushed into pieces by the impact and shear force of. In this way, the powdered beans that are crushed into smaller pieces than the holes 134a of the perforated ring 134 leak into the powder collection path 136 through the holes 134a.

By the way, the high-speed rotation of the crushing blades 133 generates wind, and this wind helps the crushed bean powder leak out from the holes 134a of the perforated ring 134, and also causes the crushed bean flour to leak out from the holes 134a of the perforated ring 134. The bean flour is conveyed to the cycle separator 137 via the connecting air passage 138.

The air mixed with the bean flour conveyed into the cyclone separator 137 flows down the conical part in a spiral shape, causing the stalled rice flour to fall into the sample bottle 139 from its lower end. On the other hand, bean flour that is even finer than these bean flours (for example, about 20 microns or less) and dust pass through the inner tube 145, the connecting vibrator 146, and the upper ring 143 with the airflow, reach the filter 142, and are filtered by the filter 142. Only the airflow flows out of the filter 142, causing ultrafine bean flour and dust unsuitable for the desired sample to fall from the lower ring 144 into the dust collector 147. The air flowing out from the filter 142 is exhausted to the outside of the machine via a louver or the like (not shown).

In this way, the sample bean flour, which has been made into a uniform size, is
The sample container 33 is filled and inserted into the measurement section 11 from the external supply section, and measurement of absorbance is started.

(above) In the quality evaluation device on the E-stream side, the absorbance is measured when coffee beans are irradiated with near-infrared light of a specific wavelength by measuring the intensity of the reflected light from the coffee beans. Although an infrared spectrometer was used, it is also possible to use a transmission-type near-infrared spectrometer that measures the intensity of transmitted light that has passed through coffee beans.
Absorbance is measured based on both reflected light and transmitted light,
More precise near-infrared spectroscopic analysis device (effects of the invention) As detailed above, the coffee bean quality evaluation device according to the present invention can perform sensory tests based on individual differences in taste,
Alternatively, anyone can easily and quickly obtain accurate coffee bean quality evaluation values without using methods such as chemical quantitative analysis that are time-consuming and require skill.

Furthermore, when the quality evaluation device according to the present invention is equipped with a sample supply device, when measuring the content rate of a predetermined component of coffee beans and obtaining a quality evaluation value of the coffee beans based on this, fine particles of the coffee beans are used. The grinding work into particles, the filling work into sample containers, etc. are all automated, making the measurement easier and more reliable.

[Brief Description of the Drawings] Figure 1 is a schematic front view of a coffee bean quality evaluation apparatus according to an embodiment of the present invention, and Figure 2 is a schematic diagram of a near-infrared spectrometer used in the quality evaluation apparatus of Figure 1. Figure 3 is a graph showing the relationship between near-infrared irradiation wavelength and absorbance for different brands of coffee beans (absorption curve I!j), Figure 4 is a partially broken front view of the sample crushing device. , FIG. 5 is a plan view of a partially broken surface of the sample crushing device shown in FIG. 4, and FIG. 6 is a right side view of the same (partially broken surface). 2・
...Cabinet, 3...Near infrared spectrometer, 4...
・Control device, 4a... Input/output signal processing device, 4b...
・Storage device (ROM, RAM), 4c... arithmetic device,
5... Sample container mounting box, 6... Display device, 7... Button for operation, 8... Printer, 9... Input device (keyboard), 31... Light source, 32...・Anti-OA! 1.33...Narrow band pass filter 33a~
33...filter 34...integrating sphere, 35a. 35b...detector, 36...lighting window, 37...measuring section, 52...sample container, 55...sample (coffee) beans), 77... Temperature setting device, 78... Humidifier, 7
9... Humidity sensor 117... Sample crushing device, 1
18... Constant mother supply section, 119... Crushing section, 120.
...Division part 1, 121...Discharge part, 122...Supply gutter, 123...Input hopper, 124...Drop port,
125A, 125B, 125C... leaf spring, 126.
... Vibrator-1127 ... Supply hopper, 12
8... Supply port, 129... Grinding board, 130... Particle regulating motor, 131... Shaft, 1'32... Boss, 133... Grinding blade, 134... Perforated ring ,1
35... Outer ring, 136... Powder collection path, 137...
... Cyclone separator 138 ... connecting air passage, 13
9...1 sample bottle, 140...bottle stand, 141...
Spring, 142... Filter, 143... Upper ring, 144... Stock ring, 145... Inner cylinder,
146...Connection pipe, 147...Dust collection device.

Claims (10)

[Claims] (1) The content of components contained in a certain amount of roasted coffee beans is determined by the absorbance measurement value using near-infrared spectroscopy and the known chemical component analysis of coffee beans to calculate the content. The content is determined by a component conversion factor predetermined based on the content and the absorbance measurement value of the known coffee beans by the near-infrared spectroscopy method. A method for evaluating the quality of coffee beans, characterized in that a quality evaluation value is calculated based on a quality evaluation value obtained by a sensory test or the like and a quality evaluation coefficient predetermined based on the known ingredient content of the coffee beans. (2), Claim (2), wherein the coffee beans are ground;
1) The coffee bean quality evaluation method described above. (3) The coffee bean quality evaluation method according to claim (2), wherein the coffee beans are ground into fine powder using a grinding blade that rotates at high speed. (4) an irradiation means for irradiating a roasted coffee bean sample with near-infrared rays in a plurality of wavelength bands; a light-receiving means for receiving the near-infrared rays irradiated onto the coffee beans; A signal processing means of a near-infrared spectrometer that is equipped with a signal processing means that converts infrared rays into absorbance and outputs the absorbance is electrically connected to a control device,
The control device includes a storage device in which is set a component conversion coefficient calculated from the component content measured by known chemical component analysis of coffee beans and the known absorbance of the coffee beans output by the signal processing means. and an arithmetic device that calculates the component content of the coffee beans by applying the absorbance of the coffee beans to be measured outputted from the signal processing means and the component conversion coefficient, and stores known coffee beans in the storage device. A quality evaluation coefficient calculated by calculating the component content of the beans and the known quality evaluation value of the coffee beans evaluated by the sensory test is also set, and the components of the coffee beans calculated by the calculation device are set. A coffee bean quality evaluation device characterized in that a quality evaluation value is calculated by applying a content rate and the quality evaluation coefficient. (5) The plurality of wavelength bands are 1100nm to 2500nm.
Claim (4) wherein the wavelength range of m is continuously scanned.
The described coffee bean quality evaluation device. (6) The inclination angle of the near-infrared rays in the plurality of wavelength bands is variable so that the angle of incidence of the incident optical axis with respect to an optical filter surface disposed between the light source and the measuring section can be changed. 4) The coffee bean quality evaluation device described above. (7) Claim (4), wherein the coffee beans supplied to the measurement section of the near-infrared spectrometer are ground.
The described coffee bean quality evaluation device. (8) The coffee bean quality evaluation device according to any one of claims (1) to (4), wherein the coffee beans are powdery particles of 500 microns or less. (9) The coffee beans according to any one of claims (4) to (8), wherein the measuring device is provided with a heating device and a temperature setting device for keeping the measuring device at a constant temperature for measurement. Quality evaluation equipment. (10) According to any one of claims (4) to (9), a temperature detector is provided in or near the sample container in order to correct the circuit of the control device based on the temperature of the coffee beans or the air temperature. Coffee bean quality evaluation device.