DE102007019650A1 - Foodstuff casing useful as artificial sausage casing, comprises a fiber reinforcement that is a fiber paper or fiber fleece, protein, filling material and glycerin - Google Patents

Abstract

The foodstuff casing useful as artificial sausage casing, comprises a fiber reinforcement that is a fiber paper or fiber fleece, protein, filling material and glycerin. The foodstuff casing is obtained from cellulose dissolved in an ionic liquid by extrusion and subsequent precipitation, is chewable and is stretched in longitudinal and transverse direction, whose stretching degree is 1:1.2 to 1:1.8. An independent claim is included for a procedure for the production of food casing.

Description

The The invention relates to a cellulose-based food casing, a process for their preparation and their use, in particular as an artificial sausage casing.

cellulose is insoluble in common solvents. It has no melting point or range, but decomposes when heated and therefore can not be processed thermoplastic This is why it is normally used to make food casings the cellulose is chemically converted. These procedures are however associated with degradation of the cellulose, d. H. the average Degree of polymerization DP of the cellulose is reduced, resulting in a correspondingly reduced mechanical strength of the produced therefrom Covers leads.

Currently the viscose process is particularly widespread. Therein is the cellulose with caustic soda and then with carbon disulfide implemented. In this way, a yellow-orange cellulose xanthate solution (= Viscose), which is then extruded through a spinneret becomes. This process can also be fiber-reinforced Make covers. This is usually a Fiber material - particularly preferred is hemp fiber paper - first formed into a tube, which is then inside, outside or Viscose is applied on both sides (also called as internal, external or double viscose). With help of precipitating and washing baths becomes the cellulose xanthogenate then regenerated to cellulose. However, the viscose process requires technically complex and correspondingly expensive devices for cleaning exhaust air and waste water.

Finally, the (now outdated) copper oxide ammonia process is also known, in which the cellulose is complexed by Cu (NH ₃ ) _m (OH) ₂ and thus rendered soluble. This process is technically complex and polluting.

The traditional methods of breaking the cellulose break the polymer backbone of the cellulose, thereby regenerating Products arise, the molecules average about 500 to 600 glucose units per molecule. Furthermore the processes used for pulp production are over Xanthate intermediates. They tend to have some residual derivatives bound to glucose residues, e.g. B. containing xanthogenate groups Cellulose, leave behind.

In other processes use cellulose derivatives which are easier to dissolve than the cellulose itself. These derivatives contain substituents which are bonded to the cellulose and often still present in the finished cellulose product. These are in particular cellulose esters, such as cellulose acetate. in principle Other substituents can also be bonded to the cellulose be, for example, alkyl, carboxyalkyl and / or hydroxyalkyl groups (especially hydroxyethyl or hydroxypropyl groups). Generally are organic groups with, independently of each other, respectively to name one to six C atoms. Derivatization is common with a decrease in the average degree of polymerization DP linked to the cellulose chains.

Later were N-oxides of tertiary amines, in particular N-methyl-morpholine-N-oxide (NMMO) monohydrate, used as a solvent for cellulose. The cellulose purely physically dissolves in NMMO monohydrate, without itself thereby chemically changing. It only finds a relative low degradation of the cellulose chains and thus almost no reduction the average degree of polymerization DP instead, z. B. from about 750 to about 700. From the solutions can be through Extrude into a precipitation bath Make threads and foils. The precipitation bath generally consists of a cooled diluted (about 10 to 15 wt .-%) aqueous NMMO solution. This can be the NMMO recover virtually quantitatively again. solutions of cellulose in hydrous N-methyl-morpholine-N-oxide (NMMO) However, when exceeding certain Ignite temperature limits. You can under Even spontaneously at temperatures above 130 ° C decompose explosively. Therefore, the usable thermal workspace highly limited. In addition, the maximum possible concentration of dissolved cellulose relative low, usually less than 12 wt .-%, based on the Total weight of the solution.

In the US Pat. No. 6,824,599 B2 and the US Pat. No. 6,808,557 B2 describes a method for dissolving cellulose in anhydrous ionic liquids, which have their melting point at a temperature of about -80 to + 100 ° C. The ionic liquids are preferably pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrazolium, oxazolium, [1,2,3] triazolium, [1,2,4] triazolium, thiazolium, Piperidinium, pyrrolidinium, quinolinium or isoquinolinium salts, each of which may also be substituted. The anions in these salts are preferably halide ions (chloride, bromide, iodide), Perchlo rat, cyanate, thiocyanate or (C ₁ -C ₆ ) carboxylates. Particularly suitable for dissolving cellulose is 1-butyl-3-methyl-imidazolium chloride. In it, relatively much cellulose can be solved. Cellulose concentrations of up to 25% by weight, based on the weight of 1-butyl-3-methylimidazolium chloride, are disclosed. However, salts with tetrafluoroborate or hexafluorophosphate anions do not dissolve cellulose according to the US patent. Also described are shaped articles, such as films or tubes, which are produced from the cellulose dissolved in the ionic liquids. They are obtained, for example, by extruding the cellulose dissolved in an ionic liquid into a water bath. The organic salts used to prepare the ionic liquids are very readily water-soluble and can thus be easily removed from the cellulose moldings.

In the DE 10 2004 031 025 A1 discloses a process for the preparation of moldings from press-moist cellulose, in which the cellulose is dissolved in an ionic liquid of 1,3-dialkylimidazolium halides, such as 1-butyl-3-methylimidazolium chloride or 1-ethyl-3-methylimidazolium chloride, is dissolved with the addition of basic substances. The solution can then be spun into threads or formed into shaped bodies. Here, a spin pack, designed as a heat exchanger distributor plate and spinning capillary to be used. The fibrous or flat shaped bodies or staple fibers should also be refined.

Tubular films of chemically derivatized and then regenerated cellulose or precipitated cellulose as artificial sausage casings are usually not chewable and therefore not suitable for consumption. With the amine oxide method, however, it has been possible to produce edible or at least chewable Kunstdärme. The cellulose was mixed with proteins and fillers ( DE 101 295 39 A1 ). Until then, commercially available artificial casings based on collagen were known to be eaten together.

in the In connection with the present application, the term "sheaths", especially with sausage casings, synonymous with "intestines" or "hoses" used.

Starting from a state of the art, as in US Pat. No. 6,824,599 B2 and in DE 10 2004 031 025 A1 was presented, the object was to modify the moldings described therein and their production process so that they can be used as food casings, especially as artificial sausage casings. In the food casings, the cellulose should have a substantially uniform structure. The cellulose chains should also not be oriented in a preferred direction. The process for producing the food casings should be as simple as possible and bring with it little, if possible no problems with contaminated wastewater or contaminated exhaust air. It should not pose a risk of explosion and if possible no environmental impact from him.

It It has now been found that food casings Cellulose-based with an advantageous structure and advantageous other properties of solutions of cellulose in ionic Obtain liquids, especially from solutions in liquid imidazolium salts.

object Accordingly, the present invention is a food casing based on cellulose, characterized in that it from a solution dissolved in an ionic liquid Cellulose by extrusion and subsequent precipitation is available.

To the Precipitation of the cellulose is preferably water or an aqueous solution, the - Setting special properties - Additives in dissolved May contain form.

The Extrusion is generally not directly into the precipitation bath, but the extruded solution goes through first an air gap in which it stretches in the longitudinal direction can be. Tubular extrudates can an internal gas pressure additionally in the transverse direction be stretched. After extrusion and longitudinal or longitudinal and transverse stretching, the cellulose is in one precipitated (aqueous) precipitation bath.

The term "cellulose" within the meaning of the present invention comprises cellulose in various forms, optionally including common impurities of the cellulose used - as may be contained in wood pulp, for example - and / or degradation products of the cellulose. The proportion of cellulose derivative (s) may be up to 60% by weight of the cellulose content and may be proportionally subsumed under the term "cellulose". Since the cellulose derivatives have very different properties, the properties of the precipitated cellulose can be adjusted in a precise fit by targeted addition of at least one cellulose derivative. As cellulose derivative (s) can / Kings in particular at least one cellulose ester or / and at least one cellulose ether such as cellulose carboxylate (s) are added to the spinning liquid and / or the precipitation bath, among others particularly preferably benzylcellulose, carboxyalkylcellulose such as carboxymethylcellulose, cellulose acetate, especially cellulose triacetate, cellulose acetobutyrate, cellulose butyrate, cellulose carbamate, cellulose nitrate, Cellulose carboxylate, cellulose propionate, cyanoethylcellulose, hydroxyalkylcellulose such as hydroxymethylcellulose and / or alkylcellulose such as methylcellulose. In this case, different degrees of substitution for the derivatives can be selected. For example, adding a cellulose acetate to the spinning liquid or / and to the precipitation bath can give the cellulosic casing particularly high strength and hardness. It is possible to partially or completely derivatize the cellulose already dissolved in an ionic liquid, for example by reaction with acetic anhydride and / or other acylating or alkylating agents, and then further processing the solution in the manner described.

"Ionic liquids" and processes for their preparation are known per se ( P. Wasserscheid, P. Keim, Angewandte Chemie 112 [2000] pp. 3926-3945; published simultaneously in Angewandte Chemie, Int. Ed. 39 [2000] p. 3772 ). In general, anhydrous salts of organic, nitrogen-containing bases are generally referred to, which have a melting point of less than 200 ° C, preferably less than 120 ° C, more preferably less than 60 ° C or even less than 10 ° C. They are already liquid at comparatively low temperatures and act as good solvents for many substances. Many ionic liquids can cellulose at temperatures in the range from 10 to over 200 ° C, in particular in the range from 30 to over 180 ° C or from 60 to over 150 ° C, particularly preferably at temperatures of 80 ° C or from 120 ° C to to their decomposition temperature, dissolve. Ionic liquids have virtually no vapor pressure. There is therefore no loss due to evaporation.

preferred ionic liquids contain as cations 5- or / and 6-membered heterocyclic aromatic rings or ring systems with one or more nitrogen atoms in the ring or in the rings. Preferably they contain one or two aromatic rings. To name in particular Pyrimidinium, pyrazinium, imidazolium, quinolinium and isoquinolinium ions or / and their salts. Oxygen, sulfur or other heteroatoms preferably do not occur as ring atoms in the heterocyclic aromatic rings or ring systems of these ions or compounds in front. Also, the nitrogen atoms in the ring or in the ring system should not be tied directly to each other.

All it is particularly preferred that at least one ionic liquid, in the spinning liquid and / or in the precipitation bath is used, a compound is as a cation one or two 5- or / and 6-membered aromatic rings each having one or two or three nitrogen atoms per ring, wherein the nitrogen atoms in the Ring or in the rings are not directly bonded to each other and where no other heteroatoms than nitrogen in the ring or in the Rings occur, wherein the nitrogen atoms in the ring or in the Rings are the same or different independently of each other may be substituted with at least one substituent, these substituents in turn are independent each other the same or different with at least one substituent may be substituted.

Because of their particularly good solubility for cellulose imidazolium salts or corresponding ions are preferred. The nitrogen atoms in the heterocycle may be the same or different substituted. Preferred substituents are straight-chain or branched (C ₁ -C ₂₀ ) -alkyl group or straight-chain or branched (C ₁ -C ₂₀ ) -alkoxy group, especially methyl, ethyl, propyl, isopropyl, cyclobutyl, butyl, isobutyl, sec Butyl, tert-butyl, cyclobutyl, pentyl, cyclopentyl, hexyl, cyclohexyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, (C ₁ -C ₆ ) alkoxy groups or (C ₁ -) C ₈ ) alkyl groups. The alkyl groups or / and the alkoxy groups may in turn be substituted independently of one another: they may in particular be chlorinated, perchlorinated, fluorinated or / and perfluorinated, but they may also have in their place or in addition other substituents which lead to an increased ionic strength.

Particular preference is given to ionic liquids comprising salts with heterocyclic cations which have at least one nitrogen atom in the ring or in the rings and are optionally substituted identically or differently with at least one substituent. Here, preferably, at least one substituent is a straight-chain and / or branched (C ₁ -C ₂₀ ) alkyl group and / or a straight-chain and / or branched (C ₁ -C ₂₀ ) alkoxy group. It is particularly preferred in this case that the at least one substituent in turn is substituted independently of one another.

The anions of at least one ionic liquid and / or to these cations are in particular halide ions such as fluoride, chloride, bromide and / or iodide ions; Carboxylate ions, perchlorate ions and / or pseudohalide ions in particular, such as cyanate ions and / or thiocyanate ions. chloride ions or / and fluoride ions or chlorides and / or fluorides are generally preferred for the halide ions or corresponding compounds. Suitable carboxylate anions are in principle the anions of mono-, di-, tri- or / and polycarboxylic acids, preferably with 1 to 30 C atoms, particularly preferably with 2 to 20 C atoms. These include, for example, anions of aliphatic carboxylic acids which optionally also have hydroxyl group (s), in particular acetate, trifluoroacetate, adipate, citrate, formate, fumarate, hydroxyacetate, itaconate, glutarate, lactate, Propionate, succinate, tartrate, methanesulfonate, trifluoromethanesulfonate or para-toluenesulfonate anions. In general, an increase in the anion with the same charge leads to a lowering of the melting point of the ionic liquid.

Especially preferred ionic liquids are from 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methyl-imidazolium chloride, the latter has the advantage of lower toxicity. These Salts show in DSC studies in addition to a melt peak in Range of about 60 to 90 ° C in the subsequent Temperature range up to about 250 ° C no further reactions. In the ionic liquids can be up to about 40% by weight, based on the weight of the solution, of cellulose be solved. The maximum solution to be brought Quantity also depends on the DP of the cellulose. The ionic Liquids show virtually no vapor pressure, so that gaseous Emissions are avoided. That in production Personnel is therefore only to a very small extent potentially exposed to hazardous substances. In addition, so far none Danger of explosion when using ionic liquids been found.

Solved is the cellulose - depending on the type of ionic Liquid - preferably at temperatures in the Range of 10 to 180 ° C, more preferably in the range from 60 to 160 ° C, most preferably in the range of 100 to 130 ° C. Generally, cellulose can be used in ionic liquids especially depending on substances and temperature in quantities in the range be dissolved between 3 and 40 wt .-%, preferably in Range between 5 and 30 or between 6 and 25 wt .-%, especially preferably in the range between 8 and 20 or between 10 and 16 wt .-%. In the most preferred 1-butyl-3-methyl-imidazolium chloride are preferably about 8 to 22 wt .-%, in particular about 10 to 16 wt .-%, dissolved in cellulose. This ionic liquid decomposes only at temperatures of about 213 ° C, so that a very large temperature range as a work area can be used for loosening and spinning.

Description of the general manufacturing process of food casings:

As starting materials for the cellulose to be dissolved in principle all types of cellulose, regardless of the sources of raw materials, in question. Generally preferred are cotton cellulose and / or wood cellulose, such as cellulose from cotton, birch, beech, spruce, pine, pine and / or poplar. As starting materials for the cellulose to be dissolved are basically all types of cellulose regardless of the recovery process such. As sulfate cellulose, sulfite cellulose, ASAM cellulose and / or cellulose from ^® Organosolv method in question. These types of cellulose can be mixed as desired.

Of the average degree of polymerization (DP) of the cellulose may be in wide limits vary. He is often in a range of 400 to 1400, often in a range of 500 to 1000, very often in a range of 550 to 900, each determined by the Cuoxam method. Degradation of the chain molecules of the cellulose, d. H. a Diminution of the DP occurs after dissolving in the ionic Liquid only to a small extent or practically not at all one. Generally, the solubility of the cellulose in the ionic liquid, the lower, the higher her DP is.

The Spinning solution should be as homogeneous as possible and brought largely or completely degassed state become. This often requires intense or / and longer Stir, in particular for 0.5 to 12 hours. The spinning solution is preferably previously degassed, filtered and transferred to the spin container, especially with casings for edible intestines or peeling intestines. She becomes from the spinning container then fed to the extrusion die.

The Dope may be combined with one or more stabilizers if required are added, preferably in each case from 0.01 to 8 wt .-%, in particular each with 0.5 to 5 wt .-% of at least one stabilizer, the reduces oxidative degradation of the cellulose. As a stabilizer For example, hydroquinone or / and a phenol derivative can be added become. One dissolved in an ionic liquid Cellulose or a derivative thereof has a significantly higher thermal stability and can be higher temperatures (up to about 200 ° C) are exposed as a dissolved in NMMO, and without the risk of deflagration of the solvent, like the NMMO.

The chemical composition of the spinning solution can - in particular depending on the intended use of the case - within wide limits be varied and contain very different substances. This usually also varies some of the processing conditions and parameters.

The Dope contains, in addition to an ionic liquid, which is liquid at the selected temperature and the main constituent of the spinning solution, generally 8 to 40 wt .-%, preferably or 12 to 30 wt .-% cellulose, and optionally 0.05 to 10 wt .-%, preferably 0.3 to 8 wt .-%, of Stabilizer (s) included. It is essentially anhydrous, d. H. it contains less than about 1% by weight of water, and in the essential also free (<1 Wt .-%) of aliphatic organic amines, such as ethylamine, diethylamine or Triethylamine. The ionic liquid can be made from the spinning solution recovered virtually quantitatively.

A edible or chewable according to the invention Covers contains expedient 3 to 60 wt .-%, preferably 6 to 42 wt .-%, of at least one filler in particular for interrupting the structure of the cellulose and 5 to 50% by weight, preferably 8 to 42% by weight, of at least one protein and / or networked protein. If necessary, it can be 0.1 to 25 Wt .-%, preferably 0.8 to 18 wt .-%, of at least one organic Polymer or / and organic copolymer. To achieve special properties, the shell can also 0.05 to 20 wt .-%, preferably 0.3 to 16 wt .-%, of at least one hydrophilic Additive, 0.1 to 8 wt .-%, preferably 0.4 to 6 wt .-% and / or at least one organic and / or inorganic dye and / or Pigments included. To permanently soften the covers, it can be 0.1 to 12 wt .-%, preferably 0.5 to 10 wt .-%, based on their dry weight, at least one primary plasticizer contain. Such primary plasticizers are, for example Alginates, chitosan or similar hydrophilic, high molecular weight Polymers of natural origin.

With reference to the spinning solution, the quantitative ranges listed in the following table thus result: general% by weight preferably wt.% most preferably wt% Components of the spinning solution 3-40 10-32 14-25 Cellulose and / or cellulose derivative 30-90 38 - 78 46 - 66 ionic liquid 0.01-1 0.1-0.5 0.2-0.3 water optional 0.01-8 0.3-6 1-4 Stabilizer (s) 1-40 2-32 3-24 Filler (e) 0.1-20 1-16 3-12 at least one protein or / and cross-linked protein 0.1-15 1-12 3-8 an organic polymer and / or organic copolymer 0.1-10 1-8 3-6 at least one additive, in particular a hydrophilic additive , 05-6 0.05 0.05-6 0.5-4 at least one dye and / or pigment 0.5-30 2-24 3-18 at least one primary plasticizer

When primary (i.e., not leachable from the finished shell) Plasticizer may contain at least one high molecular weight substance, such as alginate, Chitosan or / and a polysaccharide added to the spinning solution become. As a secondary (i.e., leachable) plasticizer can be a water-soluble, low molecular weight, organic Substance such as glycerine in the drop bath and / or a subsequent softener bath be added.

Preferably is the proportion of cellulose derivative (s) 1 to 60 wt .-% the sum of cellulose and cellulose derivatives, particularly preferred 8 to 35 wt .-%. Contains as a solvent mixture the spinning solution preferably 88 to 99.5 wt .-% ionic liquid and less than 1% by weight of water, the water being from the residual moisture the cellulose and optionally other additives can. In addition, contain the inventive Fiber casings additionally fibers or fibrous structures, in particular a nonwoven or fiber paper (for example, a wet-strength hemp fiber paper), as mechanical Gain.

It can select such ionic liquids in which the cellulose is already at low temperature, in some cases, even at room temperature, dissolves. Preferably, the solvent used as dissolves ionic liquid, the cellulose in the temperature range from 10 to 160 ° C, more preferably in the temperature range from 15 to 80 ° C, especially at about room temperature. Further, an ionic liquid may be selected which dissolves a high amount of cellulose. About that In addition, the ionic liquids are also highly suitable also to dissolve the other constituents of the spinning solution, for example, primary plasticizers, proteins or dyes, and usually even in high concentrations.

The Precipitation bath (= spinning bath) preferably contains water or a dilute aqueous solution. Generally, the precipitation bath contains a solvent, in which cellulose is insoluble and precipitated and at the same time the ionic liquid the envelope absorbs. The ionic liquid can recovered practically quantitatively from the precipitation bath which is necessary for cost reasons alone. In addition, this bath can be tempered so that the extruded and blown casing further cooled becomes. In addition, the precipitation bath can additional additives are added, in particular those which the precipitation conditions and thus the structure of the precipitated Modify cellulose.

The Precipitation bath containing the dissolved cellulose tube the outside surrounds and to its precipitation, solidification and stabilization can, in some cases have a different concentration and / or composition than the Fällbadlösung used in the interior of the cellulose tube. This makes it possible, the precipitation conditions to do things differently inside than outside. As a result of it can get a shell with unsymmetrical properties become.

To the spinning bath usually passes through the spinning bath several more water-filled skimmers, where leftovers be removed on ionic liquid. After that, before the casing is dried, she can still do a softening cream run through. This contains a dilute aqueous Solution of a secondary plasticizer, as a rule Glycerol. In addition, the softener blade can still be antimicrobial containing active agents.

The chemical composition of the finished shell can, depending on Purpose, vary within wide limits and next to the cellulose include very different components.

The finished casing generally contains from 30 to 95% by weight, preferably 40 to 90% by weight, based on the total dry weight, on cellulose, including any cellulose derivatives present. In particular embodiments, it may be up to 50% by weight, preferably 8 to 42% by weight of optionally crosslinked protein (s), up to 25 wt .-%, preferably 0.8 to 18 wt .-%, of other organic Polymers or copolymers, up to 20% by weight, up to 8% by weight, preferred From 0.4 to 6% by weight, of dye (s) or / and pigment (s), up to 18 wt .-%, preferably 0.5 to 15 wt .-%, of plasticizer (s), wherein this may be primary or / and secondary plasticizer can. The sheath is generally wetted, if necessary even pre-wetted ready for filling. She points accordingly generally a water content of 8 to 30 wt .-%, preferably from 12 to 20 wt .-%, based on the total weight.

Further the finished case can still be on one or both if needed Pages coated and / or impregnated. Leave it For example, the water vapor and / or the oxygen permeability to adjust. It can also be the strength of liability to the Surface of a food in the shell set become. This can be an adhesive impregnation, which is the adhesion the shell, or a so-called "easy-peel" impregnation, which reduces the adhesion, so that the shell peel off easily. It can Also, color, flavor and / or odorants are applied, for example Liquid smoke, in the course of further processing on the food, which is preferably a sausage meat transferred becomes.

The Sheath is preferably a seamless tubular Foil, for example, as sausage casing, but if necessary for other foods, such as dairy products, vegetable products, Semi-prepared meals and ready meals can be used. The Cases of the invention have a very much smoother surface than sheaths that after Viscose were prepared. Your surface is even smoother than that of sheaths made by the NMMO process were obtained. The cellulose peeling casings according to the invention can be deducted accordingly particularly easy. In general, you can apply an additional impregnation omitted the inside to improve the peelability become.

Preferably, the method and the composition of the spinning solution and the precipitation bath are chosen so that the cellulose does not or only slightly crystallized. Particularly preferred are the method and the composition of the spinning solution and the precipitation bath chosen so that the cellulose does not crystallize or substantially not crystallized, without that therefore a special addition to the corresponding solution must be added. A crystallized cellulosic shell is typically brittle and therefore undesirable. The degree of crystallization can be influenced by varying the precipitation conditions. By defined longitudinal and transverse extension of the shell, the tear strength can also be optimized depending on the direction.

The Cellulose-based shaped bodies according to the invention have proved to be much more homogeneous than z. B. in the viscose process prepared shaped bodies based on cellulose. Due to the Precipitation conditions from the solution show the Cellulose chains practically no more preferred direction, so that the Strength of the shell in the longitudinal direction (= machine direction) and is substantially equal in transverse direction. The is an essential difference to one after the NMMO procedure manufactured case. Compared to other dissolution methods for cellulose arise because of the possibility dissolve significantly higher concentrations of cellulose, much larger scope for the design of the molded body structure and for the process variation. With increasing concentration of cellulose in the ionic liquid decreases the swelling capacity the envelopes thus obtained.

Of the Degradation of the average degree of polymerization DP is clear lower than other cellulose dissolving processes. The DP usually does not decrease by more than 40, d. H. the degradation is significantly lower than in the amine oxide process with NMMO monohydrate as solvent. Compared to other Solvents is a higher proportion of dissolved Cellulose possible. This can wrap with increased mechanical strength obtained accordingly also have a higher clip and shear strength than before known cellulose casings. By the longitudinal, if necessary Querverstreckung takes the strength of the shell considerably to.

Except the higher thermal stability and thus safety the manufacturing process brings the at least one ionic liquid, in particular 3-butyl-1-methylimidazolium chloride, a number of others decisive advantages over the previously known Method. Due to the much higher dissolution temperature are above all also higher cellulose concentrations in the solution possible. This can be done while felling optionally achieve different structures. The variations rise by increasing the precipitation bath temperatures.

By the extremely low vapor pressure of the ionic solvents and thus reduced emissions is the process very environmentally friendly; In addition, the health of the staff is essential less at risk than any other procedure.

The food casings according to the invention can be designed in various ways. Below are some of the possible variants more accurate and then disclosed in detail in Examples. in this connection it is a) peeling intestines, b) cellulose casings, c) fiber casings or d) edible casings. The procedure for the preparation of a fibrous cellulosic casing is with the Process for cellulose casings, peeling casings and edible intestines similar only in the rough flow chart. Rather, the individual conditions vary depending on the purpose, Composition of spinning solution, precipitation bath, and / or Shell as well as characteristics of the shell strong, so that all four types of sheaths mentioned under a) to d) distinguish significantly. For all these variants apply the above general statements.

a) cellulose casings without fiber reinforcement, cellulose casings:

cellulose casings are used in conjunction with the present invention as surface area or tubular food casings Understood cellulose base, which by extrusion ("spinning") of cellulose dissolved in ionic liquid can be produced. They generally do not contain any Fiber reinforcement and have a relatively small caliber. They are from sausage producers - usually on fully automated plants - peeled off the meat, z. B. in the production of Frankfurter sausages.

The Cellulose usually comes from wood or cotton. at rising temperature, the cellulose is stirred in the submitted solvent entered until the required Final temperature (for example 120 ° C) a clear, viscous Solution is obtained. The spinning solution then becomes preferably degassed, filtered and transferred to the spin container.

The spinning solution preferably contains from 3 to 40% by weight of cellulose (including any cellulose derivatives present), preferably from 8 to 25% by weight, based in each case on the total weight of the spinning solution, in an ionic liquid. To increase the suppleness and reduce the tendency to crystallize The cellulose solution, the spinning solution may optionally be mixed with other organic polymers or copolymers. That example, copolymers of methyl vinyl ether units and / or maleic anhydride units (for example, available under the name Gantrez ^®) and / or Zuckerester. The proportion of these further compounds may be up to 25 wt .-%, preferably 1 to 20 wt .-%, particularly preferably 3 to 12 wt .-%, in each case based on the weight of the cellulose.

The Temperature of the spinning solution is appropriate in the range of 100 to 150 ° C, in particular in the range of 110 to 125 ° C, held. The composition as well as the Temperature significantly determine the viscosity and the Flow behavior of the spinning solution.

The Cellulose-containing spinning solution is using an annular die extruded. The extrusion temperature corresponds approximately to the temperature the spinning solution in the spinning container and is for example in the range of 110 to 120 ° C. The annular gap is in general 0.1 to 2.0 mm wide, preferably 0.2 to 1 mm. The width of the gap must be adapted to the delay.

When Delay is the quotient of outflow velocity and Referred to withdrawal speed of the hose. The delay is preferably at values in the range of 2.3 to 0.43, the outflow velocity preferably at values in the range 0.05 to 2.0 m / s, in particular at values in the range of 0.25 to 1.70 m / s. The discharge velocity is also determined by the caliber. On the extruded tube Only a small amount of tension should be exerted longitudinally be, preferably no higher train than he is through Dead weight comes about.

After that cross-stretched in the air by blow molding. The "air route", d. H. the distance between annular gap and surface of the Precipitation bath in which the blow-molding takes place has been preferred a length in the range of 1 to 50 cm, more preferred in the range of 2.5 to 35 cm or in the range of 5 to 20 cm. she depends largely on the caliber of the hose. Blowing is caused by compressed air and / or other gases through openings in the nozzle body in get inside the hose. This increases the transversal strength of the hose due to the transverse stretching considerably. Depending on the internal pressure, the diameter of the blown Hose up to 100% larger or up to 50% smaller, preferably up to 80% larger or up 20% smaller than immediately leaving the annular gap. Prefers the diameter of the blow-molded tube is 10 to 100% larger, more preferably 20 to 80% greater than immediately when leaving the annular gap.

To diminished the entry of the shell in the precipitation bath the diameter of the hose. Preferably, the Fällbadlösung passes by appropriate devices in the interior of the cellulose tube. As a result, the hose solidifies faster. At the same time prevents sticking of the insides. By different Temperatures and / or compositions of the precipitation bath for Inside and outside, the cooling behavior and affects the interface of the shell targeted become. The liquid level inside the hose should not be much higher or higher in many embodiments lower than that of the surrounding precipitation bath, whereby nevertheless over Temperature differences and / or differences in the Composition of the precipitation bath between inside and outside the properties of the shell can be modified. The precipitation bath itself is an aqueous solution, often 5 to 50 wt .-%, often 8 to 20 wt .-%, of at least contains an ionic liquid. The temperature of the precipitation bath is preferably in the range between 0 and 80 ° C, more preferably in the range between 40 and 70 ° C. It can determine the structure of the cellulose film influence. In many molding variants it is desired that the structure of the film of the moldings as possible is even and that the cellulose not crystallized, since the shell crystallized through Cellulose becomes brittle. In particular for further consolidation the optionally flattened hose then preferably passes several more skimmers. The first skimmer contains preferably 5 to 40 wt .-%, in particular 10 to 20 wt .-% of at least an ionic liquid; in the following skimmers preferably decreases its share. It has proven to be advantageous the temperature from one skid to the next to reduce, for. B. up to about 60 to 70 ° C in the last Reduce skid.

At this so-called precipitation distance over several runners close often filled with water skimmers in which traces of at least one ionic liquid are removed. The temperature of these skids is preferably in the range between 15 and 70 ° C, more preferably in the range between 40 and 60 ° C. Often followed by a Weichmacherkufe containing an aqueous solution of at least one plasticizer for cellulose. For example, polyol (s) or / and polyglycol (s), but in particular glycerol, are suitable for this purpose. The aqueous solution preferably contains from 4 to 30% by weight, more preferably from 6 to 15% by weight, of plasticizer (s). The temperature of this solution is preferably in the range between 20 and 80 ° C, more preferably in the range between 30 and 70 ° C.

After that the hoses are dried when inflated, for example, passing through a hot air dryer can be. Appropriately, will then dried at decreasing temperature, z. B. of about 150 ° C. at the entrance or beginning to about 80 ° C at the exit or end. By an increased internal pressure during drying can at Need an additional cross-orientation can be achieved.

During drying, the swelling value of the cellulose casing according to the invention preferably falls from values in the range of 200 to 240% to values of 130 to 180%, particularly preferably to values of 140 to 170%, depending on the drying conditions and the content of plasticizer (s), such as glycerol. In comparison, the swelling value of a casing produced by the viscose process drops from 180 to 200 to 130 to 140, and that of a shell produced by the NMMO process from 160 to 180 to 120 to 130. The hose is then moistened until the water content at preferably 8 to 20 wt .-%, particularly preferably 15 to 18 wt .-%, is located. Subsequently, the sheath can now be laid flat with the help of a pair of nip rolls and wound up if necessary. Depending on the caliber and depending on the water and plasticizer content, the finished hoses have a basis weight preferably in the range from 20 to 150 g / m ² , particularly preferably in the range from 30 to 120 g / m ² . For a glycerol content z. B. in the range of 20 to 22 wt .-% and at a water content z. B. in the range of 8 to 10 wt .-% usually results in a basis weight in the range of 30 to 120 g / m ² , preferably in the range of 35 to 80 g / m ² . The basis weight generally increases with increasing caliber. The burst pressure is also dependent on the caliber, with smaller caliber have a higher burst pressure. In general, the burst pressure is in the range of 12 to 75 kPa. For a hose with a caliber of z. B. 16 mm is the burst pressure at about 60 kPa, with a caliber of z. B. 30 mm at about 40 kPa, with a caliber of z. B. 140 mm at about 15 kPa. The burst pressure is determined in each case on a watered sheath.

The Tubular cellulose casings according to the invention can be on their inside and / or outside with an impregnation be provided, for. B. with a liquid smoke impregnation or / and with an "easy peel" internal preparation.

If the cellulose hoses used as sausage casings can be, the filling caliber about inner diameter of the Ring gaps are equal or up to 120% higher. The filling caliber preferably exceeds 10 to 80% the inner diameter of the annular gap.

Of the average degree of polymerization of cellulose lies after these Process steps preferably in the range of 300 to 750, often in the range of 400 to 700, very often in the range of 450 to 650, but is often only 0 to 40 DP lower than the average Degree of polymerization of the cellulose added to the spinning solution.

One significant advantage of the tubular according to the invention Cellulose casings lies in the uniform Structure and thus uniform density, the Cases is achieved. Cases made by the viscose process are manufactured, in contrast, have a density gradient on, at which a higher density at the surface and a lesser occurs inside.

The finished shell can be made entirely of cellulose. However, it preferably contains 60 to 99 wt .-%, especially preferably from 75 to 97% by weight, in particular from 80 to 95% by weight, of cellulose, in each case based on the dry weight.

Of the Degree of stretching of the cellulose casing is preferably from about 1: 1.1 to 1: 2, more preferably from 1: 1.2 to 1: 1.8 in each case in the longitudinal and transverse directions, wherein the degree of stretching longitudinally not identical with the one in the transverse direction have to be. The shell is preferably a seamless one Tubular film that can be used as a sausage casing. The peeling intestines according to the invention are excellent as sausage casings, as they are very shake well and after filling with the sausage meat and peel off the broth of the sausages well to let.

b) Cellulose fiber casings:

The process for producing a cellulosic fibrous casing is similar to the process for cellulose casings, peeling casings and edible casings only in the rough flow diagram. Rather, the individual conditions can vary greatly depending on the purpose and composition. In addition, however, fibers or / and at least one fibrous insert (fiber insert) are required here. The insert inserted in the case is introduced, is preferably an insert based on fibrous paper, fiber paper and / or non-woven fabric, such as a paper made of sisal or hemp fibers. Especially advantageous are long hemp fibers. They may optionally be conditioned and / or coated, in particular to make them wet-strength and / or to effect a stronger adhesion of the precipitated cellulose to the fiber paper. Preferably, the insert is initially withdrawn from a roll. If necessary, they are or were previously treated with emulsifiers, wetting agents and / or anchoring agents. They are then formed into a tubular casing with overlapping longitudinal seam. It is preferably glued in front of the nozzle block. Before the nozzle block, the insert preferably passes through a heating section in which it is approximated by hot air to the temperature of the extruded cellulose-containing solution.

Generally The methods and devices are designed to be for coating liners formed with tubing with solutions of cellulose in at least one ionic liquid are well suited and a uniform penetration allow the deposits.

The Device for producing a reinforced by an insert Cellulosic tube by extruding a solution of Cellulose in at least one ionic liquid the insert, with a nozzle block and with a precipitation bath is preferably characterized by the fact that a supply roll for the insert, a pulley with a device for applying additives to the insert, a route for heating the deposit or / and a forming line in which the deposit to a Hose is formed with overlapping longitudinal seam, are connected.

in the Nozzle block is at least one annular nozzle, which is heated with a heating medium; Inlet, suction tube and the conduit for the supporting air can are guided centrally through the caliber ring, the preferably concentric with the annular nozzle inside the tube is arranged and preferably forms with this an annular gap, through which the hose passes. The hose goes through the nozzle block, optionally an adhesive device for bonding the longitudinal seam is connected upstream and the one Ring nozzle contains, through the nozzle gap the cellulose-containing solution is extruded. Preferably In the nozzle block is the cellulose-containing solution applied to the deposit and then penetrates this. By the Nozzle block should be passed through the tubular insert become. Into the inside of the hose is after leaving the nozzle block if necessary, pressure-controlled support air is injected. Of the Hose can via a heated caliber ring be passed, which flows through a heating medium can be. The spinning solution is preferably by the Nozzle block filled in the tube interior and possibly also aspirated, with inlet and suction spatially kept separate. The inlet in the hose is preferably adjustable in height. The suction is preferred made so that the level in the tube up to 20 mm higher and up to 45 mm lower than that Level in the precipitation bath is variable. When extruding the spinning solution based on at least one ionic liquid and Cellulose and optionally containing at least one organic polymer, on at least one organic copolymer, at least one addition to at least one further compound such as B. a sugar ester and / or stabilizer is the deposit together with the cellulose-containing casing formed by the Guided nozzle block. This will be a Einlagenverstärkter Foil tube received. The film tube emerges from the nozzle block from and into a precipitation bath.

Between the exit from the nozzle block and the precipitation bath is preferably in the spinning vat a temperature-adjustable air gap and preferably near the bottom a guide roller. The interior of the film tube can do this with an aqueous solution of at least an ionic liquid filled as precipitation medium to solidify the extruded shell and to stabilize. It is preferably deflected in the precipitation bath and led out of the precipitation bath.

To This method is a uniform penetration the insert achieved with the cellulose solution, so that after passing through the further stages of manufacture a fiber reinforced Cellulose tube is obtained in the cellulose hydrate and fiber insert are firmly connected and can not be pulled apart.

The finished shell contains preferably 50 to 95 wt .-%, particularly preferably 60 to 90% by weight of cellulose, in each case obtained on the dry weight of the shell. The proportion of fiber reinforcement may be about 10 to 40% by weight, preferably about 15 to 25% by weight, respectively based on the total weight.

The fiber-reinforced cellulose tube according to the invention exhibits better properties than a fibrous casing produced by the viscose method, since the cellulose is uniformly densely precipitated without formation of a density gradient or of membranes on the surface. In addition, the surface especially smooth, smoother than a fibrous casing made by the NMMO method. The shell is preferably designed as a seamless tubular film. It is particularly suitable as an artificial sausage casing. In the embodiment without additional barrier coating are particularly suitable for raw sausage, such as salami or cervelate.

c) Edible cellulose-containing intestines:

The previously as a replacement for natural and collagen intestines developed cases have the requirements to be met with regard to chewability and / or toxicological safety not fulfilled. The previously known methods of processing of proteins are also associated with a high number of process stages connected, which is technically complex and therefore expensive equipment requires.

It It was therefore desirable to have an edible, d. H. a suitable for food packaging film for food to create physiologically and toxicologically safe, good chewable and still easy and inexpensive without great environmental impact can be produced. The raw materials for it should be easy and inexpensive available. Preferably it contains cellulose, at least one protein and at least one Filler. It can also be more natural and / or contain synthetic polymers. The filler (eg very finely ground wheat bran) will be in the ionic Fluid usually not or not completely dissolve, so that a dispersion is formed. These However, it can be easily extruded and the cellulose contained therein be readily felled.

Of the Proportion of cellulose is generally from 30 to 70% by weight, particularly preferably from 30 to 65% by weight, based on the dry weight the shell. The protein is preferably a natural, globular protein, especially casein, soy protein, gluten, Zein, hydein or / and pea protein. In principle, each is suitable Protein, which together with the cellulose in the ionic liquid is soluble. The proportion of the protein is preferably Values in the range of 5 to 50 wt .-%, more preferably in the range from 8 to 45 wt .-%, each based on the dry weight of Shell, d. H. the weight of the water and unplasticized, in particular glycerol-free, shell.

Around the water solubility of the protein in the finished envelope to minimize or cancel it has proved expedient proven to crosslink the protein beforehand. That can be for example, by reacting the protein with an aldehyde, methylol, Reach epoxide and / or enzyme. The terms "aldehyde", "methylol" etc. include compounds with more than one carbaldehyde or methylol group. So are Dimethylolethylenharnstoff and Dialdehydes, in particular glyoxal, malonaldehyde, succinaldehyde and Glutaraldehyde, particularly suitable crosslinkers. The networking takes place preferably in the presence of Lewis acids; the temperature in the reaction is preferably in the range of 0 to 160 ° C. In the cross-linking, not only the free amino groups react and the acid amide groups of the protein, but also the imino groups of the peptide bonds and hydroxy groups of serine. A cross-linking enzyme is, for example, transglutaminase. The proportion of crosslinker (s) depends on its type. Often it is 0.5 to 5.0 wt .-%, preferably 1.0 to 3.0 Wt .-%, each based on the weight of the protein.

The Protein that dissolves and that the interactions of the Cellulosic molecules interrupts, that helps Strength of the film reduced to a "chewable" level becomes.

By Addition of filler (s) can be the set second essential property for chewability, namely a correspondingly low elongation at break. The peculiarity is that the shell in the wet Condition has a significantly lower elongation at break than in the dry.

The fillers should dissolve in the spinning solution as little as possible. In the ionic liquid insoluble fillers can be added already at the beginning. Fillers which have a certain solubility in the ionic liquid are expediently mixed with the spinning solution only immediately before the extrusion. If necessary, the solubility of the fillers in the ionic liquid can be reduced by pre-crosslinking. Like the proteins, the fillers disrupt the structure of the cellulose. They reduce the stretchability of the film without affecting its strength. Particularly suitable organic fillers are bran, in particular finely ground wheat bran, ground natural fibers, in particular ground flax, hemp or cotton fibers, cotton linters, chitosan, guar gum, locust bean gum or microcrystalline cellulose. Instead of the organic fillers or in addition also finely divided inorganic fillers can be used. Examples thereof are ground calcium carbonate or powdered SiO ₂ . The proportion of filler (s) is generally 3 to 60 wt .-%, preferably 4 to 50 wt .-%, each based on the dry weight of the shell.

The finished shell contains preferably 20 to 70 wt .-%, particularly preferably from 30 to 60% by weight of cellulose, from 5 to 50% by weight, more preferably 8 to 45% by weight of protein (s) and 10 to 70% by weight, particularly preferably from 30 to 60% by weight of filler (s). This cover is characterized by a good chewiness at the same time high mechanical strength in the dry state out. It is therefore good as an artificial sausage casing suitable for sausages or bratwurst.

Around Being chewable well, the film must not be very wet and also not be tough. By the addition of hydrophilic additives the chewiness can be further improved. The hydrophilic additives are also present in the spinning solution soluble. Particularly suitable are homopolysaccharides and their derivatives - especially their esters and ethers - such as z. As starch, starch acetate, chitin, chitosan or Pectin; Heteropolysaccharides and their derivatives, e.g. Carrageenan, Xanthan, alginic acid and alginates; after all also toxicologically harmless synthetic polymers and / or Copolymers, e.g. As polyvinylpyrrolidone, polyvinyl alcohol and / or Polyethylene oxide (e). The proportion of hydrophilic additives is generally about 0.5 to 15% by weight, preferably 1 to 10% by weight, respectively based on the dry weight of the shell.

Yet can be further modified the shell with the help of primary plasticizers or lubricants. That's for example Triglycerides, waxes, e.g. Shellac, hydrocarbons, rubbers, for example, edible natural rubbers, and / or paraffins.

expedient contains the finished shell also at least a secondary plasticizer, especially glycerol. Of the secondary plasticizer is preferably, as is common practice, in a plasticizer skid immediately before drying the casing added.

It A mixture is created, which turns into a chewable film leaves. This edible film lends itself preferably as a tubular film, which is used as a sausage casing can be.

Of the average degree of polymerization DP of the cellulose used is preferably in the range between 400 and 650, particularly preferred in the range between 480 and 600.

In the process for the preparation of the invention Intestines become the cellulose and the protein in at least one ionic one Liquid dissolved, the solution with the Filler mixed and the resulting suspension extruded through an annular die. The hose is going through drove a precipitation bath containing a heated watery Solution based on at least one ionic liquid contains. The devices that pass the hose through precipitation bath, Wash skids, softener skid and / or dryer should transport work very gently because of the lability of the hose. It is expedient to all deflection rollers in the individual Baths in the finest gradations run separately adjustable.

It has proven to be favorable, the tubular film first pre-dry with hot air in the deflated state. The largely dehydrated tubular film is then on the intended end caliber inflated and with hot air dried to the predetermined final moisture. By doing so Longitudinal and transverse stretching become essential properties like strength and / or caliber constancy, first set. To drying the hose is wound up and then optionally gathered.

The edible casing according to the invention wet exhibits a tensile strength in the longitudinal direction of 3 to 12 N / mm ² , in particular from 4 to 8 N / mm ² . In the dry state, the tensile strength is significantly higher; it is then preferably 15 to 50 N / mm ² , in particular 20 to 45 N / mm ² . The elongation at break in the longitudinal direction is generally 10 to 21% in the dry state, generally 15 to 20% in the wet state. In the transverse direction, the elongation at break in the dry state is 24 to 28%, in the wet state 20 to 23%.

Should the shell can be used as a sausage casing, then it is generally designed as a seamless tubular film. The burst pressure of the tubular film is usually about 15 to 32 kPa.

The edible casing according to the invention preferably has the following mechanical properties, in particular for calibres 20 to 23: Tensile strength: wet: along 6 to 8 N / mm ² , across 4 to 6 N / mm ² , Dry: along 22 to 35 N / mm ² , transversely 18 to 30 N / mm ² . Elongation at break: wet: along 15 to 20%, transversely 24 to 28%, Dry: along 10 to 21%, transversely 20 to 23%. Burst pressure: wet: 18 to 30 kPa.

in the ready-to-fill state has the invention tubular casing generally a moisture content from 8 to 20 wt .-%, preferably 10 to 18 wt .-%.

use finds the tubular according to the invention Cover especially as an artificial sausage casing, in particular for sausages, sausages and small-caliber Brewed and cooked sausages.

Surprisingly succeeded, perfectly suitable edible intestines according to the production method of the invention which do not have the disadvantages of the prior art.

The The following examples serve to illustrate the invention. percentage are weight percentages, unless stated otherwise or from the Context immediately apparent.

Example 1: Cellulose without fiber reinforcement

5 kg of ground wood pulp with an average degree of polymerization DP of 550, determined by the Cuoxam method, was at 5% humidity pre-dried and in powder form with good mixing in a Temperature of 100 ° C to 95 kg of nearly anhydrous 1-butyl-3-methyl-imidazolium chloride added. Under heating and stirring was then after several Hours to get a clear solution.

These Dope was then at a temperature of 95 ° C through a heated annular slot nozzle with a diameter of 20 mm and a gap width of 0.5 mm extruded. Right in the Following this, the extruded tube was blow-molded.

Of the Foil tube first passed through an air gap of 30 mm at a speed of 10 m / min. He got through in it From the inside acting gas pressure querverstreckt, by its own weight the already extruded shell also in the longitudinal direction. In the hose interior was a constantly renewed Innenfällbad consisting of an aqueous solution with about 20% by weight of 1-butyl-3-methyl-imidazolium chloride which is at 90 ° C warmed up, introduced. Then went through the film tube a Fällbadstrecke of 2 m length, where he was diverted half way. The precipitation bath contained a solution of nearly the same composition and temperature as the Innenfällbad. The hose had then a flat width of 38 mm.

The film tube was then passed over a length of 200 m through skids, each Waschkufe several pulleys up and down had. At the end of the last runner water was introduced in countercurrent process. The wash skids were temperature-controlled, and the bath temperature dropped to 60 ° C in the last skid. At the exit of the first runner, the 1-butyl-3-methyl-imidazolium chloride concentration was maintained at about 15% by weight. Finally, the tube was passed through a softening blade containing a 12% glycerol solution at a temperature of 60 ° C. The flat width was 36 mm when leaving the plasticizer skid. Between two nip rolls, the tube was then dried with hot air at a surface temperature in the range of 50 to 80 ° C to a water content of 10 to 12%, based on the weight of cellulose. The basis weight of the tube was 40 g / m ² , the burst pressure 55 kPa, its swelling value 110%. The cross-section through the shell proved to be largely homogeneous. Thus, the Cellulosedarm showed excellent properties.

The Cover was then in a further treatment step moistened to 16 to 18%, with an "easy peel" preparation equipped and gathered into caterpillars. The caterpillars were on an automatic filling machine with sausage meat filled, scalded and smoked. After that the sausages were peeled. The peeling behavior was also excellent.

Example 2: Cellulose fiber intestine

5 kg of ground wood pulp with an average degree of polymerization DP of 550, determined by the Cuoxam method, was at 5% humidity pre-dried and in powder form with good mixing and at a temperature of 100 ° C to 95 kg practically anhydrous 1-Butyl-3-methylimidazolium chloride added. Under heating and stirring was then obtained after several hours a clear solution.

A wet-strength hemp fiber paper of appropriate width was withdrawn from a supply roll and preheated to a temperature of 120 ° C by means of hot air. It was then formed into a tube with overlapping longitudinal seam. Inside the nozzle block, the fiber paper tube was passed over a heated caliber ring, which was flowed through by a heating medium in a regulated circuit. In the Dü Senblock was applied with the coating ring nozzle a spinning solution prepared according to Example 1 on the outside of the fiber paper tube. The spinning solution penetrated the insert. Thereafter, the film tube from the nozzle block and passed first passed through the air gap on the spinning vat, which was held with inwardly acting compressed air in its form. The cellulose was precipitated in the spinning vat. On a roller arranged at the bottom of the spinning runner, the film tube was deflected and led out of the runner again. A continuously renewed precipitation bath of a 20% strength by weight aqueous 1-butyl-3-methylimidazolium chloride solution, which had been heated to 90 ° C., was brought into the interior of the tube.

After passing through the air gap and the spinning vat to the spinning blade deflecting roller, the hose was guided upwards in the flat state. The film tube was then passed through several skids. Overall, the hose went through a distance of 300 m in the skids. At the end of the last runner water was introduced in countercurrent process. The skids were temperature controlled and the bath temperature dropped to 60 ° C in the last skid. At the exit of the first runner, the 1-butyl-3-methyl-imidazolium chloride concentration was kept at 15%. Finally, the tube was passed through a softening blade containing a 12% glycerol solution at a temperature of 60 ° C. Between two nip rolls, the tube was then dried with hot air at a surface temperature in the range of 55 to 90 ° C to a water content of 10 to 12%, based on the weight of cellulose. The basis weight of the dried tube was 80 g / m ² , the burst pressure 135 kPa, the test caliber at 42 kPa 45.1 mm, its swelling value 110%. The cross-section through the shell proved to be largely homogeneous. Thus, the fibrous intestine showed excellent properties.

The Material was gathered to caterpillars, filled with sausage meat and smoked. There were no differences to known fibrous intestine. Thus, the fibrous gut proved to be very good suitable.

Example 3: Edible intestine

9.1 kg wood pulp of pine wood with less than 1% residual moisture were in 114 kg of 1-butyl-3-methyl-imidazolium chloride, as a melt was placed in a stirred tank, stirred, slowly heated to 130 ° C and stirred for about 3 h, until the cellulose has dissolved clearly. This solution contained 7 wt .-% cellulose content.

In this solution was then 4.0 kg zein, i. H. 44% by weight, based on the weight of cellulose, stirred and about Stirred for 30 min until complete dissolution. Subsequently, 6.5 kg, corresponding to 71.4 wt .-%, based on the weight of the cellulose, very finely ground wheat bran evenly stirred into the solution. The dope thus prepared was then passed through at 130 ° C an annular die of 20 mm diameter extruded.

Of the Hose passed an air gap of 10 cm, in which they pass through from the inside acting compressed air was stretched in the transverse direction. Subsequently he went through the spinning bath, where he reached until the pulley was kept in wrinkle-free round shape. In the tube interior was a 20% aqueous 1-butyl-3-methyl-imidazolium chloride solution filled at about 100 ° C. The outdoor bath also consisted essentially of about 20% aqueous 3-Butyl-1-methyl-imidazolium chloride solution at about 100 ° C was maintained.

Of the Hose went through a 3 m long felling line, where he was deflected after passing through half the distance. When leaving The hose was stretched so far across the hose that it did a flat width of 30 mm. Then happened the hose 4 skids with 8 guide rollers at the top and bottom, with a bath depth of 2.5 m and with an air gap of 0.5 m. At the end of the last skid water was introduced, in countercurrent was led. The temperature went from one to the next Run down to a temperature in the range of 70 to 60 ° C lowered. At the end, the tube passed with a 10% glycerol call a temperature of 60 ° C. The flat width was at Leaving the softener skid 20 mm. The hose was then in a nozzle dryer in the inflated state floating pre-dried. Then he was between 2 nip rolls dried in the inflated state with hot air. At the entrance The temperature was 120 ° C, at the output at about 80 ° C. The water content was maintained at 8 to 12%, then increased to 16 to 18%. The cross section through the shell proved to be largely homogeneous. This showed the edible Intestine excellent properties. After that, the finished shell gathered to caterpillars.

The caterpillars were filled with sausage meat, steamed and smoked on an automatic filling machine of the type ^® Frank AMatic. The casing of the sausages was very easy to chew.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 6824599 B2 [0008, 0012]
• - US 6808557 B2 [0008]
• - DE 102004031025 A1 [0009, 0012]
• - DE 10129539 A1 [0010]

Cited non-patent literature

• P. Wasserscheid, P. Keim, Angewandte Chemie 112 [2000] pp. 3926-3945; published simultaneously in Angewandte Chemie, Int. Ed. 39 [2000] p. 3772 [0018]

Claims (19)

Food casing based on cellulose, characterized in that it is obtainable from a cellulose dissolved in an ionic liquid by extrusion and subsequent precipitation. Food casing according to claim 1, characterized in that they in longitudinal and / or Transverse direction is stretched. Food casing according to claim 1 or 2, characterized in that the degree of stretching 1: 1.1 to 1: 2, more preferably 1: 1.2 to 1: 1.8, measured respectively in the longitudinal or transverse direction, is. Food casing according to claim 1, characterized in that the one fiber reinforcement wherein the fiber reinforcement preferably a Fiber paper or non-woven fabric is. Food casing according to claim 1, characterized in that it contains at least one protein and at least one filler and chewable is. Food casing according to claim 1, characterized in that it has a secondary Contains plasticizer, preferably glycerol. Process for producing a food casing according to claim 1, characterized in that cellulose is dissolved in an ionic liquid, the resulting spinning solution extruded and the extrudate is passed through an aqueous bath, that the cellulose precipitates. Process according to claim 7, characterized characterized in that cellulose, optionally together with at least one additional additive, at a temperature in the range from 10 to 180 ° C in at least one ionic liquid dissolved and extruded through at least one annular die is, the resulting tubular casing is stretched in the longitudinal and transverse directions. Process according to claim 7, characterized characterized in that the cellulose and optionally further additives at a temperature of 15 to 80 ° C, preferably at room temperature, be dissolved in the ionic liquid. Method according to one of the claims 7 to 9, characterized in that the extruded shell in an air gap between annular gap and surface the precipitation bath is cross-stretched by glass deformation. Process according to claim 7, characterized characterized in that a fiber reinforcement with Spinning solution is applied. Method according to one of claims 7 to 11, characterized in that in the precipitation bath washed cellulose washed in at least one run and optionally in at least one subsequent bath with at least an additive, preferably a secondary plasticizer treated becomes. Method according to one of the claims 7 to 12, characterized in that the ionic liquid a Compound is that as a cation one or two 5- and / or 6-membered aromatic rings each having one, two or three nitrogen atoms has per ring, wherein the nitrogen atoms in the ring or in the Wrestling is not tied directly to each other and being no other Heteroatoms occur as nitrogen in the ring or in the rings. A method according to claim 13, characterized in that at least one of the nitrogen atoms is substituted, preferably with a straight-chain or branched (C ₁ -C ₂₀ ) alkyl group or a straight-chain or branched (C ₁ -C ₂₀ ) alkoxy group. A method according to claim 14, characterized characterized in that the substituent is in turn chlorinated, fluorinated and / or by at least one other substituent substituted, which has an increased ionic strength the ionic liquid causes. Method according to one of the claims 13 to 15, characterized in that the anions of ionic liquid carboxylate ions, halide ions, Perchlorate ions and / or pseudohalide ions, preferably cyanate ions and / or thiocyanate ions. Method according to one of the claims 13 to 16, characterized in that the ionic liquid Pyrimidinium, pyrazinium, imidazolium, quinolinium or / and Contains isoquinolinium ions. Use of the food casing according to one of claims 1 to 6 as a food casing, preferably as an artificial sausage casing. Use according to claim 18, characterized in that the artificial sausage casing a fiber-free cellulose arm, a cellulose fibrous gut or a edible intestine is.