DE10201094B4 - Single-grain analyzer and method for single-grain analysis - Google Patents

Abstract

Single Grain Analyzer (10) with
(A) a conveying and separating unit (14) in which a grain to be examined (28) (single grain) from a plurality of grains (material to be measured) separated and isolated a spectrometer (16) is supplied and
(B) a spectrometer (16) having a measuring device (34) on which the grain (28) is conveyed during the measurement and the one directed to the grain (28) radiation source for electromagnetic radiation and a reflection of the radiation from the grain (28) or the transmission of the radiation through the grain (28) detecting detector (42).

Description

The The invention relates to a single-grain analyzer, an associated method for single-grain analysis and their use for determining the homogeneity of the endosperm modification especially of barley and malts.

since Grain is used for millennia, be it in processed condition or directly as a raw product, the diet of human and animal. For breeding new varieties have always been necessary grains with the desired To separate properties from the bulk of the crop entry. To In the course of time, numerous procedures have been developed which essentially on physical separation methods and manual-optical Sorting based. Information about the salary of one or more Ingredients of the individual grains can at most be roughly estimated in this way. An exact determination according to chemometric methods leads to destruction of the grain - what in breeding procedures Of course undesirable is. In addition, the previously developed methods for the selection of individual grains very time-consuming and thus cost-intensive.

modern industrial production processes continue to demand the use of raw materials not only in their physico-chemical analysis data meet the requirements, but also in large uniform Batches are available. For example, the high and consistent quality of the used Raw materials are an essential prerequisite for rational and cost-effective production high-quality malts and beers. As a result of increasing mechanization and automation of the production processes of malt and beer and the development to ever larger production units The demands on the quality of the raw materials have further increased and their weighting postponed. Inhomogeneous barley with different processing properties are not suitable for an industrial malting process with a uniform malting process. Inhomogeneous malts can lead to significant technological problems in the brewery. she complicate and make more expensive the brewhouse, warehouse and filter cellar work and affect the quality of the product beer.

The inhomogeneity of the raw material usually has many reasons. In practice, grain lots from several trading partners and different growing areas are often combined and processed together (blending). However, even with an identical origin of a single plant, there are sometimes considerable differences, as the competition between the grains within an ear of corn and between the ears / stalks of a plant also has an effect. Adjacent plants within the same field impact are subject to different growth conditions (nutrient and water supply, disease pressure, etc.). Additional inhomogeneities arise from inconsistent drying and varying storage conditions, as well as from technological influences during processing (eg, malting) due to dehydration, varying O ₂ - / CO ₂ concentrations, different thermal conditions, or the like.

The more Inclusion of homogeneity in the evaluation of grain batches is an essential requirement for one precise Prediction of processability and a noticeable improvement in the quality of the raw materials (control function). The few methods developed to date for the investigation of homogeneity are indeed partly for Research purposes well suited for However, in practice they are too complicated, too time-consuming, too little reproducible, too expensive or have other serious ones Disadvantages. For example, the results of today available and recommended methods of malt analysis the character of means. They do not allow conclusions to be drawn the homogeneity the solution properties within a batch and the actual processing characteristics of a malt under the conditions of an industrial beer production. Also compliance with agreed specifications and the content contained therein Standard parameters offer often no guarantee for one easy processing in the brewhouse. Only through increased involvement of homogeneity criteria in the assessment of barley and malt can make more precise predictions about the actual Processing properties in malting brewing process and other noticeable improvements in raw material quality become.

When so far only chemometric method for the determination of the homogeneity could the specific staining high molecular weight β-glucans in the cell walls and establish cell wall residues of the malt endosperm by means of calcofluor. Although the development of single-grain analysis on the basis of Calcofluor staining for understanding homogeneity significantly contributed to an important criterion of malting quality and through the development of computer-aided automatic image analysis systems also the construction of a practicable and reproducible routine analysis possible still have methodological disadvantages and weaknesses homogeneity analysis unmissable, that oppose a wider application.

A nondestructive analysis method is spectroscopy. Referred to as spectroscopy in general, the interaction between light and matter. In IR spectroscopy, the vibration degrees of freedom of the irradiated molecules are excited. It comes to absorption bands in the IR spectrum, the fundamental tones in the MIR range (mid-infrared range, 400-4000 cm ^-1 ) and the combination or overtones in the NIR range (near infrared range, 4000-10000 cm ^{- 1} ) can be found. While very sharp peaks are observed in the MIR, the bands in the near infrared are significantly broadened by superposition of the vibrational states. An assignment of the bands to certain vibrations in the molecule, such as in the mid-infrared, is difficult or impossible.

In spite of The problem mentioned, the NIR spectroscopy has several advantages on, which has been growing steadily over the last two decades Field of application led to have. So it proves to be advantageous that the reflection of the NIR light radiation is much larger than those in the MIR, i. despite the low intensity of the vibration overtones can still satisfactory spectra are registered. Furthermore, it is Quartz in the NIR range largely permeable, which allows the use of fiber optic cables. That's just how it is possible in in-process control, to separate the sample location and spectrometer location. The application of multivariable calculation methods, supported by available today standing computer capacities, allows the quantitative evaluation of NIR spectra after previous Calibration creation within a very short period of time. The fundamental Suitability of the methodology was assessed by selective NIR microscopic measurements occupied in different areas half malt grains, the significant Differences in the spectral properties well resolved and badly solved Areas of the malt endosperm showed (K. Uhlenkamp, Investigation of barley malt using N1R spectrometry, University of Applied Sciences Duisburg, Diploma thesis, 1999).

task The present invention is a single grain analyzer and a related procedure to create, with which the aforementioned disadvantages of the state of the Technology overcome can be. The method or the single-grain analyzer should allow a large number on grains in no time Time to investigate. It should be in a non-destructive way information about the Salary of selected Ingredients are obtained and from this ultimately the homogeneity of the grain batch be determined more accurately and reproducibly.

• (a) eine Förder- und Separationseinheit, in der ein zu untersuchendes Korn aus einer Vielzahl von Körnern (Messgut) separiert und vereinzelt einem Spektrometer zugeführt wird sowie
• (b) ein Spektrometer mit einer Messeinrichtung, an der das Korn während der Messung vorbeitransportiert wird und die eine auf das Korn ausgerichteten Strahlungsquelle vorzugsweise für den sichtbaren Bereich und den nahen Infrarot-Bereich (VIS/NIR) und einen die Reflektion vom Korn erfassenden Detektor vorzugsweise im spektralen Messbereich von 380 bis 2400 nm beinhaltet,

umfasst, können erstmalig in sehr kurzer Zeit und mit geringem Arbeitsaufwand Informationen über eine große Anzahl von Messobjekten gewonnen werden.According to the invention this object is achieved by the single-grain analyzer with the features mentioned in claim 1 and the method for single-grain analysis according to claim 27. As a result, the single-grain analyzer

• (A) a conveying and separating unit, in which a grain to be examined from a plurality of grains (material to be measured) separated and occasionally fed to a spectrometer, and
• (B) a spectrometer with a measuring device, on which the grain is transported during the measurement and the a grain-oriented radiation source, preferably for the visible and the near infrared region (VIS / NIR) and a reflection of the grain detecting detector preferably in the spectral measuring range from 380 to 2400 nm,

For the first time, information about a large number of DUTs can be obtained in a very short time and with little effort.

The Measuring device is preferably a measuring cell through which the material to be measured individually conveyed through becomes. Radiation source and detector can also be arranged that instead of or in addition to the reflected radiation and the transmission of radiation is measured. Especially in the case of an open measuring device Instead of a closed measuring cell, the transport of the material to be measured close to the radiation source and the detector also with help a conveyor belt done.

A preferred measuring cell of the spectrometer preferably comprises a Sample feed from one in the area of the radiation source and the detector NIR-transparent Material. In particular, a glass tube of quartz glass can be used as a sample feed be used. The detector and the radiation source are on this way protected from direct contact with the grain, so the impurities or damage can be avoided. At the start and end times for the measurement as possible To determine exactly, it is also advantageous if the measuring cell comprises two light barriers for detecting the entry and exit of the measurement object.

alternative or additionally The measuring device can also be a treadmill for transporting the material to be measured include.

It has also proven to be advantageous if the measuring cell are assigned means with which a conveying speed of the grain in the measuring cell and thus a measuring time can be influenced. These means may comprise a controllable compressed air supply, through the generated air flow, the grain is entrained in a defined manner. It is also conceivable that the means mechanically, elek comprise tromagnetically or pneumatically adjustable joints, with which a tilt angle of the measuring cell is changeable. For example, a vertical orientation of the measuring cell leads to a maximum gravitational acceleration of the grain and an orientation with less inclination, due to the resulting friction on the walls of the measuring cell, for braking the grain.

In a further advantageous embodiment of the invention the detector and the radiation source based on fiber optics realized measuring attachment implemented. These include these components Fiber probes from a light-guiding Material that reflects the reflected radiation from the site to the detector (Detector probes), or the generated radiation from the Route the radiation source to the measuring location (radiation probes). advantageously, is the measuring cell from one or more individual probes, the in each case at least one radiation probe and at least one detector probe exist, built up. Here you can the individual probes in particular from a centrally located radiation probe and annular therefore arranged detector probes exist.

Disturbing influences of Grain shape, grain size or the respective orientation of the grains can by special arrangements of at least two individual probes in the Measuring cell to be compensated. These individual probes are so Placed that measurement simultaneously in transverse to the conveying direction offset areas of the grain (measuring points) takes place (transversal Single probe and measuring point arrangement). Preferably, the measuring points the at least two individual probes in such a transverse single probe arrangement on a perpendicular to the conveying direction extending plane offset in an approximately 90 ° angle to each other arranged. It is also conceivable, several individual probes ring around to arrange the measuring cell. After one explained in more detail below Orientation of the measuring points on the grain can be unsuitable in this way Reflection spectra are selected in the further evaluation thus further improving the accuracy and flexibility of the method become.

It has also proven to be advantageous if at least two individual probes are arranged in the measuring cell such that a measurement in the conveying direction offset measuring points (longitudinal individual probe and measuring point arrangement). As a result, the asymmetrical in the longitudinal direction Structure of the grain can be compensated and taken into account the circumstance Be that distribution of ingredients in the grain usually is uneven. With the increase The number of measuring points it is also possible to target in different Areas of grain same or different ingredients according to their salary. It has proved to be particularly favorable if 2 to 20, in particular 8 to 12, such differentiable measuring points are given in a longitudinal arrangement.

Of the Detector is preferably a diode array detector with a photodiode array and as a high-speed detector with sampling intervals of 0.01 to 50 ms, in particular 1 to 10 ms designed. His spectral Measuring range is preferably 350 to 2000 nm, in particular 1000 to 1700 nm the direct coupling with the optics of the detector probes can provide integration times of <10 ms become. Overall, the measurement of a single grain takes about 0.5 s, so that thousands of grains per Hour can be measured.

The conveying and separation unit comprises in a preferred embodiment the invention frequency-controlled vibrators or rotary disks for sorting the grains (Rotary separation) and a module for singling the grains (linear separation). The individual components are intended to further automate the Enable detection and in conjunction with that in just a few fractions of a second actual spectral measurement take the throughput of several hundred to several thousand grains in very short periods of time enable.

Farther is preferred that the measuring cell downstream of a sorting unit is, with which the previously measured grains can be stored defined. With Such, from the prior art known per se sorting unit can, for example, seed according to the content of certain ingredients be separated. In addition, it is also possible in this way, the Content of contents determined by the method on chemometric Ways to check. This is in particular when creating new reference data for the evaluation meaningful.

In A preferred embodiment of the invention comprises the single-grain analyzer an evaluation unit in which the spectrums recorded by the spectrometer of each grain with a stored in a storage medium Data set from reference spectra to match (correlation model). By integrating the evaluation unit into the single-grain analyzer the evaluation can be automated and even at lower Qualification of employees a high reproducibility and process safety be guaranteed.

Modular structure: single-grain module (Probe module), spectrometer (measuring module), evaluation module

Further will be a model for the grain is created and deposited in the storage medium. The model, in which characteristic spectral features (benchmarks) for certain Areas of the grain (modeled measuring points) are incorporated, allows an assignment of the spectra recorded at individual measuring points to the modeled measuring points (position assignment). When determined was, at which defined point of the grain the respective spectrum was recorded, depending on from a task underlying the measurement a selection the spectra are done. This allows on the one hand the computational effort on the other hand, can be customized for each measuring point be determined according to which criteria it is to be evaluated. Next a local one Selecting the spectra, it is also conceivable that certain spectra Measuring points that exceed a given deviation from the reference value of the model, before being compared with the reference spectra (qualitative Selection of spectra). The defined outliers (leverage value, Residual values) are self-evident for each Measurements to be recorded in advance in the underlying calibration model. If the set limit is exceeded, so this spectrum is no longer for further evaluation (for example, averaging) used. Hereby can In particular, empty measurements on the optics are suppressed.

With Help of the reference spectra determined according to the correlation model can estimates for the Content of one or more ingredients in the grain predicted become. So it is possible, for example, the content of β-glucans in malts to forecast. The estimates for the single grains of the material to be measured are evaluated statistically in the evaluation unit and can among other things, a measure of the homogeneity of the material to be measured deliver.

With previously described single-grain analyzer and developed practical The method of single grain analysis will be overall qualitative Characteristics of the material to be measured simplified and a more accurate prediction of the Processing properties allows. About that It also offers to the plant breeder a new instrument for a non-destructive Selection.

It has proved to be particularly advantageous, the single-grain analyzer and the associated procedure for the Measurement of barley or malt to use. In particular, the measurement can be to determine the protein content (especially β-glucans) of the Serve malt and a measure of the degree an endosperm transformation of the malt.

Further advantageous embodiments of the device are the subject of the remaining dependent claims.

The Invention will be described below in an embodiment with reference to the accompanying drawings explained in more detail. It demonstrate:

1 a block diagram of the operation of a Einzelkornanalysators;

2 a schematic representation of a measuring cell of the single-grain analyzer;

3 a schematic diagram for influencing the conveying speed by changing a tilt angle;

4 a schematic representation of a single probe;

5 an annular, transverse single probe arrangement;

6 an alternative transversal single probe arrangement;

7 a longitudinal single probe assembly;

8th a longitudinal and transverse measuring point arrangement on a grain;

9 at the measuring points of a grain detected reflection spectra and

10 Reflection spectra of different grains at the same measuring point.

The 1 shows a block diagram of the basic structure of a single-grain analyzer 10 , In a storage container 12 the test material to be examined, here a batch of malt grains, is provided. Depending on the design of the single-grain analyzer, the material to be measured may be 10 consist of several hundred to several thousand individual grains. In a reservoir 12 subsequent conveyor and separation unit 14 The grains are separated, isolated and in a defined manner a spectrometer 16 fed. This includes the conveying and separation unit 14 for example, a module 18 for rotational separation, in which the separation of the material to be measured takes place via an apertured, rotating disk. In another module 20 there is a linear separation of the grains, whereby an alignment of the objects to be measured is possible - in particular such that a longitudinal axis of the grains parallel to the conveyor direction in the spectrometer 16 runs. The individual grains have a defined distance from each other. In addition to the singling of the grains, the material to be measured is in the modules 18 . 20 cleaned from small adherent particles. Such modules 18 . 20 have long been known from the prior art. Since they are highly variable to the respective requirements customizable and interchangeable, a further explanation is omitted. It should be noted at this point that the material to be measured must be provided in a defined manner for the spectral measurement, with several hundred to several thousand individual grains being separated per hour.

Part of the single grain analyzer 10 is an evaluation unit 22 that provide an immediate evaluation of the in the spectrometer 16 measured spectra allowed. The evaluation unit 22 includes common components for electronic data processing, such as a storage medium, memory, a processor unit, a keyboard, devices for information reproduction and interfaces to other peripherals. The evaluation of the spectra will be explained in more detail below and in particular provides estimates of the content of certain ingredients in the grain. The flow of information between the evaluation unit 22 and the spectrometer 16 and between the evaluation unit 22 and a downstream sorting unit 24 is indicated by the dashed arrows. The sorting unit 24 serves for the defined storage of previously measured grains according to criteria determined by the evaluation unit 22 be specified. Such a procedure is useful, inter alia, if grains with certain content levels are to be selected for breeding purposes. The selected grains may also be checked for calibration purposes or to create new models for the underlying evaluations preferably chemometrically or alternatively with other reference methods to the 'actual' content.

sorting units 24 for such purposes are well known, so that is dispensed with a further description.

A subrange of the spectrometer 16 is in 2 outlined. The illustrated area comprises a glass tube 26 in which a grain to be measured 28 is transported, a first and second photocell 30 . 32 and the actual measuring cell 34 in which the spectral measurement is performed.

The glass tube 26 consists of quartz glass and is permeable to electromagnetic radiation in the VIS / NIR range (380 to 2400 nm). The pipe cross-section can be chosen so that twisting of the grain 28 in the conveying direction - indicated by the arrows - is prevented. The speed with which the grain 28 in the glass tube 26 moved forward, for example, by a not shown here controllable or adjustable compressed air supply, the one the grain 28 entraining airflow generated be influenced. Alternatively, it is conceivable, the inclination angle α of the measuring cell 34 and with it the glass tube 26 at a joint 36 to adjust ( 3 ). When vertical, the grain falls 28 unbraked through the glass tube 26 However, if the inclination angle α is decreased, the resulting friction of the grain will result 28 on the walls of the glass tube 26 to a reduction of the conveying speed. The joint 36 can be regulated or controlled by mechanical, electromotive or pneumatic means. For the regulation or control of the conveying speed are controlled variables such as a grain weight or with the help of the light barriers 30 . 32 certain conveying speed in previous measurements available.

The photocells 30 . 32 serve to detect the entry and exit of the grain 28 from the spectrometer 16 , If the grain 28 the first photocell 30 happens or optionally with a predetermined delay, the measurement is started and when passing through the second light barrier 32 completed.

In the 2 are two single probes 38 the measuring cell 34 shown, for feeding the measuring radiation and measuring the reflection on the grain 28 serve. The single probes 38 in turn are composed of individual fiber probes - based on a light-conducting material - and allow the distance from the location of the measurement arrangement of radiation source 40 and detector 42 ( 4 ). In the present example, six form a ring around a radiation probe 46 arranged detector probes 44 a single probe 38 , Several individual probes 38 can in later described manner in the measuring cell 34 to be ordered. Overall, all detector probes 44 on the central detector 42 , or all radiation probes 46 to the central radiation source 40 , switched together.

The radiation source 40 provides a measuring radiation in the near-infrared spectral range. In order to achieve integration times <10 ms, the detector is 42 a polychromatic high-speed diode array detector with 256 photodiode lines used (available, inter alia, the company Carl Zeiss Jena GmbH, Germany). The detector 42 is equipped with an InGaAs diode array, which allows measurement intervals of 1 to 10 ms and is characterized by a very good wavelength stability and a very high sensitivity in the near-infrared spectral range of 400 to 2400 nm. The detector 42 is due to its high resistance to vibration and temperature change for the ver suitable fields of application and offers clear advantages over the filter and monochromator technology. The measurement is carried out with a resolution of 0.5 nm, whereby about 280 measurements per second are performed. Per grain, the total measurement time is about 0.5 s.

A special arrangement of several individual probes 38 in the measuring cell 34 should increase the validity of the measurement and bring greater flexibility in the measurement with it. It has proven to be useful, transverse to the conveying direction at least two individual probes 38 to arrange, because this can be compensated based on the irregular grain shape or a different grain orientation measurement differences in the evaluation. For such a transverse single probe and resulting measurement point arrangement on the grain 28 show the 5 and 6 two alternatives. After a first variant ( 5 ) become three or more single probes 38 annular, with a suitable distance around the glass tube 26 arranged and allow the measurement at correspondingly many measuring points on the grain 28 , If, for structural reasons, such a multiple arrangement is not possible, according to a second variant ( 6 ) two single probes 38 in a direction perpendicular to the conveying direction plane at an angle of about 90 ° to each other on the glass tube 26 be attached. The 8th shows by way of example seven measuring point pairs (a / a 'to g / g') which consist of a transverse single probe arrangement with two individual probes each 38 result. In the evaluation unit 22 the spectra of the measuring point pairs are compared and, given existing differences, the spectra suitable for further evaluation are selected on the basis of a model which will be described below.

It is possible, too radiation detected with single fibers in a single fiber combine, so that there is a middle spectrum that is fed to the detector.

Because the grain 28 Also in the longitudinal direction is constructed inhomogeneous and the resulting inaccuracies in the measurement can be significant, has a multiple arrangement of individual probes 38 also proved advantageous in the conveying direction. In 7 are exemplary five individual probes 38 for such a longitudinal single probe arrangement, the distance of which, of course, to the dimensions of the grain 28 must be coordinated. The resulting longitudinal measuring point arrangement for seven individual probes 38 is the 8th to take (measuring points a to g or a 'to g'). In practice, arrangements with 8 to 12 measuring points in longitudinal extent have proved particularly suitable. These longitudinally different spectra can also be combined to form an average spectrum.

For a concrete malt grain resulting from such a measurement in 9 indicated spectra. It becomes clear that the reflection at different measuring points a to g provides different shaped spectra. To determine the absolute position of the individual measuring points - the grain 28 can indeed in two directions in the glass tube 26 be fed - is on one in the evaluation unit 22 deposited model for malt grains used. Such a model can, for example, be prepared in such a way that malt grains are first measured spectroscopically at the measuring points in question, and the data obtained are assigned to specific contents by chemometric determinations or alternative reference methods. Due to the inhomogeneity of the grain structure, the ratio of the individual measuring points to one another is characteristic for the longitudinal structure of the grain and therefore provides a reference for the orientation of measuring points with unknown orientation of the grain 28 ,

Under certain circumstances is another selection of the now concrete measurement points assigned Spectra necessary. For example, the content of one for the reflection particular ingredient in a particular area be characteristic and / or it should be at a measurement areas with different reflection behavior due to the presence of different ingredients are separated. With previously described orientation is a local selection especially simply by only predetermined in the respective evaluation Taken into account measuring points become. Furthermore, it makes sense to include qualitative criteria in the Selection of spectra for to incorporate the further evaluation. By default of limits for one Deviation from the reference values stored in the model can lead to empty measurements be suppressed.

Once the selection is complete and the location of the measurement points is determined, the spectra of several grains 28 be compared at the same measuring point. Exemplary shows 10 such a comparison for seven malt grains at the measuring point d. Even here it can be seen that there are considerable differences. In the case of malt grains, the measured reflectance is a measure of the β-glucan content and thus an indication of the state of endosperm transformation. Accordingly, estimates of the β-glucan content can be determined from the intensities of the individual spectra. Since the intensity of the individual spectra in the relevant spectral range can deviate from Lambert-Beer's law, First, a calibration function should be determined chemometrically. With the help of the in the evaluation unit 22 stored calibration function can then be determined in practice well with the actual contents corresponding estimates. However, according to a simpler correlation model, the acquired spectra can also be compared with a data set of reference spectra stored in the storage medium for agreement and thus provide meaningful estimates. The data obtained can be statistically evaluated in a known manner and, due to the large number of individual measurements (> 7000 measurements per h) available in a short time, allow a reliable estimation of the homogeneity of the material to be measured.

Of the here claimed and described single-grain analyzer is, for example also as a single piece analyzer e.g. for the analysis of pharmaceutical products such as pills or can be used for other samples.

10

Einzelkornanalysator

12

reservoir

14

Promotional and separation unit

16

spectrometer

18

module for the rotary separation

20

module for the linear separation

22

evaluation

24

sorting unit

26

glass tube

28

grain

30

first photocell

32

second photocell

34

cell

36

joint

38

Single Lead

40

radiation source

42

detector

44

detector probes

46

radiation probes

Claims (39)

Single-grain analyzer ( 10 ) with (a) a conveying and separating unit ( 14 ), in which a grain to be examined ( 28 ) (Single grain) separated from a large number of grains (measured material) and separated into a spectrometer ( 16 ) and (b) a spectrometer ( 16 ) with a measuring device ( 34 ), where the grain ( 28 ) is conveyed past the measurement and the one on the grain ( 28 ) directed radiation source for electromagnetic radiation and a reflection of the radiation from the grain ( 28 ) or the transmission of the radiation through the grain ( 28 ) detecting detector ( 42 ). Single-grain analyzer according to claim 1, characterized in that that the radiation source at least electromagnetic radiation in a spectral range between 350 and 2400 nm and delivers the detector comprises a measuring range of 350 to 2400 nm. Einzelkornanalysator according to claim 1 or 2, characterized in that the measuring device is a measuring cell ( 34 ) from one in the area of the radiation source ( 40 ) and the detector ( 42 ) NIR-transparent material. Single-grain analyzer according to claim 3, characterized in that the measuring cell ( 34 ) a sample tube serving as a glass tube ( 26 ), in particular of quartz glass. Single-grain analyzer according to one of claims 1 to 4, characterized in that the measuring cell ( 34 ) Means are associated with which a conveying speed of the grain ( 28 ) in the measuring cell ( 34 ) and thus a measuring time can be influenced. Single-grain analyzer according to claim 5, characterized in that that the means for influencing the conveying speed have a regular or controllable compressed air supply include. Einzelkornanalysator according to claim 6, characterized in that the means for influencing the conveying speed mechanically, electromotively or pneumatically adjustable joints ( 38 ), with which an angle of inclination α of the measuring cell ( 34 ) is changeable. Single-grain analyzer according to one of claims 1 to 7, characterized in that the measuring cell ( 34 ) two light barriers ( 30 . 32 ) for detecting the entry and exit of the grain ( 28 ). Single-grain analyzer according to one of claims 1 to 8, characterized in that the detector ( 42 ) Comprises fiber probes of a light-guiding material, which transmits the reflected or transmitted radiation from the measuring location to the detector ( 42 ) (detector probes ( 44 )). Single-grain analyzer according to one of claims 1 to 9, characterized in that the radiation source ( 40 ) Comprises fiber probes of a light-conducting material which absorb the generated radiation from the radiation source ( 40 ) to the measuring point (radiation probes ( 46 )). Single-grain analyzer according to claims 9 and 10, characterized in that the measuring cell ( 34 ) one or more individual probes ( 38 ) from in each case at least one radiation probe ( 46 ) and at least one detector probe ( 44 ). Single-grain analyzer according to claim 11, characterized in that the individual probes ( 38 ) from a centrally located radiation probe ( 46 ) and ring-shaped detector probes ( 44 ) consist. Single-grain analyzer according to claims 11 or 12, characterized in that at least two individual probes ( 38 ) in the measuring cell ( 34 ) are arranged such that a measurement simultaneously in transverse to the conveying direction areas of the grain ( 28 ) (Measuring points) can take place (transversal single probe and measuring point arrangement). Single-grain analyzer according to claim 13, characterized in that the measuring points of the at least two individual probes ( 38 ) are at an approximately 90 ° angle to the conveying direction to each other for the transverse single probe assembly. Single-grain analyzer according to claim 13, characterized in that a plurality of individual probes ( 38 ) for the transversal single probe arrangement in a ring around the measuring cell ( 34 ) are arranged. Single-grain analyzer according to claims 11 or 12, characterized in that at least two individual probes ( 38 ) in the measuring cell ( 34 ) are arranged such that a measurement in the conveying direction offset areas of the grain ( 28 ) (Measuring points) (longitudinal individual probe and measuring point arrangement). Single-grain analyzer according to claim 16, characterized in that that the 2 to 20 in longitudinal arrangement distinguishable measuring points are predetermined by the longitudinal single probe arrangement. Single-grain analyzer according to claim 17, characterized in that that the 8 to 12 in longitudinal arrangement distinguishable measuring points are predetermined by the longitudinal single probe arrangement. Single-grain analyzer according to one of claims 1 to 18, characterized in that the detector ( 42 ) is a high-speed detector with measurement intervals of 0.01 to 50 ms. Single-grain analyzer according to claim 19, characterized in that the detector ( 42 ) is a high-speed detector with measurement intervals of 1 to 10 ms. Single-grain analyzer according to one of claims 1 to 20, characterized in that the spectral measuring range of the detector ( 42 ) Is 400 to 2000 nm. Einzelkornanalysator according to claim 21, characterized in that the spectral measuring range of the detector ( 42 ) Is 1000 to 1700 nm. Single-grain analyzer according to one of claims 1 to 22, characterized in that the detector ( 42 ) is a diode array detector with a photodiode array. Single-grain analyzer according to one of claims 1 to 23, characterized in that the conveying and separating unit ( 14 ) Frequency-controlled vibrators for sorting the grain ( 28 ). Single-grain analyzer according to one of claims 1 to 24, characterized in that the conveying and separating unit ( 14 ) a module for separating the grain ( 28 ). Single-grain analyzer according to one of claims 1 to 25, characterized in that the measuring cell ( 34 ) a sorting unit ( 24 ), with which the previously measured grains ( 28 ) can be stored defined. Single-grain analyzer according to one of claims 1 to 26, characterized in that the single-grain analyzer ( 10 ) an evaluation unit ( 22 ), in which the spectrometer ( 16 ) recorded spectra of each grain ( 28 ) are compared with a stored in a storage medium record of reference spectra. Method for single-grain analysis, in which a single-grain analyzer ( 10 ) (a) a grain to be examined ( 28 ) (Single grain) from a plurality of grains (measured material) in a conveying and separating unit ( 14 ) separated and separated a spectrometer ( 16 ) and (b) the grain ( 28 ) during the measurement by a measuring device ( 34 ) of a spectrometer ( 16 ) and transported by one to the grain ( 28 ) aligned radiation source ( 40 ) is irradiated preferably in the visible range and the near infrared range (VIS / NIR) and the reflection from or the transmission through the grain ( 28 ) by a detector ( 42 ) is detected preferably in the spectral measuring range of 380 to 2400 nm. Method according to claim 28, characterized in that the spectrometer ( 16 ) recorded spectra of each grain ( 28 ) in an evaluation unit ( 22 ) are compared with a stored in a storage medium record of reference spectra to match (correlation model). Method according to claims 28 or 29, characterized in that a model stored in the storage medium for the grain ( 28 ) in which characteristic spectral features (reference quantities) for certain areas of the grain ( 28 ) (modeled measuring points) are incorporated and an assignment of the spectra recorded at individual measuring points to the modeled measuring points takes place (position assignment). Method according to claim 30, characterized in that that the spectra of certain measuring points according to the position allocation in dependence be selected from a task underlying the measurement and these spectra are compared with the reference spectra (local Selection of spectra). Method according to claim 30, characterized in that that spectra of certain measuring points that have a given deviation exceed the reference size of the model, before being compared with the reference spectra (qualitative Selection of spectra). Method according to one of Claims 29 to 32, characterized in that the reference spectra determined according to the correlation model are estimated values for the content of one or more ingredients in the grain ( 28 ) be assigned. Method according to claim 33, characterized in that the estimated values for the individual grains ( 28 ) of the material to be measured are statistically evaluated and provide a measure of the homogeneity of the material to be measured. Method according to one of claims 28 to 34, characterized in that the measuring cell ( 34 ) Means are associated with which a conveying speed of the grain ( 28 ) in the measuring cell ( 34 ) and one measuring time per grain ( 28 ) is set by specifying a certain conveying speed. Method according to one of claims 28 to 35, characterized in that the measuring cell ( 34 ) two light barriers ( 30 . 32 ) for detecting the entry and exit of the grain ( 28 ) and with entry of the grain ( 28 ) started the measurement or with exit of the grain ( 28 ) the measurement is ended. Method according to one of claims 28 to 36, characterized in that by the conveying and separating unit ( 14 ) an orientation of the grain ( 28 ) in the measuring cell ( 34 ) he follows. Using a single-grain analyzer after one the claims 1 to 27 and / or the method according to one of claims 28 to 37, characterized in that the measured material is barley or malt. Use according to claim 38, characterized that the measurement serves to determine the protein content (β-glucans) of the malt and a measure of the degree an endosperm transformation of the malt.