Cellulosic food casings

Start of patent period: 1984 09 15

Longest possible duration:

t Issued: 1985 04 25

Inventor:

© dependence:

AT 377 681 © References which have been considered to delimit the prior art: DE-OS 2721427

ERICH LÜCKI CHEMICAL FOOD CONSERVATION (SPRINGER VERLAG 1977) / PAGES 52-54

Nr.377681

The invention relates to improved food casings, and more particularly to large diameter tubular cellulosic food casings which are pre-moistened to such an extent in a controlled manner that they can be stuffed without adding further moisture prior to stuffing and which contain a mold growth preventing substance. These food casings are treated with chloride salts as antifungal agents to combat the formation and growth of mold, yeast and bacteria which would otherwise readily occur on moistened casings.

Synthetic food casings, such as are used all over the world in the processing of a variety of meat and other food products, for example sausages of various kinds, cheese rolls, turkey rolls and the like, are generally made of regenerated cellulose, among other cellulosic materials. The casings have different diameter sizes to cope with the different types of food products. They are offered reinforced or un reinforced, the reinforced casings, usually referred to as fiber casings, contain a fibrous support fabric embedded in the wall of the shell.

In the production of many food products, especially meat products, a common measure is to stuff the mixture of consumable ingredients, usually termed emulsion, under pressure into a wrapper. The processing of the food product is then done after filling. The food product may also be stored and shipped after it has been contained in the casing, although in many cases, especially for small sausage products such as frankfurters, the casing is removed from the food product after completion of processing.

The term small food casings generally refers to the casings used in the production of small sausage products such as frankfurters. As the name implies, this type of food casing has a small stuffing diameter, generally a diameter in the range of 15 to 40 mm, and usually such food casings are thin-walled tubing of very long length. For ease of handling, these casings, which may be 20 to 50 meters long or even longer, are gathered and compressed to yield the 20 to 60 cm long products, commonly referred to as shirred casings. Shirters and the products thus obtained are described, inter alia, in US Pat. Nos. 2,983,949 and 2,984,574.

Large diameter food casings used for the production of larger food products, such as salami and Bolognese sausage, meat loaf, cooked and smoked ham pieces and the like, are made with stuffing diameters of 50 to 200 mm or more. In general, such casings have a wall thickness about three times that of small diameter casings, and are equipped with a fibrous reinforcing ply embedded in the wall, although they can be made without such a pylon. To date, large diameter tubular casings have been supplied to the food processor in flat condition and in lengths of between 0.6 and 2.2 meters. Improvements in shirring and packaging technology,

Large diameter tubular cellulosic food casings suitable for use in the invention may be obtained by various known methods. The sheaths are flexible, seamless tubes of regenerated cellulose, cellulose ethers and the like. and can be prepared by known methods such as the Cuprammonium method, deacetylation of cellulose acetate, denitration of cellulose nitrate and preferably by the viscose method. Tubular sheaths and the like with fibers such as rice paper, hemp, rayon, flax, sisal, nylon, polyethylene terephthalate and the like. reinforced are used with advantage for applications in which tubular food casings of large diameter are required. Tubular fiber casings can be produced by means of, for example, US Pat.

- 3 - No.377681

As is well known in the art, the tubular cellulosic casings made by any of the known processes are generally treated with glycerin as wetting, softening and plasticizing agents to provide resistance to drying or blasting of the casings during storage and handling prior to stuffing to effect. The glycerol treatment is generally carried out by passing the shell, while still in its gel state, through an aqueous glycerol solution, after which the plasticized shell is dried to a predetermined moisture content before being further processed or wound up on wheels for storage. Generally, large size tubular casings contain about 25 to 35% glycerin based on the weight of dry cellulose,

In the production and use of synthetic food casings, particularly small diameter regenerated cellulose casings, the moisture content of the casings is of paramount importance. When producing small diameter cellulosic casings, it is generally necessary to dry them to a relatively low water content, usually in the range of about 10 to 13 wt%, to allow shirring without damaging the casing. To allow easy stretching of the compressed shirred cellulosic sheath of small diameter and to prevent tearing and breaking of the sheath during stuffing, shirred shells of small diameter have an average moisture content of 14 to 18 wt%. This relatively narrow range of moisture content is important

In recent years, a number of patents have been issued which address the problem of the moisture content of shirred small diameter tubular food casings, and propose various methods of achieving and maintaining the desired moisture content, also during storage and shipping. For example, U.S. Patent Nos. 2,181,329, 3,250,629, and 3,471,305 disclose packaging means which allow a plurality of small diameter shirred sheaths to be moistened during packaging. U.S. Patent Nos. 3,222,192, 3,616,489, 3,657,769 and 3,809,576 disclose various means for wetting food casings before or during the gathering process.

The invention is directed to large diameter food casings which require a relatively high moisture content, generally greater than about 20%, to allow satisfactory plugging. The large diameter food casings are characterized by relatively thicker walls than those of small diameter food casings and, therefore, require higher levels of moisture to allow for the expansibility required for plugging without undesirably high internal pressures. The invention is concerned with the class of large diameter food casings and in particular with fiber reinforced casings.

Large diameter sheaths, heretofore available in short lengths of essentially flat flat tubes, are very stiff when dry and are softened for soaking by soaking in water to increase the moisture content to near full saturation. Heretofore, there has been no need to provide such shells with a predetermined moisture content, and the controlled moistening by the sheath maker in making either short or long shirred pieces of the large sheaths was unnecessary. More recently, however, the proliferation of automatic stuffing devices for products using large tubular food casings and the increased demand for such longer length casings in a gathered form has compounded the problems experienced in moistening such casings as compared to the long used flat and flat pieces Soaking occurs immediately before the stuffing process. In addition, the need for greater quality control in every respect in the manufacture and use of large diameter food casings has gained substantial importance. For example, the uniformity of the diameter size of stuffed food casings and processed food products has become significantly more important commercially, especially during further processing using automatic weighing or counting of slices during packaging of the product. The moisture content of the shell was found to be a factor in controlling product regularity and as a factor in meeting the requirements for continuous economic plugging of the casings without damage or breakage with reproducible results.

Small diameter sheathed casings having a relatively narrow range of evenly distributed moisture as required for stuffing have been most efficiently and economically achieved by casing production during casing fabrication, shirring or packaging. It has become increasingly apparent that the benefits of controlled humidification, as could be achieved in the field of small diameter sheaths, can be realized with regard to large diameter sheaths when shroud manufacturers can develop shrouds having a large diameter both flat and shirred, which is easy for stuffing, especially a fully automatic stuffing operation,

Although, because of the general application of soaking of large diameter casings prior to stuffing, it has not heretofore been necessary to keep the moisture content of such food casings within a specific critical range, it is known that in order to achieve the desired flexibility of such casings, somewhat higher moisture contents are compared necessary for small diameter envelopes. As larger amounts of water and the associated mass gain substantially increase the cost of packaging, handling, storage and shipping of the casings, it is important to moisten to the required extent, but not more than is necessary.

Another problem encountered in the handling and processing of high moisture cellulosic food casings relates to the growth of mold, yeast and bacteria since high moisture content is one of the necessary factors to effect such growth on cellulosic casings. It is known, for example, that cellulosic food casings have a critical moisture content above which the growth of perishable microorganisms during storage is promoted to a high degree. In general, the critical moisture content for mold is lower than for yeast and bacteria, so that a moisture content which protects the envelopes from spoiling by mold also prevents spoilage by yeast and bacteria. It was found, that maintaining a moisture content in cellulosic casings below a predetermined value, generally below about 20% by weight based on the total weight of the casing, is an effective means of controlling such growth. In cases where the restriction of moisture content can not be used to prevent such growth, eg if a higher moisture content is intentionally provided or if higher moisture concentrations occur on stored casings because of random temperature differences in the shell's cross-section, it is necessary to have other means of prevention to provide for the growth of spoilage microorganisms. -% based on the total mass of the shell, is an effective measure to control such growth. In cases where the restriction of moisture content can not be used to prevent such growth, eg if a higher moisture content is intentionally provided or if higher moisture concentrations occur on stored casings because of random temperature differences in the shell's cross-section, it is necessary to have other means of prevention to provide for the growth of spoilage microorganisms. -% based on the total mass of the shell, is an effective measure to control such growth. In cases where the restriction of moisture content can not be used to prevent such growth, eg if a higher moisture content is intentionally provided or if higher moisture concentrations occur on stored casings because of random temperature differences in the shell's cross-section, it is necessary to have other means of prevention to provide for the growth of spoilage microorganisms.

Tubular cellulosic food casings with a large diameter, in particular tubular fiber casings, which can easily be stuffed onto modern, essentially fully automatic stuffing devices without damage or breakage, can thus advantageously be obtained by

1. The moisture content is adjusted so that sufficient flexibility is given, and eliminates the need for the usual soaking step immediately before the stopper, and

2. appropriate means for preventing the growth of mold including microorganisms during transport, handling and storage are provided.

The problem of mold growth in vulnerable food products and the

No.377681 food spoilage has been the subject of a series of studies over the years. Various treatments have been developed and recommended, such as combinations of sugars and polyhydric alcohols as inhibitors of the growth of microorganisms generally found responsible for food spoilage. The antifungal treatment of cellulosic food casings poses a further and more complex problem with regard to processing techniques in the preparation and stuffing of the casings. Some proposals for overcoming these problems and for providing antifungal treatment of sausage casing casings or, in some cases, preventing mold growth on the surface of sausage products after stuffing have been the subject of various patents. For example, according to U.S. Patent No. 3,617,312, an antifungal agent is applied to cellulosic casings as a component of a curable water-insoluble coating, and in U.S. Patent No. 3,935,320, cured water-insoluble cationic thermosetting resin coatings on the surfaces of the casings prevent damage by enzymatic action , AT-PS No. 365414 and no. No. 3,637,070 describe the antifungal treatment of controlled humidified envelopes with aqueous solutions of various agents including propylene glycol and propionates and sorbates of potassium, sodium and calcium. U.S. Patent No. 4,409,251 relates to the use of high levels of glycerol to achieve an antifungal effect. DE-OS 2721427 describes in detail antifungal agents, in particular propylene glycol u.ähnl. chemical additives, as essential features. It is nowhere to be found that chloride salts with the same antifungal activity as the antifungal substances discussed there can be used. In particular in claim 1 and on page 15 there is a discussion of the polyhydric alcohols glycerol, triethylene glycol,

A significant difference with respect to the cited references is that US Pat. No. 3,617,312 is directed to preventing mold growth on the surface of the sausage product after stuffing and does not relate to preventing the growth of perishable microorganisms in the sausage casing prior to stuffing , as is the case with the invention.

The inclusion of moisture in the shell to any extent raises the problem of water activity. The water activity represented by the symbol A_w, is defined as the ratio of the partial vapor pressure of water in a solution to the vapor pressure of pure water, both measured at the same temperature. It is used in conjunction with the description of the invention because it is a common and useful parameter for quantifying the moisture content in casings treated with chloride salts in accordance with the teachings of the invention. As a reference describing the phenomenon of water activity in more detail, Ross, Estimation of Water Activity in Intermediate Moisture Foods, Food Technology, March 1975, p.26 and 41. Journal of Food Science, p.352, May to June 1976, may be cited ,

The invention is characterized in that a tubular cellulosic food casing for the prevention of mold growth has such a content of chloride salt, namely sodium chloride, magnesium chloride, ammonium chloride, calcium chloride and potassium chloride, based on the mass of cellulose in the casing, that the water activity in the casing is held at most 0.81.

The controlled added moisture can vary from as little as 20 to 40% of the total mass of the casing. A preferred range for the moisture content in the casings is about 20 to 25%. A chloride salt, namely sodium chloride, magnesium chloride, ammonium chloride, calcium chloride or potassium chloride, is added, preferably by adding to the humidifying water, and the solution is applied to the shell by any known method, for example by spraying or slurrying or a combination of these techniques. The particular chloride salt used, the moisture content selected for the shell and, to some extent, the intended storage life of the shell determine the salt concentration required to adjust the water activity A_w in the casing to a value low enough, preferably below about 0.75, to ensure the prevention of mold growth.

- 6 - No.377681

Sodium chloride has been found to be most effective in that relatively small amounts of from about 2 to 22.6% of the mass of cellulose in the shell account for the A_wValue to about 0.75, thereby avoiding mold growth at moisture levels of 20 to 40% based on the total weight of the shell. In addition, sodium chloride is a common ingredient in processed foods and a recognized addition to food casings.

Higher concentrations are required of most other chloride salts to prevent the formation of mold in casings, which are similarly wetted by setting an A ^ value of at most 0.75: about 2.9 to 22.0%. Magnesium chloride, about 3.1 to 33.2% ammonium chloride, about 4.1 to 35.9% calcium chloride, and about 2.6 to 68.7% potassium chloride based on the weight of cellulose in the shell.

It was by no means obvious to use common salt instead of other antimycotics. During the fabrication of fibrous casings, a thorough wash is provided prior to drying to remove salts from the gel casings. Water-soluble salts are generally considered to be undesirable components of fibrous sausage casings. Those skilled in the art believe that such salts reduce the strength of the fibrous casings. Therefore, those skilled in the art would not use chloride salts to replace propylene glycol to protect shells from mold.

According to the invention, not only are chloride salts added to the shell. Calculated amounts of chloride salts are added to give the shells a water activity low enough to protect the shells from mold growth.

The protective effect of the chloride salts is solely due to their ability to reduce the water activity of the high moisture casings to 0.81 or below, while the protective effect of the propylene glycol for the moisture containing casings is due to its antifungal property. As defined in U.S. Patent No. 4,409,251, the term antimycotic refers to a substance that has a direct toxic effect on mold organisms, regardless of their effect on water activity.

To demonstrate the known effectiveness of sodium chloride in controlling mold growth, a mold growth test was carried out in a culture dish.

A standard potato dextrose agar solution was used as the base medium into which various amounts of sodium chloride and polyol were introduced. The solutions of agar, salt and polyol were sterilized and treated with tartaric acid to adjust a ρθ of about 3.5 in the final agar medium.

The mold culture used as inoculant in this experiment was obtained in the following manner:

A mixture of mold spores of 31 different mold cultures in 1% sodium citrate solution was prepared using conventional aseptic procedures at a concentration of about 1 to 500,000 mold spores / ml of solution. Among the mold cultures in the mixture were Aspergillus niger (ATCC 1004), Chaetonium globosum (ATCC 16021), Memnoniella echinata (ATCC 11973), Myrothecium verrucaria (ATCC 9095), Trichoderma viride (ATCC 26921), and Whetzelinia sclerotiorum (ATCC 18657). Mold spores of 9 mold cultures found on various cellulosic food casings and mold spores of 16 mold cultures isolated as naturally occurring airborne contaminants in casing production were also added.

Test solutions of agar medium and mold inoculum were combined with sodium chloride alone (2.5, 5.7, 5.10 and 12.5%) and with propylene glycol alone (5, 7.5, 10, 12.5 and 15%) and with combinations both agents produced in the amounts shown in Table 1.

The test solutions were stored in covered trays for 7 days at ambient temperature and visually checked for mold growth.

The following Table 1 shows the results of these experiments, indicating the effect of salt and propylene glycol.

No. 377681 + = present mold growth

- = mold growth inhibited

Table 1:

<td rowspan="2">NaCl (%)</td><td colspan="4">propylene glycol</td><td colspan="2">(%)</td>

<td>0</td><td>5</td><td>7.5</td><td>10</td><td>12.5</td><td>15</td>

<td>0</td><td>+</td><td>+</td><td>+</td><td>+</td><td>+</td><td></td>

<td>2.5</td><td></td><td>+</td><td>+</td><td>+</td><td>-</td><td>-</td>

<td>5.0</td><td>+</td><td>+</td><td>+</td><td>-</td><td>-</td><td>-</td>

<td>7.5</td><td></td><td>+</td><td>-</td><td>-</td><td>-</td><td>-</td>

<td>10.0</td><td>+</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>

<td>12.5</td><td>+</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td>

These experimental results show that sodium chloride has distinct mold inhibiting properties when present in relatively small amounts along with other antifungal agents, in this case propylene glycol.

⁵ Example 1: This example shows that sodium chloride at a concentration of only 4% and calcium chloride at a level of 7% of the cellulosic content of the casing are effective as antifungal agents for fibrous casings having moisture contents greater than 30% based on the total weight of the casing.

This example further demonstrates that envelopes containing glycerol and water are resistant to mold ¹⁰ can be protected if the water activity A_w is controllably reduced by adding chloride salts to the shell. Thus, a relatively large moisture fibrous cellulosic casing having a relatively high moisture content, which contains enough moisture to stuff the casing in any manner without soaking before stuffing or adding moisture, can be stored stable and antimycotically protected by adding salts.

For this example, a number of pieces of shirred tubular fibrous cellulosic sausage casing with a maximum stuffing diameter of 12.1 cm were made with the components shown in Table 2 in the amounts specified therein. The casings were unwound from a wounded stock, the salt was introduced by slurrying the shell with a saline solution, and the moisture content was raised to the desired level,²⁰ by spraying water onto the outer surface of the envelope immediately before shirring. The amounts of glycerol in these samples were identical to the amounts of glycerin present as plasticizers in conventional fibrous cellulosic casings which are water-soaked before plugging. In none of the samples of this example was propylene glycol added.

Table 2:

<td rowspan="2">casing sample</td><td rowspan="2">glycerin w^IJ</td><td rowspan="2">humidity (%)²⁾</td><td rowspan="2">salt kind</td><td rowspan="2">(%)³)</td><td colspan="2">A calculated W</td><td rowspan="2">mold growth⁴)</td>

<td>without salt</td><td>with salt</td>

<td>A</td><td>29.0</td><td>42.7</td><td>no</td><td>0</td><td>0.91</td><td>0.91</td><td>+</td>

<td>B</td><td>27.0</td><td>33.3</td><td>NaCl</td><td>4.4</td><td>0.90</td><td>0.86</td><td>-</td>

<td>C</td><td>30.8</td><td>32.3</td><td>NaCl</td><td>4.1</td><td>0.89</td><td>0.84</td><td>-</td>

<td>D</td><td>28.5</td><td>39.4</td><td>NaCl</td><td>Λ9</td><td>0.90</td><td>0.83</td><td></td>

<td>e</td><td>29.7</td><td>38.4</td><td>NaCl</td><td>9.4</td><td>0.90</td><td>0.81</td><td></td>

<td>F</td><td>30.6</td><td>33.6</td><td>NaCl</td><td>8.4</td><td>0.89</td><td>0.80</td><td></td>

<td>G</td><td>30.6</td><td>31.7</td><td>NaCl</td><td>8.8</td><td>0.89</td><td>0.78</td><td>-</td>

<td>H</td><td>25.1</td><td>39.1</td><td>NaCl</td><td>18.1</td><td>0.91</td><td>0.77</td><td>-</td>

<td>I</td><td>28.8</td><td>32.8</td><td>NaCl</td><td>18.1</td><td>0.90</td><td>0.73</td><td>-</td>

<td>J</td><td>32.9</td><td>34.0</td><td>CaCl₂</td><td>16.5</td><td>0.90</td><td>0.79</td><td>-</td>

based on the total mass of the shell, based on cellulose, visible mold growth after 3 months at 35 ° C, + visible mold growth, - no visible mold growth.

- 8 - No.377681

Sheath samples used in the experiments of this example were gathered and compressed to reduce 53.34 m in length to 61 cm in length.

The mold inoculant for this experiment was prepared in the following manner:

Five separate suspensions of mold inoculans were used: Aspergillus niger (ATCC 1004), Aspergillus glaucus, Geotricum candidum, and Penicillium molds found in very wet sheaths were all used separately and then added to another mixed suspension containing Chaetonium globosum (ATCC 16021 ), Mennothecium verrucaria (ATCC 9095), Trichoderma viride (ATCC 26921) and Whetzelinia sclerotiorum (ATCC 18657). To this fifth inoculum were also added mold spores of 9 mold cultures isolated from mold found on various cellulosic food casings and mold spores of 16 mold cultures isolated from airborne contaminants in casing manufacturers.

The suspensions contained 1 to 5,000,000 colony forming units / ml of 1% sodium citrate solution and were prepared using standard aseptic procedures.

The sheath samples were inoculated by brushing several ml of each of the above-described mold suspension into 1.27 cm strips of the shirred surface in the longitudinal direction of each shirred sheath. Each of the five mold suspensions was inoculated in a separate strip on a shirred casing. After inoculation, each sheath was cut into 5 pieces perpendicular to the shirred length. Each piece was placed in a separate large glass hermitage glass, the jar sealed and stored at a constant temperature of 35 ° C. The results are shown in Table 2 above.

The results in Table 2 show that Envelope Sample A, the only sample without any added salt as an antifungal, was the only sample showing visible mold growth within 3 months. Envelope sample BI, which all contained enough sodium chloride antifungal, showed no visible mold growth within 3 months. The addition of the sodium chloride in the shells BI reduced the water activity A_w in these samples from the values ​​they would have without added salt, namely 0.89 to 0.91, at which levels mold growth would occur, at 0.73 to 0.86, at which levels no mold growth occurred within 3 months.

Shell Sample J contained calcium chloride as the antifungal and showed no visible mold growth. The calcium chloride in Sample J reduced the water activity from 0.90 where mold growth can be expected to 0.79 where no mold growth occurred.

The example shows that large, high moisture fibrous sausage casings can be protected by the addition of relatively small amounts of chloride salts.

Example 2: This example demonstrates that chloride salts other than sodium chloride can be used as antifungals for large fibrous high moisture cellulosic sausage casings.

Calculations were made by known methods to calculate the relationship between salinity and water activity and, if necessary, water activity was also determined experimentally. These relationships have been used to calculate the levels of various chloride salts to protect moist fibrous sausage casings on the assumption that a water activity of 0.75 will provide effective antimycotic protection of the casing, as determined by other attempts in connection with the Invention proved.

In carrying out the experimental work, the water activities of solutions of the chloride salts MgCl₂ , NH₄C1 and CaCl₂ by measuring the relative humidity with a Sina moisture meter, and the values ​​of water activity for solutions of KCl and NaCl were taken from the literature of Sloan and Labuza, Food Product Development, December 1975, p.68.

The data were plotted on Cartesian co-ordinates as a set of curves, with each

Curve represents a chloride salt, and the relationship between the water activity and the ratio of water: salt, expressed in g of water / 100 g of anhydrous solid salt, is shown. The drawing shows this graphic data.

Using the drawing of the known composition of the fibrous sausage casing

No.377681 and water activity, the amount of each chloride salt was calculated according to the method of Ross described to protect a moist fibrous casing at various moisture contents and a content of 33% glycerol. The calculations were based on the use of a single chloride salt in each case and the assumption that a water activity of 0.75 is low enough to protect the shell for 10 months storage at 35 ° C.

Table 3 below summarizes the calculations of this example.

Table 3:

<td rowspan="3">wt. Moisture content (% of total mass)</td><td rowspan="3">water activity without salt</td><td colspan="5">required conc, of chloride salt for A_w = 0.75</td>

<td rowspan="2">NaCl</td><td colspan="3">Wt.% Based on d. Cellul.)</td><td rowspan="2">KCl</td>

<td>MgCl₂</td><td>NHi, CI</td><td>CaCl₂</td>

<td>20</td><td>0.79</td><td>2.0</td><td>2.9</td><td>3.1</td><td>4.1</td><td>2.6</td>

<td>25</td><td>0.83</td><td>5.4</td><td>6.7</td><td>8.0</td><td>9.7</td><td>8.3</td>

<td>30</td><td>0.87</td><td>10.4</td><td>11.3</td><td>16.7</td><td>18.5</td><td>21.0</td>

<td>40</td><td>0.90</td><td>22.6</td><td>22.0</td><td>33.2</td><td>35.9</td><td>68.7</td>

The data of Table 3 show that the amount of chloride salt required to protect a high moisture fibrous sausage casing, as appropriate for a plug without addition of further soaking or pre-plugging, depends on the moisture content of the casing. In general, 20 to 25% total mass based moisture was found to be suitable for large cellulosic fibrous casings without pre-stuff soaking or wetting.

As can be seen from the data in Table 3, the amount of chloride salt differs for protection against mold growth, depending on the nature of the chloride salt of this example. It is noteworthy that less sodium chloride is required to achieve an antifungal effect than other chloride salts. Only 2% by weight based on the cellulose is required to protect a shell having a moisture content of 20%. In contrast, it can be seen that larger amounts of other salts are required for shell protection. It can be seen that at a humidity range of 20 to 25% and with the preferred chloride salt sodium chloride, 2.0 to 5.4% by weight of sodium chloride based on the cellulose is required to protect the shell.

Example 3: To compare the utility in the practical processing of a tubular fibrous cellulose casing according to the invention containing 5% sodium chloride and 25% moisture to an identical casing with propylene glycol as antifungal, experiments were carried out.

In the preparation of the salt-protected casings, fibrous cellulosic sausage casings with a maximum packing diameter of 8.28 cm were treated with a solution containing 8.8% sodium chloride, 2% glycerol and 89.2% water to give desired values ​​of 5% by weight. % Sodium chloride based on the cellulose and 25% moisture based on the total mass.

Sheath samples A and B for this example were shirred compressed casings 53.34 m in overall length, compressed to 61 cm in length, and enclosed in an elastic packaging material. A plastic disk was inserted into one end of each shirred piece and this end was closed with a metal lock. The behavior of the two samples during shirring, compression, encasing in the elastic packaging material, insertion of the disc and sealing was identical.

The content of sodium chloride, propylene glycol and moisture of the two sample casings A and B is summarized in Table 4.

Table 4:

<td>casing sample</td><td>Sodium chloride (%) Ö</td><td>Water (%) ^^</td><td>Glycerine (%)¹)</td><td>Propylene glycol (%)¹)</td>

<td>A</td><td>4.9</td><td>25.5</td><td>39.3</td><td>0</td>

<td>B</td><td>0</td><td>24.0</td><td>37.9</td><td>7.2</td>

Ö based on the cellulose, based on the total mass of the shell.

Nr.377681

The sample tubes of this example were then placed on an automatic tamping machine

Bolognese sausage emulsion filled. The stuffing of the two cases was the same. The diameters of both stuffed sausages, measured before and after smoking the products, were identical. Also, the color and appearance of the sausage samples from cases A and B were the same.

This example shows that a shirred fibrous sausage casing containing 5% by weight based on the

Contains cellulose at sodium chloride and 25% based on the total amount of moisture, just as fully functional as a same shell containing as an antifungal agent propylene glycol when processed in a modern stuffing equipment for large sausage products without soaking before stuffing.

Example 4: This example demonstrates that a chloride salt applied to the inner surface of a fibrous cellulosic sausage casing migrates through the wall of the casing and is found on the outer surface of the casing. Such migration of the choride salt is necessary when the salt is to be applied to a surface, but to prevent mold growth on both surfaces.

In carrying out this experiment, a 84 cm piece of fibrous sausage casing with a moisture content of 6% based on the casing mass on the inner surface was treated with 75 ml of a saturated sodium chloride solution by means of a slurry technique. The sheath was opened and the 75 ml saline solution was contacted with all parts of the inner surface for a short time, after which the excess saline solution was discarded.

After slurrying, the outer surface was examined at intervals with the tongue and the taste sensation was determined. Each time a different part of the envelope surface was tested. The results are shown in Table 5.

Table 5:

Time after treatment (s) taste of outer shell surface

<td>5</td><td>just sweet, no salt</td>

<td>20</td><td>just sweet, no salt</td>

<td>30</td><td>more sweet than salty</td>

<td>45</td><td>more sweet than salty</td>

<td>55</td><td>more sweet than salty</td>

<td>80</td><td>more sweet than salty</td>

<td>100</td><td>more salty than sweet</td>

<td>120</td><td>more salty than sweet</td>

<td>150</td><td>just salty, not sweet</td>

<td>180</td><td>only very salty.</td>

This example illustrates the migration of an internal saturated sodium chloride solution to the outer surface of a shell. In the first 20 seconds after application of the saline solution, only the sweet taste of the glycerine on the outer surface of the envelope could be noticed. 30 to 80 s after application, the salt could be detected in the presence of the more sweet taste of glycerol. The salt taste was stronger than the sweet taste of the glycerin 80 to 120 s after being applied. After 150 seconds, the salty taste was so strong that the sweet taste of the glycerine could no longer be observed. After 180 seconds, the salty taste was even stronger. After 180 seconds, the envelope was cut open so that both the inner surface and the outer surface could be tasted.

Thus, salt applied to the inner shell surface is easily found on the outer shell surface and therefore can prevent mold growth on both shell surfaces.

Example 5: This example demonstrates that the inclusion of chloride salts in high moisture fibrous cellulosic sausage casings has no adverse effect on the tear strength of the casing.

In the production of fibrous cellulosic sausage casings is thoroughly washed before drying. One purpose of this washing step is to remove sulphate salts from the gelatinous shell (No.377681). Such salts, prior to the date of the invention, have been accepted by those skilled in the art as possible factors in reducing the strength of the shell. This

Example shows that by the inclusion of chloride salts as antimycotics in highly moist fibrous cellulosic sausage casings, which without soaking in water or other moisture addition before ⁵ the plug can be stuffed, no unwanted reduction in strength occurs.

Fibrous sheaths of Examples 1 and 3 were selected for tear strength measurement. The covers were inflated with air and the pressure at which the cover burst was recorded. The results are shown in Table 6.

Table 6:

<td>casing sample</td><td>Type d. salt</td><td>Amount of salt (% based on Cellul.)</td><td>Burst pressure (mm Hg)</td>

<td>1A</td><td>none</td><td>0</td><td>530</td>

<td>IE</td><td>NaCl</td><td>9.4</td><td>534</td>

<td>1H</td><td>NaCl</td><td>18.1</td><td>515</td>

<td>1y</td><td>CaCl₂</td><td>16.5</td><td>522</td>

<td>3A</td><td>NaCl</td><td>4.9</td><td>771</td>

<td>3B</td><td>none</td><td>0</td><td>745</td>

The shells ΙΕ, 1H, 1J and 3A containing chloride salts have burst pressures that are not significantly different from those of control sheaths 1A and 3B which do not contain chloride salts. The substantially equal observed burst pressure indicates that no adverse effect of the chloride salts on shell strength occurs. The test samples showed no brittleness due to the presence of the chloride salts.

¹⁵ Example 6: This example shows that protection of high moisture fibrous casings that are not soaked prior to stuffing is also achieved prior to mold deterioration when an antifungal solution of a chloride salt is added directly at the opening of a shirred casing. Effective protection is achieved despite observed uneven application of the antifungal saline solution. The direct addition of antifungals to the shirred²⁰ Shell is in contrast to the usual method of addition by uniform impregnation of the shell with the solution before shirring and therefore represents another embodiment of the implementation of the invention.

In the production of sheaths for this example, 15.3 cm long pieces of shirred tubular fibrous cellulosic sausage casing with a maximum stuffing diameter ²⁵ of 12.1 cm, a moisture content of 12% based on the total casing mass and a glycerol content of 29.5% based on the cellulose used. In order to obtain shells with different moisture and chloride salt contents, the sample solutions were added at the openings of the shirred sheaths. The addition was made as evenly as possible over the entire length of the shirred casing, and the casings were rotated about their longitudinal axis after the addition, thus³⁰ the solution can penetrate into the shell as evenly as possible. Despite all these precautions, a tendency was found for the solution to collect in the gathered wrinkles.

After a 4-week equilibration period in a plastic wrap, the skin samples were inoculated with mold cultures, minced, stored at 35 ° C, and tested for visible mold growth as described in Example 1.

³⁵ It was observed that the results of the mold growth in this example are comparable and consistent with the results obtained in Example 1, where a saline solution was uniformly applied to the shell surface prior to shirring. Envelope sample A, which had no salt added as an antifungal, showed a visible mold growth because of its high water activity of 0.89. The shell sample B, to which no salt was added, showed

4 ° no mold growth due to their lower water activity of 0.84. Shell samples C to G contained salt as an antifungal and did not show mold growth because of their low water activities. The observed uneven addition of saline as an antifungal agent by direct addition into the opening of shirred casings did not affect the results of mold growth in terms of the water activity of the casing.

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The uneven addition of chloride salt solution thus does not prevent the chloride salt acts as an antifungal in not pre-stuffed sheaths.

Table 7:

<td>sample cover</td><td>Humidity (%)</td><td>Glycerine (%)²^</td><td>NaCl (%)²⁾</td><td>A_w calc.</td><td>q) Mold is growing. '</td>

<td>A</td><td>34.0</td><td>29.5</td><td>0</td><td>0.89</td><td>+</td>

<td>B</td><td>24.0</td><td>29.5</td><td>0</td><td>0.84</td><td>-</td>

<td>C</td><td>34.0</td><td>29.5</td><td>5.9</td><td>0.83</td><td>-</td>

<td>D</td><td>24.0</td><td>29.5</td><td>2.4</td><td>0.80</td><td>-</td>

<td>e</td><td>34.0</td><td>29.5</td><td>9.8</td><td>0.79</td><td>-</td>

<td>F</td><td>24.0</td><td>29.5</td><td>4.5</td><td>0.78</td><td>-</td>

<td>G</td><td>34.0</td><td>29.5</td><td>14.4</td><td>0.76</td><td>-</td>

1) 2) 3) Based on the total mass, based on the cellulose, 'mold growth after 13 months at 35 ° C.

Example 7: This example deals with the recent study of envelopes of Example 1, ⁵ which were examined for 3 months storage at 35 ° C and after 6, 8 and 10 months for mold growth. Table 8 below summarizes the HUUS samples of Table 2 of Example 1, with all values ​​given in Table 2 remaining the same and only visible mold growth after further storage periods, along with those obtained after 3 months