FR2631704A1 - METHOD FOR THE AUTOMATIC DETERMINATION OF PHYSICO-CHEMICAL PARAMETERS OF A GRAIN BATCH, AND APPARATUS FOR IMPLEMENTING SAID METHOD - Google Patents

Abstract

Apparatus and process for the automatic determination of a relation between a first surface of a grain cutting (1), previously coloured in function of a physical-chemical parameter of interest, and a second surface corresponding to the albumine of the grains of the cutting. The apparatus comprises in combination: an object holder (20) which supports the grain cutting (1) to be analyzed, a first assembly (15a, 15b) for illuminating the cutting (1) with selective light to display said first surface, a second assembly (5a, 5b) for illuminating the cutting (1) with selective light to display said second surface, a video camera (50), cooperating with an optical filter, a numerical image analyzer (70), a microcomputer (40) for controlling the apparatus. Application to the food stuff industry and in particular to brewing.

Description

 The present invention relates to a method for automatically determining a physicochemical parameter of a batch of grains, in particular the disintegration of a batch of malted barley grains intended for the brewery, as well as the homogeneity of this batch. grains, and an apparatus for carrying out this process.

A known method for determining the disintegration and homogeneity of a batch of malted barley grains is based on the calcofluor method (see ANALYTICA-EBC, 4th edition: 4.13 Malt modification, Calcofluor
Carlsberg Method).

This process is based on the specific staining of betaglucans by calcofluor, making it possible to visualize for each grain the part d '' non-disaggregated starch, which is fluorescent under actinic light (UV rays)
The chemical treatment of the calcofluor grains is preceded by the following operations, aimed at preparing a plate of grains to be analyzed - application, in dorsal position, of fifty grains
of the same lot of malted barley, on a plate of
thermosetting plastic, fixing the grains on
the plate being obtained by pressure in the plate
deformable so as to drive the grains on about the
half of their height, - longitudinal section of the upper half of the kernels
by sanding.

The visual effect is enhanced by a contrast dye.

 After washing and drying the plate, a visual examination of the grains one by one is carried out under the magnifying glass, and the classification of these grains according to six pre-defined classes corresponding to the following percentages of disaggregation 0%, 5%, 25% , 50%, 75%, 95%, 100%.

 It is thus possible to delimit the disaggregated starch surface, relative to the total area of starch.

 The analysis is performed by a person who, by observing malted, calcofluor-treated barley grains under actinic light, can discern the fluorescent (ie, non-disaggregated) starch surface of the total starch (ie, disaggregated and not disintegrated).

 For reasons of statistical validity, related to the visual estimation of the proportion of disaggregated starch surface, the observation is carried out on two plates of the aforementioned type, which involves the visual examination of 100 grains followed by calculations. manuals of disintegration and homogeneity, according to known formulas of the lamatiere technicians.

 This process thus makes it possible to obtain an overall assessment of the degree of disintegration and homogeneity of the malt before its use in the beer manufacturing process.

 However, it has the major disadvantage of a visual grading of each grain based on the percentage of fluorescence, which makes it inaccurate (ie, doubly inaccurate in terms of approximate appreciation of the fluorescent surface and the total area starch) -, as well as the manual execution of calculations that are long and tedious. In addition, this process requires trained and trained personnel, therefore expensive.

 The present invention therefore aims to provide a method for determining the disintegration and homogeneity of a batch of grains, including malted barley grains, which avoids the disadvantages mentioned above. I1 is based on the fact, unexpectedly, to be able to visualize the total surface of starch (disaggregated and not disaggregated) under non-actinic light, which lends itself - together with the visualization, known per se, of the non-starch surface disintegrated under actinic illumination - to automatic evaluation, by computer image processing of the surfaces involved in the determination of disaggregation and homogeneity, eliminating the double inaccuracy mentioned above.

The subject of the present invention is a method for automatically determining a ratio between a first surface of a grain section prepared from a sample taken from a batch of grains, this grain section being previously chemically treated with using a dye for coloring said first surface according to a physico-chemical parameter sought for grains - and a second surface corresponding to the albumen grains of the aforementioned cup, characterized in that it comprises the following steps: a) visualization (ie visual delineation of
outlines) of said first and second surfaces,
sequentially illuminating said grain cut using
first and second sources of light,
respectively, each having a length band
selective waves for their visualization, b) detection of the first and second surfaces thus visualized
by a video camera, equipped
an optical filter, and digitizing surfaces as well
detected by a digital image analysis device, c) numerical calculation of the first and second surfaces and
digitized followed by calculation of the percentage ratio
between these first and second surfaces, and d) using this report to determine said para
meter as well as the homogeneity of said batch of grains, the steps a) to d) being controlled by computer.

 According to a preferred embodiment of the method according to the invention, the grain section is divided into n optical fields of substantially identical surface, and each optical field is divided into i calculation boxes for which the steps are performed) to c) before proceeding to the next field, step d) being performed after having thus analyzed all n fields.

 According to an advantageous embodiment of this embodiment, the successive analysis of the n optical fields is done by rotaticnssuccessivesde the cutting of grains under the camera.

 According to the invention, when said desired parameter is constituted by the disintegration of the grains, the first illumination of the grain section is done in actinic light, the grain section having been previously chemically treated with the aid of a dye enabling the visualization under such actinic illumination of the undivided albumen surface of each grain which thus corresponds to said first surface, while the second illumination of the grain section is made in non-actinic light, which makes it possible to visualize said second surface, namely the total area of albumen. Of course, non-actinic light clipping can precede or follow actinic light illumination.

The present invention also relates to an apparatus for implementing the method, characterized in that it comprises in combination - a stage-object intended to support the cutting of
grains to be analyzed, - a first set of lighting of the cutting of grains in
light having a first wavelength band
selective, allowing to visualize said first
surface, - a second set of lighting of the cut of grains in
light having a second wavelength band
selective, allowing to visualize said second on
face, - a video camera, cooperating with a
optical filter, - a device for digital image analysis, - a microcomputer for controlling the device.

 According to a preferred embodiment of the apparatus according to the invention, the first and second lighting assemblies are disposed within a light-tight housing and equipped with an access door.

 According to another preferred embodiment of the apparatus according to the invention, the object stage cooperates with a rotation drive motor, allowing the successive analysis of n optical fields of the grain section, each field having a substantially identical surface and being delimited by means of a viewing diaphragm carried by the camera.

 According to the invention, the number of image fields is n = 4.

 In addition to the foregoing, the invention also comprises other provisions, which will emerge from the description which follows.

The invention will be better understood with the aid of the additional description which follows, which refers to the appended drawings in which - FIGS. 1 and 1 illustrate, respectively, a diagram
synoptic of the apparatus according to the invention and a
diagram showing the links between
components, - Figure 2 is a perspective view of the housing of which
is equipped with the apparatus according to the invention, which is devoid of
the access door to illustrate the components that
are contained, - Figure 3 is a top view of the housing shown in
Figure 2, which is devoid of its ceiling for illus
arrange the different components of each
compared to the others, - Figure 4 is a schematic top view of a
plate to be analyzed, - Figure 5 illustrates a diagram providing the correlated
between the disintegration obtained by
of the method and apparatus according to the invention and
obtained by the official manual method ANALYTICA IV
EBC (European Brewery Convention), - Figure 6 illustrates the diagram providing the correlated
between the homogeneity values calculated
using a computer with which the device is equipped
according to the invention, and the homogeneity obtained using
the calculation method proposed by the EBC.

It should be understood, however, that these
drawings and the corresponding descriptive parts, are
given only as an illustration of the purpose of
the invention, of which they do not constitute in any way
a limitation.

The method of determining the disintegration
and the homogeneity of a batch of grains, particularly
malted barley intended for the brewery, requires the
preparation. prior to a cut of grains to be analyzed,
as shown in Figure 4.

On a plate 1 about 6g of
10 grains (corresponding to about 150 grains) that are fixed
to the plate using a glue with hardener, type
fast epoxy or araldite.

In the illustrated example, it is a plate
of glass 85 mm long, 60 mm wide and 3 mm thick
the use of a plastic plate
has been abandoned as part of the
present invention for the following reasons
- poor light contrast for taking pictures
exploitable;
- poor resistance of the grains during abrasion, which
would result in uneven grain cutting and therefore
important errors in the interpretation.

The preparation of the grain cut, namely the plate, takes place in the following manner - weighing about 60 g of grains (corresponding to about 150
grains), put them on a first glass plate and
spread them on it - on a second plate, put a thin regular layer
glue and hardener well homogenized together, then,
place this glue on the plate where
the grains, return the whole and distribute the grains
so that they do not overlap, but without respec
no alignment - allow this plate to dry in an oven at 500C for 2
hours - block the plate in the vice and sand the grains to the
half of their thickness - pour 20 cl of the calcofluor solution on the grains and
let stand for about 15-20 seconds, then rinse with
ethanol solution absorb the above with paper
blotter - pour 20 cl of the fast green solution on the grains and
let stand for 15-20 seconds, then rinse again
with the ethanol solution, while absorbing the excess, and
leave to dry to bind: the plate is thus ready for
automatic reading.

 Once the plate 1 has been prepared, as specified above, it is placed on a turntable 20, digitally controlled, disposed inside a housing 30, where it projects from the bottom 22 of this housing, which is tightly closed to ambient light (the closing door of this housing has not been shown).

This housing also contains two lamps 5a, 5b, emitting non-actinic light in diffuse form, especially white light, and two lamps 15a, 15b, emitting actinic light in also diffuse form, in particular consisting of the light of violet color. These lamps are arranged at X around the plate to be analyzed 1 and the turntable 20, as shown in FIG. 3, and fixed to two parallel and parallel side walls 23 and 24 of the casing 30.

 In FIGS. 2 and 3, it is also possible to notice the presence of four position sensors 7a to 7d intended to cooperate with a positioning notch 8 formed on the periphery of the turntable 20.

 A monochrome video camera, 50, with a 25mm / 1.8 close-up lens, provided with a Y48 optical filter (not shown) is attached to the ceiling 25 of the housing 30 and disposed, relative to to the plate to be analyzed, so as to aim a dial thereof with each rotation of the plate 20 (see Figure 3). Any undesired movement of the plate to be analyzed, in particular during successive rotations of the support plate, is prohibited thanks to the presence of stops 21.

 After closing the case, the progress of all the operations and calculations takes place automatically thanks to a specific image processing and calculation control software, the support of which consists of an 8-bit microcomputer 40, comprising a keyboard 45 and a 3 "floppy disk drive as well as a control input / output interface 35.

 This computer can also cooperate with a monochrome video monitor 60 with a graphic display, as well as with a printer 70 for printing the results of the analysis. In the figure also visible is a real-time image digitizer, 90, which is directly connected to the camera 50, as well as a power supply 55.

 According to the invention, a first surface measurement is performed on substantially 1/4 of the plate 1 illuminated with the lamps Sa, 5b, namely by non-actinic light, so as to visualize the total area of starch (comprising the disintegrated portion and the undissociated portion thereof).

 Then, under the control of the above-mentioned software, the actinic light is illuminated by means of the lamps 15a and 15b as well as the surface measurement of the non-disareagated part of the starch of the grains 10.The plate 1 turns then 1/4 turn and the same measurements are executed for a second dial thereofLa platinum 20 rotates four times, the stopping of each rotation being triggered in turn by one of the four aforementioned sensors 7a to 7d at the passage of the notch 8 of the plate 20. The subdivision of each of the four dials of the plate in a number of boxes is performed by the software. The number of boxes chosen in the example is 9, which gives 36 units of analysis in total. The software also allows the calculation of the percentage ratio between the surface measured under actinic light and the surface measured under non-actinic light. , thanks to the camera of shots 50 and to the digitization of the surfaces carried out by the device 99. The individual computer treatment of the two superimposed images of each box makes it possible, by a judicious choice of gray levels, not to consider that the strictly relevant part for the intended calculations, namely: the total area of starch 10b (disaggregated and undissociated) of the malt, - by spreading the remaining part of each grain 10 (ie the seed 10c and the bark) as well as the bottom of the plate, and the fluorescent surface 10a, respectively (for the sake of simplification of the drawings, the unadulterated starch surface 10a and the total surface area of starch 1 are illustrated 0b for a single grain in FIG. 4: this total area corresponds to the area of each cut grain minus the seed 10c). It is thus possible to calculate these surfaces accurately and, consequently, reliable disintegration and homogeneity values.

CALCULATION OF THE DISAGGREGATION
The 36 squares give 36 surface ratios, the average (X) of which corresponds to the percentage of undissociated surface. The result (100 - X) corresponds to the disaggregation. This calculation is done automatically by the software.

CALCULATION OF HOMOGENEITY
For each cell, we have a disaggregation value; it is these 36 disintegration values that will be used to calculate the homogeneity, performed in a manner known to technicians in the field and specified above.

 To test the reliability of the method and apparatus according to the invention, a correlation was sought between the results thus obtained and those provided by the EBC method. For this purpose, N = 28 malts were analyzed according to the latter method. (see Table 1, indicating the nature of malts analyzed). The reading was done twice by the same operator for all the samples. Then, the analysis was carried out using the automatic apparatus according to the invention, implementing the method proposed by the Applicant. Table 2 shows the disaggregation obtained automatically compared with the disaggregation obtained by the manual reference method. A linear correlation calculation results in a correlation coefficient r = 0.95, as shown in Figure 5. This coefficient is satisfactory, given the repeatability and reproducibility coefficients given in the official method (from 1.6% to 11%, depending on the disintegration of the malt).

 With regard to the correlation between the homogeneity obtained manually and that obtained automatically, it is necessary to specify the following: from the disaggregation values of the 36 fields mentioned above, the disaggregation was calculated by considering the standard deviation 36 boxes (on average.

comme représentatif de l'hétérogénéité du malt et en calculant une désagréga tion en pourcentage pour la comparer au calcul recommandé par 1'EBC et connu des techniciens en la matière (ceci est illustré au diagramme de la figure 6)
Dans ce cas, on obtient l'homogénéité H par le 0' calcul suivant : H = 100 (1 - ), comme illustré dans 0,5 l'Article "Determination of malt modification" de JENSEN et AASTRUP, paru dans la Revue CEREVISIA, 1985,3,page 113.3 grains per box

as representative of the heterogeneity of the malt and calculating a percentage disaggregation for comparison with the calculation recommended by the EBC and known to technicians in the field (this is illustrated in the diagram of FIG. 6)
In this case, the homogeneity H is obtained by the following calculation: H = 100 (1 -), as illustrated in the article "Determination of malt modification" of JENSEN and AASTRUP, published in the CEREVISIA Review. 1985, 3, page 113.

 The correlation coefficient between this calculation method and the results obtained with the manual EBC reference method is 0.90.

 Since the method according to the invention is not based on any classification, but on the actual values of disaggregation, it makes it possible to recover the maximum of information: in fact, the disaggregation values are continuous in the automatic reading method, while they are distributed discontinuously in the manual method.

 The above-mentioned correlation coefficient is also good with regard to the repeatability and reproducibility coefficients given by the EBC (from 3.6% to 17% depending on the disaggregation of the malt).

REPEATABILITY
A repeatability test (30 values) of the reading and calculation of the disaggregation of 2 Malts was also performed
Malt 1 Malt 2
Average Disaggregation:: 79.5% 55.3%
Standard Deviation -: 3.0 1.5
Coefficient of variation ...: 3.8% 2.7%
Homogeneity
Average:: 71.4% 63.9%
Standard deviation .................: 5.1 1.8
Coefficient of variation ...: 7.1% 2.8%
The coefficient of variation is here defined by the formula: standard deviation × 100.

average
In Figures 5 and 6 the coefficients a and b represent, respectively, the slope of each line and the ordinate at the origin, while N = 28 refers to the number of malts analyzed.

TABLE 1

<tb><SEP> NATURE <SEP> OF <SEP> SAMPLES
<tb> N <SEP> of <SEP> sample <SEP> NATURE
<tb><SEP> 1 <SEP> Malt <SEP> 2RP
<tb><SEP> 2 <SEP> Malt <SEP> 2RP
<tb><SEP> 3 <SEP> Malt <SEP> 2RP
<tb><SEP> 4 <SEP> Malt <SEP> 2RP
<tb><SEP> 5 <SEP> Malt <SEP> Spring
<tb><SEP> 6 <SEP> Malt <SEP> Spring
<tb><SEP> 7 <SEP> Malt <SEP> Spring
<tb> 8 <SEP> Malt <SEP> Spring
<tb><SEP> 9 <SEP> Malt <SEP> Spring
<tb><SEP> 10 <SEP> Malt <SEP> Winter
<tb><SEP> 11 <SEP> Malt <SEP> Malt <SEP> Winter
<tb><SEP> 12 <SEP> Malt <SEP> Malt <SEP> Winter
<tb><SEP> 13 <SEP> Malt <SEP> Winter
<tb><SEP> Lathe <SEP>#<SEP><SEP> Output <SEP> trenpe <SEP>#
<tb><SEP> 14 <SEP> 50 <SEP> 50
<tb><SEP> 15 <SEP> 60 <SEP> 40
<tb><SEP> 16 <SEP> 61 <SEP> 39
<tb><SEP> 17 <SEP> 67 <SEP> 33
<tb><SEP> 18 <SEP> 72 <SEP> 28
<tb><SEP> 19 <SEP> 79 <SEP> 21
<tb><SEP> 20 <SEP> 92 <SEP> 18
<tb><SEP> 21 <SEP> 3rd <SEP> day <SEP> of <SEP> germination
<tb><SEP> 22 <SEP> 3rd <SEP> day <SEP> of <SEP> germination
<tb><SEP> 23 <SEP> 4th <SEP> day <SEP> of <SEP> germination
<tb><SEP> 24 <SEP> 4th <SEP> day <SEP> of <SEP> germination
<tb><SEP> 25 <SEP> 5th <SEP> day <SEP> of <SEP> germination
<tb><SEP> 26 <SEP> 5th <SEP> day <SEP> of <SEP> germination
<tb><SEP> 27 <SEP> Tour <SEP> aille
<tb><SEP> 28 <SEP> Tour <SEP> aille
<Tb>
TABLE 2

<tb><SEP> RESULTS <SEP> FROM <SEP> DESAGREGATION
<tb> SAMPLE <SEP> Disaggregation <SEP> m @@ uel @@ <SEP><SEP> Disintegration <SEP> video
<tb><SEP> 1 <SEP> @ <SEP> 88
<tb> 2 <SEP> @ 9 <SEP> 60
<tb><SEP> 3 <SEP> 66 <SEP> 60
<tb><SEP> 4 <SEP> 72 <SEP> 69
<tb><SEP> 5 <SEP> 89 <SEP> 85
<tb> 6 <SEP> 85 <SEP> 84
<tb><SEP> 7 <SEP> 90 <SEP> 92
<tb> 8 <SEP> 93 <SEP> 93
<tb><SEP> 9 <SEP> 91 <SEP> 91
<tb><SEP> 10 <SEP> 75 <SEP> 82
<tb><SEP> 11 <SEP> 81 <SEP> 79
<tb><SEP> 12 <SEP> 87 <SEP> 89
<tb><SEP> 13 <SEP> 62 <SEP> 67
<tb><SEP> 14 <SEP> 46 <SEP> 52
<tb><SEP> 15 <SEP> 54 <SEP> 64
<tb><SEP> 16 <SEP> 59 <SEP> 68
<tb><SEP> 17 <SEP> 62 <SEP> 73
<tb><SEP> 18 <SEP> 69 <SEP> 75
<tb><SEP> 19 <SEP> 76 <SEP> 83
<tb><SEP> 20 <SEP> 88 <SEP> 89
<tb> 21 <SEP> 57 <SEP> 60
<tb><SEP> 22 <SEP> 64 <SEP> 60
<tb><SEP> 23 <SEP> 84 <SEP> 80
<tb><SEP> 24 <SEP> 84 <SEP> 82
<tb><SEP> 25 <SEP> 97 <SEP> 91
<tb><SEP> 26 <SEP> 98 <SEP> 92
<tb><SEP> 27 <SEP> 96 <SEP> 95
<tb><SEP> 28 <SEP> 96 <SEP> 96
<Tb>
TABLE 3

<tb><SEP> RESULTS <SEP> OF ROMOGENEITY
<tb> SAMPLE <SEP> HOMOGENEITY <SEP> VISUAL <SEP> HOMOGENEITY <SEP> WITH <SEP> SIGMA
<tb><SEP> 1 <SEP> 64 <SEP> 72
<tb><SEP> 2 <SEP> 68 <SEP> 63
<tb><SEP> 3 <SEP> 3 <SEP> 69 <SEP> 69
<tb><SEP> 4 <SEP> 70 <SEP> 72
<tb><SEP> 5 <SEP> 70 <SEP> 79
<tb><SEP> 6 <SEP> 70 <SEP> 76
<tb><SEP> 7 <SEP> 77 <SEP> 86
<tb><SEP> 8 <SEP> 75 <SEP> 83
<tb><SEP> 9 <SEP> 73 <SEP> 83 <SEP>
<tb><SEP> read <SEP> 61 <SEP> 79
<tb><SEP> 11 <SEP> 56 <SEP> 58
<tb><SEP> 12 <SEP> 67 <SEP> 76
<tb><SEP> 13 <SEP> 62 <SEP> 69
<tb><SEP> 14 <SEP> 4 <SEP> 41
<tb><SEP> 15 <SEP> 7
<tb><SEP> 16 <SEP> 4 <SEP> 34 <SEP>
<tb><SEP> 17 <SEP> 6 <SEP> 55
<tb><SEP> 18 <SEP> 12 <SEP> 55
<tb><SEP> 19 <SEP> 18 <SEP> 55
<tb><SEP> 20 <SEP> 41 <SEP> 58
<tb><SEP> 21 <SEP> 45 <SEP> 69
<tb><SEP> 22 <SEP> 47 <SEP> 65
<tb><SEP> 23 <SEP> 59 <SEP> 69
<tb><SEP> 24 <SEP> 56 <SEP> 72
<tb><SEP> 25 <SEP> 73 <SEP> 79
<tb><SEP> 26 <SEP> 73 <SEP> - <SEP> 76
<tb><SEP> 27 <SEP> 72 <SEP> 72
<tb><SEP> 28 <SEP> 75 <SEP>. <SEP> 79
<Tb>
The method and apparatus forming the subject of the present invention therefore constitute a satisfactory solution to the technical problem which is the basis of this, since they make it possible to avoid the subjective assessment of the surfaces involved in the determination of the disaggregation and homogeneity & a lot of grains.

 In addition, they make it possible to compare the results corresponding to different manipulators, since the manual interventions are reduced to a minimum, which explains the repetitive nature of the measurement.

 In addition, the present invention contributes to the operational application of an evaluation test of the quality of malting.

 As is apparent from the foregoing, the invention is not limited to any of its modes of implementation, implementation and application which have been described more explicitly; it embraces, on the contrary, all the variants that may come to the mind of the technician in the field, without spacer frame or scope of the present invention. In particular, it should be noted that, although the description refers to the use of a violet light source of actinic light, it goes without saying that any equivalent source is likely to be used in the context of the present invention, including UV rays; however, these are not indispensable as the EBC method would suggest. In addition, although the description of the determination of the value of the surfaces viewed under actinic and non-actinic light - which are necessary for the evaluation of the disaggregation and the homogeneity of a batch of grains - has been limited to the use of the image processing means (ie, the use of a camera associated with an image digitizer under the control of a computer, whose program allows the execution of the calculations of disaggregation and homogeneity, according to the terms mentioned above), it goes without saying that other equivalent means are likely, at least theoretically, to be used in the same purpose.

 In addition, it is also possible to optimize the homogeneity calculation - thus measuring the true value of homogeneity - by placing the grains on the analysis plate so that there is only one grain per box (instead of three grains on average, as indicated in the evaluation of the aforementioned standard deviation), without departing from the method object of the present invention.

Claims (10)

 1. A method for automatically determining a ratio between a first surface (10a) of a grain section (1) prepared from a sample taken from a batch of grains, the grain section being previously chemically treated with a dye for coloring said first surface (lova) according to a physico-chemical parameter sought for the grains (10) -, and a second surface (10b) corresponding to the albumen of the grains (10) of the section (1) above, characterized in that it comprises the following steps a) visualization (namely visual delineation of  outlines) of said first and second surfaces- (10a,  lOb), by illuminating successively said section (1) of  grains (10) using a first (15a, 15b) and a  second (5a, 5b) light sources, respectively,  each having a band of selective wavelengths  allowing their visualization, b) detection of the first and second surfaces (10a, 10b)  thus visualized by a camera (50) of shots  equipped with an optical filter, and digitization of  surfaces thus detected by an analysis device  digital image (70), c) numerical calculation of the first and second surfaces (10a,  lOb) thus digitized followed by the calculation of the  percentage between these first and second surfaces, and d) use of this report to determine said para  meter as the homogeneity of said batch of grains, the steps a) to d) being computer-controlled (40).  2. A process according to claim 1, characterized in that the section (1) of grains (10) is divided into n optical fields, of substantially identical surface, and in that each optical field is divided into i calculation boxes for which steps a) to c) are performed before proceeding to the next field, step d) being performed after having thus analyzed all the n fields.  3. A process according to claim 2, characterized in that the successive analysis of the n optical fields is done by successive rotations of the section (1) grains (10) under the camera (50).  4.- Method according to any one of claims 1, 2 or 3, characterized in that, when said desired parameter is constituted by the disintegration of the grains, the first illumination (15a, 15b) of the section (1) grain (10) is made in actinic light, -the section (1) of grains (10) having been previously chemically treated with a dye allowing the visualization, under such actinic lighting (15a, 15b), the undivided albumen surface (lova) of each grain (1O), which thus corresponds to said first surface-, while the second illumination (5a, 5b) of the section (1) of grains (10) is made in light non-actinic, which allows to visualize said second surface (lOb), namely the total surface of albumen.  5. A process according to claim 4, characterized in that the step of illuminating the grain section in non-actinic light precedes the step of illuminating actinic light.  6. A process according to claim 4, characterized in that the step of illuminating the grain section in non-actinic light follows the actinic light lighting step.  7. Apparatus for carrying out the process according to claims 1 to 6, characterized in that it comprises in combination - an object stage (20) intended to support the  cutting (1) of grains (10) to be analyzed, - a first set (15a, 15b) of illumination of the cut  (1) light grains (10) having a first band of  selective wavelengths, allowing to visualize  said first surface, - a second lighting assembly (5a, 5b) of the section (1)  light grains (10) having a second  selective wavelengths for visualizing  said second surface, - a video camera (50) cooperating with  an optical filter; a digital image analysis device (70); a microcomputer (40) for controlling the apparatus.  8. Apparatus according to claim 7, characterized in that the first (15a, 15b) and second (Sa, 5b) lighting assemblies are disposed inside a housing (30) sealed to ambient light and equipped with an access door.  9. Apparatus according to any one of claims 7 or 8, characterized in that the stage holder (20) cooperates with a drive motor in rotation, allowing the successive analysis of n optical fields of the section ( 1) grains (10) each field having a substantially identical surface and being delimited with a viewing diaphragm carried by the camera (50).  10. Apparatus according to claim 9, characterized in that the number of image fields is n = 4.