WO2004058862A1

WO2004058862A1 - Edible flat film

Info

Publication number: WO2004058862A1
Application number: PCT/EP2003/014441
Authority: WO
Inventors: Herbert Gord; Klaus-Dieter Hammer; Rainer Neeff; Klaus Berghof; Markus Eilers; Eberhard Taeger
Original assignee: Kalle Gmbh & Co. Kg
Priority date: 2002-12-23
Filing date: 2003-12-18
Publication date: 2004-07-15
Also published as: AU2003290076A8; WO2004058862A8; AU2003290076A1; DE10261496A1

Abstract

The invention relates to an edible flat film comprising cellulose, at least one filling material which is insoluble in an NMMO spinning solution or which is not dissolved, and at least one other component which is dissolved in the NMMO spinning solution and which impedes the structure of precipitated cellulose. The edible film is made of a spinning material containing NMMO monohydrate, cellulose dissolved therein and at least one other component which is dissolved therein and which impedes the structure of precipitated cellulose (said component is, preferably, a protein), at least one filling material which is not dissolved in the spinning material (preferably wheat bran) and, optionally, non-dissolved fibres. The spinning material is extruded through a wide-slotted nozzle and or an annular slotted nozzle having a large diameter and is then precipitated in a diluted aqueous NMMO bath. The flat film has substantially the same mechanical properties as a collagen shell i.e. it can be chewed just as easily. The film is used, for instance, in packing boiled ham.

Description

Edible flat film

The invention relates to an edible film containing cellulose, at least one filler which is insoluble or not dissolved in an NMMO spinning solution and at least one further component which is dissolved in the NMMO spinning solution and which causes a disturbance in the structure of the precipitated cellulose. It also relates to a process for producing the film.

So far, mainly natural casings, in particular strings made from sheep intestine, and collagen casings have been used as edible or consumable sausage casings. However, such casings are becoming increasingly popular after the appearance of animal diseases (such as BSE) and the misuse of veterinary drugs. Alternatives are therefore sought that are not made from animal material.

An edible or consumable food casing must first of all be easily chewable. This property can be described with the following parameters: The tensile strength in the longitudinal direction in the dry state is approximately 20 to 40

N / mm ² , in the transverse direction in the dry state about 18 to 27 N / mm ² , the tensile strength in the longitudinal direction in the wet state about 5 to 10 N / mm ² , in the transverse direction in the wet state about 4 to 6 N / mm ² , the Elongation at break in the longitudinal direction in the dry state about 10 to 30%, in the transverse direction about 20 to 25 N / mm ² , the elongation at break in the longitudinal direction in the wet state about 10 to 30%

20%, in the transverse direction 24 to 28 N / mm ² , and the burst pressure in the dry state 25 to 30 kPa, in the wet state about 25 to 40 kPa (the values given apply to a collagen intestine of caliber 21). It is important in any case that the tensile strength in the wet state is lower than in the dry state.

The edible sausage casings based on calcium alginate developed as a replacement have proven to be technically inadequate. By interacting with the sausage meat and the brine, the sparingly soluble calcium alginate is gradually converted into the more readily soluble sodium alginate. As a result, the covers lose Stability. Edible intestines based on other natural polymers, such as crosslinked casein, have also not been widely used.

Also known are edible moldings made from a thermoplastic mixture which contains native or modified starch and protein as essential components (WO 93/19125). Starch and protein are linked by a crosslinking agent such as formaldehyde, glutaraldehyde or epichlorohydrin. The thermoplastic mixture can also contain plasticizers, lubricants, fillers, antimicrobial agents and / or dyes, such as glycerol, glycerol mono-, di- or triacetate, sorbitol, mannitol,

Ethylene glycol, polyvinyl alcohol, methyl cellulose, diethyl citrate, fatty acids, vegetable oil, mineral oil or microcrystalline cellulose. Moldings, for example foils, capsules, trays, bottles, tubes, etc., can be produced from the mixture by deep drawing, injection molding, blow molding or using a similar process. However, the thermoplastic mixture is not very suitable for tubular food casings, in particular cook-resistant sausage casings, because starch at least partially dissolves in hot water. The material is also too tough for an edible sausage casing.

In the past, the so-called ^® Lanital

Process for the production of protein fibers from casein (GB 483731). In this process, casein, which in turn is obtained from milk by acid precipitation, is dissolved in dilute sodium hydroxide solution. The solution is then spun into an aqueous sulfuric acid precipitation bath. The resulting fibers or filaments are then hardened in a formaldehyde-containing bath.

In addition to casein, other proteins, for example maize, peanut, soybean, cottonseed or fish proteins, can also be used as raw materials. In order to harden the shaped protein bodies after coagulation, the polypeptide chains oriented by stretching are crosslinked and thus fixed. In addition to formaldehyde, other aldehydes or are also suitable as crosslinking agents

Dialdehydes, also formamide and aluminum sulfate. Finally, a method for the production of concentrated solutions of fibrillary proteins in NMMO monohydrate and the use of the solution for the production of molded articles is known (DE-A 19841 649). However, the globular proteins that occur in large numbers in nature and are often easy to obtain cannot be used for this.

Artificial casings based on cellulose, on the other hand, cannot be chewed and are therefore not suitable for consumption. However, it can be produced simply and in an environmentally friendly manner using newer processes, such as the amine oxide process, in contrast to the viscose process which was customary in the past. In the amine oxide process

Cellulose dissolved in an amine oxide, especially in N-methyl-morpholine-N-oxide (NMMO), without being chemically modified (US-A 3447 939). Enzymatically pretreated cellulose dissolves more easily in NMMO monohydrate (DE-A 44 39 149; DE-A 196 24 867). The amine oxide / cellulose solution can be on known devices, for example with the aid of

Ring slot nozzles, spin. After passing through an air gap, the extruded molded body enters an aqueous precipitation bath in which the cellulose is precipitated. Such processes have been described in numerous cases (US Pat. No. 4,246,221, DE-A 42 19 658, DE-A 42 44 609, DE-A 43 43 100, DE-A 44 26 966).

The products previously developed as a replacement for natural and collagen casings have not met the requirements for chewability and / or toxicological safety. The previously known methods for processing proteins are also associated with a high number of process stages, which requires technically complex and accordingly expensive systems.

A problem in the production of flat films is the prevention of the transverse shrinkage of the film in the aftertreatment. This is prevented in the case of plastic films by holding the film on the edges with clips or other gripping devices and thus counteracting the transverse shrinkage. Experience has shown that this leads to considerable fluctuations in the thickness the film as well as differences in elongation across the web width. A better consistency of the parameters can be achieved if a film tube is first produced by extrusion, which is separated in the longitudinal direction after going through all treatment steps and thus becomes a flat film. Another great advantage of this method is that the interfaces can be laid in an oscillating manner when the film is being wound up, so that a smooth roll that is free of visible thick spots is obtained. By further dividing the original roll obtained in this way in the longitudinal direction, partial rolls of different widths can be produced that have identical stretching properties regardless of their position in the original roll (“master roll”). Plastic films, for example those based on polyethylene or polyethylene terephthalate, are made For films based on cellulose, this is described in EP-B 668 818. A blowing process for producing cellulose tubular films is also disclosed in DE-A 44 21 482. DE-A 199 61 843 discloses oriented tubular films made from a cellulose-protein blend which are produced by the NMMO process.

Edible films and edible sausage casings that are sufficiently resistant to cooking, stable and permeable to smoke have so far been produced almost exclusively from collagen. Collagen obtained from cattle hides is processed in complex and environmentally harmful processes. The cellulose-based films mentioned above, on the other hand, are resistant to cooking and permeable to smoke, but are not edible. Above all, they are not chewable because of their high strength and toughness.

In the older, unpublished application DE 101 29 539, a novel, seamless, tubular food casing suitable for consumption is proposed. It comprises cellulose, at least one protein and at least one filler. It is made from a spinning mass, which in

NMMO monohydrate dissolved cellulose, a protein (especially casein or zein) and a filler (especially finely ground wheat bran). The envelope will specially used as an artificial sausage casing. Accordingly, it has a caliber of approximately 20 to 150 mm. A flat film of sufficient width cannot be obtained from it. Such a flat film is desirable, for example, for the packaging of cooked ham or other relatively large or irregularly shaped foods.

The task was therefore to provide an edible, i.e. in particular to provide a chewable, cook-resistant and smoke-permeable flat film with a width of at least 600 mm. The film should have no fluctuations in its thickness or other irregularities, so that a uniform film wrap can be produced without so-called piston rings. The film should also be able to be produced in a simple and environmentally friendly manner without the need for any animal materials.

It has now been found that a tubular film from DE

101 29 539 known type also with a very large caliber, i.e. with a diameter of about 200 to 2,000 mm, can be produced uniformly without tearing and without fluctuations in thickness occurring. The film is then processed into a flat film by cutting in the longitudinal direction. The film can also be produced directly as a flat film with a width of more than 600 mm with the aid of a slot die.

The invention accordingly relates to an edible film containing cellulose, at least one filler which is insoluble or not dissolved in an NMMO spinning mass and at least one further filler dissolved in the NMMO spinning mass

Component that disturbs the structure of the precipitated cellulose, the film being characterized in that it is a flat film.

The flat film generally has a width of at least 600 mm, preferably from 1,000 to 6,500 mm, particularly preferably from 1,500 to 3,500 mm.

The cellulose preferably comes from TCF or ECF pulp (Total Chlorine Free or Elemental Chlorine Free pulp). Your carbonyl and carboxyl Group content is generally less than 50 μmol / g, the proportion of heavy metals therein is less than 20 ppm. The degree of polymerization DP (determined by the Cuoxam method) of the cellulose is preferably 300 to 1,000, preferably 300 to 900, particularly preferably 500 to 850. A sulfite pulp with a Cuoxam-DP of about 800 to 850 has proven to be particularly favorable.

The proportion of cellulose in the film is generally 30.0 to 80.0% by weight, preferably 40.0 to 70.0% by weight, in each case based on the weight of the dry, i.e. water and glycerin free film.

The component that disrupts the structure of the precipitated cellulose is preferably a protein. The protein in turn is preferably a natural, globular protein, in particular casein (milk protein), soy protein, gluten (wheat protein), zein (corn protein), ardein (peanut protein) or pea protein. In principle, any protein is suitable which, together with cellulose, is soluble in NMMO monohydrate at elevated temperature (approx. 85 to 105 ° C). In order to reduce or eliminate the solubility of the protein in the precipitation and washing baths and also later when using the film, it has proven to be expedient to crosslink it beforehand. This can be achieved, for example, by reacting the protein with an aldehyde, methylol, epoxide and / or a cross-linking enzyme. The terms "aldehyde", "methylol" etc. include compounds with more than one carbaldehyde or methylol group. Thus, dimethylolethylene urea and dialdehydes, in particular glyoxal, malonaldehyde, succinaldehyde and glutaraldehyde, are particularly suitable crosslinkers. Crosslinking is usually carried out in the presence of Lewis acids. In the

Crosslinking not only reacts to the free amino groups and any acid amide groups of the protein, but also the imino groups of the peptide bonds and the hydroxyl groups of the serine. A suitable crosslinking enzyme is, for example, transglutaminase. Other suitable components for disrupting the structure of the precipitated cellulose are also homo- or heteropolysaccharides or derivatives thereof, waxes, hydrocarbons and / or synthetic (co) polymers, all of these components possibly being mixed with protein (s). A suitable one Homopolysaccharide is, for example, starch. A suitable derivative thereof is, for example, starch acetate. Of the heteropolysaccharides, carrageenan, xanthan and alginate are particularly noteworthy. The wax is, for example, beeswax, carnauba wax or candelilla wax, and the hydrocarbon is, for example, an edible natural rubber. Of the synthetic polymers or copolymers (abbreviated (co) polymers), polyvinyl alcohol and polyethylene oxide are suitable. Naturally, all of the ingredients mentioned must be toxicologically safe. The solubility of the protein in the aqueous NMMO of the precipitation bath and in the water of the wash baths is reduced, if appropriate, by reaction with suitable crosslinking agents.

The proportion of component (s) which disturb the crystal structure of the precipitated cellulose is generally about 20 to 70% by weight, preferably about 30 to 60% by weight, in each case based on the total weight of the flat film according to the invention.

Envelopes which contain at least one protein and at least one of the other structure-disrupting components mentioned are particularly preferred. In this case the proportion of protein (s) is preferably 10 to 40% by weight and the proportion of the further structure-disturbing component (s) 10 to 30% by weight, in each case based on the total weight of the dry shell.

Like the proteins mentioned above, the fillers also break the structure of the cellulose. They reduce the stretchability of a film made from the spinning mass by extrusion without significantly impairing its strength.

The filler can be organic or inorganic in nature, and comminuted natural products are preferred. So finely ground bran, especially wheat bran, is well suited. In addition, finely ground natural fibers can be used, in particular flax, hemp or cotton fibers, cotton linters, chitin, chitosan, guar gum, locust bean gum or microcrystalline cellulose. Inorganic fillers are, for example, finely ground calcium carbonate or SiO ₂ powder. The filler generally consists of particles with a grain size of less than 200 μm, preferably 20 to 150 μm, particularly preferably 30 to 100 μm. For fillers that have a certain solubility in NMMO monohydrate, the grain size refers to the period after regeneration. The particle size is practically identical to that resulting from the

Let spinning mass measured food casing. The desired grain size can be set, for example, by dry or wet grinding and, if necessary, by sieving to certain grain size fractions. The coarse grain fraction can then be returned to the grinding process. The diameter of the filler particles must in any case be less than the thickness of a film made from the spinning mass, so that no holes can form in the film. Fillers with a platelet shape are arranged essentially parallel to the surface of the film due to the flow conditions during extrusion. The length or width of the platelet-shaped particles can then also be greater than the thickness of the film. A pretreated cellulose can also be used in the production of the flat film according to the invention. The filler is then particularly evenly distributed.

The proportion of filler (s) is generally 1 to 150% by weight, preferably 5 to 100% by weight, particularly preferably 20 to 80% by weight, in each case based on the

Total weight of (dry) cellulose and structure-disrupting components.

In a preferred embodiment, the sheath comprises at least one stabilizer which prevent or slow down undesirable degradation of the cellulose or NMMO ^'s. The stabilizer expediently has an antioxidant and / or basic effect. This applies, for example, to NaOH,

alkyl esters (especially propyl gallate), reductones, phenylenediamine or hydroxylamine. These and other additives are described, for example, in EP-A 047 929. The proportion of stabilizer (s) is generally 0.2 to 2.0% by weight, preferably 0.6 to 1.0% by weight, in each case based on the weight of the cellulose.

The flat film according to the invention optionally contains fibers. Like the fillers, the fibers do not dissolve in the spinning mass. In principle, it is about are the same fibers that are used in the production of collagen casings. The fibers are, for example, cellulose fibers, cotton fibers, cotton linters, flax fibers, hemp fibers, chitosan fibrids or correspondingly insoluble synthetic polymers. They practically do not dissolve in aqueous NMMO or in NMMO monohydrate. To do this, in some cases

(this applies in particular to the cellulose fibers) by appropriate pretreatment. This is achieved, for example, by crosslinking the surface of the fibers with aldehydes, in particular glyoxal, or with citric acid. The fibers improve the mechanical stability of the film in the transverse direction. The length of the fibers is generally 250 μm to

2 mm, preferably 300 μm to 1.0 mm. Their proportion, based on the weight of the flat film, is generally about 0.5 to 10% by weight, preferably 1 to 6% by weight.

Processes for producing spinning solutions from cellulose, N-methylmorpholine-N-oxide (NMMO) and water are known in principle. Water is drawn off from a suspension of cellulose and aqueous NMMO at elevated temperature, reduced pressure and under the action of shear forces until the aqueous NMMO has essentially become NMMO monohydrate and the cellulose has dissolved in the NMMO monohydrate. The spinning solution obtained in this way can contain a proportion of dissolved cellulose of about 5 to 20% by weight, preferably about 7 to 15% by weight, based on its total weight.

The process for producing the film according to the invention can be varied as follows: First, the pretreated cellulose is mixed with aqueous (40 to 90% by weight, preferably about 60% by weight) NMMO. Stabilizers can already be contained in the aqueous NMMO or added to the mixture. In parallel, a mixture of filler, which has previously been brought to the appropriate grain size, and aqueous NMMO is produced. Stabilizers can in turn be contained in the aqueous NMMO or added to the mixture. Possibly existing water-soluble parts of the

Fillers are optionally removed and removed beforehand by treatment with water. In order to distribute the filler as evenly as possible in the aqueous NMMO, the use of a stirrer with high shear effect beneficial. The component dissolved in the dope, which disrupts the structure of the precipitated cellulose (which is preferably a protein), is likewise first mixed with aqueous NMMO, optionally with the addition of stabilizer (s). The individual suspensions produced in this way are then brought together and mixed together. Water is then drawn off from the mixture with stirring at elevated temperature and reduced pressure until the aqueous NMMO has essentially become NMMO monohydrate. The solvent then consists of approximately 87% by weight of NMMO and 13% by weight of water, recognizable by a refractive index n _D of approximately 1.4887 (measured at 85 ° C.). The cellulose as well as the component that disturbs the structure of the precipitated cellulose completely dissolve in the NMMO monohydrate.

The excess water can be removed in one or two stages. Simple mixing vessels with low shear and a large heat exchange surface, extruders, kneaders or thin film evaporators with a larger shear field and comparatively small heat exchange surface can be used for this.

Instead of suspending the components individually in aqueous NMMO and then combining the suspensions, they can also be combined in a single one

Containers are suspended. The order in which the components are added is freely selectable. However, the filler is expediently added last so that it can be ensured that the other constituents are dissolved in the NMMO monohydrate and have formed a homogeneous solution. As described, the excess water is then also drawn off in this case and the mixture is kept at an elevated temperature, optionally with stirring or kneading, until the components, with the exception of the filler, have gone into solution. Which procedure is more favorable also depends on the type of components used. A filler that is (partially) soluble in aqueous NMMO or NMMO monohydrate should be added as late as possible so that not too much of it goes into solution and the particle size does not decrease too much. The flat film according to the invention can be extruded according to generally known methods (WO 97/31970) using molding tools, for example using a wide slot die or a heated ring slot die with a large diameter, to form a flat film or a seamless tube, with a flat film again being obtained from the tube by cutting it open becomes.

Before the extrusion, the highly viscous spinning mass generally has a temperature of approximately 80 to 100 ° C., preferably approximately 90 ° C. When producing small-caliber tubular films using the NMMO process, the spinning solution is usually fed into the nozzle body through a single feed line.

With larger diameters, however, this leads to an uneven pressure distribution in the nozzle body and thus to differences in the wall thickness of the extruded hose. The problem can be eliminated in that - according to the nozzle diameter - several feed lines are arranged evenly distributed over the circumference of the nozzle body. The supply lines are expediently designed as double-jacket pipes. The interior of the nozzle expediently contains special internals which bring about a uniform distribution of the mass flow over the entire circumference of the ring slot. Uniform flow properties of the spinning mass can be achieved by an exact temperature setting of the nozzle body. For this purpose, it should be optimally insulated. The volume flow of the heating medium should be selected so that there is practically no temperature difference between its entry and exit points. It is advantageous to operate the entry and exit points alternately.

It is also important to set the nozzle gap precisely to ensure that the tubular film has a uniform thickness over the entire circumference. A concentric gap must be created between the outer nozzle ring and the inner cylindrical counter bearing. The gap can be adjusted by moving the ring nozzle, for example controlled by a

Measurement of the thickness profile on the extruded product. The shift itself can take place mechanically, thermally or piezo-electrically. The hose first runs through an air gap of about 2 to 20 cm in length, in which it is held in the cylindrical shape by an internal gas pressure (generally generated by compressed air), so that the inner walls cannot stick together. A transverse stretching preferably also takes place in the air gap. Appropriate internal pressure controls it, for example, so that the flat width of the hose is 5 to 10% greater than that of an undrawn hose. The tube then passes into a precipitation bath in which the cellulose and the other solid constituents of the spinning mass are precipitated. The precipitation bath usually consists of a dilute (about 15% by weight) aqueous NMMO solution. Precipitation liquid is also fed into the interior of the hose (so-called "inner precipitation bath"). In the case of small-caliber hoses, the inner bath solution is generally supplied via a single pipe arranged in the middle. For larger hose diameters, on the other hand, the fresh inner precipitation bath should be supplied at several points at the same time. With an imaginary division of the

Hose cross-section in sectors of equal size should have an inflow pipe per sector. The number of sectors is selected so that optimal mixing takes place, i.e. with a relatively small hose cross-section 2 sectors (180 ° pitch), with increasing cross-section then 3 sectors (120 ° pitch), 4 sectors (90 ° pitch) etc. General there should be so many entry points that there is no turbulence. The amount of the spinning bath supplied depends on the caliber, the wall thickness and the extrusion speed. The internal bath is removed in an analogous manner with a corresponding number of suction pipes, so that the pressure fluctuations inside the hose remain small. The level of the indoor pool is expediently kept constant by using pumps. In order to obtain a hose that is as constant as possible, it is advantageous to set the level of the indoor pool somewhat higher (i.e. about 5 to 50 mm higher) than that of the outdoor pool.

The gas pressure inside the extruded is also essential

Hose between the nozzle and the surface of the indoor pool. The print is for that Longitudinal and transverse orientation in the air gap are also responsible. The pressure can be regulated, for example, by measuring the pressure with a connected air supply.

It is also important that the extruded tube is under an even tension. The tension influences the stretching properties of the resulting film in the longitudinal and transverse directions to a large extent. For this purpose, the speeds of the take-off roller and the deflection roller located near the bottom of the spinning bath should be separately adjustable and coordinated with one another. The distance between the entry into the spinning bath and the deflection roller is

/ determined by the caliber of the hose, its wall thickness and the composition of the bath. It must be large enough that the film material is sufficiently solidified when it is laid flat on the deflecting roller. Otherwise, the edges of the flat hose can be damaged.

Lay the hose filled with liquid in front of the lower one

Deflecting roller is increasingly problematic with increasing hose diameter. With smaller calibres, the hose can still be laid flat without special aids. For larger diameters, it is advisable to work with additional shaping elements, which bring about a gradual adaptation to the flat form at a sufficient distance from the deflecting roller.

The tube then runs through various washing sections for further solidification, in which NMMO residues are removed. It is then usually plasticized (e.g. in an aqueous glycerol bath). The temperature of the

Plasticizer solution is generally 20 to 80 ° C, preferably 30 to 70 ° C. The tube is then dried. The drying in a hot air dryer is expediently carried out in several stages at a decreasing temperature (from approximately 150 ° C. at the entrance to approximately 80 ° C. at the outlet). If necessary, an additional internal pressure can increase during drying

Cross orientation of the hose can be achieved. Otherwise, the tube is inflated to the original caliber before the drying process is completed in order to maintain the degree of transverse orientation once achieved. Subsequently it is moistened again until its water content is about 8 to 20% by weight, preferably 15 to 18% by weight. The hose is then cut into lengthways of suitable width as required.

The mechanical properties of the food casing obtained in this way largely correspond to those of the known collagen casings. The flat film according to the invention thus has a wet tensile strength in the longitudinal direction of approximately 4 to 12 N / mm ² , preferably 5 to 8 N / mm ² , and in the transverse direction of 4 to 7 N / mm ² , a dry tensile strength in the longitudinal direction of 15 to 50 N / mm ² , preferably 20 to 45 N / mm ² , in the transverse direction from 17 to 28 N / mm ² . The elongation at break in

Longitudinal dry is about 12 to 30%, wet about 10 to 20%. The elongation at break in the transverse direction is 20 to 25% in the dry state and 23 to 28% in the wet state.

The flat film according to the invention generally has a thickness of 20 to 60 μm. preferably 30 to 50 μm. It is therefore easy to chew and is suitable as an edible packaging cover, for example for cooked ham. The production of edible food casings is also described in the unpublished application DE 101 29 539.

The following examples illustrate the invention. Percentages are percentages by weight unless otherwise stated or can be seen from the context.

Example 1: (Edible flat film with precipitated cellulose and wheat bran)

3.9 kg of ground and sieved to a grain size of less than 63 μm wheat bran with a dry matter (TG) of 92% were stirred into 67.9 kg of a 60% NMMO solution. 0.33 kg of zein (TG: 90%) and 2.87 kg of ground wood pulp (sulfite pulp, elemental chlorine-free bleached, so-called ECF pulp; particle size less than 3 mm) were added to this suspension. A pH of 11 was then set by adding NaOH. An additional 12 g of propyl gallate was added as a stabilizer. In an agitator vessel with internals to increase the shear effect, water was distilled off under reduced pressure (the pressure was about 25 mbar) and increasing temperature until an NMMO concentration of 87% was present (the NMMO was therefore almost completely in the form of NMMO monohydrate). The resulting spinning mass had a refractive index n _D of 1, 4885 and one

Zero shear viscosity of 7,100 Pa s, determined at 85 ° C.

The spinning mass was then extruded at a temperature of 90 ° C. through an annular gap die with a gap diameter of 30 cm and a gap width of 0.5 mm. The resulting film tube passed through a 10 cm air gap in which it was kept wrinkle-free by compressed air acting from the inside before entering a precipitation bath consisting of a cooled (about 15 ° C), about 15% aqueous NMMO solution , The same cooled precipitation bath liquid was also introduced into the interior of the film tube, the level of the interior precipitation bath being approximately at the same level as that of the

Outdoor fall pool lay. The indoor precipitation bath was continuously renewed.

The hose then ran through a precipitation bath section of 1.5 m in length, where it was deflected halfway by a roller located at the bottom of the precipitation bath. It was then stretched so far that the flat width after leaving the spinning skid was 51 cm. The hose then went through 4 washing runners with a total of 8 deflection rollers arranged at the top and bottom, a bath depth of 2.5 m each and an air gap of 0.5 m. At the end of the last runner, water was introduced, which was passed through the wash runners in countercurrent. In this way the NMMO content at the exit of the first runner was kept at 12 to 16%. The temperature was raised to 60 to 70 ° C in the last washing runners. Finally, the tube was passed through a plasticizer runner containing a 10% glycerol solution. The flat width of the hose was 47 cm when leaving the plasticizer runner. The tube was then pre-dried in a jet dryer in an uninflated state, floating horizontally. Then it was dried between 2 pairs of squeeze rollers in the inflated state with hot air. The dryer had multiple zones with the temperature decreasing from one zone to the next. The zone at the entrance had a temperature of 120 ° C, at the exit of 80 ° C. At the exit of the dryer, the hose had a flat width of 55 to 60 cm. The hose was then moistened again until its water content was 8 to 12% (based on the weight of the hose). The tube was then cut open in the longitudinal direction and wound up.

Example 2: (Edible film with precipitated cellulose, wheat bran and cellulose fibers) Example 1 was repeated, but this time 1.7 kg of surface-crosslinked cellulose fibers with an average length of 150 μm and a maximum length of less than 1 mm and 2.3 kg ground and sifted to a grain size of less than 63 μm wheat bran (TG: 92%) were stirred into 67.9 kg of a 60% NMMO solution. A spinning mass was produced from this as described in Example 1. This was processed into a tubular film, from which a flat film emerged in the longitudinal direction after the separation.

Example 3: (Edible flat film with precipitated cellulose and wheat bran)

3.9 kg of ground and sieved to a grain size of less than 63 microns wheat bran with a TG of 92% were in 58.2 kg of a 70% aqueous

NMMO solution stirred in. A pH of 11 was set by adding NaOH. 0.33 kg of zein (TG: 90%) and 5.4 kg of ground wood pulp, which had been broken down in water and then adjusted to a TG of 50% with the aid of a vacuum press, were then added to the resulting suspension. An additional 12 g of propyl gallate were added as a stabilizer. The mash obtained was metered into a continuously operating kneader. Water was then distilled off at a reduced pressure of about 25 mbar and a temperature of up to 99 ° C. The mash feed was adjusted so that the solution leaving the kneader had a refractive index n _D of 1.4884 and a zero shear viscosity of 7,100 Pa s at 85 ° C. The

Spinning mass was then processed into a flat film as described in Example 1. Example 4: (Edible flat film with precipitated cellulose, zein and chalk) A suspension of 34.0 kg of 75% strength aqueous NMMO with a pH of 11.3.3 kg of zein and 5.4 kg of enzymatically pretreated pulp (TG: 50%) and 12 propyl gallate as a stabilizer was metered into a continuously working kneader. As described in Example 2, excess was then in the kneader

Water is withdrawn from the suspension at reduced pressure and increasing temperature and the suspension is thus converted into a spinning solution. A suspension of 17.5 kg of NMMO monohydrate and 2.4 kg of finely ground chalk was metered into the solution leaving the kneader, the chalk being sieved to a particle size (cut-off size) of less than 63 μm. The two substreams were mixed as much as possible in a dynamic mixer. The spinning mass obtained had a refractive index n _D of 1.4885 and a zero shear viscosity of 2,300 Pa s (at 85 ° C.). The spinning mass was then further processed as described in Example 1.

Example 5: (spinning mass with ground cellulose)

3.9 kg of a crosslinked polyvinylpyrrolidone screened to an exclusion size of less than 63 μm with a TG of 92% were stirred into 67.9 kg of a 60% aqueous NMMO solution with a pH of 11.5. The suspension then became 0.33 kg zein (TG: 90%) and 2.87 kg ground

(Particle size less than 3 mm) added wood pulp (sulfite pulp). An additional 12 g of propyl gallate was added as a stabilizer.

In a container with an agitator and internals to increase the shear effect were at a reduced pressure of 25 mbar and increasing temperature

Water was distilled off until there was an NMMO concentration of 76% (this corresponds to the NMMO dihydrate). This mash was then fed continuously to a thin-film evaporator, where so much water was distilled off at 30 mbar and 105 ° C. that the spinning mass at the outlet of the thin-film evaporator had a refractive index n _D of 1.4886 at 85 ° C. The

Spinning mass was then processed into an edible flat film as described.

Claims

claims

1. Edible film containing cellulose, at least one filler which is insoluble or not dissolved in an NMMO spinning solution and at least one further component which is dissolved in the NMMO spinning solution and which causes a disturbance in the structure of the precipitated cellulose, characterized in that the film is a flat film is.

2. Edible film according to claim 1, characterized in that it has a width of at least 600 mm, preferably from 1,000 to 6,500 mm, particularly preferably from 1,500 to 3,500 mm.

3. Edible film according to claim 1 or 2, characterized in that the component which interferes with the structure of the precipitated cellulose, a protein, a homo- or heteropolysaccharide or a derivative thereof, a wax, a hydrocarbon and / or is a synthetic (co) polymer.

4. Edible film according to one or more of claims 1 to 3, characterized in that the proportion of the at least one component which causes a disturbance in the structure of the precipitated cellulose is 20 to 70 wt .-%, preferably about 30 to 60 wt. -%, is based on the total weight of the film.

5. Edible film according to one or more of claims 1 to 4, characterized in that the filler has a grain size of less than 200 microns, preferably 30 to 150 microns, particularly preferably 40 to 120 microns.

6. Edible film according to one or more of claims 1 to 5, characterized in that the filler is organic in nature, preferably one

Is a natural product.

7. Edible film according to claim 6, characterized in that the filler bran, chitin, chitosan, an insoluble in water-containing NMMO or NMMO monohydrate (co-) polymer, preferably a crosslinked polyvinylpyrrolidone, a vinylpyrrolidone / alkylvinylether copolymer, ground natural fibers, preferably ground flax, hemp or

Cotton fibers, cotton linters, guar gum, locust bean gum or microcrystalline cellulose.

8. Edible film according to one or more of claims 1 to 5, characterized in that the filler is inorganic in nature.

9. Edible film according to claim 8, characterized in that the filler is CaCO ₃ , SiO ₂ or TiO ₂ .

10. Edible film according to one or more of claims 1 to 9, characterized in that the proportion of filler (s) 1 to 150 wt .-%, preferably 5 to 100 wt .-%, particularly preferably 20 to 80 wt .-% %, each based on the total weight of (dry) cellulose and the at least one component which causes a disturbance in the structure of the precipitated cellulose.

11. Edible film according to one or more of claims 1 to 10, characterized in that it contains a stabilizer.

12. Edible film according to claim 11, characterized in that the

Stabilizer is propyl gallate.

13. Edible film according to one or more of claims 1 to 12, characterized in that it contains fibers.

14. Edible film according to claim 13, characterized in that the fibers are cellulose fibers, cotton fibers, cotton linters, flax fibers, Hemp fibers, chitosan fibrids or correspondingly insoluble synthetic polymers.

15. Edible film according to claim 13, characterized in that the fibers have a length of 250 microns to 2 mm, preferably 300 microns to 1.0 mm.

16. Edible film according to claim 13, characterized in that the proportion of fibers is 0.5 to 10 wt .-%, preferably 1 to 6 wt .-%, each based on the total weight of the film.

17. A method for producing an edible flat film according to one or more of claims 1 to 16, characterized in that an NMMO spinning mass, the NMMO monohydrate, cellulose dissolved therein and at least one dissolved component which causes a disturbance in the structure of the precipitated cellulose , and at least one insoluble or undissolved filler, extruded through an annular die and precipitated in a precipitation bath after passing through an air gap, and that the resulting tubular film is then washed, optionally softened, and finally separated in the longitudinal direction, so that a flat film is formed ,