CA2337903A1 - Method for determining the quality of fruit and berries and apparatus for sorting fruit and berries - Google Patents
Method for determining the quality of fruit and berries and apparatus for sorting fruit and berries Download PDFInfo
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- CA2337903A1 CA2337903A1 CA002337903A CA2337903A CA2337903A1 CA 2337903 A1 CA2337903 A1 CA 2337903A1 CA 002337903 A CA002337903 A CA 002337903A CA 2337903 A CA2337903 A CA 2337903A CA 2337903 A1 CA2337903 A1 CA 2337903A1
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- chlorophyll
- fruit
- berries
- fluorescence
- signal
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B13/00—Grading or sorting solid materials by dry methods, not otherwise provided for; Sorting articles otherwise than by indirectly controlled devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/02—Food
- G01N33/025—Fruits or vegetables
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
- B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
- B07C5/34—Sorting according to other particular properties
- B07C5/342—Sorting according to other particular properties according to optical properties, e.g. colour
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
- G01N21/64—Fluorescence; Phosphorescence
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- Food Science & Technology (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Engineering & Computer Science (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Medicinal Chemistry (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Investigating Or Analysing Biological Materials (AREA)
Abstract
The invention relates to a method for determining the maturity and quality o f fruit and berries by measuring the quantity of chlorophyll fluorescence and to an apparatus for sorting fruit and berries. The method is based on determini ng the quantity of fluorescence by chlorophyll of fruit and berry. The inventio n comprises causing the chlorophyll molecule to fluoresce by irradiating the fruit and berries with electromagnetic radiation of a suitable wavelength an d measuring the degree of fluorescence. Advantages of the method are the very high sensitivity, its being completely non-destructive and the very high speed. These advantages of the invention make it possible to construct a sorter apparatus in which fruit and berries are selected on the basis of the quantity of chlorophyll. Because the intensity of the chlorophyll fluorescen ce is directly related to the quantity of chlorophyll, it will now be possible to sort fruit and berries as to the stage of ripening and quality.
Description
Method for determining the quality of fruit and berries and apparatus for sorting fruit and berries.
The invention relates to a method for determining the quality of fruit and berries by irradiating fruit and berries with electromagnetic radiation. The chlorophyll present in the fruit or berries shows prompt fluorescence as a result of this irradiation. The present invention also relates to an apparatus for sorting fruit and berries, at least consisting of a feeder part for the fruit and berries, a part for irradiating the fruit and berries with electromagnetic radiation and a part for measuring the chlorophyll fluorescence signal returning from the fruit and berries, and a separation part which operates on the basis of the chlorophyll fluorescence signal returning from the fruit and berries. By chlorophyll all appearances of the chlorophyll molecule are meant, such as the chlorophyll known as leaf green, protochlorophyll, etc.
The method of the invention is particularly suitable for determining the quality of blue berries and can especially be used with frozen berries.
Below the invention will be described on the basis of blue berries.
Measuring the amount of chlorophyll of berries is a good method for measuring the maturity and thus the quality of berries. It appears that during the ripening of berries the chlorophyll content of the berry decreases. The apparatus known up until now, sorts blue berries as to colour. Green berries can be separated from red and blue berries, because the difference in colour is sufficiently evident. However, red berries cannot be separated from blue berries by means of the used method of colour measurement. These red berries are of inferior quality compared to the blue berries, because they have not fully ripened. A second problem in colour WO 00/OZ036 PCT/NL99/OU411.
The invention relates to a method for determining the quality of fruit and berries by irradiating fruit and berries with electromagnetic radiation. The chlorophyll present in the fruit or berries shows prompt fluorescence as a result of this irradiation. The present invention also relates to an apparatus for sorting fruit and berries, at least consisting of a feeder part for the fruit and berries, a part for irradiating the fruit and berries with electromagnetic radiation and a part for measuring the chlorophyll fluorescence signal returning from the fruit and berries, and a separation part which operates on the basis of the chlorophyll fluorescence signal returning from the fruit and berries. By chlorophyll all appearances of the chlorophyll molecule are meant, such as the chlorophyll known as leaf green, protochlorophyll, etc.
The method of the invention is particularly suitable for determining the quality of blue berries and can especially be used with frozen berries.
Below the invention will be described on the basis of blue berries.
Measuring the amount of chlorophyll of berries is a good method for measuring the maturity and thus the quality of berries. It appears that during the ripening of berries the chlorophyll content of the berry decreases. The apparatus known up until now, sorts blue berries as to colour. Green berries can be separated from red and blue berries, because the difference in colour is sufficiently evident. However, red berries cannot be separated from blue berries by means of the used method of colour measurement. These red berries are of inferior quality compared to the blue berries, because they have not fully ripened. A second problem in colour WO 00/OZ036 PCT/NL99/OU411.
measurement is that with frozen berries a white frost is created. As a result it is very difficult to sort berries as to colour, because of the reflec-tions of the irradiated light on the white coloured white frost and because the green, red or blue colour of the berry can no longer be measured due to the white frost. By only measuring the chlorophyll fluorescence signal of the berries, it is possible to determine the different degrees of maturity of blue berries. It has been found that green berries have a very high chlorophyll fluorescence signal, red berries have a lower chlorophyll fluorescence signal and blue berries have a very low chlorophyll fluores-cence signal. It has further been found that despite the white frost on frozen berries it is possible to sort berries as to maturity and quality on the basis of the chlorophyll fluorescence signal. Chlorophyll fluorescence is hardly hindered by the white frost and is much more sensitive than a colour measurement. There are commercially available apparatus which determine the maturity of blue berries by measuring the chlorophyll con-tents with fluorescence.
In the art it is known that by using chlorophyll fluorescence chlorophyll can be measured. In "Application of chlorophyll fluorescence to postharvest physiology and storage of mango and banana fruit and the chilling tolerance of mango cultivars", Asian Food Journal (1987), 3(2), 55-59, R.M. Smillie, S.E. Hetherinton, R.N. Grantley, R. Chaplin and N.L. Wade used the chlorophyll fluorescence technique to measure the photosynthesis activity of fruit. They examined the changes in the photosynthesis activity during ripening and under the influence of low temperatures by measuring the chlorophyll fluorescence signal of the skin. The speed with which the chlorophyll fluorescence signal decreased during exposure to low temperatures was used to select varieties that are insensitive to cold. They do not mention the possibility to sort blue berries as to maturity by measuring prompt fluorescence. Neither do they mention the possibility to sort frozen berries as to maturity by measuring prompt fluorescence. In case pf fresh fruit and leafs the chlorophyll fluorescence signal changes during the measurement, because the chlorophyll is photosyntheticafly active. This as opposed to the chlorophyll in a frozen berry, There is no photosynthesis in a frozen berry. The chlorophyll fluorescence signal is constant over a short period of time of some minutes. In the method according to the invention the prompt quantity of chlorophyll fluorescence is measured, so instantaneous to the irradiation of the berry with electromagnetic radiation. The amplitude of the chlorophyll fluorescence signal is now a measure for the quantity of chlorophyll. The measuring method of Smillie in total requires one hour because of adjustment to the dark for one hour and some seconds for monitoring the changes in the chlorophyll fluorescence signal. The measuring method according to the invention can be carried out in a fraction of a second. The usual method for measuring photosynthesis activity in plant material comprises the use of the pulse amplitude modulation (PAM) fluorometer of U. Schreiber, described in "Detection of rapid induction kinetics with a new type of high frequency modulated chlorophyll fluorometer", Photosynthesis Research (1986) 9:261-272. The photosynthesis activity does not directly depend on the quantity of chlorophyll in plant material. The chlorophyll fluores-cence signal however does directly depend on the quantity of chlorophyll.
For determining the photosynthesis activity therefore a correction for the quantity of chlorophyll has to be made. This is done by calculating a quotient, so that said quotient is independent from the quantity of chlorophyll. The method described according to the invention, however, uses the measured quantity of chlorophyll fluorescence as measure for the quantity of chlorophyll.
According to H.K. Lichtenthaler in "In vivo chlorophyll fluorescence as a tool for stress detection in plants ", Application of Chlorophyll Fluores-cence in Photosynthesis, H.K. Lichtenthaler (ed.) 1988, 121-142, Kluwer Academic Press, Dordrecht, the quantity of chlorophyll cannot be measured by means of photosynthesis measurements. The parameters measured for calculating the photosynthesis by using chlorophyll fluores-~P N L 009900411 0 9. 10. 2000 cence can even increase in signal strength when the quantity of chlorophyll decreases. This is the result of re-absorbtion of the emitted chlorophyll fluorescence decreasing because of the lower concentration of chlorophyll.
This is contrary ~to the statement according to the invention that the chlorophyll fluorescence can be used for determining the quantity of chlorophyll. In "Reflectance and chlorophyll fluorescence signatures of leaves" in Proceedings IGARSS'87 Symp. Ann. Arbor. MI (USA) 18-21 May 1987, 1201-1206, H.K. Lichtenthaler and C. Buschmann show that around 690 and 730 nm the chlorophyll fluorescence signal of leaves is not linear to the quantity of chlorophyll. It was also demonstrated that a lower quantity of chlorophyll could emit a larger chlorophyll fluorescence signal.
From these two articles it appears that the literature indicated that it was not to be expected that there was a relation between the quantity of chlorophyll and the strength of the chlorophyll fluorescence signal.
Therefore it was not likely to an expert in the field of chlorophyll fluores-cence that by means of chlorophyll fluorescence the quantity of chlorophyll could be determined. It was not likely either that blue berries with a white frost could be sorted as to maturity and quality by using chlorophyll fluorescence.
Thus an object of the present invention is to provide a method which enables one to sort fruit and berries as to maturity and thus quality on the basis of the quantity of chlorophyll. Characteristic for the invention are the very high sensitivity and the high speed with which the chlorophyll fluores-cence of fruit and berries can be measured. A further object of the inven-tion is to provide an apparatus with which fruit and berries can quickly and accurately be sorted as to quality.
electromagnetic radiation has such a ,)that the chlorophyll present in the fru' rues shows prompt fluorescence, which fluores-AMENDED SHEET
- 4a -In one aspect the invention relates to a non-destructive method for determining the maturity and quality of fleshy fruits comprising irradiating a fruit with electromagnetic radiation comprising wavelengths capable of causing the chlorophyll of the fruit to fluoresce, passing the signal returning from the fruit through a filter capable of filtering out the wavelengths used for exciting the chlo-rophyll of the fruit to obtain a chlorophyll fluorescence signal and measuring said signal.
In a further aspect the invention relates to a method for sorting fleshy fruits comprising feeding each fruit indivi-dually to a~irradiation area, irradiating the fruit in the irradiating area with electromagnetic radiation comprising wavelength capable of causing the chlorophyll in the fleshy fruit t.o fluoresce, passing the signal returning from the fruit through a filter capable of filtering out the wave-lengths used for exciting the chlorophyll of the fruit to obtain a chlorophyll fluorescence signal and measuring said signal, and separating the fruits into classes based on their individual fluorescence signal, wherein the values that define the classes are chosen on the basis of the distribution of the chlorophyll fluorescence signals of a sample of the fruits having known properties.
AMENDED SHEET
In the art it is known that by using chlorophyll fluorescence chlorophyll can be measured. In "Application of chlorophyll fluorescence to postharvest physiology and storage of mango and banana fruit and the chilling tolerance of mango cultivars", Asian Food Journal (1987), 3(2), 55-59, R.M. Smillie, S.E. Hetherinton, R.N. Grantley, R. Chaplin and N.L. Wade used the chlorophyll fluorescence technique to measure the photosynthesis activity of fruit. They examined the changes in the photosynthesis activity during ripening and under the influence of low temperatures by measuring the chlorophyll fluorescence signal of the skin. The speed with which the chlorophyll fluorescence signal decreased during exposure to low temperatures was used to select varieties that are insensitive to cold. They do not mention the possibility to sort blue berries as to maturity by measuring prompt fluorescence. Neither do they mention the possibility to sort frozen berries as to maturity by measuring prompt fluorescence. In case pf fresh fruit and leafs the chlorophyll fluorescence signal changes during the measurement, because the chlorophyll is photosyntheticafly active. This as opposed to the chlorophyll in a frozen berry, There is no photosynthesis in a frozen berry. The chlorophyll fluorescence signal is constant over a short period of time of some minutes. In the method according to the invention the prompt quantity of chlorophyll fluorescence is measured, so instantaneous to the irradiation of the berry with electromagnetic radiation. The amplitude of the chlorophyll fluorescence signal is now a measure for the quantity of chlorophyll. The measuring method of Smillie in total requires one hour because of adjustment to the dark for one hour and some seconds for monitoring the changes in the chlorophyll fluorescence signal. The measuring method according to the invention can be carried out in a fraction of a second. The usual method for measuring photosynthesis activity in plant material comprises the use of the pulse amplitude modulation (PAM) fluorometer of U. Schreiber, described in "Detection of rapid induction kinetics with a new type of high frequency modulated chlorophyll fluorometer", Photosynthesis Research (1986) 9:261-272. The photosynthesis activity does not directly depend on the quantity of chlorophyll in plant material. The chlorophyll fluores-cence signal however does directly depend on the quantity of chlorophyll.
For determining the photosynthesis activity therefore a correction for the quantity of chlorophyll has to be made. This is done by calculating a quotient, so that said quotient is independent from the quantity of chlorophyll. The method described according to the invention, however, uses the measured quantity of chlorophyll fluorescence as measure for the quantity of chlorophyll.
According to H.K. Lichtenthaler in "In vivo chlorophyll fluorescence as a tool for stress detection in plants ", Application of Chlorophyll Fluores-cence in Photosynthesis, H.K. Lichtenthaler (ed.) 1988, 121-142, Kluwer Academic Press, Dordrecht, the quantity of chlorophyll cannot be measured by means of photosynthesis measurements. The parameters measured for calculating the photosynthesis by using chlorophyll fluores-~P N L 009900411 0 9. 10. 2000 cence can even increase in signal strength when the quantity of chlorophyll decreases. This is the result of re-absorbtion of the emitted chlorophyll fluorescence decreasing because of the lower concentration of chlorophyll.
This is contrary ~to the statement according to the invention that the chlorophyll fluorescence can be used for determining the quantity of chlorophyll. In "Reflectance and chlorophyll fluorescence signatures of leaves" in Proceedings IGARSS'87 Symp. Ann. Arbor. MI (USA) 18-21 May 1987, 1201-1206, H.K. Lichtenthaler and C. Buschmann show that around 690 and 730 nm the chlorophyll fluorescence signal of leaves is not linear to the quantity of chlorophyll. It was also demonstrated that a lower quantity of chlorophyll could emit a larger chlorophyll fluorescence signal.
From these two articles it appears that the literature indicated that it was not to be expected that there was a relation between the quantity of chlorophyll and the strength of the chlorophyll fluorescence signal.
Therefore it was not likely to an expert in the field of chlorophyll fluores-cence that by means of chlorophyll fluorescence the quantity of chlorophyll could be determined. It was not likely either that blue berries with a white frost could be sorted as to maturity and quality by using chlorophyll fluorescence.
Thus an object of the present invention is to provide a method which enables one to sort fruit and berries as to maturity and thus quality on the basis of the quantity of chlorophyll. Characteristic for the invention are the very high sensitivity and the high speed with which the chlorophyll fluores-cence of fruit and berries can be measured. A further object of the inven-tion is to provide an apparatus with which fruit and berries can quickly and accurately be sorted as to quality.
electromagnetic radiation has such a ,)that the chlorophyll present in the fru' rues shows prompt fluorescence, which fluores-AMENDED SHEET
- 4a -In one aspect the invention relates to a non-destructive method for determining the maturity and quality of fleshy fruits comprising irradiating a fruit with electromagnetic radiation comprising wavelengths capable of causing the chlorophyll of the fruit to fluoresce, passing the signal returning from the fruit through a filter capable of filtering out the wavelengths used for exciting the chlo-rophyll of the fruit to obtain a chlorophyll fluorescence signal and measuring said signal.
In a further aspect the invention relates to a method for sorting fleshy fruits comprising feeding each fruit indivi-dually to a~irradiation area, irradiating the fruit in the irradiating area with electromagnetic radiation comprising wavelength capable of causing the chlorophyll in the fleshy fruit t.o fluoresce, passing the signal returning from the fruit through a filter capable of filtering out the wave-lengths used for exciting the chlorophyll of the fruit to obtain a chlorophyll fluorescence signal and measuring said signal, and separating the fruits into classes based on their individual fluorescence signal, wherein the values that define the classes are chosen on the basis of the distribution of the chlorophyll fluorescence signals of a sample of the fruits having known properties.
AMENDED SHEET
apparatus as mentioned in the preamble, which is c enzed in that the electromagnetic radiation has s wavelength that the chlorophyll present in the ~ berries shows prompt fluorescence, which fluores-part.
The present invention is based on a fluorescence measurement which is very specific to the chlorophyll present. Other substances which influence the colour of the blue berries but do not fluoresce, will not contribute to the fluorescence signal. Also according to the invention small differences in the quantity of chlorophyll in the blue berries can be shown, because of the principle that a fluorescence measurement is very sensitive.
According to the invention it now appears that a difference in chlorophyll contents of individual blue berries can be shown directly, even when the envelopes cannot be discerned by means of a colour measurement. In literature no data are known on measuring the quantity of chlorophyll fluorescence in blue berries in relation to the degree of maturity and quality. A suitable method for measuring the chlorophyll contents comprises irradiating at least a part of the chlorophyll molecules with electromagnetic radiation, preferably with a wavelength between 400 and 700 nm, as a result of which at least a part of the chlorophyll molecules are electronically excited. The excited molecules mainly loose their energy by heat dissipation and for about 3% by emission of fluorescence which preferably is measured between 600 and 800 nm.
When according to the invention the intensity of the chlorophyll fluorescence of each blue berry is separately measured, the blue berries can be sorted as to the stage of maturity and quality.
The invention is very sensitive, entirely non-destructive and very quick.
These are the characteristics of the invention which make it possible to AMENDED SHEET
The present invention is based on a fluorescence measurement which is very specific to the chlorophyll present. Other substances which influence the colour of the blue berries but do not fluoresce, will not contribute to the fluorescence signal. Also according to the invention small differences in the quantity of chlorophyll in the blue berries can be shown, because of the principle that a fluorescence measurement is very sensitive.
According to the invention it now appears that a difference in chlorophyll contents of individual blue berries can be shown directly, even when the envelopes cannot be discerned by means of a colour measurement. In literature no data are known on measuring the quantity of chlorophyll fluorescence in blue berries in relation to the degree of maturity and quality. A suitable method for measuring the chlorophyll contents comprises irradiating at least a part of the chlorophyll molecules with electromagnetic radiation, preferably with a wavelength between 400 and 700 nm, as a result of which at least a part of the chlorophyll molecules are electronically excited. The excited molecules mainly loose their energy by heat dissipation and for about 3% by emission of fluorescence which preferably is measured between 600 and 800 nm.
When according to the invention the intensity of the chlorophyll fluorescence of each blue berry is separately measured, the blue berries can be sorted as to the stage of maturity and quality.
The invention is very sensitive, entirely non-destructive and very quick.
These are the characteristics of the invention which make it possible to AMENDED SHEET
6 PCT/NL99/00411...
manufacture a sorting apparatus with which blue berries can be selected on the basis of the quantity of chlorophyll fluorescence. Because the quantity of fluorescence by chlorophyll has a direct relation to the maturity of the blue berries sorting as to quality is possible.
The present invention can also be used for many kinds of fruit, such as many other kinds of berries (for instance red berries), blackberries, cherries and strawberries. The invention also works for fruit in which the quantity of chlorophyll changes during ripening.
It is preferred to carry out a chlorophyll measurement in an apparatus as shown in figure 1. This is a simple embodiment of the apparatus. The light source has a spectral distribution of the light between 400 and 660 nm.
This light is directed to the blue berries. At least a part of the chlorophyll molecules is electronically excited. At least a part of the excited chlorophyll molecules falls to the ground state while emitting fluorescence. At least a part of the chlorophyll fluorescence is captured with a lens. The filter ensures that predominantly fluorescence is detected by the CCD camera.
After measuring the chlorophyl! fluorescence for instance a valve can subsequently be operated with an electronic circuit such as a micro processor, which valve takes out the blue berries from the main stream that have a higher or lower signal than a pre-determined value. The sorting from the main stream with a valve can take place with any known prin=
ciple, such as an air stream, liquid pulse or mechanical valve. It is pointed out that sorting can be performed on berries which are in the air, but also for berries that are contained in a liquid. Sorting in a liquid can for instance take place in order to minimize the possibility of damage of very delicate fruit.
The person skilled in the art will see that in the above-mentioned preferred embodiments of the sorting apparatus, the light source could be a lamp with optical filters, a LED or a laser. Furthermore it is also possible to use WO 00/0203b PCT/NL99/0041 a _7_ one or several photodiodes or photo multipliers for the CCD camera.
The invention can also be used in any fruit sorter apparatus. It can be built in in all kinds of sorter apparatus. The invention can particularly be used in the known colour sorter apparatus. The light source can be replaced b~ a light source in the described spectral range and the CCD camera can be provided with an optical filter so that predominantly the chlorophyll fluores-cence is measured.
manufacture a sorting apparatus with which blue berries can be selected on the basis of the quantity of chlorophyll fluorescence. Because the quantity of fluorescence by chlorophyll has a direct relation to the maturity of the blue berries sorting as to quality is possible.
The present invention can also be used for many kinds of fruit, such as many other kinds of berries (for instance red berries), blackberries, cherries and strawberries. The invention also works for fruit in which the quantity of chlorophyll changes during ripening.
It is preferred to carry out a chlorophyll measurement in an apparatus as shown in figure 1. This is a simple embodiment of the apparatus. The light source has a spectral distribution of the light between 400 and 660 nm.
This light is directed to the blue berries. At least a part of the chlorophyll molecules is electronically excited. At least a part of the excited chlorophyll molecules falls to the ground state while emitting fluorescence. At least a part of the chlorophyll fluorescence is captured with a lens. The filter ensures that predominantly fluorescence is detected by the CCD camera.
After measuring the chlorophyl! fluorescence for instance a valve can subsequently be operated with an electronic circuit such as a micro processor, which valve takes out the blue berries from the main stream that have a higher or lower signal than a pre-determined value. The sorting from the main stream with a valve can take place with any known prin=
ciple, such as an air stream, liquid pulse or mechanical valve. It is pointed out that sorting can be performed on berries which are in the air, but also for berries that are contained in a liquid. Sorting in a liquid can for instance take place in order to minimize the possibility of damage of very delicate fruit.
The person skilled in the art will see that in the above-mentioned preferred embodiments of the sorting apparatus, the light source could be a lamp with optical filters, a LED or a laser. Furthermore it is also possible to use WO 00/0203b PCT/NL99/0041 a _7_ one or several photodiodes or photo multipliers for the CCD camera.
The invention can also be used in any fruit sorter apparatus. It can be built in in all kinds of sorter apparatus. The invention can particularly be used in the known colour sorter apparatus. The light source can be replaced b~ a light source in the described spectral range and the CCD camera can be provided with an optical filter so that predominantly the chlorophyll fluores-cence is measured.
Claims (5)
1. A non-destructive method for determining the maturity and quality of fleshy fruits comprising irradiating a fruit with electromagnetic radiation comprising wavelengths capable of causing the chlorophyll of the fruit to fluores-ce, passing the signal returning from the fruit through a filter capable of filtering out the wavelengths used for exciting the chlorophyll of the fruit to obtain a chlorop-hyll fluorescence signal and measuring said signal.
2. A method for sorting fleshy fruits comprising feeding each fruit individually to an irradiation area, irradiating the fruit in the irradiating area with electromagnetic radiation comprising wavelengths capable of causing the chlorophyll in the fruit to fluoresce, passing the signal returning from the fruit through a filter capable of filtering out the wavelengths used for exciting the chlo-rophyll of the fruit to obtain a chlorophyll fluorescence signal and measuring said signal, and separating the fruits into classes based on their individual fluorescence signal, wherein the values that define the classes are chosen on the basis of the distribution of the chlorophyll fluores-cence signals of a sample of the fruits having known properties.
3. A method according to claim 1 or 2, wherein the irradia-ted electromagnetic radiation has a wavelength between 400 and 700 nm and the fluorescence is measured between 600 and 800 nm.
4. A method according to claim 1, 2, or 3, wherein the fleshy fruits are frozen.
5. A method according to any one of the preceeding claims, wherein the fleshy fruits comprises blueberries.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL1009556 | 1998-07-03 | ||
| NL1009556A NL1009556C2 (en) | 1998-07-03 | 1998-07-03 | Method for determining the quality of fruit and berries and device for separating fruit and berries. |
| PCT/NL1999/000411 WO2000002036A1 (en) | 1998-07-03 | 1999-07-01 | Method for determining the quality of fruit and berries and apparatus for sorting fruit and berries |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2337903A1 true CA2337903A1 (en) | 2000-01-13 |
Family
ID=19767422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002337903A Abandoned CA2337903A1 (en) | 1998-07-03 | 1999-07-01 | Method for determining the quality of fruit and berries and apparatus for sorting fruit and berries |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP1095263A1 (en) |
| AU (1) | AU4803499A (en) |
| BR (1) | BR9911822A (en) |
| CA (1) | CA2337903A1 (en) |
| NL (1) | NL1009556C2 (en) |
| NZ (1) | NZ509205A (en) |
| PL (1) | PL345405A1 (en) |
| WO (1) | WO2000002036A1 (en) |
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| PT103290B (en) * | 2005-06-14 | 2007-04-30 | Univ De Coimbra | A NEW METHOD AND APPARATUS FOR CONTROLLING FRUIT QUALITY AND MATURITY USING LIGHT INDUCED LUMINISCENCE |
| CN102323221B (en) * | 2011-05-31 | 2013-03-13 | 河南农业大学 | Tobacco maturity detection method and device |
| US9027759B2 (en) | 2011-11-22 | 2015-05-12 | Key Technology, Inc. | Sorting apparatus |
| US8714362B2 (en) | 2011-11-22 | 2014-05-06 | Key Technology, Inc. | Sorting apparatus |
| RU2492469C1 (en) * | 2012-06-19 | 2013-09-10 | Российская Академия сельскохозяйственных наук Государственное научное учреждение научно-исследовательский институт кондитерской промышленности (ГНУ НИИКП) | Method for determination of apple puree weight fraction in marmalade and sweet jelly body |
| RU2492468C1 (en) * | 2012-06-19 | 2013-09-10 | Российская Академия сельскохозяйственных наук Государственное научное учреждение научно-исследовательский институт кондитерской промышленности (ГНУ НИИКП) | Method for determination of pectins weight fraction in marmalade |
| ES2445245B1 (en) * | 2012-08-28 | 2014-12-11 | Universidad De Extremadura | Cell for fruit quality control through an intelligent multispectral vision system and robotic system |
| RU2530640C1 (en) * | 2013-10-18 | 2014-10-10 | Государственное научное учреждение научно-исследовательский институт кондитерской промышленности Российской академии сельскохозяйственных наук (ГНУ НИИКП Россельхозакадемии) | Method for determination of apple puree weight fraction in pastille product by organic acids ratio |
| RU2536207C1 (en) * | 2013-12-04 | 2014-12-20 | Государственное научное учреждение научно-исследовательский институт кондитерской промышленности Российской академии сельскохозяйственных наук (ГНУ НИИКП Россельхозакадемии) | Method for determination of apple puree weight fraction in marmalade and pastille products |
| NL2017235B1 (en) * | 2016-07-25 | 2018-01-31 | De Greefs Wagen Carrosserie En Machb B V | MEASURING DEVICE FOR MULTISPECTRAL MEASUREMENT OF QUALITY CHARACTERISTICS OR DEFECTS OF PRODUCTS AND METHOD FOR THIS |
| CN110270517A (en) * | 2019-05-28 | 2019-09-24 | 江苏师范大学 | A kind of fruit sorting system and its method based on fluorescence detection |
| CN114113009A (en) * | 2021-10-27 | 2022-03-01 | 西北农林科技大学 | Apple tiger skin disease early warning method |
| FR3139909A1 (en) | 2022-09-21 | 2024-03-22 | Bucher Vaslin | OPTICAL SORTING OF NON-CEREAL FRUITS BY COMBINATION OF ELECTROMAGNETIC RADIATION |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4279346A (en) * | 1978-12-12 | 1981-07-21 | Southeastern Blueberry Council, Inc. | Asynchronous blueberry sorter |
| US4866283A (en) * | 1988-08-12 | 1989-09-12 | Southwest Research Institute | Optical inspection of food products |
| DD293748A5 (en) * | 1990-04-23 | 1991-09-12 | Martin.Luther-Universitaet Halle-Wittenberg,De | METHOD AND DEVICE FOR SORTING TOMATOES ACCORDING TO THEIR WHEAT |
| NL1002984C2 (en) * | 1996-05-02 | 1997-11-06 | Cpro Dlo | Method for determining the ripeness and quality of seeds by means of the chlorophyll content and device for selecting seeds by means of such a method. |
-
1998
- 1998-07-03 NL NL1009556A patent/NL1009556C2/en not_active IP Right Cessation
-
1999
- 1999-07-01 EP EP99931583A patent/EP1095263A1/en not_active Ceased
- 1999-07-01 PL PL99345405A patent/PL345405A1/en unknown
- 1999-07-01 CA CA002337903A patent/CA2337903A1/en not_active Abandoned
- 1999-07-01 NZ NZ509205A patent/NZ509205A/en unknown
- 1999-07-01 AU AU48034/99A patent/AU4803499A/en not_active Abandoned
- 1999-07-01 BR BR9911822-0A patent/BR9911822A/en not_active Application Discontinuation
- 1999-07-01 WO PCT/NL1999/000411 patent/WO2000002036A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| NZ509205A (en) | 2003-03-28 |
| WO2000002036A1 (en) | 2000-01-13 |
| PL345405A1 (en) | 2001-12-17 |
| AU4803499A (en) | 2000-01-24 |
| BR9911822A (en) | 2001-03-27 |
| NL1009556C2 (en) | 2000-01-07 |
| EP1095263A1 (en) | 2001-05-02 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |