WO2005061610A1

WO2005061610A1 - Foodstuff casing based on regenerated cellulose and impregnated or coated with polyvinylamines

Info

Publication number: WO2005061610A1
Application number: PCT/EP2004/014264
Authority: WO
Inventors: Theresia Rieser; Volker Effern
Original assignee: Kalle Gmbh
Priority date: 2003-12-19
Filing date: 2004-12-15
Publication date: 2005-07-07
Also published as: DE10360609A1

Abstract

The invention relates to a cellulose-based foodstuff casing that is impregnated or coated. The impregnation substance or coating comprises at least one polymer containing vinylamine units. The invention also relates to a method for producing said casing and to the use of the latter as a synthetic sausage casing.

Description

Food casing impregnated or coated with polyvinylamines based on regenerated cellulose

The invention relates to a coated or impregnated food casing based on cellulose, a process for its production and its use as an artificial sausage casing.

Food casings based on regenerated cellulose have been known for a long time (see e.g. G. Effenberger, Wursthüllen - Kunstdarm, Holzmann Buchverlag, Bad Wörishofen, 2nd edition [1991] pp. 21-24). Food casings which are produced by the viscose process are widespread. In it, cellulose is converted into cellulose xanthate using sodium hydroxide solution and carbon disulphide. Tubular casings can be produced from this alkaline cellulose xanthate solution, generally referred to as a “viscose solution”, by extrusion with the aid of an annular die. After the extrusion, the casings are passed through various precipitation and washing baths After going through the wash baths, excess

Water is removed from the so-called gel tube by drying. The viscose solution can also be applied to a fiber paper formed into a tube. The cellulose in the fiber casings thus formed is then regenerated in the same way.

The viscose process is extremely complex in terms of equipment and requires extensive measures for the purification of waste water and waste air. Therefore, the much less complex amine oxide process has recently been developed. The cellulose is dissolved therein in an aqueous amine oxide of a tertiary amine, particularly preferably in N-methyl-morpholine-N-oxide (NMMO) monohydrate. In this process, the cellulose is no longer chemically derivatized, but dissolved physically. The NMMO / cellulose solution can be extruded into seamless tubes using ring dies. The cellulose is precipitated in a precipitation bath which contains dilute aqueous amine oxide. The NMMO / cellulose solution can also be applied to fiber paper, so that cellulose fiber casings can also be produced by this process.

It is also known to modify the cellulose casings, for example by treating them with a plasticizer (such as glycerol) or by applying additives to their inner surface which influence the adhesion to the filling material in the desired manner. Because on the one hand the casing should be easy to peel, on the other hand it should adhere sufficiently to the sausage meat during the production of the sausage. Furthermore, casings are known which have a layer with barrier properties for water vapor and / or oxygen, for example made of vinylidene chloride copolymers, and casings which are impregnated with a biocide. Also described are coatings for increasing the

Surface roughness.

Components that improve the properties of the cellulose hydrate shell can also be added directly to the viscose solution or the cellulose / amine oxide solution. By this measure, the liability of the shell can be

However, sausage meat does not improve much. An additional adhesive impregnation is generally necessary. In contrast, impregnated casings often show an uneven distribution of the additives due to the process.

The subject of EP-B 0 635 211 and EP-B 0 878 133 are food casings based on regenerated cellulose, in the production of which cationic resins or mixtures of cationic resins were mixed with viscose proteins. Melamine / formaldehyde and polyamine / polyamide / epichlorohydrin resins are specifically disclosed. However, such resins are disadvantageous in a number of ways. Melamine / formaldehyde resins contain or form small amounts of formaldehyde, which is why they are hardly used for food commodities in general and food packaging in particular still be used. Polyamine / polyamide / epichlorohydrin resins increase the proportion of AOX in wastewater during the production of the casings and can contain substances that are hazardous to health, such as monochloropropanediol and dichloropropanol. The permissible limit values for these connections have been lowered several times in recent years. Cases with these additives must also cure at elevated temperature or - for a correspondingly longer period - at room temperature.

DE-A 36 20 165 discloses a tubular food casing based on regenerated cellulose, which on the inside increases the

Meat cling is coated. The inner coating comprises a film-forming plastic resin, in particular a polyamine-polyamide-epichlorohydrin resin, a polyethyleneimine resin, a urea or melamine-formaldehyde resin, and also a protein coagulant, such as tartaric acid, citric acid, ascorbic acid or sorbic acid.

DE-A 37 11 712 also describes a tubular food casing based on regenerated cellulose. The casing contains, mixed with the cellulose, alkali-soluble or alkali-dispersible and hydrolysis-resistant protein compounds and crosslinking agents. In addition, the shell can have an inner coating of cross-linked cationic compounds. These are, in particular, cross-linked protein compounds, especially casein cross-linked with glyoxal.

DE-A 199 57 454 describes an optionally fiber-reinforced food casing based on regenerated cellulose, which has a layer which is impermeable to water vapor on the outside and also has a coating on the inside. The coating comprises a crosslinked polyamine / polyamide / epichlorohydrin resin, a wax, for example montan wax or beeswax, and optionally a synthetic polymer, such as

Polyvinyl alcohol. The coating on the inside increases the adhesion to the sausage meat. It was therefore the task of providing cellulose-based food casings with a coating or impregnation which brings about a defined and uniform adhesion of the casing to the respective food. The coating or impregnation should, if possible, also do without additional crosslinking agents, and the cellulase resistance of the casing should also be improved.

The tasks can be solved with polyvinylamines. Polyvinylamines show surprisingly good adhesion to cellulose. This is attributed to the large number of primary amino groups.

The present invention accordingly relates to an impregnated or coated food casing based on cellulose, which is characterized in that the impregnation or coating comprises at least one polymer containing vinylamine units. The sheath is preferably tubular.

The polymer containing vinylamine units is preferably a polyvinylamine. Polyvinylamines as such are known and commercially available, for example under the names © Luresin PR 8086, © Polymin PR 8182, © Catiofast

VFH special, © Catiofast PR 8212 special, © Catiofast PR 8153 or © Basocoll PR 8086 (all from BASF Aktiengesellschaft). Regardless of the manufacturing process, polyvinylamines with a proportion of 5 to 100 mol%, preferably 30 to 95 mol%, of vinylamine units are suitable for causing the cellulose casing to adhere to the sausage meat. The salts of

Polyvinylamines such as polyvinylamine hydrochloride can be used. A common process for the production of polyvinylamines consists in the hydrolysis of polymers with units made of N-vinylcarboxamides. Suitable N-vinylcarboxamides for the polymerization are represented by formula I R ² H ₂ C = CH - N (I) C - R ¹ o

characterized in which R and R ² independently represent a hydrogen atom or C _r to C ₆ alkyl. By splitting off the formyl or alkanoyl

Group according to formula II

- C - R ¹ (II) II O

where R ^{1 is} H or C _r to C ₆ alkyl, the hydrolyzed polymers are accessible. The primary or secondary amino groups obtained can also be present as hydrochlorides or in another salt-like form.

In connection with the present invention, the term “polyvinylamine” should therefore also be understood to mean polymers with N-vinylcarboxamide groups in which more than 5 mol%, preferably 75 to 95 mol%, of the N-vinylcarboxamide units are hydrolyzed hydrolyzed homopolymers of N-vinylformamide, N-

Vinyl acetamide, N-vinyl-N-methyl-formamide, N-vinyl-N-methyl-acetamide, N-vinyl-N-ethyl-acetamide or N-vinyl-N-methyl-propionamide.

In addition to polyvinylamines and hydrolyzed homopolymers of N-vinylcarboxamides, copolymers are also suitable in principle. They generally contain at least 5 mol%, preferably at least 30 mol%, of vinylamine units. The further units can be derived from largely any monomers copolymerizable with N-vinylcarboxylic acid amides. They can also have functional groups, preferably basic or neutral. Such monomers are, for example, ethylene and / or propylene, but preferably monoethylenic unsaturated monomers from the group of vinyl acetate, Vinyl propionate, the C _r to C ₄ alkyl vinyl ether, the esters, nitriles and amides of acrylic acid and methacrylic acid and N-vinyl pyrrolidone. In the context of the present invention, “copolymers” are also to be understood as meaning polymers which contain more than two different monomer units, that is to say also terpolymers, etc.

The hydrolysis of the N-vinylcarboxylic acid unit can by suitable mineral acids, such as hydrogen halide (gaseous or in aqueous solution), sulfuric, nitric or phosphoric acid, C ₁ -C ₅ carboxylic acids, such as formic, acetic or propionic acid, or by aromatic sulfonic acids, such as methane,

Benzene or toluenesulfonic acids. However, hydrolysis processes with bases, such as alkali metal or alkaline earth metal oxides (for example sodium or calcium hydroxide) can also be carried out. Ammonia or alkyl derivatives thereof can also be used. Hydrolysis is also possible with the help of enzymes. A neutralization of the solutions is often carried out after the acidic or basic hydrolysis.

The average molecular weight M _{w of the} vinylamine polymers is generally about 500 to 3,000,000 daltons, preferably about 100,000 to 2,000,000 daltons. Due to the large number of free primary amino groups combine

Polyamines even without crosslinkers with the cellulose.

The application amount of the vinylamine polymers is generally about 10 to 1500 mg / m ² , preferably 50 to 500 mg / m ² , particularly preferably 60 to 200 mg / m ² . The adhesion of the casing to the food can be adjusted according to the requirements by the quantity applied.

In addition to polyvinylamine, the inner coating or impregnation can also comprise further components. These are, in particular, organic and / or inorganic particles, such as cellulose powder or fibers or silica particles.

Liquid smoke or bioeide can also be added. In some cases it may make sense if the impregnation or coating contains substances which reduce the adhesion of the casing to the food. Diketenes with long-chain (10 to 18 carbon atoms) alkyl radicals, chromium fatty acid complexes, lecithins, cellulose ethers (in particular carboxymethyl, hydroxyethyl and methyl cellulose), fats, oils and / or waxes are particularly suitable for this.

In the case of light-colored, in particular white, fiber-reinforced casings, the impregnation or coating can discolor the surface. This can be suppressed by adding suitable additives such as gluconic acid δ-lactone.

Although the polyvinylamine alone already has a strong bond to the cellulose of the casing, crosslinking can also be carried out. Suitable crosslinkers are, in particular, dialdehydes, such as glyoxal or glutaraldehyde, and also diiisocyanates or diepoxides.

In a further embodiment, the coating or impregnation containing polyvinylamine is located on the outside of the casing. It increases the resistance of the shell to cellulitic enzymes (cellulases), such as those formed by molds. In addition, it is possible to anchor organic or inorganic particles on the shell surface with polyvinylamines. With such particles, the surface roughness of the casing can be increased even further.

In addition, the shell can be equipped with a barrier layer for oxygen and / or water vapor. For example, this is a layer based on

Vinylidene chloride copolymers. A previous coating or impregnation with polyvinylamine acts as an adhesion promoter for such additional layers.

The coating or impregnation containing polyvinylamine can be applied to a pure cellulose casing. However, the cellulose casing according to the invention preferably also comprises a fiber reinforcement, preferably from a wet-strength fiber paper, particularly preferably from a hemp fiber paper. The required wet strength can be achieved by treatment with a resin, with a dilute viscose solution or in a similar manner known to the person skilled in the art. The fiber reinforcement has a (dry) weight of generally 15 to 29 g / m ² , preferably 17 to 25 g / m ² . It is shaped into a tube and is charged with the cellulose from the inside and / or outside.

The proportion of polyvinylamine in or on the shell can be calculated by a nitrogen determination according to Kjeldahl. The nitrogen content must be taken into account, which may be due to the fiber reinforcement and / or the

Crosslinker is introduced.

The food casing according to the invention can be further modified in subsequent treatment steps, e.g. B. by treatment with a plasticizer, such as glycerol, and / or a bioid. In addition, the

Cover with a barrier layer or be impregnated with liquid smoke. A combination of several of these measures is also possible.

Envelopes with a moisture content of 8 to 13% by weight typically contain 17 to 25% by weight of glycerin. The casing weight is generally 65 to 140 g / m ² , preferably 70 to 120 g / m ² . Depending on the type of use envisaged, the diameter of the tubular casing is generally 40 to 300 mm, preferably 49 to 250 mm.

The casings according to the invention are produced with the aid of methods and devices which are known per se to the person skilled in the art. In the manufacture of the casings by the viscose process, other additives, e.g. B. cellulose ether added. The mixture is then extruded using a ring die. In the manufacture of fiber casings, the viscose mixture is applied from the inside, from the outside or from both sides to a fiber insert which is shaped into a tube (known as internal, external or double viscosity). The fiber-reinforced hose, if necessary, an acidic precipitation bath then runs in which the cellulose xanthate is regenerated to cellulose. The gel tube then runs through further precipitation and washing baths, is then dried and then conditioned to the desired final moisture by spraying with water. The final moisture is generally 8 to 13% by weight. The casing can also be pre-moistened ready for filling. Then she has one

Moisture of about 21 to 30 wt .-%. Pre-moistened covers are often delivered with a water vapor-tight outer packaging.

When the casing according to the invention is produced by the amine oxide process, it is dissolved in water-containing amine oxide, in particular in NMMO monohydrate

Cellulose used. Additional additives can also be added here. Because the amine oxide process is less harsh than that

Viscose process, the selection of additives is even larger here. The amine oxide

As in the viscose process, spinning solution is extruded through an annular die. The cellulose is then precipitated in a bath containing a dilute aqueous solution

Contains amine oxide solution. The preferred amine oxide is N-methyl-morpholine-N-oxide.

Fiber casings can also be produced using the NMMO process. The

Spinning solution is then applied to a fiber material formed into a tube.

The coating or impregnation is then applied by methods which are known in principle to the person skilled in the art.

The food casing according to the invention is primarily used as an artificial sausage casing which can be used for raw, scalded or cooked sausage. The casing can be available as rolled goods, in the form of individual sections tied off at one end or otherwise closed and / or in an increased form to form so-called shirred sticks. The moisture in the shirred sticks is 14 to 35%, preferably 16 to 30%, depending on the field of application. The following examples serve to illustrate the invention. Percentages are percentages by weight unless otherwise stated or can be seen from the context.

To characterize the adhesion properties of the casings according to the invention to the sausage meat, filling tests were carried out with standard salami and cooked sausage meat.

Filling tests The peeling properties of the polyamine-modified casings were tested in the

Tested against an unmodified shell. A grading scale was defined that characterizes the adhesion of the casing to the meat. The rating was as follows: 0 = no liability 0.5 = very weak adhesion 1, 0 = weak adhesion 1, 5 - 1, 75 = medium-strength adhesion 2.0 - 2.25 = strong adhesion 2.5 = very strong adhesion

raw sausage

A sausage meat from 70% meat (from the shoulder of the pork) and 30% bacon (back bacon from the pork), which was stored at -30 ° C., and 24 g / kg nitrite curing salt were used. The water activity (a _w value) was 0.98-0.99 and the pH 6.0 (measured 24 hours after slaughter). The ingredients were at

-5 to 0 ° C crushed (a _w value 0.96 to 0.97; pH value to 5.9). The casing was filled at a temperature of -3 to +1 ° C. The ripening took place in three sections in a dark room after an equalization time of about 6 h at room temperature (about 20 to 25 ° C and a relative humidity of less than 60%). The ripening sections are shown in Table 1. Table 1: Overview of the maturity stages in raw sausage stripping

cooked sausages

A meat sausage was made; the filled intestine was heated with the caliber 4560-70 min and with the caliber for 902 hours at 75-78 ° C.

Examples

In Examples 1 to 4, a standard NaloFiber type, single-viscosity, with a diameter of 45 mm (caliber 45) and a weight per unit area of about 77 g / m ^{2 was} used. While in Example 1 the casing remained uncoated for comparison purposes, in Examples 2 to 3 it was coated on the inside with polyvinylamine (© Luresin PR 8086 from BASF Aktiengesellschaft). For this purpose, solutions were used which, in addition to polyvinylamine, also contained water and 4% glycerol in the proportions given in the table. The solutions were adjusted to a pH of 6.5 to 7.0. They were in the form of a

Liquid bubble passed through the tube (“slug coating”). The shell was then dried by standard methods known to the person skilled in the art. A standard NaloFiber type, double-viscous, caliber 90 with a basis weight of about 87 g / m ^{2 was} used in Examples 5 to 8. The cellulose was divided into 50% each of the inside and outside viscose. The casing according to Comparative Example 5 was not impregnated on the inside. The casings according to Examples 6 to 8 were impregnated on the inside with polyvinylamine as described (pH value of the solutions again 6.5 to 7.0).

Table 2

Table 3

As Table 3 shows, the adhesive properties of the casing can be specifically adjusted to the respective food by varying the amount of polyvinylamine.

Claims

claims

1. Impregnated or coated food casing based on cellulose, characterized in that the impregnation or coating comprises at least one polymer containing vinylamine units.

2. Food casing according to claim 1, characterized in that it is tubular.

3. Food casing according to claim 1 or 2, characterized in that the average molecular weight M _{w of} the vinylamine polymer is 500 to 3,000,000 daltons, preferably about 100,000 to 2,000,000 daltons.

4. Food casing according to one or more of claims 1 to 3, characterized in that the vinylamine polymer is a polyvinylamine or a polymer with hydrolyzed N-vinylcarboxamide units.

5. Food casing according to claim 4, characterized in that the degree of hydrolysis of the N-vinylcarboxamide units is 5 mol% or more, preferably 75 to 95 mol%.

6. Food casing according to one or more of claims 1 to 3, characterized in that the vinylamine polymer is a copolymer which has at least 5 mol%, preferably at least 30 mol%, of vinylamine units.

7. Food casing according to one or more of claims 1 to 6, characterized in that at least one vinylamine polymer in an amount of 10 to 1500 mg / m ² , preferably 50 to 500 mg / m ² , particularly preferably 60 to 200 mg / m ² is present.

8. Food casing according to one or more of claims 1 to 7, characterized in that the impregnation or coating comprises at least one further component.

9. Food casing according to claim 8, characterized in that the further component consists of organic and / or inorganic particles, preferably cellulose powder or cellulose fibers or silica particles.

10. Food casing according to claim 8 or 9, characterized in that the further component is liquid smoke or a bio-oath.

11. Food casing according to one or more of claims 1 to 10, characterized in that it has a fiber reinforcement.

12. Food casing according to claim 8, characterized in that the fiber reinforcement is a fiber paper, preferably a hemp fiber paper.

13. Food casing according to claim 9, characterized in that the fiber paper has a dry weight of 15 to 29 g / m ² , preferably from 17 to 25 g / m ² .

14. Food casing according to one or more of claims 11 to 13, characterized in that it has a fiber reinforcement and that it is impregnated or coated with at least one polymer containing vinylamine units.

15. Food casing according to one or more of claims 1 to 14, characterized in that it contains a plasticizer, preferably glycerin.

16. Food casing according to one or more of claims 1 to 15, characterized in that it is additionally provided with a barrier layer.

17. Food casing according to one or more of claims 1 to 16, characterized in that the impregnation or coating with polyvinylamine acts as an adhesion promoter for additional layers.

18. Food casing according to one or more of claims 1 to 17, characterized in that the coating or impregnation with polyvinylamine may additionally contain crosslinking agents, in particular dialdehydes, such as glyoxal or glutardialdehyde, and also diisocyanate or diepoxides.

19. A method for producing the food casing according to one or more of claims 1 to 16, characterized in that the polyvinylamine is applied with in the form of an aqueous solution.

20. Use of the food casing according to one or more of claims 1 to 17 as an artificial sausage casing.