JP2745024B2 - 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, quality and quality of coffee beans related to the taste, aroma and richness of coffee.

[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 determining the quality of coffee beans is to evaluate the acidity, bitterness, sweetness, and aroma by actually crushing the coffee beans roasted in the roasting step, adding boiling water and extracting the extracted beans. This is based on a so-called sensory test, which requires a plurality of people and a long time to be fair. Moreover, the judgment is made based on human taste greatly influenced by human factors, and cannot be an objective and universal judgment, so that a skilled person is required.

From the above, it goes without saying that the development of a method and an apparatus for evaluating the quality of coffee beans in which sensory evaluation can be performed objectively and easily regardless of human factors is desired.

[Object of the invention]

Table 1 shows the results of chemically measuring and analyzing the chemical components of raw beans and those of roasted beans.

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.

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

[Means for solving the problem]

According to the present invention, the component content contained in a certain amount of coffee beans, the measured absorbance by near-infrared spectroscopy, the component content measured by chemical component analysis of known coffee beans and the known coffee Determined by a component conversion coefficient determined in advance by measuring the absorbance of the beans by the near-infrared spectroscopy, the component content, the characteristic values obtained by a sensory test or the like of known coffee beans, and the known coffee beans. Means for solving the above problem by a coffee bean quality evaluation method in which at least one characteristic evaluation value among sourness, bitterness, sweetness, and aroma is calculated by a characteristic evaluation coefficient predetermined by an ingredient content and And

Further, according to 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, and a light-receiving means A near-infrared spectroscopy device having signal processing means for converting the converted near-infrared light into absorbance and outputting the absorbance, and the signal processing means of the near-infrared spectroscopy device are electrically connected. A component conversion coefficient determined by the component content measured by a chemical component analysis or the like of a known coffee bean and the absorbance of the known coffee bean output from the signal processing means, and the component content of the known coffee bean. A storage device that stores a characteristic evaluation coefficient obtained based on at least one known characteristic value of coffee beans among sourness, bitterness, sweetness, and aroma evaluated by a sensory test or the like; and the signal processing. Calculate the component content of the coffee beans to be measured from the absorbance of the coffee beans to be measured output from the stage and the component conversion coefficient of the storage device, and calculate the component content of the coffee beans and the characteristic evaluation coefficient of the storage device. An arithmetic unit for calculating at least one characteristic evaluation value among sourness, bitterness, sweetness, and aroma, and a coffee bean quality evaluation device comprising:

(Operation)

The coffee beans are pulverized, and the contents of proteins, lipids, sucrose, chlorogenic acid, and the like, which are the main components that create the taste and flavor of coffee, contained in the sample beans are measured by a near-infrared spectroscopic analysis method. That is, the absorbance of the sample beans is measured by a narrow band pass filter that passes only a specific wavelength suitable for measuring the content of the component to be measured, and the detected value is used for calculating the content determined in advance by a multiple regression analysis method. The content of each of the components is determined by the component evaluation coefficient, and further, the characteristic evaluation is performed by using the value and a characteristic evaluation coefficient for quality evaluation obtained based on a correlation between the value and a characteristic value obtained in advance by a sensory test or the like. The value is calculated.

〔Example〕

Hereinafter, an 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 includes an input / output signal processing device 4a connected to the light source, the detector, the display device 6, the operation push button 7, the printer 8, and the like of the near-infrared spectroscopic analyzer 3 for processing various signals. A component conversion coefficient value for calculating the content ratio of a component, a specific coefficient individually set for each main component of coffee beans for calculating a quality evaluation value, and are input through an input device (keyboard) 9. A storage device 4b for storing various correction and various control procedures and the like, and a calculation device for calculating a characteristic evaluation value of coffee beans and the like based on the measured value obtained by the near-infrared spectroscopic analyzer 3 and the specific coefficient. 4c. A specific coefficient and a necessary correction value individually set for each main component of the coffee beans are stored in a read-only memory (hereinafter, referred to as a
ROM). 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 measuring unit 37 provided with an opening at the bottom of the container 34, and thus the coffee beans 55 in the sample container 52 described at a predetermined position behind the sample container mounting box 5, is 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 symmetrical positions around the measurement unit 37, Thereby, the intensity of the reflected light is measured. 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,
As described in detail for the temperature setting device 77, the analysis value is corrected based on the sample temperature. In the illustrated embodiment, in order to correct the optical symmetry and efficiently receive the reflected light from the coffee beans 55, a pair of detectors, that is, the reference numeral 35a is used.
And 35b are provided, 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 replaced 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 pass 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 log I ₀ / I is a 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) I ₀ . 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 content of a predetermined component contained in coffee beans using this phenomenon, as a wavelength of near-infrared light irradiated on coffee beans for measurement, the wavelength region 1100 A specific peak is observed on the absorbance curve for each component among 〜2500 nm (Anm,
Bnm ... Fnm). Accordingly, each of the filterers 33a to 33f included in the narrow bandpass filter 33 has a specific pass characteristic for each wavelength, in order to generate near-infrared light of each wavelength suitable for measurement of each component contained in coffee beans, that is, It is required to have the dominant wavelength.

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 the completion of the metric,
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.
The respective measurement values based on the reference irradiation light amount detected by the detectors 35a and 35b and the reflected light amount from the coffee beans 55 are the protein, sucrose, lipid, chlorogenic acid,
The data is communicated to the control device 4 as actual measurement data for calculating each content ratio of moisture and the like, and is temporarily stored in a writable memory (hereinafter, referred to as a RAM) in the storage device 4b.

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 for calculating the content ratio of each component as in the previous case,
It is temporarily stored in the RAM in the storage device 4b. Similarly, the remaining respective 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 stored in the RAM. Note 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 the next specific wavelength after the absorbance measurement at a specific wavelength is completed is normally performed by the memory of the control device 4. The measurement is automatically performed according to a procedure program previously written in the ROM in the device 4b. However, in the case of the present embodiment, the absorbance measurement does not necessarily have to be performed for all of the six wavelengths, and the measurement is performed. The wavelength can be arbitrarily selected in consideration of the accuracy required for the required characteristic evaluation value or the time required for the measurement, and the selection can be made using the measurement wavelength selection button in the operation push button 7. it can.

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.
Numerous measured data obtained by the absorbance measurement stored in the storage device 4b, that is, the measured values of the reference irradiation light amount and the reflected light amount at each measurement wavelength, and the content ratio calculation of each component stored in the ROM of the storage device 4b in advance. Based on the component conversion coefficient value for
Calculate the content of protein, sucrose, lipids, chlorogenic acid, water, etc., which are important components in evaluating the quality of coffee beans. Note that the component conversion coefficient value written in advance to the ROM of the storage device 4b for each component is based on the content of each component measured using, for example, a chemical quantitative analysis method for a large number of coffee beans. Is a constant obtained by performing signal processing on the absorbance measurement value from the above and performing multiple regression analysis.

Here, an example of a multiple regression analysis for obtaining a component conversion coefficient will be described. For example, six filters P ₁ nm, P ₂ nm, P ₃ nm, P ₄ n
When the absorbance of the component A of coffee beans is measured with a detector using m, P ₅ nm, and P ₆ nm, the following linear relationship holds.

_{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: atomic absorption preparative coffee bean components A.

F ₀ a~F ₆ a: component conversion coefficient value by multiple regression analysis.

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

ε _n : error.

It is.

Substituting into n multiple regression equation performs absorbance analysis for the samples in the same _{manner, 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 a component in terms of coefficient values to determine if _{A = F 0 a + F 1} a · X 1 + F 2 a · X 2 + ... + F 6 a · X 6 next to the relationship to perform absorbance measurements at component A detector The equation holds.

However, the filter of the filter P ₁ to P ₆ is an illustration of an example, selection of the optimal filter for accuracy were subdivided the regression analysis in the wavelength range of 1100nm~2500nm wavelength It is found by combining all in a matrix using the absorbance obtained at an interval of 2 nm, for example.

Next, using the six filters, one component B of coffee beans
, The absorbance of n samples is measured by a detector, and the following equation is established similarly to the component A.

_{= F 0 b + F 1 b} · X 1 + F 2 b · X 2 + ... F 6 b · X 6 where _{F 0 b, F 1 b,} B ..., F 6 b is a component conversion coefficient value of component B.

As described above, multiple regression analysis is performed on each component to determine the respective component conversion coefficient, and the content of each component is determined from the absorbance measurement of the detector and the component conversion coefficient.

Next, the arithmetic unit 4c calculates a characteristic evaluation value by a calculation formula based on the respective contents of the protein, sucrose, lipid, chlorogenic acid, water and the like obtained as described above.

Next, an example of a multiple regression analysis for obtaining a characteristic evaluation coefficient will be described, which is substantially the same as the case of the component conversion coefficient described above.
It is clear that the properties of coffee such as sourness, bitterness, sweetness, aroma, and richness are affected by the content of each component determined by this component conversion coefficient, that is, protein, sucrose, lipid, chlorogenic acid, water, and the like. For example, the tannin component of chlorogenic acid in coffee beans exhibits sourness and bitterness. In addition, diketopyrazines formed from proteins may cause coffee to have a bite.
For example, sour if holds for acidity of a coffee sample following relation _{= G 0 + G 1 · Y} 1 + G 2 · Y 2 + ... + G n - 1 Y n - 1 + GnYn + ε where G ₀ ~G _n: Weight Sensory evaluation coefficient by regression analysis Y _{1 to} Y _n : Content of each of n kinds of components of coffee beans Acidity: Characteristic value by sensory test etc. ε: Error, which is the characteristic value of multiple coffee samples and content of each component by detector Perform multiple regression analysis with multiple regression equation with quantity
When the characteristic evaluation coefficients of G _{0 to} G _n are obtained, the characteristic evaluation value of sourness = G ₀ + G ₁ Y ₁ +... + G _n · Y _n , and other characteristic items such as bitterness and sweetness are thus obtained. , Aroma, richness, etc., are used to determine characteristic evaluation coefficients from a plurality of coffee samples. The characteristic evaluation value is obtained from the characteristic evaluation coefficient and the content of each component thus obtained.

The obtained characteristic evaluation coefficient and the characteristic evaluation value calculated by the characteristic evaluation calculation formula are visually displayed on the display device 6 at the same time when the calculation in the arithmetic unit 4c is completed, and are automatically or automatically operated. Printer 8 based on instructions to 7
Is sent out as a hard copy. In addition, the contents of the respective components such as protein, sucrose, lipid, chlorogenic acid, and moisture determined in the course of obtaining the characteristic evaluation value may be simultaneously displayed on the display device 6 together with the characteristic evaluation value. .

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

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 characteristic evaluation value is reduced to some extent.

Now, in the analysis of the coffee beans by the quality evaluation device, the coffee beans are pulverized and analyzed. For the pulverization of the coffee beans, a so-called centrifugal type sample pulverization device including pulverizing blades rotating at high speed in a wire mesh is used. 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 They are connected by a letter-shaped connecting pipe 146. Further, a dust (dust) collecting device 147 is detachably connected to the lower end of the lower ring 144 and is provided in an airtight manner.

When using this sample crusher 117, the sample crusher 1
When the 17 vibrator 126 is operated and the coarsely ground bean powder is introduced by the coarse grinding roller in the input hopper 123, the bean powder in the vicinity of the dropout 124 is appropriately and uniformly fed 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,
The bean powder in 36 is conveyed to cyclone separator 137 via communication air passage 138.

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 its lower end. On the other hand, finer bean flour than these bean flours (for example, about 20μ or less)
And dust, together with the airflow, reach the filter 142 through the inner cylinder 145, the communication pipe 146, and the upper ring 143,
It is filtered by 142 and only the air flow flows out of the filter 142,
Ultra-fine bean powder and dust inappropriate for a desired sample are dropped from the lower ring 144 into the dust collector 147. The air that has flowed out of the filter 142 is, for example, loose (not shown).
The air is exhausted to the outside of the machine via.

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 measurement of the absorbance when the coffee beans are irradiated with near-infrared light of a specific wavelength is performed by measuring the intensity of the reflected light from the coffee beans. Although the analyzer was used, a transmission type near-infrared spectroscopic analyzer that measures the intensity of transmitted light transmitted through coffee beans can also be used.
A more accurate near-infrared spectrometer that measures absorbance based on both reflected light and transmitted light can be provided.

〔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 easily and accurately obtain a characteristic evaluation value of coffee beans in a short time.

Further, when the quality evaluation device according to the present invention includes a sample supply device, the content of a predetermined component of the coffee bean is measured, and based on this, the characteristic evaluation value of the coffee bean is obtained. 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-2-120647 (JP, A) JP-A-2-143147 (JP, A) JP-A-63-188743 (JP, A) JP-A-62-1987 299743 (JP, A) JP-A-63-33644 (JP, A) JP-A-62-291546 (JP, A)

Claims (10)

(57) [Claims] 1. A method for measuring the content of a component contained in a fixed amount of coffee beans by measuring the absorbance by near-infrared spectroscopy, the component content by a chemical component analysis of a known coffee bean, and the like. Determined by a component conversion coefficient determined in advance by measuring the absorbance of the beans by the near-infrared spectroscopy, the component content, the characteristic values obtained by a sensory test or the like of known coffee beans, and the known coffee beans. A quality evaluation method for coffee beans, wherein a characteristic evaluation value of at least one of acidity, bitterness, sweetness, and aroma is calculated based on a characteristic evaluation coefficient predetermined based on a component content. 2. The method for evaluating the quality of coffee beans according to claim 1, wherein said coffee beans are ground. 3. The method for evaluating the quality of coffee beans according to claim 2, wherein the pulverization of the coffee beans is performed by fine pulverization by a high-speed rotating grinding blade. 4. 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 reception by the light receiving means. A near-infrared spectroscopy device having signal processing means for converting the near-infrared light into absorbance and outputting the absorbance, and the signal processing means of the near-infrared spectroscopy device are electrically connected; A component conversion factor determined by the component content measured by a known chemical component analysis of coffee beans and the absorbance of the known coffee beans output from the signal processing means,
A characteristic evaluation coefficient obtained from a known coffee bean component content and at least one of the characteristic values of a known coffee bean among acidity, bitterness, sweetness, and aroma evaluated by a sensory test or the like was stored. A storage device, calculates the component content of the coffee beans to be measured from the absorbance of the coffee beans to be measured output from the signal processing means and the component conversion coefficient of the storage device, and calculates the calculated component content and the storage Acidity / bitterness /
An arithmetic unit for calculating at least one characteristic evaluation value of sweetness and aroma, and a quality evaluation device for coffee beans. 5. The apparatus for evaluating the quality of coffee beans according to claim 4, wherein said plurality of wavelength bands continuously scan a wavelength band of 1100 nm to 2500 nm. 6. An incident angle of an incident optical axis of the near-infrared light in the plurality of wavelength bands with respect to an optical filter surface disposed between a light source and a measurement unit for irradiating the coffee bean sample to be measured with light. The apparatus for evaluating the quality of coffee beans according to claim 4, wherein the inclination angle is variable so that the inclination angle can be changed. 7. The apparatus for evaluating the quality of coffee beans according to claim 4, wherein the coffee beans supplied to said measuring section are pulverized. 8. The apparatus for evaluating the quality of coffee beans according to claim 7, wherein said coffee beans are made into powdery particles of 500 microns or less. 9. The quality of coffee beans according to claim 4, wherein a heating device and a temperature setting device are provided inside the near-infrared spectroscopic analyzer for measuring the temperature of the measuring section at a constant temperature. Evaluation device. 10. The apparatus for evaluating the quality of coffee beans according to claim 4, wherein a temperature detector is provided at or near the sample container in order to correct the circuit of the control device according to the temperature or temperature of the coffee beans. .