Patent Description:
The process of preparation of frozen food requires removing unnecessary parts of the raw material, preferably by mechanical means. Methods for processing of vegetables or fruits, including their machine peeling or removing other unnecessary organic components are known in the state of the art. Also various methods for obtaining sliced and frozen vegetables are known in which conventionally vegetables are peeled before being cut, like in <CIT>. <CIT> discloses a method for producing a cut, frozen vegetable. The method comprises the steps of select fresh spinach and "water cleaning". Thereafter the spinach is cut to <NUM>-<NUM>. Then the spinach is blanched at <NUM>. Thereafter the spinach is quick-frozen to below -<NUM>. And finally the frozen product is run through a metal detector for detecting and rejecting any metal objects. Also other methods for metal detection are discussed in the state of the art. In such conventional methods, organic contaminants are removed in the process of water cleaning. Such methods are not dedicated for vegetables with skins, as far as sole water cleaning do not result in peeling of the skins, desired in processing of bulbous vegetables such as onions or garlic.

For example in the patent <CIT> method of processing of tomatoes is disclosed. Freezing is an initial step of processing of tomatoes before separation of the skin; freezing concerns only the surface layer of the vegetable. During separation of the skin of the tomato, the product is defrosted. The vegetables treated in the disclosed manner are not sliced.

In the document <CIT>, a method of peeling fruit and vegetables is disclosed. The following examples of fruit and vegetables are disclosed in the document: peaches, apricots, nectarines, plums, cherries, grapes and tomatoes. The products are alternately heated and cooled. It was pointed, that in order to separate the skin it is necessary to heat the product - heating results in separating the skin.

In the document <CIT> stoning of fruits - berries - after freezing is disclosed.

In the international application <CIT> a method of peeling plant seeds including a plant seed cooling step is disclosed. Freezing is followed by a step of seeds selection. Invention discloses a machine enabling separation of the skin of frozen seeds.

Invention disclosed in <CIT> includes a machine for peeling garlic. In the document an advantageous technical effect of peeling the garlic after its previous cooling is disclosed.

The document <CIT> discloses a garlic freezing method, in which before freezing garlic is sliced and the skin is peeled.

The capacities of peeling machines are very low and the peeling process (whether manual or by machine) is laborious and expensive.

In the document <CIT> a method of obtaining frozen tomatoes and peeled tomatoes is disclosed. The tomatoes are peeled in a frozen state.

The international application <CIT> discloses a method of cryogenic peeling of fruits or vegetables. In the method according to the invention the surface of the fruit or the vegetable is frozen cryogenically. The key step of the process is defrosting of the skin before its separation. The partially frozen fruit/vegetable is heated e.g. in a hot water bath for a certain period of time. Indicated temperature range, to which the skin should be heated is about <NUM> - <NUM>. In the application the possibility of an initial incision of the skin in order to its softening is indicated. Such incision enables subsequent squeezing the vegetable out of the skin and obtaining final flesh. The vegetables subjected to the processing according to the disclosed method are not sliced.

The invention disclosed in <CIT> includes a method of processing, especially fruits. Semi-finished products are frozen as a whole, and then they are subjected to the processing aiming at i.e. removing the stones from inside the fruit.

The objective of the invention was to develop a method of processing vegetables, in order to obtain a sliced frozen vegetables free of organic contaminants as a final effect, without the classical step of peeling using industrial peelers. In particular, the objective of the invention was to develop a method, which will allows to obtain sliced frozen vegetables - onion, shallot and garlic, devoid of skins and other contaminants. The objective of the invention was also to develop a production line to realize this method, devoid of low-performing peeling machines.

A method for manufacturing a sliced frozen onion, shallot or garlic, comprising cleaning, slicing and freezing of a raw material, according to the invention is characterized in that the unnecessary organic components are removed, at least partly mechanically, from the raw material which was first sliced and then frozen. Unexpectedly during tests it turned out, that unnecessary organic components in the raw material first sliced and then frozen can be easily removed. Performing the slicing step and the freezing step before the step of removing unnecessary organic components allows for abandonment of a step of peeling with an use of the industrial peelers, and as a result a simplification of the production line and a reduction of the manufacturing time of frozen vegetables is possible.

Advantageously, in the method according to the invention, the raw material is frozen to a temperature between -<NUM> do -<NUM>. Freezing of the raw material before removing the organic components allows for easier removal of the organic components, which are still present on the raw material after slicing (e.g. skins). Particularly advantageously is to freeze the raw material to a temperature between -<NUM> and -<NUM>, and even more advantageously to a temperature between -<NUM> and -<NUM>. In justified cases, an initial freezing is advantageous, and then freezing the raw material to the desired temperature.

Advantageously, the unnecessary organic components are removed at temperatures below zero, advantageously not higher than -<NUM>. By maintaining a negative temperature of the raw material during removing of the unnecessary organic components it is easier to remove those components and contaminants.

Advantageously, the unnecessary organic components are removed through of at least one process selected from: shaking, air sorting, optical sorting followed by air blowing, laser sorting followed by air blowing, sorting with an use of LED diodes followed by air blowing. Those processes can be combined in any order. Using more processes or cascading of the same processes allow for more effective removing of the unnecessary organic components.

Advantageously, cleaning of the raw material includes washing of the raw material.

Advantageously, before freezing of the raw material, a heat treatment of the raw material is carried out at the temperatures between <NUM> and <NUM>. The heat treatment of the raw material may be carried out by blanching, boiling or steaming. Advantageously, after the heat treatment, the raw material is cooled, so that its temperature is closer to the final temperature in the freezing step.

Advantageously, before freezing of the raw material, a disinfection of the raw material is carried out.

A production line for manufacturing a sliced frozen onion, shallot or garlic, comprising a pre-treatment line, a line for at least partly mechanically removing of unnecessary organic components and a freezing station according to the invention is characterized in that the pre-treatment line comprises a raw material cleaning station and a raw material slicing station while the freezing station is situated between the pre-treatment line and the line for at least partly mechanically removing of unnecessary organic components such that at least partially mechanical removing of unnecessary organic components is carried out on the sliced and frozen raw material.

Advantageously the pre-treatment line comprises an inspection table.

Advantageously the pre-treatment line comprises a washing station of the raw material.

Advantageously, the pre-treatment line comprises a disinfection station of the raw material.

Advantageously, the freezing station comprises a station chosen from: a fluidization tunnel and/or a static freezing chamber.

Advantageously, the line for at least partly mechanically removing of unnecessary organic components comprises at least one station chosen from: a shaking station, air sorting station, a station for optical sorting followed by air blowing, a station for laser sorting followed by air blowing, a station for sorting with the use of LED diodes followed by air blowing.

Advantageously, the pre-treatment line comprises a station for heat treatment of the raw material at the temperature between <NUM> and <NUM>.

A production line according to the invention allows in particular realization of the method according to the invention of manufacturing sliced frozen vegetables, in particular onion, shallot or garlic. A production line according to the invention is cheaper and more efficient than lines known in the state of the art, because the processed raw material is not subjected to the processing in expensive and ineffective industrial peelers.

The invention is described below in more details with reference to its embodiments, presented in the attached drawings, in which.

White onions are used as raw material in one embodiment of the invention (e.g. Allium Cepa L. Cepa Group - Onion, Echalion). Parameters of the method giving good results are summarized in Tab. <NUM>, and a block diagram of the steps of the method according to this embodiment of the invention is presented in <FIG>.

For manufacturing frozen vegetables it is advisable to use good quality vegetables of consumable maturity, which are uniform in variety in lots, fresh, hard, reasonably uniform in size and colour, healthy, not mechanically damaged, free of chemical plant protection agent residues, free of extraneous odours and tastes.

Good effects were obtained for the onion which was clean, whole, dry, free from chives, free from all signs of mould, rot and disease discoloration, healthy, hard, free from pests, free from external moisture, free from frost, free from foreign smell and taste, and stored properly.

In the first step of the method according to the invention, cleaning <NUM> of the raw material is performed. Cleaning <NUM> includes in particular washing <NUM>, which is performed by an water-air cleaner. The person skilled in the art routinely chooses water pressure depending on the type and quality of the vegetables used.

Washed raw material is subjected to disinfection <NUM>. Good effects were obtained as well as while treating the raw material with a product listed below or with a solution of the product, either directly or using products diluted in water. Good effects were obtained by performing disinfection with a mixture of peracetic acid with hydrogen peroxide, whereas the person skilled in the art will routinely propose other products for this purpose.

In the next step the raw material is sliced <NUM>. For slicing, industrial slicing machines for vegetables are used. In this embodiment, onion was sliced into cubes of side dimensions <NUM>. It was shown in experiments, that the cubes with the dimensions in the range of <NUM> to <NUM> performed equally well, in particular the cubes with the dimensions <NUM>, <NUM>, <NUM> performed well. The size of the cube is dictated by the needs of the recipient of the resulting material, the person skilled in the art routinely sets the parameters of the machine to obtain the cubes with the desired side dimension.

Good results were obtained also for the raw material cut into slices. The method according to the invention gave good results for the slices with the thickness of <NUM> to <NUM>, the slices with the thickness of <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> performed well in particular. The thickness of the slice is dictated by the needs of the recipients of the resulting material, the person skilled in the art routinely sets the parameters of the machine (e.g. electrical industrial slicer) so that to obtain the cubes with the desired thickness slices.

In the method according to the invention the raw material having skin and other organic components is sliced.

Then the sliced raw material is frozen in the freezing step <NUM> up to temperature -<NUM>. Experiments showed, that the temperature on the range of -<NUM> to - <NUM> gives good results. In particular good effects were obtained for the temperature of freezing below -<NUM>. In the justified situation a higher temperature of the raw material assuming post-freezing in refrigerating chambers is allowed. Onion freezing in this embodiment was realized by a passage of the raw material through a fluidization tunnel.

In the next step <NUM> organic components in the form of skins and other contaminants, present in sliced and frozen raw material, are removed. Surprisingly it turned out, that thanks to earlier implementation of slicing <NUM> and freezing <NUM>, it is possible to obtain sliced frozen vegetables particularly efficiently, because the use of industrial peelers is not necessary.

Removing <NUM> of the unnecessary organic components is realized on the raw material, which temperature is below -<NUM>. Good effects were obtained in particular when the temperature was below <NUM>, in particular not higher than -<NUM>.

In such realization of the method, the skins are removed from the raw material which is frozen and sliced. This means, that, before the step <NUM>, fragments of the skins were still present on the raw material, that did not fall off during slicing. The raw material after the step <NUM> is still frozen.

In this embodiment, the skins of the onions are removed by shaking (e.g. on sieves) <NUM>. Good effects were obtained by using vibration calibrators - single, double or multi deck, e.g. triple deck.

Good effects were obtained, when the raw material was evenly distributed to the free-fall chute after shaking on the sieves. The raw material was directed downwards towards a control zone, where it was scanned (optical sorting <NUM>), e.g. by lasers (laser sorting <NUM>), cameras, BSI or BSI+ (Biometric Signature Identification) or their combination.

Organic components in the form of the skins and if need be other contaminants are hit with a precise powerful burst of air (blowing), which directs them into the rejection zone, while the good raw material continues its natural process of free falling.

Such prepared material is packaged. At every step, whether it is after or before the cleaning step <NUM>, slicing <NUM>, freezing <NUM>, removing <NUM> unnecessary organic components it is possible to use the inspection by a worker with the use of inspection tables. However experiments showed, that it is not necessary, because the method according to the invention is characterized by very high effectiveness.

Experiments with onion showed, that by the use of the method it is possible to obtain sorting of the organic components. Experiment showed that it is possible to obtain reject lower than <NUM>% of the initial weight of the raw material.

In turn experiments with red onion with the side dimension of the cube equal to <NUM> showed, that with the use of the method it is possible to obtain sorting of the organic components. Experiment showed that it is possible to obtain reject lower than <NUM>% of the initial weight of the raw material.

Shallotes were used as raw material in one embodiment of the invention (e.g. Allium Cepa L. Aggregatum Group - Shallot). Parameters of the method which results in good effects are summarized in Tab. <NUM>, and a block diagram of the steps of the method according to this embodiment of the invention are presented in <FIG> and <FIG>.

Good effects were obtained for the shallot which was clean, whole, dry, free from chives, free from all signs of mould, rot and disease discoloration, healthy, hard, free from pests, free from external moisture, free from frost, free from foreign smell and taste, and stored properly.

In the first step of the method according to the invention, cleaning <NUM> of the raw material is performed. Cleaning <NUM> includes in particular washing <NUM>. Washing <NUM> was performed under a water spray. In most cases, washing is sufficient to obtain good results of cleaning <NUM>.

Washed raw material is subjected to heat treatment <NUM>. Heat treatment is that the raw material, whole or sliced, is blanched or boiled (blanching, boiling in water or by steam) at temperature of <NUM> to <NUM>.

Good effects were obtained by performing heat treatment both by blanching whole shallots at temperature <NUM>-<NUM> for <NUM>-<NUM> or by boiling it for <NUM>-<NUM> minutes. Good effects were obtained also thanks to subsequent cooling of the blanched shallot in a cooling tank, i.e. device, to which very cold water is fed. As a result the raw material has lower temperature before the freezing step <NUM>. If the duration of the process is not crucial, cooling is not necessary.

Such prepared raw material is sliced <NUM> in the next step. In this embodiment shallot was sliced into cubes with the side dimension <NUM> by means of an industrial slicer for vegetables.

The sliced raw material is frozen <NUM> to temperature of -<NUM>. Freezing of the shallot in this embodiment was realized by using a static freezing chamber. Good effects were obtained in particular for the freezing temperature in the range of -<NUM> to -<NUM>.

Next, in the step <NUM> organic components in the form of skins and are removed, which are present in the sliced and frozen raw material.

Removing <NUM> unnecessary organic components is realized with the raw material, whose temperature is lower than -<NUM>,<NUM>.

In such realization of the method, the skins are removed from the raw material which is frozen and sliced. This means, that on the raw material, before the step <NUM>, there were still the fragments of the skins, that did not fall off during slicing. The raw material after the step <NUM> is still frozen.

In this embodiment shaking <NUM> is performed first - input shaker evenly distributes the raw material on the free-fall chute.

Then the raw material is directed downwards towards the control zone, where it is scanned by a special set of various pulsing LED diodes and a combination of cameras (optical sorting with the use of LED diodes <NUM>).

Good effects are possible to be obtained by means of sorting with the use of air, e.g. by using a winnower, e.g. after shaking and before optical sorting. It is also clear that in the step of removing <NUM> unnecessary organic components, which can comprise steps like shaking, air sorting , optical sorting, laser sorting, optical sorting with the use of LED diodes, blowing, those steps can be repeated what will result in a greater precision of removing organic components out of the raw material. Application of at least one of listed steps will result in satisfactory results.

Experiments with shallot showed, that by the use of the method it is possible to obtain sorting of the organic components. Experiment showed that it is possible to obtain reject lower than <NUM>% of the initial weight of the raw material.

Garlic is used as raw material in one embodiment of the invention (e.g. Allium sativum L. Parameters of the method which result in good effects are summarized in Tab. <NUM>, and a block diagram of the steps of the method according to this embodiment of the invention are presented in <FIG> and <FIG>.

Good effects were obtained for the garlic which was clean, whole, dry, free from chives, free from all signs of mould, rot and disease discoloration, healthy, hard, free from pests, free from external moisture, free from frost, free from foreign smell and taste, and stored properly.

In the first step of the method according to the invention, cleaning <NUM> of the raw material is performed. Cleaning <NUM> includes in particular washing <NUM>. Washing <NUM> was performed in a tank.

Washed raw material is subjected to heat treatment <NUM>. Good effects were obtained by performing heat treatment of the garlic by its blanching using water vapour. Good effects were obtained also thanks to subsequent cooling of the blanched garlic in a cooling tank, i.e. device, to which very cold water is fed. Thanks to that the raw material has lower temperature before the step of freezing <NUM>. If the duration of the process is not crucial, cooling is not necessary. It is also possible to perform both disinfection and heat treatment, in any order.

Such prepared raw material is sliced <NUM> in the next step. In this embodiment garlic was sliced into cubes with the side dimension <NUM> by means of industrial slicer for vegetables. Good effects were also obtained for the garlic sliced into cubes with the side dimension <NUM>, <NUM>, <NUM>, <NUM>.

Sliced raw material is frozen <NUM> to a temperature of -<NUM>. Freezing of the garlic in this embodiment was realized by using a static freezing chamber. Good effects were obtained in particular for the freezing temperature in the range of -<NUM> to -<NUM>.

Next, in the step <NUM> organic components in the form of skins, which are present in sliced and frozen raw material.

Removing <NUM> unnecessary organic components is realized with the raw material, whose temperature is lower than -<NUM>.

In this embodiment first shaking <NUM> is performed - input shaker evenly distributes the raw material on the free-fall chute.

Then the raw material is air sorted <NUM>, e.g. by using a winnower.

Then the raw material is directed downwards towards the control zone, where it is scanned (optical sorting <NUM>), e.g. by lasers (laser sorting <NUM>), cameras, BSI or BSI+ (Biometric Signature Identification) or their combination.

Organic components in the form of the skins and if need be other contaminants are hit with a precise powerful burst of air (blowing), which directs them into the rejection zone, while the good raw material continue their natural process of free falling.

Organic components in the form of the skins and if need be other contaminants are hit with a precise powerful burst of air (blowing), which directs them into the rejection zone, while the good raw material continues their natural process of free falling.

Cascade arrangement of the steps of optical sorting: laser sorting and sorting with the use of LED diodes allows particularly effective separation of foreign bodies, but also residues from mechanical preparation - mainly in the form of loose skins (organic components), its fragments adhered to the good raw material or cross-contaminations.

This is how the relatively low, acceptable level of reject is obtained. Preliminary mechanical cleaning of the raw material (e.g. during washing) or using air sorting (e.g. by using a winnower) after shaking allows for further limitation of defects concentration in a final product.

The raw material is packaged and further stored under appropriate conditions.

Embodiment of the production line according to this embodiment of invention is presented in <FIG> and <FIG>.

The production line according to this embodiment allows for realization the method according to the invention according to the embodiment <NUM>.

The production line for manufacturing sliced frozen vegetables, in particular onion, shallot or garlic, comprises a pre-treatment line <NUM>. The production line comprises further a line <NUM> for at least partly mechanically removing of unnecessary organic components and a freezing station <NUM>.

The pre-treatment line <NUM> comprises further a raw material cleaning station <NUM> and a raw material slicing station <NUM>.

A freezing station <NUM> is situated between the pre-treatment line <NUM> and the line <NUM> for at least partly mechanically removing of unnecessary organic components such that at least partially mechanical removing of unnecessary organic components is carried out on the raw material which is sliced and frozen.

Transport of the raw material between particular lines and stations is realized by chutes known-in-the-art, belt conveyors, feeders or other transport equipment allowing a transport of the raw material.

The cleaning station <NUM> in this embodiment comprises a washing station <NUM> and a station for heat treatment of the raw material <NUM>. Washing station <NUM> is realized by using a tank, in which the raw material is rinsed. The station for heat treatment of the raw material <NUM> in principle allows the heat treatment of the raw material at the temperature of <NUM> to <NUM>. In this embodiment stand for the heat treatment of the raw material <NUM> comprises a device for blanching using water vapour. Good effects were obtained by providing a cooler, in the form of a device to which very cold water is fed, behind the device for blanching with the use of water vapour.

The raw material is directed from the cleaning station <NUM> to the slicing station <NUM>. The slicing station can be realized e.g. by using industrial slicers or shredders.

The raw material is directed to the freezing station <NUM> from the slicing station <NUM>. In this embodiment the freezing station <NUM> comprised static freezing chamber. Good effects may be achieved also by using fluidization tunnels. It is also possible to realize the refrigerated chambers enabling post-freezing of the raw material. The freezing station <NUM> allows for obtaining the raw material temperature in the rage of -<NUM> to -<NUM>.

The raw material is directed from the freezing station <NUM> to the line <NUM> for at least partly mechanically removing of unnecessary organic components. Good effects can be achieved if, during the stay of the raw material on the line <NUM> for at least partly mechanically removing of unnecessary organic components, the temperature of the raw material does not exceed -<NUM>, in this embodiment -<NUM>. Exceeding this temperature can result in decreased effectiveness of the process, but not necessarily below an acceptable value.

Fragments of the skins, that did not fall off during slicing are still present in the raw material (sliced and frozen), directed to the line <NUM> for at least partly mechanically removing of unnecessary organic components.

In this embodiment, the raw material passing through the line <NUM> for at least partly mechanically removing of unnecessary organic components, is directed subsequently to:.

Although in this embodiment the sorting stations are multiplied, it will be clear for the person skilled in the art, that a change of number/order of sorting stations is possible. For the person skilled in the at it will be also clear, that increasing the number of the sorting station allows achieving better results.

For the person skilled in the art such modification of the pre-treatment line <NUM> is also clear a that e.g. a disinfection station <NUM> is added - instead of, before or after the heat treatment station of the raw material <NUM> (see <FIG>). Such modified line allows realization of the method according to the embodiment <NUM> or <NUM> of the invention.

Claim 1:
A method for manufacturing sliced frozen vegetables, containing unnecessary organic components in the form of skins, comprising cleaning (<NUM>), slicing (<NUM>) and freezing (<NUM>) of a raw material, characterized in that unnecessary organic components are removed (<NUM>), at least partly mechanically, from the raw material which was first sliced and then frozen.