DE69520543T2 - Method and device for extracting vegetable juices from vegetable waste - Google Patents

Description

[0001] The invention relates to a method or a device for obtaining vegetable juices from vegetable peels, whether processed or not, or from similar juice-containing vegetable residues.

During the industrial processing of vegetables into, for example, preserved vegetables, frozen vegetables, etc., as is done with carrots and swedes, a considerable amount of vegetable waste is produced after rinsing and peeling, such as carrot and/or swede peels (commonly called vegetable pulp), which is considered unfit for human consumption. Not only is this vegetable waste usually thrown away or used as animal feed, but as a result of environmental legislation, the disposal costs of this rapidly fermenting vegetable pulp are relatively high. Analyses of these residues show that the vegetable waste/feed still contains a considerable amount of recoverable vegetable juices, which would be suitable for human consumption. In any case, research shows that the dry matter content of this pulp is no higher than 10%, which means that the remaining 90% consists of moisture. The invention relates to a method or a device for obtaining a vegetable juice from the above-mentioned vegetable peels (vegetable pulp which is, however, suitable for human consumption).

[0002] It is clear that if, for example, 20,000 tonnes of pulp obtained by (steam) peeling of, for example, carrots or similar products (turnips, cabbage) were processed annually, a considerable amount of carrot juice and/or other vegetable juices could be preserved, but which has so far been disposed of and thus wasted.

[0003] According to the invention, however, it has been found, most surprisingly, that it is possible to obtain a juice that is perfectly suitable for human consumption from the (steam-peeled) carrot peels. The extraction takes place by separating the juice from the vegetable residue by means of pressing and/or centrifugal and/or similar separation techniques known per se. By appropriately arranging a separator, an astonishingly high percentage of juice that is extremely suitable for human consumption can thus be extracted from the pulp. What remains is a residual product with a remarkably and astonishingly high dry matter content, which is now very suitable and usable as animal feed.

[0004] According to the invention, the method for obtaining vegetable juices, in particular from vegetable peels, whether pretreated or not, or similar, juicy vegetable residues (pulp) with a relatively low dry matter content, e.g. lower than about 10%, and a many times higher vegetable juice content, comprises the following processing stages:

a. grinding and/or shredding (if necessary) of the vegetable scraps and/or the chopped vegetable pulp pieces with a low dry matter content;

b. Addition (if necessary) of pH reducing additives to the vegetable pulp pieces;

c. Separation of the vegetable juice from the vegetable residues, in particular the residues obtained by steam peeling vegetables. The separation can be carried out by means of a so-called pressing and/or centrifugal unit and/or similar separation techniques. This produces an exceptionally high yield of high-quality vegetable juices;

d. Removal (if necessary) of sand and/or other impurities such as residual components from the vegetable juice;

e. Dosing and addition of one or more additives;

f. Conditioning of the vegetable juice obtained and/or the vegetable residues containing juice, consisting of pasteurisation and/or pH reduction;

g. bottling and/or freezing and/or storing in bulk the vegetable juice obtained;

h. Removal of the residual product with a relatively high dry matter content that was formed during the separation process.

[0005] The invention further relates to a device for carrying out the method described above. This device comprises the combination of a series of successive processing steps, which could (possibly) consist of:

a. (if it appears advisable due to the coarseness of the residues), first, mechanical means of refining/reducing, for example by grinding and/or shredding the juicy vegetable residues or vegetable pulp pieces with a low dry matter content;

b. second, mechanical means, such as a motor pump, for a first addition of pH-reducing additives;

c. thirdly, mechanical means for separating the juice from the vegetable residues (pulp) to obtain vegetable juices;

d. (if it appears advisable due to the composition of the vegetable juice obtained), fourthly, mechanical means for removing sand or other impurities such as residual components from the vegetable juice;

e. fifthly, mechanical means for conditioning the expressed vegetable juice and/or the vegetable residues containing the juice, consisting of pasteurisation and/or standardisation of the pH of the juice, and mechanical means for adding additives;

f. sixth, mechanical means for bottling and/or freezing and/or storing in bulk the juice obtained;

g. seventh, mechanical means for removing the dry residual product obtained during the separation process.

[0006] According to the invention, firstly, mechanical means are constituted by a unit known per se for grinding and/or shredding, if the fineness of the vegetable residues supplied makes this advisable.

According to the invention, second mechanical means comprise a device for first adding pH-reducing additives to the vegetable residues.

Thirdly, according to the invention, mechanical means for separating the vegetable juice from the vegetable residues by means of a technique known per se, such as squeezing and/or centrifuging and/or the like.

Fourthly, according to the invention, mechanical means consist of means known per se for removing sand or other undesirable residual components from the vegetable juice, for example by means of a sand and/or dirt cyclone, if the composition of the juice obtained makes this advisable.

According to the invention, fifthly, mechanical means are provided for separating the vegetable juice and/or the juice-containing vegetable residues which have been separated, namely these means consist in pasteurization and/or pH reduction and/or sixthly, mechanical means for adding other additives.

According to the invention, seventhly, mechanical means provided with the device are used for filling and/or deep-freezing and/or for bulk storage.

Eighthly, according to the invention, mechanical means are provided for removing the residual product with a relatively high dry matter content obtained during the separation process.

[0007] In the following, the invention is explained in more detail by means of a drawing of a creative embodiment.

Fig. 1 shows in a block diagram several processing steps in the processing of steam-peeled carrot peels, as an example of vegetable waste, into carrot juice suitable for human consumption;

Fig. 2 shows a diagram of a device according to the invention, indicating the separate processing stages.

[0008] Fig. 1 shows a diagram of the production process of a carrot juice from carrot residues. The steam-peeled carrot peels are acidified in pulp buffer tank 1 by means of an additive from dosing meter 2 that prevents fermentation. In a separation unit, the pulp is then separated into vegetable juice and residual product, which has a dry matter content of 15% or higher. The residual product ends up in pulp tank 4, while the obtained vegetable juice is collected in juice buffer tank 5 after sand and/or other impurities, if present, have been removed.

The vegetable juice is then passed through a tray pasteurizer, whereupon an acid solution is dosed and added from dosing meter 8 into storage tank 7, bringing the pH of the carrot juice to the desired value. To meet the taste needs of the consumers, a sweetener and/or acid crystals and/or other additives can be added, if necessary, immediately before and/or immediately after the second tray pasteurizer, by means of dosing meter 10 in preparation tank 9.

[0009] The vegetable juice can then be filled into filling unit 12 and the bottles can be encapsulated in encapsulation unit 13. If desired, the vegetable juice can also be frozen and/or stored loose and/or filled in another way.

[0010] Fig. 2 shows a schematic structure of a process device for producing carrot juice from steam-peeled carrot peels, in which the method according to the invention is used. Dosing meter A adds a pH reducing additive to the steam peeled carrot peels which have been refined, if necessary, in pulp buffer tank C. This mixture is then sent to pulp/juice separation unit D. This unit may consist of e.g. a squeezing and/or a centrifugal unit and/or another separation unit. A dry pulp removal device E has been provided at the bottom of the separation unit. This method makes it possible to obtain an astonishingly high yield of carrot juice from the residue, which, however, is not yet suitable for human consumption. Furthermore, the residual product removed from separator D turns out to have a relatively high dry matter content of about 15% or higher, making it perfectly suitable for sale to the feed industry.

The carrot juice thus obtained, which still contains minor impurities, now first passes through dirt cyclone F. The clarified carrot juice is then passed through first pasteurization plant G. After that, additives from dosing meter A are added to the carrot juice in storage tank I, mixed by agitator B and cooled by heat exchanger H. The juice is then passed into mixing tank J, which is also equipped with a dosing meter A and agitator B. After the carrot juice has been mixed with the necessary nutrients, flavors and preservatives, it passes through the second pasteurization plant G. After that, it can be filled and encapsulated in filling unit K.

[0011] It is known that the purpose of the method and the device is to provide a novel way of converting peels and the like, which have not been used to date for obtaining vegetable juice, into vegetable juice suitable for human consumption.

[0012] However, the method and device according to the invention also make it possible to obtain a maximum yield of vegetable juice from completely unpeeled vegetables, since in this case the favorable end result obtained corresponds to that obtained according to the invention with, for example, steam-peeled peels. For an expert it is obvious that an end result obtained in the same way from completely unpeeled vegetables can also be covered by this invention.

[0013] The squeezing system chosen for carrying out the method is already known as such for squeezing very juicy fruits. Never has the slightest thought been put forward to connect such a fruit squeezing system in any way with the "extraction" of vegetable juice left in vegetable peels, since this extraction possibility has always been considered completely impossible and the usual squeezing methods considered sufficient. It is the merit of this invention that now for the first time a successful result has been achieved in obtaining these recoverable, large quantities of vegetable juice from waste. At the same time, the remaining residue is given such a firmness that it can be used as directly administrable feed, all this without undue and unacceptable burdens on the environment as a seasonal production result.

Regarding the special pressing systems for this new purpose, a belt filter pressing system and/or a centrifugal system can also be used. None of these systems has ever been considered applicable for the processing of peels or similar.

Claims (13)

1. Method for obtaining vegetable juices, in particular from vegetable peels or similar vegetable residues containing juice, such as vegetable pulp and steam-peeled vegetables, whose dry matter content is relatively low, e.g. less than approximately 10%, whereas the vegetable juice content is many times higher, characterized in that the following processing steps must be carried out: a. grinding and/or shredding (if necessary) of the vegetable scraps and/or the chopped vegetable pulp pieces with a low dry matter content; b. Addition (if necessary) of a pH reducing additive; c. Separating the vegetable juice from the vegetable residues, especially the residues obtained by steam peeling vegetables. Which, surprisingly, give a significantly higher vegetable juice yield, perfectly suitable for human consumption; d. Alternatively, removing (if necessary) sand particles or other undesirable residual components from the vegetable juice; e. Dosing and adding to the juice one or more additives; f. Conditioning of the pressed vegetable juice and/or the vegetable residues containing juice, consisting of pasteurisation and/or pH reduction; g. bottling and/or freezing and/or storing in bulk of the juice obtained; h. Removal of the relatively dry residual product that has formed during the separation process. 2. Device for carrying out the method according to claim 1, characterized by the combination of a series of processing steps which have been provided and which comprise : a. First, mechanical means for grinding and/or shredding the juicy vegetable scraps or vegetable pulp pieces with a low dry matter content (if this seems advisable due to the fineness of the vegetable scraps); b. Second, mechanical means for adding pH-reducing additives to the vegetable residues; c. Thirdly, mechanical means for separating the vegetable juice from the vegetable residues to obtain vegetable juices; d. (if it seems advisable due to the composition of the vegetable juice obtained), fourthly, mechanical means for removing sand or other unusable residual components from the vegetable juice; e. Fifth, mechanical means for adding the required additives; f. Sixth, mechanical means for conditioning the expressed vegetable juice and/or the juice contained in the vegetable juices, consisting of pasteurisation and/or pH reduction; g. Seventh, mechanical means for bottling and/or freezing and/or storing in bulk the juice obtained; h. Eighth, mechanical means for removing the relatively dry residual product formed during the separation process. 3. Device according to claim 2, with the characteristic feature that the processing stage under a. consists of a unit for grinding and/or shredding which is common on its own. 4. Device according to claim 2, with the characteristic feature that the processing stage under b. consists of a dosing device which is conventional in itself. 5. Device according to claim 2, with the characteristic feature that the processing stage under c. for separating the vegetable juice from the vegetable residues consists of a system which is common in itself, such as a pressing system and/or a belt filtering pressing system and/or a centrifugal system. 6. Device according to claim 2, with the characteristic feature that the processing stage under d. consists of a sand and/or dirt cyclone which is common on its own. 7. Device according to claim 2, with the characteristic feature that the processing stage under e. consists of at least one dosage measuring device which is conventional on its own. 8. Device according to claim 2, with the characteristic feature that the processing stage under f. consists of a conditioning unit, which is common on its own, for pasteurization and/or pH reduction. 9. Device according to claim 2, with the characteristic feature that the processing step under g. consists of a filling and/or freezer unit and/or a bulk storage unit. 10. Device according to claim 2, with the characteristic feature that the processing stage h. consists of a removal device, which is conventional in itself, for removing the relatively dry residual product from the separation system. 11. Device according to claim 2, with the characteristic feature that the processing stages under e. and f. are equipped with dosage measuring units for one or more additives. 12. Device according to claim 2, with the characteristic feature that the processing stage under f. is equipped with a pasteurizer. 13. Vegetable juice obtained from vegetables and/or vegetable residues, pretreated or not, by means of the method and device according to any one of the preceding claims 1-12.