Decortication method and plant

Abstract

Method (10) and corresponding plant for decortication of psyllium seeds. The method (10) comprising at least a step of feeding (20) the seeds, a step of decortication (40) of the seeds, a step of separating (50) husks from decorticated seeds and a step of packaging (80) the husks.

Description

[0001] “DECORTICATION METHOD AND PLANT”

[0002] FIELD OF THE INVENTION

[0003] The present invention concerns a method and a corresponding plant for decortication of psyllium seeds, that is, plants of the Plantago genus, for the production of high purity teguments, or husks, with high production yields.

[0004] BACKGROUND OF THE INVENTION

[0005] In the industrial production of psyllium husks, the seeds of plants of the Plantago genus, for example Plantago ovata seeds, once cleaned of any contaminants, are introduced into continuous open-cycle decortication plants, without recirculation or reprocessing. Such a decortication plant comprises a battery of decortication devices used for the process. Each decortication device comprises impacting elements, for example rollers or rotating plates. The battery of decortication devices provides a progressive narrowing of the distance between the impacting elements, with the aim of first removing the husk of the larger sized seeds, and subsequently and progressively that of the smaller sized seeds, thus simultaneously achieving the decortication of the seed and a selection of the seed based on size.

[0006] The mix produced (husks, seeds and flour) is then separated with physical systems, as disclosed for example by CA 1322928 C and GB 2224628 A. In some cases, the physically selected husks can be further purified using liquid fluorinated hydrocarbons, at different densities, which in particular intervals are capable of separating the husks from the impurities arising from the seed’s hull, as disclosed for example by AU 199216790 A.

[0007] The husks produced are normally graded according to their purity, which is higher the lower the content of the product not represented by husks. The latter is mainly represented by the residual content of caryopsis in the product. This purity is associated with the technological performance of the husks; therefore it is the parameter generally used to measure the quality of the husk itself. Conventionally, purity is divided into four different grades: 99%, 98%, 95% and 85%. Current decortication methods allow to achieve a production of psyllium husks that has a percentage distribution of the different purities, the decorticated husks being equal, which is unbalanced in favor of lower purity products and therefore of less interest. In addition, current decortication methods are characterized by a substantial production inconsistency, which significantly affects the technological performance of the husk, such as its water absorption.

[0008] US 4 813 613 A discloses a method for obtaining high purity mucilage from Plantago psyllium seeds and, more specifically, it concerns a process for obtaining the pulverized skin of the Plantago psyllium seeds, with a high mucilage content and with a purity of up to 98%.

[0009] US 5 699 724 A discloses a method for cleaning by separating or selecting bulk material in the form of foodstuffs, such as cereals, rice, soybeans, sunflower seeds, coffee and suchlike, with the cleaning and selection provided as part of the preparation of these foodstuffs for further processing.

[0010] US 2022 / 000140 Al discloses methods and systems for producing improved products based on hemp seeds, such as proteins and oils.

[0011] There is therefore the need to perfect a decortication method and plant that can overcome at least one of the disadvantages of the state of the art.

[0012] To do this, it is necessary to resolve the technical problem of reducing the content of the final product not represented by husks as much as possible.

[0013] In particular, one purpose of the present invention is to develop a method, and a corresponding plant, for decortication of psyllium seeds that is high performing, that is, capable of obtaining a percentage of product with a high purity grade (> 95%) equal to or greater than approximately 18.5% of the total weight of the processed seed.

[0014] Another purpose of the present invention is to develop a method, and a corresponding plant, for decortication of psyllium seeds that allows to standardize production, and consequently the qualitative parameters of the finished product, and to increase the percentage of higher purity husks.

[0015] Another purpose of the present invention is to develop a method, and a corresponding plant, for decortication of psyllium seeds capable of dividing the product into batches with different purity grades.

[0016] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0017] SUMMARY OF THE INVENTION The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0018] In accordance with the above purposes and to resolve the technical problem described above in a new and original way, also achieving considerable advantages compared to the state of the prior art, a method for decortication of psyllium seeds according to the present invention comprises at least one step of feeding the seeds, a step of decortication of the seeds, a step of separating husks from decorticated seeds and a step of packaging the husks.

[0019] In accordance with one aspect of the present invention, the method comprises a step of grading the husks into predefined purity grades, and the subsequent packaging step provides to package the husks into different packages on the basis of this grading. The division of the husks into purity grades before packaging them prevents, or at least limits, mixing husks of different purity grades, advantageously allowing to obtain a greater quantity of product at the higher purity grade.

[0020] In the present document, purity is quantified as the percentage content, by weight, of husks in the product separated from the decorticated seeds. For example, a purity of 85% corresponds to a product containing approximately 85% by weight of husks and approximately 15% by weight of impurities, mainly represented by the residual content of caryopsis in the product. Hereafter, for brevity, the term “husks” can indicate a product at least separated from the decorticated seeds and possibly subjected to subsequent processing, consisting predominantly, that is, more than 50% by weight, of husks.

[0021] The grading of the husks into purity grades can be carried out on a colorimetric basis.

[0022] In accordance with another aspect, the method provides, before the decortication step, a step of calibrating the seeds to be decorticated, which provides to divide them according to their sizes. The decortication step is then carried out separately for each seed caliber, so that a decortication device used for this purpose can be adjusted and dedicated to the single selected caliber on each occasion, so as to reduce the abrasion of the hull, and therefore the presence of impurities deriving therefrom in the husks produced, to values close to zero, further increasing the portion of higher purity husks produced. The method can also comprise, following the separation step, a recirculation or discharge step, which provides to selectively recirculate or discharge the decorticated seeds.

[0023] According to another aspect, the aforementioned grading can provide a lower purity grade, comprising husks with a purity lower than or equal to 85%, an intermediate purity grade, comprising husks with a purity greater than 85% and lower than or equal to 95%, and a higher purity grade, comprising husks with a purity greater than 95%. In this case, the grading can also provide to use a digital colorimeter to obtain a set of husk colorimetric coordinates according to the CIELab international standard. CIELab is the latest international standard in chronological order introduced by the International Commission on Illumination (CIE - Commission Internationale de I’Eclairage, http: / / cie.co.at / ) in 1976 for the representation of color. The Lab or CIELab or CIE 1976 color space (L*, a*, b*) is a color-opponent space with the dimension L* for brightness, and a* and b* for the color-opponent dimensions, based on the coordinates of the compressed nonlinear color space CIE XYZ (itself one of the first color spaces defined mathematically by the CIE in 1931). In the CIELab standard, the Hunter 1948 coordinates are therefore L*, a* and b*. The brightness L* is calculated using the cube root of the relative luminance. A colorimeter can provide colorimetric coordinates according to the CIELab international standard L*, a*, b* (L* = 100 white, 0 black; a* = + red, - green; b* = + yellow, - blue. The value known as “total color

[0024] For example, using the CIELab standard, the husks can be graded into the lower purity grade if they have a first coordinate L* lower than or equal to 64.49, a second coordinate a* greater than or equal to 4.5, and a third coordinate b* greater than or equal to 13.51; into the intermediate purity grade if they have the first coordinate L* comprised between 64.5 and 69.49, the second coordinate a* comprised between 3.51 and 4.49, and the third coordinate b* comprised between 13.51 and 15; and into the higher purity grade if they have the first coordinate L* greater than or equal to 69.5, the second coordinate a* comprised between 1.7 and 3.5, and the third coordinate b* comprised between 13 and 13.5.

[0025] Some embodiments described here also concern a plant for decortication of psyllium seeds configured to implement the method described above. In accordance with another aspect of the present invention, the plant comprises pneumatic means and / or means based on gravitational fall for transporting and recirculating the products being processed, in place of the more widespread mechanical transport means responsible for the damage to the caryopsis and consequently the fall in quality of the husk produced.

[0026] DESCRIPTION OF THE DRAWINGS

[0027] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0028] - fig. 1 is a diagrammatic representation of a method for decortication of psyllium seeds according to the present invention;

[0029] - fig. 2 is a schematic representation of a plant for decortication of psyllium seeds according to the present invention.

[0030] We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0031] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

[0032] Some embodiments described here concern a method 10 for decortication of psyllium seeds, understood as a plant of the Plantago genus, preferably Plantago ovata. With reference to fig. 1, the method 10 can comprise at least a step of feeding 20 the seeds, a step of decortication 40 of the seeds, a step of separating 50 the husk from the decorticated seeds, a step of grading 70 the husks, and a step of packaging 80 the husks.

[0033] The feeding step 20 provides to make available a plurality of psyllium seeds to be treated, for example by feeding them to a decortication plant 110 (fig. 2).

[0034] In the subsequent decortication step 40, the seeds are decorticated, that is, the husk is removed from the seed’s underlying part, or hull. The decortication preferably occurs with physical systems, for example by means of a known decortication device 142, such as a decortication device 142 typically used in the milling industry, preferably a stone device.

[0035] In the separation step 50, the husks are separated from the decorticated seeds, so that they can be directed toward a dedicated processing. This separation can occur, for example, by means of a known physical air system, such as a sifter or fan screen 151.

[0036] The subsequent grading step 70 provides to grade the husks into predefined purity grades. As a non-limiting example, the grading can provide three purity grades.

[0037] In some embodiments, the grading provides a lower purity grade, comprising husks with a purity lower than or equal to 85%; an intermediate purity grade, comprising husks with a purity greater than 85% and lower than or equal to 95%; and a higher purity grade, comprising husks with a purity greater than 95%.

[0038] Depending on the application for which the husks are intended and / or the sensitivity or tolerance with respect to the husks’ purity, the grading adopted can also provide different amplitudes of the purity ranges compared to the above and / or a number of purity grades different from three.

[0039] Establishing the husks’ purity can be done, in a new and innovative manner, on a colorimetric basis. In fact, while the pure husks are substantially white, the caryopsis, the main component of the residual impurities, is brown. There is therefore a direct correlation between color and husk quality. However, to every purity grade of husks obtained with the methods according to the state of the art, there corresponds a colorimetric range that is too broad, with direct and obvious effects on the quality of the products in which the husks are used. This is due to the open-cycle and continuous nature of the decortication plants according to the state of the art: they do not allow to check the purity of the husks during the production process, but only to measure the subsequent purity, on the final product. This also constitutes a limit for establishing narrow and defined colorimetric ranges. The extreme colorimetric variability also negatively influences the percentage distribution of the different purities with the same decorticated husks, with an imbalance in favor of darker products of less interest to the Applicant.

[0040] The Applicant has developed a colorimetric selection strategy based on rigorous and defined qualitative parameters. The direct correlation between color and purity allows to determine the purity of the husks during the production process, and therefore to divide the husks according to their purity before packaging them, thus obtaining a greater quantity of product at the higher purity grade.

[0041] The grading step 70 can provide to use a digital colorimeter 172 to obtain a colorimetric reading of the husks obtained from the decortication of the psyllium seeds, obtaining for example a set of colorimetric coordinates L*, a *, b* according to the CIELab international standard, or any other colorimetric reading whatsoever that allows to quantify the color of the husks (for example using absorbance spectrophotometric reading). The grading step 70 therefore provides to assign a purity grade to the husks on the basis of the colorimetric reading obtained.

[0042] By way of example, with reference to the CIELab international standard, the lower purity grade (< 85%) can correspond to a set of colorimetric coordinates with a first coordinate L* lower than or equal to 64.49, a second coordinate a* greater than or equal to 4.5, and a third coordinate b* greater than or equal to 13.51; the intermediate purity grade (> 85% and < 95%) can correspond to a set of colorimetric coordinates with the first coordinate L* comprised between 64.5 and 69.49, the second coordinate a* comprised between 3.51 and 4.49, and the third coordinate b* comprised between 13.51 and 15; the higher purity grade (> 95%) can correspond to a set of colorimetric coordinates with the first coordinate L* greater than or equal to 69.5, the second coordinate a* comprised between 1.7 and 3.5, and the third coordinate b* comprised between 13 and 13.5.

[0043] The subsequent packaging step 80 provides to package the husks, preferably into different packages based on the grading into purity grades obtained in the grading step 70. By way of a non-limiting example, the grading step 70 can provide a grading into three purity grades and the packaging step 80 can provide to package the husks into three different packages, each corresponding to one of the three purity grades.

[0044] According to possible embodiments, the method 10 can provide, before the decortication step 40, a step of calibrating 30 the seeds to be decorticated. The calibration step 30 can provide to divide the seeds according to their sizes, by means of a calibration device 131, for example a device typically used in the milling industry such as a sieve calibrator, for example with four sieves. Providing a separate calibration step 30 that precedes the decortication step 40 advantageously allows to carry out the decortication step 40 separately for each caliber of seed. Consequently, the decortication device 142 can be adjusted and dedicated to the single selected caliber on each occasion, so as to reduce the abrasion of the hull, and therefore the consequent presence of impurities deriving from it in the husks produced, to values close to zero, thus further increasing the fractions of higher purity husks produced.

[0045] The method 10 can provide a step of recirculation or discharge 60 of the decorticated seeds, following the separation step 50. The recirculation or discharge step 60 can be carried out at the same time as the grading step 70 and / or the packaging step 80, or it can precede or follow the steps 70 and 80.

[0046] The recirculation or discharge step 60 can provide to transport the decorticated seeds obtained in the separation step 50 toward the inlet of the decortication device 142 or preferably, if provided, toward the inlet of the calibration device 131, so as to subject the decorticated seeds to a new decortication step 40, possibly preceded by a new calibration step 30. This realizes a step of recirculating 61 the decorticated seeds in the plant 1 10, with the aim of obtaining from the seed the totality of the husk present on the seed, and thus increasing the productivity of the plant 110.

[0047] Alternatively or additionally, the recirculation or discharge step 60 can provide to transport the decorticated seeds obtained in the separation step 50 toward suitable second discharge means 163, so as to allow the decorticated seeds to exit from the plant 110 in a discharge step 62, for example packaging them in a known manner in order to transport and / or store them.

[0048] The recirculation or discharge step 60 can provide an automatic or manual decision-making process to decide whether to recirculate or discharge the decorticated seeds. For example, the discharge step 62 can be provided after a predetermined number of recirculations, or on the basis of a predetermined reading of suitable sensors, or the choice between recirculation step 61 and discharge step 62 can be made by an operator.

[0049] Preferably, the method 10 realizes a discontinuous, automatic dormant (that is, requiring an operator only to start and close a production cycle) and closed cycle production process. The Applicant has found that the method 10 described above allows to obtain a percentage of product with a high purity grade (> 95%) equal to or greater than approximately 18.5% of the total weight of processed seeds, specifically equal to or greater than approximately 18.75% of the total weight of processed seeds, or equivalently equal to or greater than approximately 80% of the weight of the husks of the processed seeds (remembering that the husk represents approximately 23.5% of the weight of the respective seed).

[0050] Some embodiments described here also concern a decortication plant 110 that can carry out the method 10 described heretofore, configured to optimize the performance of the production process thanks also to recirculation and reprocessing systems.

[0051] The plant 110 can comprise pneumatic means and / or means based on gravitational fall for transporting and recirculating the products being processed, such as thrust fans, Venturi injectors and Venturi cyclones. This reduces the presence of mechanical elements, the consequent maintenance, the spaces required for installation as well as the energy demand of the plant 110. In addition, the mechanical transport means, which are more common in the state of the art, are generally responsible for the damage to the caryopsis and consequently the fall in quality of the husk produced.

[0052] Alternative embodiments can comprise mechanical transport means for transporting the products being processed.

[0053] With reference to fig. 2, the plant 110 comprises a feeding unit 120, configured to carry out the feeding step 20.

[0054] For example, the feeding unit 120 can comprise a first thrust fan 121 to feed psyllium seeds to be decorticated, coming from a loading hopper 122, to the plant 110. The plant 110 can comprise a plurality of conduits 111 to transport the products being processed into the various components of the plant 110.

[0055] Optionally, the plant 110 can comprise a calibration unit 130, configured to carry out the calibration step 30. The calibration unit 130 can comprise the calibration device 131 , connected to the feeding unit 120 by means of one of the conduits 111. In some embodiments, the calibration unit 130 comprises at least one first silo 132, preferably a plurality of first silos 132, configured to contain the seeds at exit from the calibration device 131. Preferably, the plant 110 comprises at least as many first silos 132 as there are caliber categories into which the seeds are divided in the calibration step 30. In some embodiments, the calibration unit 130 also comprises first discharge means 134, configured to allow any waste, separated from the seeds being processed by means of the calibration device 131, to exit from the plant 110. Each first silo 132 can be provided with a rotary valve 133, or similar selective closing and opening mean, thus allowing to select which category of caliber of seeds to feed to the subsequent components of the plant 110.

[0056] The calibration unit 130 can comprise a second thrust fan 136, configured to make the calibrated seeds advance in the duct 111 downstream of the first silos 132.

[0057] The calibration unit 130 can comprise first packaging means 135, configured to suitably package the calibrated seeds, in the event that they constitute the finished product.

[0058] The plant 110 can comprise a decortication unit 140, configured to carry out the decortication step 40. The possible calibration unit 130 is provided upstream of decortication unit 140.

[0059] In some embodiments, the decortication unit 140 comprises a first vibration feeder 141, configured to feed the seeds fed by the feeding unit 120 and possibly at exit from the calibration unit 130 to the decortication device 142.

[0060] The plant 110 can comprise a separation unit 150, configured to carry out the separation step 50. In some embodiments, the sifter 151 of the separation unit 150 can be provided immediately downstream of the decortication device 142.

[0061] The plant 110 can comprise, downstream of the separation unit 150, a recirculation and discharge unit 160, configured to carry out the recirculation or discharge step 60. In some embodiments, the recirculation and discharge unit 160 can comprise at least one second silo 161, configured to act as a buffer for the decorticated seeds obtained in the separation step 50. The recirculation and discharge unit 160 can also comprise a third thrust fan 162, configured to thrust the decorticated seeds back toward the inlet of the decortication unit 140 or, if present, toward the inlet of the calibration unit 130, or toward the second discharge means 163.

[0062] The plant 110 can comprise a grading unit 170, configured to carry out the grading step 70. The grading unit 170 can also comprise the digital colorimeter 172 and a second vibration feeder 171 configured to feed the husks obtained in the separation step 50 to a measuring shoot 173. The measuring shoot 173 is configured to accommodate the husks during the grading step 70 and to allow the husks to advance toward subsequent components of the plant 110.

[0063] The plant 110 can comprise a packaging unit 180, configured to carry out the packaging step 80. In some embodiments, the packaging unit 180 comprises a loading shoot 181 and second packaging means 182. Preferably, the second packaging means 182 are configured to package the husks into at least as many packages as the disclosed purity grades into which the husks are divided in the grading step 70. In some embodiments, the loading shoot 181 is configured to direct the graded husks at exit from the measuring shoot 173 toward the second packaging means 182 corresponding to the purity grade of the same husks.

[0064] In some embodiments, the plant 110 is modular, in the sense that, in order to increase its hourly productivity, it is sufficient to add one or more decortication devices 142 to the plant 110.

[0065] We must clarify that in those embodiments in which the plant 110 realizes a discontinuous, closed cycle, automatic dormant production process, the autonomous working times of the plant 110 can be increased or decreased as desired, simply by appropriately sizing the volumes of the first and second silos 132, 161 and adjusting the flow rate of the second and third thrust fan 136, 162 accordingly.

[0066] It is clear that modifications and / or additions of parts may be made to the method 10 and to the plant 110 as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0067] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of high performance decortication method and plant, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0068] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Method (10) for decortication of psyllium seeds, comprising at least the feed (20) of said seeds, their decortication (40) and separation (50) as well as packaging (80) of the husks thus obtained and also comprising a grading, characterized in that said grading is a grading (70), carried out on a colorimetric basis, of said husks into predefined purity grades, thus determining said step of packaging (80) into different packages on the basis of said grading.

2. Method (10) as in claim 1, characterized in that it comprises, before said decortication (40), a calibration (30) of the seeds to be decorticated, providing a separation thereof on the basis of their sizes, said decortication (40) being carried out separately for each caliber of seeds.

3. Method (10) as in any claim hereinbefore, characterized in that it comprises, following said separation (50), a step of recirculation or discharge (60) to selectively recirculate (61) or discharge (62) said decorticated seeds.

4. Method (10) as in any claim hereinbefore, characterized in that the transport of the products being processed is pneumatic and / or based on gravitational fall.

5. Method (10) as in any claim hereinbefore, characterized in that said grading (70) provides a lower purity grade, comprising husks with a purity lower than or equal to 85%; an intermediate purity grade, comprising husks with a purity greater than 85% and lower than or equal to 95%; and a higher purity grade, comprising husks with a purity greater than 95%.

6. Method (10) as in any claim hereinbefore, characterized in that said grading (70) provides to use a digital colorimeter (172) to obtain a set of colorimetric coordinates (L*, a*, b*) of said husks according to the CIELab international standard.

7. Method (10) as in claims 5 and 6, characterized in that said grading (70) grades- into said lower purity grade, husks with a first coordinate (L*) lower than or equal to 64.49, a second coordinate (a*) greater than or equal to 4.5, and a third coordinate (b*) greater than or equal to 13.51;- into said intermediate purity grade, husks with the first coordinate (L*) comprised between 64.5 and 69.49, the second coordinate (a*) comprised between 3.51 and 4.49, and the third coordinate (b*) comprised between 13.51 and 15; and- into said higher purity grade, husks with the first coordinate (L*) greater than orequal to 69.5, the second coordinate (a*) comprised between 1.7 and 3.5, and the third coordinate (b*) comprised between 13 and 13.5.

8. Plant (110) for decortication of psyllium seeds comprising at least one unit (120) for feeding them, one unit (140) for their decortication and one unit (150) for separating husks from said decorticated seeds, also comprising a grading unit (170) and a packaging unit (180), characterized in that said grading unit (170) comprises a colorimeter (172) configured to obtain a colorimetric reading of said husks.

9. Plant (110) as in claim 8, characterized in that it comprises a calibration unit (130) upstream of said decortication unit (1 0), configured to divide said seeds on the basis of their sizes.

10. Plant (110) as in any claim from 8 to 9, characterized in that it comprises a recirculation and discharge unit (160) downstream of said separation unit (150), configured to selectively recirculate or discharge said decorticated seeds.

11. Plant (110) as in any claim from 8 to 10, characterized in that it comprises pneumatic means (121, 136, 162) and / or means based on gravitational fall (141, 171) for transporting and recirculating the products being processed.

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