EP1074605B1 - Process and apparatus for producing a cooking oil from rapeseed - Google Patents

Abstract

Production of food oil from rapeseed and/or other oil seeds comprises sieving, heating, dehusking and cold pressing. Production of food oil from rapeseed and/or other oil seeds comprises sieving to give three fractions of different grain size comprising trimmings, cleaned rapeseed and waste grain, transporting the trimmings and waste grain to a silo, heating the cleaned rapeseed at below 40 degrees C to give a water content of 4.5-5.5% and grinding it to give three further fractions, adding the unusable fractions to the silo, and dehusking the usable grain and cold pressing it and removing solids. Independent claims are included for the apparatus used comprising a sieve, a drier, a rolling mill, a further sieve, a separator, a conditioner, a flocking rolling mill and a press.

Description

The invention relates to a method for producing Edible oil from rapeseed or other oil seeds, the Rapeseed or oilseed after going through a classifying deck is first dried, broken and sighted and finally after preparing a press is fed. The invention further relates to a Establishment for the implementation of the procedure. to In the following, simplification is only related to rapeseed taken.

In the known processes for the production of cooking oil the rapeseed is processed without prior peeling, although rape peeling is known are (DE-PS 21 35 173, DD-PS 131 530, DE-OS 40 41 994).

One of the cited references (DE-PS 21 35 173) relates to a process for peeling granular oil fruits, where the grains are subjected to an impact become. This is done in a short time interval Grains heated to about 45 ° C using a stream of cold air against diagonally to the flow direction Impact plates thrown. The broken up Grains are then made mechanically by friction without oil extraction separated from the shell by the one with the Airflow blended grains of a helical shape Be subjected to movement between friction walls.

The second cited reference (DD-PS 131 530) relates to a process for the disclosure of oil and proteinaceous seeds, the casing by a Deformation of the seeds removed from the core meat and then shell and core meat separated become. To remove the shell from the core meat, the Seeds of a defined deformation between two exposed to rigid surfaces, causing the shell to flake off. This then takes place in a subsequent viewing process Separation of the casing from the core meat.

The other cited reference (DE-OS 40 41 994) relates to a method and an arrangement for rape peeling, that with the extraction of core fractions Shell proportions <5% as required for later use extracted oils for fuel purposes or for other technical purposes are required. This is done through a combined pressure and impact treatment of the seeds. The won The core fraction can be used directly for the production of fuel following processes. The known method sees u. a. before that cleaned Rapeseed hot - at a temperature of 95 ° C - dried and then by single-stage rolling is peeled, the nip 0.2 times to 0.4 times the average seed grain diameter. Detaching the broken shells from the Core meat is made by impact impact loops at one pneumatic conveying, if necessary by a Air separation and separation of the shells from the core meat through electrical separation. The technological The rape peeling arrangement consists of a seed bunker, a scale, a roller peeler, a cyclone, one Air classifier and an electric separator. This well known The process has significant disadvantages in terms of technology. The hot drying of the seeds leads to the known quality disadvantages that of thermally stressed material extracted crude oils. The one-time rolling for disassembly the seed with a wide grain spectrum in one Roll gap of 0.45 mm leads to crushing of the seeds and thus to oil leakage, whereby the disassembly of the Mixtures in the subsequent visual process is difficult. The known method therefore requires an additional one pneumatic conveyance with loosening by impact impact and an additional, energetically unfavorable wind sifting for separating unpeeled seeds before the actual separation of the mixture on the electric classifier he follows.

Rapeseed peeling has gained no importance in practice. Rather, it is usually used in manufacturing of edible oil, the crushed rapeseed first and then pressed. Here pass through the high shin content relatively many waxes and other ingredients into the cooking oil, which is only a small Quality. The known methods of manufacture of cooking oil from oilseeds therefore need Cleaning the oils a chemical and physical Refining.

There has been no shortage of attempts at processing unpeeled rapeseed on colander screw presses due to the high caused by the shells Friction inevitably occurring pressing temperatures of lower significantly above 40 ° C. So one became Screw press with complex cooling of a ring strainer basket proposed (DE 41 09 229 C2). The continuous Cooling of the surrounding press geometry is said to dissipate high frictional heat during the pressing process, to low pressing temperatures below 38 ° C to reach.

Conventional rapeseed processing works to increase yield in plants with larger processing capacity with a hydro-thermal treatment of the Sowing before pressing. The usual conditioning temperatures of up to 100 ° C increase the adverse influences of the high press temperatures. The Contents of free fatty acids and phosphatides in the press oil are further increased compared to non-preheated seeds.

By pressing the whole rapeseed with husks shell-specific ingredients such as chlorophyll, Waxes, free fatty acids and tannins (bitter substances) in the crude oil, thereby reducing the quality of the crude oil about the negative influence of high press temperatures is also negatively influenced. chlorophyll and its breakdown products act as prooxidants; they reduce the durability and impair the sensory quality of the oil. The tannins deteriorate the sensors and give the oil a bitter grassy Taste. Those that cannot be removed even by refining Waxes of the shells remain in the oil and act as Crystallization nuclei in cool storage.

The high levels of unwanted ingredients the conventional processing of whole rapeseed Shells have to be removed from the crude oils become. The oils pressed from not preheated seeds are used to improve sensor technology and durability often damping at temperatures above 100 ° C subjected. The oils pressed from conditioned seeds must be refined at temperatures> 200 ° C become. The high temperatures of damping and Refining lead to the formation of nutritionally negative trans fatty acids and to reduce the Contains volatile, valuable vitamins.

The invention has for its object a method and to create a facility to cold press To produce cooking oil while avoiding the oil thermally stressful and energetically complex Refining or damping immediately as high quality Cooking oil can be used.

• daß die Rapssaat mittels einer Siebmaschine in drei Fraktionen verschiedener Partikelgrößen getrennt wird, und zwar in Besatz, in gereinigte Rapssaat und in Kümmerkorn,
• daß die gereinigte und klassierte Rapssaat anschließend bei einer Trocknungstemperatur unterhalb einer Grenztemperatur von 40 °C auf einen Wassergehalt des ganzen Rapskorns von 4,5 % bis 5,5 % getrocknet wird und der Besatz und das Kümmerkorn einem Silo zugeführt werden,
• daß danach die getrocknete Rapssaat in einem Walzwerk gebrochen wird,
• daß dann die gebrochene Rapssaat - der Rapsbruch - durch Klassieren in drei Fraktionen verschiedener Partikelgröße getrennt wird, und zwar in Anbruch, in Nutzbruch und in Feinbruch,
• daß der Nutzbruch in einem Sichter in Schälraps und Schalen zerlegt und der Anbruch sowie der Feinbruch dem Silo zugeführt werden,
• daß sodann der Schälraps befeuchtet und anschließend in einem weiteren Walzwerk - einem Flockierwalzwerk - flockiert wird,
• daß danach der flockierte Schälraps in einer Presse kalt verpreßt wird
• und daß schließlich durch Reinigung des aus der Presse austretenden Preßöls von Trubstoffen (Feststoffen) Speiseöl gebildet wird.

The solution to the problem in a method of the type mentioned at the outset is

• that the rapeseed is separated into three fractions of different particle sizes by means of a screening machine, namely in stocking, in cleaned rapeseed and in grain
• that the cleaned and classified rapeseed is then dried at a drying temperature below a limit temperature of 40 ° C. to a water content of the whole rapeseed grain of 4.5% to 5.5% and the trimmings and the grain of the grain are fed to a silo,
• that the dried rapeseed is then broken up in a rolling mill,
• that the broken rapeseed - the rapeseed - is then separated into three fractions of different particle sizes, namely in the first part, in useful part and in fine part,
• that the useful break in a sifter is broken down into peeled rape and shells and the opening and the fine break are fed to the silo,
• then the peeled rape is moistened and then flaked in another rolling mill - a flaking mill,
• that the flaked rape is then cold pressed in a press
• and that, finally, edible oil is formed by cleaning the press oil emerging from the press from turbid substances (solids).

Here the trimmings consist of foreign seeds, parts of plants and various contaminants, the cleaned Rapeseed from whole rapeseed and a small one Proportion of plant parts and the caraway grain from stunted or opened rapeseed, plant parts and Fine dust together.

It may be useful to rapeseed before classifying through a metal separator.

The obtained by means of the method according to the invention Cooking oil only shows extremely low levels unwanted ingredients. It is therefore high-quality cooking oil. A subsequent one Post-treatment by refining or steaming is not required. With the cooking oil obtained, one fine nutty own taste to be evaluated positively has, the high levels of get volatile vitamins. This is achieved by removing the majority of the rape shells and due to the low pressing temperatures. To the current state of knowledge can be assumed be that for press oils that come from the press with a limit temperature below 40 ° C, none quality-damaging processes are to be expected. at Pressing the reduced-seed seed without further pretreatment may be more intense due to warming Friction in the colander screw press the mentioned Limit temperature must not be fallen below.

Due to the low drying temperature below the Limit temperature of 40 ° C will reduce quality Enzyme activation excluded and by the close A spectrum in the water content of 4.5% to 5.5% becomes a Simplified seed peeling enables.

It has proven advantageous that the separation rapeseed is divided into three fractions in such a way that the particle size of the fill is more than 1.1 times, the particle size of the cleaned rapeseed between 0.7 times and 1.1 times and the Particle size of the kernel grain is less than 0.7 times of the average rapeseed grain diameter.

The drying temperature is expediently the cleaned and classified rapeseed maximum 35 ° C. This measure contributes significantly to a Damage to fatty acids, denaturation of proteins and prevent activation of the seed enzymes.

In an embodiment of the invention, the breaking of the cleaned and dried rapeseed in two consecutive Rolling operations, and that takes place first Prebreak and then post-break, each in one Rolling mill with smooth rolls, the mean gap width of the nip is larger in the pre-break than in the Postbreak is set. Expediently the mean gap width of the roll gap during the preliminary break the average gap width of the roll gap at the pre-break to 0.4 times to 0.5 times and at the refraction to 0.3 times to 0.4 times the medium rapeseed diameter set.

Due to the realized double load with reduced Nip will be the peeling of shells and Core meat with a high degree of seed laying already reached during breaking. By the defined Deformation of the seeds is achieved that the Peeling off without crushing the core meat becomes. The rapeseed core only disintegrates into its natural five elements, like two outer and two inner Cotyledons as well as the seedling because the elements are only in in a closely localized area are. An essential oil leak from the rapeseed elements is avoided.

It has also proven advantageous that the Separation of the rapeseed into three fractions in this way that the particle size of the crack is more than that 0.7 times the particle size of the usable fraction between the 0.2 times and 0.7 times and the particle size of the Fine fraction less than 0.2 times the average Rapeseed diameter.

The pressing of the peeled rape with a low shell content on screw presses at low temperatures to enable the peeling rape to be conditioned by humidifying at a temperature below 40 ° C, a water content of 5% to 7%, preferably is set from 5.5% to 6.5%. Through the Had removal of the rape pods with high water content the water content of the peeled rape compared to the entire seeds previously reduced by approx. 1%.

It has proven to be particularly advantageous that the Conditioning the peel rape at a temperature of maximum 35 ° C.

In a further embodiment of the invention moistened peeled rape on a flaking mill Smooth rolling and a slip of approx. 5% open. By the set according to the invention The core meat is plasticized to the extent that that fine breakage is avoided and a high degree of disintegration, so a high proportion of mechanically opened cells is achieved.

When flaking the peeled rape, it is useful the nip of the smooth rollers of the flaking mill set such that the mean gap width of the nip 0.04 times to 0.05 times the average rapeseed grain diameter.

The by-products collected in the silo can be one be used for further use, for example as Feed.

In addition to the primary effect of the novel process of extracting high-quality and minimally thermally contaminated edible oils, three other important effects are achieved. First of all, the pressed reeds from peeled rapeseed already have a significantly higher feed value than reeds from unshelled seeds due to a significantly lower raw fiber content. Secondly, the low power consumption and the low wear of the screw press are to be mentioned, which significantly increases the service life. Thirdly, the energetic use of the separated by-products, but especially the shell fraction, provides a CO ₂ -neutral full supply of the production process with both electrical and thermal energy.

• eine Siebmaschine,
• ein Trockner,
• ein Walzwerk,
• eine weitere Siebmaschine,
• ein Sichter,
• ein Konditionierer,
• ein Flockierwalzwerk
• und eine Presse.

The following units are arranged one behind the other in the device for carrying out the method according to the invention:

• a screening machine,
• a dryer,
• a rolling mill,
• another screening machine,
• a sifter,
• a conditioner,
• a flaking mill
• and a press.

With such a device, the invention Procedure can be carried out without problems.

The facility can still be improved in that the rolling mill two pairs of rolls arranged one above the other has, which are provided with smooth rollers, the Roller gap of the upper pair of rollers is chosen larger, than the nip of the lower pair of rollers. Conveniently, is the nip width of the nip of the upper pair of rollers 0.4 times to 0.5 times and the nip width of the nip of the lower pair of rollers 0.3 to 0.4 times the mean Rapeseed grain diameter set.

This will further improve the facility achieved that the sifter in which the usable waste in Peeled rape and shells are disassembled as wind sifters is trained.

The press is advantageous as a continuous one Colander screw press with a reed breaker.

The inventive method and the inventive Device are explained in more detail with reference to the drawing.

As can be seen from the drawing, when the method according to the invention is carried out, the rapeseed AA supplied initially arrives in a metal separator 1 in which metal parts AB present in the rapeseed are separated.

Thereafter, the rapeseed AC freed from metal parts is separated in a screening machine 2 into three fractions of different particle size, namely in fill AD , for example straw or foreign seeds, into cleaned rapeseed AE and Kümmer grain AF , which also includes cracked grain. The cleaned and classified rapeseed AE is then dried in a dryer 3 and then broken. The trimmings AD and the Kümmer grain AF are fed to a silo 12 .

The dried rapeseed AG is expediently broken in a rolling mill 4 with two pairs of rolls arranged one above the other in two consecutive rolling processes without intermediate sighting. Both pairs of rollers have smooth rollers that run without slippage. There is first a preliminary breaking by means of the upper pair of rollers and then a subsequent breaking by means of the lower pair of rollers of the rolling mill 4, the roller gap of the upper pair of rollers being chosen larger than the roller gap of the lower pair of rollers.

The broken rapeseed - the rapeseed rape AH - is separated in a further screening machine 5 into three fractions of different particle sizes, namely in opening AJ, consisting of broken rapeseed or components of rapeseed, in useful fraction AM , consisting of rapeseed husks and rapeseed elements separated from one another , and in Feinbruch AN , consisting of rapeseed husk particles and rapeseed meat particles. The usable breakdown AM is broken down into a sifter 7 in peeled rape AO, consisting of rapeseed core elements with a small proportion of shell fragments, and in shells AP with a small proportion of core meat particles, while the opening AJ either via a distributor 6 - as described AK indicated - is returned to the rolling mill 4 or - as indicated by the designation AL - in the silo 12 . The fine fraction AN and the shells AP are also fed into the silo 12 . The classifier 7 can be designed as an air classifier or electrical classifier.

The peeling rape AO is designated PA in the area of the pressing process. The water content of the peel rape PA is increased in a conditioner 8 , namely by cold wetting with water. The peel rape PA is then - without preheating - broken down in a flaking mill 9 by means of smooth rolling with a defined shear field.

The flaked peeled rape PC is then cold pressed in a press 10 , which is expediently designed as a strainer screw press with a reed crusher, the press oil PD obtained in this way subsequently being cleaned of trub substances (solids) in a filter 11 and the press oil PD in cooking oil PF and is separated into filter cake PE . The filter cake PE is returned to the press 10 .

The mixture PH accumulated in the silo 12 from the by-products trimming AD, Kümmerkorn AF, opening AL Feinbruch AN and trays AP can be used energetically as animal feed or as fuel.

Claims (16)

1. Method of producing edible oil from rapeseed or other oil seeds, wherein the rapeseed or oil seed after passage through a classifying tier is initially dried, crushed and sifted and finally after processing fed to a press, characterised in that

   1.1 the rapeseed (A.A) is separated by means of a screening machine (2) into three fractions of different particle sizes and, in particular, into stock (A.D), into refined rapeseed (A.E) and into stunted grain (A.F),

   1.2 the refined and classified rapeseed (A.E) is subsequently dried at a drying temperature below a limit temperature of 40° C to a water content of the whole rape grain of 4.5% to 5.5% and the stock (A.D) and stunted grain (A.F) are fed to a silo (12),

   1.3 thereafter the dried rapeseed (A.G) is crushed in a rolling mill (4),

   1.4 then the crushed rapeseed - the rape crush (A.H) - is separated by classification into three fractions of different particle sizes and, in particular into incipient crush (A.J), into useful crush (A.M) and into fine crush (A.N),

   1.5 the useful crush (A.M) is broken down in a sifter (7) into shelled rape (A.O) and shells (A.P) and the incipient crush (A.J) as well as the fine crush (A.N) are fed to the silo (12),

   1.6 then the shelled rape (A.O) is moistened and subsequently flocculated in a further rolling mill, i.e. a flocculating rolling mill (9),

   1.7 thereafter the flocculated shelled rape (P.C) is cold-pressed in a press (10) and

   1.8 finally edible oil (P.F) is formed by cleaning the pressings oil (P.D), which exits the press (10), from turbid substances (solids).
2. Method according to claim 1, characterised in that the separation of the rapeseed (A.A) into three fractions is carried out in the manner that the particle size of the stock (A.D) is more than 1.1 times, the particle size of the refined rapeseed (A.E) is between 0.7 times and 1.1 times and the particle size of the stunted grain (A.F) is less than 0.7 times the mean rape grain diameter.
3. Method according to claim 1 or 2, characterised in that the drying temperature of the refined and classified rapeseed (A.E) is at most 35° C.
4. Method according to claim 1, 2 or 3, characterised in that the crushing of the refined and dried rapeseed (A.G) takes place in two consecutive rolling processes and, in particular, initially a preliminary crushing is carried out and subsequently an after crushing in each instance in a rolling mill (4) with smooth rollers, wherein the mean gap width of the rolling gap is set to be greater in the preliminary crushing than in the post-crushing.
5. Method according to claim 4, characterised in that the setting of the mean gap width is carried out in the manner that the mean gap width of the rolling gap in the preliminary crushing is set to 0.4 to 0.5 times and in the after-crushing to 0.5 times and in the after-crushing to 0.3 to 0.4 times the mean rape grain diameter.
6. Method according to one of claims 1 to 5, characterised in that the separation of the rape crush (A.H) into three fractions is carried out in the manner that the particle size of the incipient crush (A.J) is more than 0.7 times, the particle size of the useful crush (A.M) is between 0.2 times and 0.7 times and the particle size of the fine crush (A.N) is less than 0.2 times the mean rape grain diameter.
7. Method according to one of claims 1 to 6, characterised in that the conditioning of the shelled rape (P.A) is carried out by a moistening at a temperature below the limit temperature of 40° C, wherein a water content of 5% to 7% is set.
8. Method according to claim 7, characterised in that the conditioning of the shelled rape (P.A) is carried out in the manner that the water content is 5.5% to 6.5%.
9. Method according to claim 7 or 8, characterised in that the conditioning of the shelled rape (P.A) is carried out a temperature of at most 35° C.
10. Method according to claim 7, 8 or 9, characterised in that the moistened shelled rape (P.B) is broken down on a flocculating rolling mill (9) with smooth rollers and a slip of approximately 5%.
11. Method according to claim 10, characterised in that in the flocculation of the shelled rape (P.B) the rolling gap of the smooth rollers of the flocculating rolling mill (9) is set in such a manner that the mean gap width of the rolling gap is 0.04 times to 0.05 times the mean rape grain diameter.
12. Equipment for carrying out the method according to one of claims 1 to 11, characterised in that the following units are arranged one after the other in the flow direction of the rapeseed or the like:

    a screening machine (2),

    a drier (3),

    a rolling mill (4),

    a further screening machine (5),

    a sifter (7),

    a conditioner (8),

    a flocculating rolling mill (9) and

    a press (10).
13. Equipment according to claim 12, characterised in that the rolling mill (4) comprises two roller pairs which are arranged one above the other and which are provided with smooth rollers, wherein the gap width of the rolling gap of the upper roller pair is selected to be greater than the gap width of the rolling gap of the lower roller pair.
14. Equipment according to claim 13, characterised in that the gap width of the rolling gap of the upper roller pair is set to 0.4 times to 0.5 times and the gap width of the rolling gap of the lower roller pair is set to 0.3 times to 0.4 times the mean rape grain diameter.
15. Equipment according to one of claims 12 to 14, characterised in that the sifter (7) in which the useful crush (A.M) is broken down into shelled rape (A.O) and shells (A.P) is constructed as a wind sifter.
16. Equipment according to one of claims 12 to 15, characterised in that the press (10) is constructed as a continuous strainer worm press with reed crusher.

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