CH654268A5 - CELLULOSE RESISTANT TO MOLD RESISTANT AND MOISTURIZED IN A SPECIFIED MANNER. - Google Patents

Description

This invention relates to improved food envelopes and more particularly large, tubular, cellulose food envelopes, particularly fibrous food envelopes, which are moistened in a controlled manner to avoid the need to soak them before stuffing or stuffing, and they are treated with chloride salts as antimycotic agents to inhibit the formation and spread of molds, yeasts and bacteria which would otherwise tend to grow in such humidified envelopes.

Artificial food wraps used around the world in the processing of a wide variety of meats and other food products, such as sausages of various types, cheese rolls, turkey rolls and the like, are usually prepared from regenerated cellulose and other cellulose materials. The envelopes are of several types and of different dimensions to accommodate the different categories of food products to be prepared and are produced in a support form 45 or without support, the support envelopes, generally known as fibrous envelopes, having a sheet of fibrous support embedded in the wall of the envelope.

A common feature of many processed food products, particularly meat products, is that the so mixture of edible ingredients, usually called an emulsion, is stuffed or stuffed in a pressure envelope, and the processing of the food product takes place after wrap. The food product can also be stored and transported when wrapped in the envelope, although in many cases, and particularly with small sausages, such as frankfurters, the envelope is removed from the food product. once the treatment is finished.

The designation small food envelopes generally relates to these envelopes used in the preparation of small products 60 in the form of small sausages, such as frankfurters. As the name suggests, this type of food wrap has a small packing diameter, generally around 15 to 40 mm in diameter, and is most often produced in the form of thin-walled tubes of very large length. -65 cheers. For ease of handling, these envelopes, which can be 20 to 50 m or more in length, are rubberized and compressed to produce what are generally called rubberized envelope sticks of about 20 to about 60 cm

3

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length. Rubberization machines and their products are illustrated in US patents Nos. 2983949 and 2984574, among others.

Large food envelopes, the usual designation for envelopes used in the preparation of generally larger food products, such as salamis and bologna, meatloaf, cooked and smoked hams, and others, are produced with a filling diameter of about 50 to about 200 mm, or even more. In general, such envelopes have a wall having a thickness approximately three times greater than the thickness of the walls of small envelopes and are provided with a fibrous sheet-like reinforcement embedded in the wall, although they may be prepared without such a support means. Traditionally, large tubular casings have been supplied to the food processor under flat conditions, cut into predetermined lengths of about 0.6 to about 2.2 m. Improvements in rubberization and packaging techniques, and the increasing use of automatic tamping equipment have increased the demand for large envelopes of both types, fibrous and unsupported, in the form of rubberized sticks or rods containing up to 'at about 30 m and even more envelopes.

Large tubular food envelopes of cellulosic material suitable for use as the envelopes of the present invention can be prepared by any of a number of known methods. The envelopes are flexible, seamless tubes formed from regenerated cellulose, cellulose ethers and the like, and can be prepared by known methods, such as the cuprammonium process, deacetylation of cellulose acetate, denitration cellulose nitrate and preferably the viscose process. Tubular envelopes reinforced with fibers such as rice paper and the like, hemp, rayon, flax, sisal, Nylon, polyethylene terephthalate and the like are advantageously used in applications where food envelopes are required , tubular, of large diameter. Fibrous tubular casings can be manufactured by methods and with apparatuses described, for example, in U.S. Patents Nos. 2105273, 2144899, 2910380, 3135613 and 3433663.

As is well known in the art, tubular cellulose casings prepared by any of the well known methods are generally treated with glycerin, as a moisturizing agent and as a softener or plasticizer, to give a resistance to drying or cracking of the envelope during storage and handling before stuffing. Treatment with glycerin is usually carried out by passing the envelope while it is still in its gel state through an aqueous solution of glycerin, after which the plasticized envelope is dried until a predetermined content is obtained. moisture before further processing or winding on storage reels. Generally, large tubular casings contain about 25 to 35% glycerin based on the weight of dry cellulose and have a moisture content of about 5 to 10% based on the total weight of the casing, before be moistened for stuffing.

In the preparation and use of artificial food envelopes, particularly small envelopes made of regenerated cellulose, the moisture content of the envelopes is of extreme importance. When small size cellulose envelopes are produced, they are generally required to be dried to a relatively low water content, usually in the range of about 10 to 13% by weight, to allow rubberization to be carried out without damaging the envelopes. To allow the rubberized envelope of small, compressed, rubberized cellulose to be uncut, and to prevent tearing and breakage of the envelope during tamping operations, small rubberized envelopes having an average moisture content of between about 14 and 18% by weight are used. This moisture content in a relatively narrow range is important, because it has been found

that an excessive number of casing breaks occurred during stuffing with lower moisture contents, and a higher moisture content results in excessive plasticity of the casing material and excessive stuffing.

Several patents have been filed in recent years which have addressed the problem of the moisture content of small, tubular rubberized food wrappers, and have suggested several methods of obtaining and maintaining the desired level of humidity during storage. and transportation. For example, in American patents Nos. 2181329 of Hewitt, 3250629 of Turbak and 3471305 of Marbach, packaging means are described and allow a plurality of rods of rubberized envelopes of small, tubular envelopes, d 'be' moistened while being wrapped. In American patents 15 Nos 3222192 from Arnold, 3616489 from Voo et al., 3657769 from Martinek and 3809576 from Marbach et al., Several means are described for moistening the food envelopes before or during the rubberizing operation.

The present invention relates to so-called large food casings which, in order to be properly packed, require relatively high moisture contents, generally greater than about 20%. Large food envelopes are characterized by relatively thicker walls than the walls of small food envelopes and, therefore, require higher moisture contents, to provide the extensibility required for tamping operations without causing undesirable levels of internal pressure. This invention relates to the class of envelopes identified by the designation large food envelopes and particularly those of the fibrous type.

Large envelopes, traditionally supplied in short lengths of substantially dry flattened tubing, are very stiff in the dry state and are softened for tamping operations by soaking them in water to increase the moisture content up to 35 at or near full saturation. Hitherto there has been no need to provide such envelopes with a predetermined moisture content, and humidification controlled by the envelope manufacturer in the production of short cut lengths or large rubberized lengths of envelopes large di-40 mension was not ensured. More recently, however, the more general use of automatic product stuffing equipment using large tubular food envelopes, and the growing demand for these envelopes in longer lengths in the rubberized form, compared to the 45 Short flat feeders, which have been used for a long time, have highlighted the problems concerning the humidification of these envelopes by soaking just before the tamping operation. In addition, the need for greater control over all aspects of the manufacture and use of large food envelopes 50 has become increasingly pressing. For example, the uniformity of the dimensions of stuffed food envelopes and the food products treated inside have become increasingly important problems in the commercial field and, more particularly, in the subsequent treatments concerning the packaging of the product 55 with automatic determination of the weight and number of slices. The moisture content of the envelope has been found to be a factor in controlling product uniformity and stuffing of the envelopes economically and continuously, without damaging or breaking the envelopes, and achieving 6o reproducible results. consistently.

The manufacture of small, rubberized envelopes with a relatively narrow range of moisture content uniformly distributed and required for tamping operations has been most efficiently and economically carried out by the manufacturer. envelopes during manufacture, rubberizing, or packaging of the envelopes. It has become increasingly evident that the benefits of controlled humidification from small envelope technology can be realized.

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worn on large envelopes, if means were developed and made available to the envelope manufacturer to manufacture large envelopes, both in flattened and rubberized forms which could be ready for use in tamping operations or stuffing the envelopes, particularly almost entirely automated stuffing operations, without the need to soak the envelopes just before the stuffing and without the caterer needing to carry out other manipulations of the manual type.

Although the envelope manufacturer has not considered it necessary in the past, because quenching before stuffing large envelopes has been universally accepted, to maintain the moisture content of large food envelopes in a particular critical range, it is known, as mentioned above, that somewhat higher humidity contents are required to allow the desired flexibility to be given to such envelopes in contrast to the humidity contents required for small envelopes. Since larger amounts of water and therefore greater weight significantly increase the costs of packaging, handling, storing and transporting the envelopes, it is important to moisten the envelopes to an appropriate degree , but not beyond what is necessary.

Another problem which arises during the handling and processing of large food envelopes, made of cellulose, with a high moisture content, relates to the growth or development of molds, yeasts or bacteria, since a high humidity is one of the factors necessary to induce or promote such growth or development on cellulose envelopes. It is known, for example, that cellulose food envelopes have a critical moisture content above which the development of destructive microorganisms - during storage periods - is greatly promoted. Generally, the critical moisture content is lower for molds than for yeasts and bacteria, so that a moisture content preserving the envelopes from deterioration, or damage, by molds will also protect the envelopes from damage by yeasts or bacteria. Keeping the moisture content of cellulose envelopes below a predetermined level, generally less than about 20% by weight of moisture based on the total weight of the envelope, has been found to be an effective measure for control the development of such growth. In cases where the moisture content cannot be limited to inhibit such growth, for example when intentionally higher moisture contents are given, or when higher moisture concentrations may occur in stored envelopes because of the varying temperature differences over sections of the envelope, it is necessary to provide other means to inhibit the growth of spoilage microorganisms.

Therefore, large, tubular, cellulose food wrappers and, in particular, fibrous tubular wraps which can be stuffed with a substantially fully automatic stuffing machine, without damage or breakage, can be advantageously produced with i) Moisture contents which allow adequate flexibility and avoid the need to go through the so far usual soaking step, just before stuffing, and also with ii) suitable means to inhibit the growth of molds or other semi-cro- organisms during periods of transport, handling and storage.

The problem of mold growth in food products due to the presence of foods or nutrients that promote microorganisms and cause spoilage of food has been the subject of several studies for many years. Various treatments have been evaluated and recommended, including combinations of sugars and polyhydric alcohols as inhibiting agents to prevent the growth of microorganisms generally recognized to be responsible for spoilage or spoilage of food. The antimycotic treatment of cellulose food envelopes presents additional and more complex problems because of the treatment techniques used in the preparation and stuffing of the envelopes. Some suggestions for overcoming these problems and performing the antimycotic treatment of envelopes used for sausage products or, in some cases, to prevent the growth of mold on the surface of sausages after stuffing, are the subject of several patents. For example, in American patent N ° 3617312 of Rose, an antimycotic agent is applied to the envelopes of cellulose like component of a polymer-risable coating insoluble in water and, in the American patent N ° 3935320 of Chiù et al., water-insoluble polymerized cationic thermoprocess resin coatings applied to the surfaces of the envelopes reduce the deterioration caused by the enzymatic action. Also described is the antimycotic treatment of envelopes moistened in a determined manner with aqueous solutions of various agents including, inter alia, a propylene glycol and the propionates and sorbates of potassium, sodium and calcium. An important distinction to note with respect to these aforementioned references is that US Patent No. 3617312 relates to preventing the growth of mold on the surface of sausages after stuffing and does not relate to preventing the growth of micro- organisms of damage or deterioration in the envelope of the sausage before stuffing, as is the case in the present invention.

The inclusion of moisture in the envelope in any degree or quantity gives rise to consideration, among other things, of the phenomenon known as water activity. The water activity represented by the symbol Aw is defined as the ratio between the partial pressure of water vapor in a solution and the pressure of pure water vapor, both measured at the same temperature . It is used in conjunction with the description of the present invention insofar as it represents an advantageous and useful parameter for quantifying the humidity levels in the envelopes treated with chloride salts according to the technique of the invention. Literature references dealing with the phenomenon of water activity are found in detail in Ross, "Estimation of Water Activity In Intermediate Moisture Foods", in 40 "Food Technology", March 1975, p. 26, and in No. 41 of the "Journal of Food Science", p. 352, May-June 1976.

The present invention is based on the use of chloride salts as well as preselected amounts of moisture added to the envelope prepared according to the invention to lower con-45. controls the activity of water, Aw, up to a level, measured with the specific level of humidification of a given envelope, at which mold growth is inhibited during the expected shelf life of the envelope .

The invention relates to a large, tubular, fiber-reinforced cellulose food envelope which is pre-wetted by the addition of carefully controlled amounts of wetting water to a degree or value that allows for stuffing. of the envelope without the need to soak the envelope before stuffing. The humidity added in a specific manner can vary from a value of approximately 20% to a value of approximately 40% of the total weight of the envelope. A preferred range of moisture content in the envelopes is between about 20 and about 25%. A chloride salt, selected from the group consisting of sodium chloride, magnesium chloride, ammonium chloride, calcium chloride and potassium chloride, is preferably added by inclusion in water. humidification, and the solution is applied to the envelope by one of the many known methods, such as by atomization or by loading or by a combination of the two, for example. The particular chloride salt used, the target humidity level selected for the shell and, to some extent, the expected shelf life of the shell determine the salt concentration required to maintain the activity of

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water, Aw, in the envelope, at a sufficiently low value, preferably not exceeding approximately 0.75, to ensure protection against the growth of mold.

Sodium chloride has been found to be most effective, in that relatively small amounts, from about 2 to about 22.6% of the weight of the cellulose in the shell, provide protection against mold growth in envelopes, with moisture contents of from about 20 to about 40% of the total weight of the envelope while maintaining the activity of the water in the envelope, Aw, at about 0.75. In addition, sodium chloride is a normal constituent of processed foods and is an accepted additive in envelopes.

Higher concentrations of other chloride salts are necessary to effect inhibition of mold in similarly humidified envelopes, keeping Aw at a value not exceeding about 0.75: magnesium chloride of 2.9 about 22.0% or so; ammonium chloride from about 3.1 to about 33.2%; calcium chloride from about 4.1 to about 35.9%, and potassium chloride from about 2.6 to about 68.7% of the weight of the cellulose in the shell, to obtain the same results in general.

Example I:

In order to demonstrate the effectiveness of sodium chloride in inhibiting mold growth, a mold growth test was performed in a culture dish.

A conventional potato agar / dextrose solution was used as the base medium in which varying proportions of sodium chloride and polyol were incorporated. The solutions of the agar and salt and polyol components were sterilized and tartaric acid was added to the combined solutions to obtain a pH of about 3.5 in the final agar medium.

The mold culture used as an inoculant in this test was prepared as follows: a mixture containing 31 different mold spores in a 1% sodium citrate solution was prepared using conventional aseptic methods with a concentration of about 1 to 5 million mold spores per milliliter of solution. Among the mold cultures included in the mixture are Y Aspergillus niger (ATCC N ° 1004), Chaeto-nium globosum (ATCC N ° 16021), Memnoniella echinata (ATCC N ° 11973), Myrothecium verrucaria (ATCC N ° 9095), Trichoderma viride (ATCC No. 26921) and Whetzelinia sclerotiorum (ATCC No. 18657), all purchased from the American Type Culture Collection, Rockville, Maryland. Also included were mold spores from nine mold cultures which were isolated from mold contamination found on various cellulose food wraps, and mold spores from sixteen mold cultures which were isolated as natural contaminants. found in the air, obtained in places of manufacture of envelopes.

Test solutions of agar medium and mold inoculum were prepared with sodium chloride and propylene glycol separately, and in cross-combined concentration changes of 0, 2.5, 5, 7.5 , 10.12.5%, and in a 15% propylene glycol only, by total weight of the test solution.

Test solutions were stored in covered cuvettes for 7 d at room temperature and monitored visually to monitor the growth of mold.

Table 1, below, illustrates the results of the test.

(Table at the top of the next column)

The results of these tests illustrate that sodium chloride has obvious mold-inhibiting properties when it is present in relatively small amounts with another antimycotic agent, for example propylene glycol.

Table 1

Studies of mold growth in culture dishes - effect of propylene salt and glycol

NaCl concentration (%)

Propylene glycol concentration (%) 0 5 7.5 10 12.5 15

0

+

+

+

+

-

2.5

+

+

+

+

-

-

5.0

+

+

+

-

-

_

7.5

+

+

-

-

-

-

10.0

+

-

-

-

_

-

12.5

+

-

-

-

-

-

Negative blank order = no growth Legend: + = presence of mold growth - = mold growth inhibited

Example II:

This example demonstrates that sodium chloride in a concentration as low as 4% and calcium chlorine at 7% of the cellulose content of the envelope are effective antimycotic agents for fibrous envelopes with moisture contents greater than about 30% by total weight of the envelope.

This example also shows that envelopes containing glycerol and water can be preserved against deterioration by molds, if the activity of water, Aw, is reduced in a controlled manner by incorporation in the envelope of chloride salt. Thus, a large, highly humidified, fibrous cellulose envelope containing sufficient moisture to stuff the envelope without having to soak it before packing or without having to add additional moisture in one way or another. , can have a stable shelf life and be antimycotic protected with salt additives.

As an experimental preparatory work for this example, several pieces of sausage envelopes, made of fibrous cellulose, tubular, rubberized, size 8, having a maximum stuffing or stuffing diameter of 4.76 in, or 12.1 cm, with the proportions of the ingredients appearing in table 2 below, were prepared by unwinding the lengths of envelopes of a flat width supply reel, by introducing the salt by loading the envelope with a solution of a salt and raising the moisture content to the target level by spraying water on the outer surface of the envelope just before it is rubberized. The glycerol levels in these experimental shell samples were identical to the glycerol levels included as a softener in a conventional fibrous cellulose shell which must be soaked in water before packing. There was no propylene glycol included in these envelope samples in this example.

(Table at the top of the next page)

The envelope samples used in the experiment in this example were rubberized and compressed to make 175 ft (53.34 m) of envelope lengths into 24 in (61 cm) lengths of rods wrapped in elastic sheaths.

The mold inoculant from this experiment was prepared as follows: five separate suspensions of mold inoculants were used. Aspergillus niger (ATCC No. 1004), Aspergillus glaucus, Geotricum candidum and a species of Penicillium mold found in envelopes with high humidity were all used separately and then added to an additional mixed suspension containing Chaetonium globosum (ATCC No. 16021), Memnoniella echinata (ATCC No 11973), Myrothecium verrucaria (ATCC No 9095), Trichoderma viride (ATCC No 26921) and Whetzelinia sclerotiorum (ATCC No 18657). Also included in this fifth inoculant were mold spores from nine mold cultures that had been isolated from mold contamination found on various cellulose cellulose envelopes, and

5

10

15

20

25

30

35

40

45

50

55

60

65

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Table 2

Observations of mold growth on casings for sausages, in fibrous cellulose with high moisture content,

preserved with chloride salts

Envelope sample

Glycerol (% cellulose)

Humidity (% of total envelope weight)

Chloride type

Amount of salt (% cellulose)

Water activity (Aw)

Growth3 '

visible from molds no salt added

added salt

AT

29.0

42.7.

no

0

0.91

0.91

+

B

27.0

33.3

NaCl

4.4

0.90

0.86

-

VS

30.8

32.3

NaCl

4.1

0.89

0.84

-

D

28.5

39.4

NaCl

7.9

0.90

0.83

-

E

29.7

38.4

NaCl

9.4

0.90

0.81

-

F

30.6

33.6

NaCl

8.4

0.89

0.80

-

G

30.6

31.7

NaCl

8.8 18.1

0.89

0.78

-

H

25.1

39.1

NaCl

0.91

0.77

-

I

28.8

32.8

NaCl

18.1

0.90

0.73

-

J

32.9

34.0

CaCl2

16.5

0.90

0.79

-

a) after 3 months 35 "C + = visible growth of molds - = no visible growth of mold spores of molds from sixteen mold cultures isolated from contaminating agents carried by the ambient air obtained in envelope manufacturing premises.

The suspensions contained from one to five million units 25

forming colony per milliliter of 1% sodium citrate and were prepared using conventional aseptic methods.

The cultures identified by the ATCC designations were purchased from the American Type Culture Collection, Rockville, Maryland. 30

The envelope samples were inoculated by brushing several milliliters of each of the mold suspensions described above into the in (1.27 cm) strips of rubberized surface along the length of each rubberized rod. Each of the five mold suspensions was inoculated into a separate strip over a length of rubberized casing. After inoculation, each inoculated envelope was cut into five slices perpendicular to the length of the rubberized rod. Each slice was placed in a large mouth-opening, closed and 4Q canister stored at a constant temperature of 35 ° C. The results of mold growth are illustrated in Table 2 above. Results were recorded as positive (+) if visible mold growth could be seen in any of the five regions where the separate mold suspensions 45 had been inoculated, and negative (-) if mold growth did not occur. was not visible in any of the inoculated regions.

The results in Table 2 illustrate that the envelope sample A, the only sample that received no salt as the antimycotic agent, was the only sample that had visible growth of 50 molds within three months. The Bài envelope samples, all of which had sufficient sodium chloride (NaCl) added as an antimycotic agent, did not show visible mold growth within three months. The incorporation of sodium chloride in the Bài envelopes reduced the water activity, 55 Aw, in these samples from what it would have been if salt had not been added, from 0.89 to 0, 91, values at which mold growth occurs, up to 0.73 to 0.86, values where no mold growth occurred within three months.

The J envelope sample had calcium chloride incorporated as an antimycotic agent and did not show visible mold growth. Calcium chloride in sample J reduced water activity, Aw, from 0.90, the value at which mold growth occurs, to 0.79 where no mold growth occurs. took place. 65

The example illustrates that fibrous envelopes of large sausages, with high humidity, can be preserved by incorporating relatively small amounts of chloride salts.

Example III:

This example included experimental work done to show that chloride salts other than sodium chloride can be used as antimycotic agents for large, fibrous cellulose sausage husks with high humidity.

Basic data calculations were carried out according to known methods to establish the relationship between the salt content and the activity of water, Aw, also determined experimentally, when necessary. The relationships were used to calculate the amounts of the various chloride salts required to preserve envelopes of fibrous sausages at high humidity, based on the estimate, reinforced by another experimental work carried out within the framework of this invention, according to which a water activity, Aw, of 0.75 is an indication of effective antimycotic protection of the envelope.

By carrying out the experimental work of this example, the solutions of the chloride salts MgCl2, NH4C1 and CaCl2 had a water activity, Aw, values determined by measuring RH with a Sina humidity detector, and the activity values of the water for the KCl and NaCl solutions was introduced according to the values reported by Sloan and Labuza, "Food Product Development", December 1975, p. 68.

The data were projected onto Cartesian coordinates in the form of a family of curves, each curve representing one of the chloride salts, illustrating the relationship between the activity of water, Aw, and the water / salt ratio expressed in grams. of water per 100 g of anhydrous solid salt. Fig. 1 illustrates these reported data.

Using fig. 1, the known composition of the fibrous sausage envelope and the water activity, Aw, the calculation method described by Ross, the amount of each chloride salt required to preserve fibrous envelopes at high humidity for levels different humidity and 33% glycerin was calculated. The calculations were based on the use of a single chloride salt in each case, and it was assumed that a water activity, Aw, 0.75 was low enough to preserve the envelope for six months of storage at 35 ° C.

Table 3 below summarizes the calculations in this example.

(Table at the top of the next page)

The data in Table 3 illustrates that the amount of chloride salts required to preserve a high humidity fibrous sausage wrap, capable of being packed without soaking or further wetting before packing, depends on the moisture content of the jacket. Generally, a humidity between about 20 and about 25% of the total weight of the casing has been found to be the advantageous range of moisture content for

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Table 3

Chloride salt contents of envelopes required to reduce water activity in the envelopes, A ,,. ,, up to an envelope conservation value of A „, = 0.75

Humidity, envelope target (% of total envelope weight)

Water activity in the salt-free envelope

Chloride salts (% by weight of cellulose) required to reduce the final water activity in the envelope to an Aw value = 0.75

NaCl

MgCl2

NH4C1

CaCl2

KCl

20

0.79

2.0

2.9

3.1

4.1

2.6

25

0.83

5.4

6.7

8.0

9.7

8.3

30

0.87

10.4

11.3

16.7

18.5

21.0

40

0.90

22.6

22.0

33.2

35.9

68.7

large fibrous cellulose envelopes which can be used without additional soaking or moistening before stuffing.

The quantity of chloride salts required for preserving the envelopes against mold growth, this can be verified with the aid of Table 3, differs according to the different chloride salts used in this example. It should be noted that less sodium chloride is required to obtain an antimycotic effect than is the case with other chloride salts. As little as 2% by weight of envelope cellulose is required to preserve the envelope with a moisture content of 20%. In contrast, it can be seen from the table that larger amounts of other salts are required for the preservation of the envelopes. It can be noted that, in the humidity range of between 20 and 25% approximately and with the preferred chloride salt, sodium chloride, between 2.0 and 5.4% of sodium chloride by weight of envelope cellulose for preserving envelopes.

Example IV:

An experiment was carried out to compare the practical working utility of a tubular fibrous cellulose casing prepared according to this invention, containing 5% sodium chloride and 25%

humidity with an identical envelope containing propylene glycol as an antimycotic agent, prepared according to American invention application No. 686248.

When preparing the salt-protected shell sample, a length of reel of cellulose, fibrous, tubular, size 4 sausage wraps with a maximum packing diameter of 3.26 in (8.28 cm) was treated with 8.8% sodium chloride, 2% glycerol, 89.2% water solution to give the target envelope values of 5% sodium chloride by weight of cellulose, and 25 % humidity based on the total weight of the envelope.

Envelope samples A and B for this example were rubberized, compressed to give 175 ft (53.34 m) of envelopes in a 24 inch (61 cm) rod length and wrapped in elastic sheath material. A plastic dimensional disc was inserted into one end of each rubberized length and this end was closed with a metal clip. The behavior of the two samples during rubberizing, compression, covering or packaging with elastic sheaths, insertions of the dimensional discs and stapling, were identical.

The contents of sodium chloride, propylene glycol and humidity of the two envelope samples A and B are summarized in Table 4 below.

Table 4

Composition of envelope samples containing sodium chloride and propylene glycol as antimycotic agents

Composition of the envelope

Sample

Sodium chloride

Water (% of weight

Glycerol

Casing propylene glycol

(% of cellulose)

total of the envelope)

(% of cellulose)

(% of cellulose)

AT

4.9

25.5

39.3

0

B

0

24.0

37.9

7.2

The envelope samples of this example were then stuffed with an emulsion of Bologna mortadella on an automatic tamping machine. The padding performance of the two samples was identical. The diameters of the lengths of stuffed sausages using the salt envelope A were identical to the diameters of the propylene glycol envelope B both measured before and after the treatment in the smoker of the products. The color and appearance of the A and B envelope sausage samples were also identical.

This example illustrates that a rubberized fibrous sausage casing containing 5% sodium chloride by weight of casing cellulose and 25% moisture content of the total casing weight is as functional as similar to a casing containing propylene glycol as an antimycotic agent, in modern stuffing or stuffing plants for large sausage products where the envelope is stuffed without soaking before stuffing.

50 Example V:

This example illustrates that a chloride salt applied to the internal surface of a fibrous envelope of cellulose sausage moves and crosses the wall of the envelope and it is detected on the external surface of the envelope. Such migration of chloride salts is necessary if the salt is applied to one surface and prevents the growth of mold on both surfaces.

In the execution of this example, a 33 inch size 2 Zi fibrous sausage wrap having a moisture content of 6% of the total weight of the wrap had its internal surface treated with 75 ml 60 of a saturated solution of sodium chloride by a charging technique. The envelope was opened and the 75 ml salt solution was brought into contact with all parts of the interior surface for a brief period, after which the excess salt solution was discarded.

65 At time intervals after charging, the outer surface was tasted with the tongue and the sensation of taste was recorded. At each time interval, a different part of the surface of the envelope was tasted. The results are illustrated in Table 5.

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Table 5

Migration of sodium chloride from the inner surface of the envelope to the outer surface of the envelope

Time after loading the inner surface of the envelope with a saturated solution of salt (s)

5

20 30 45 55 80 100 120 150 180

Taste of the outer surface of the casing only mild, no salt only sweet, no salt sweeter than salty sweeter than salty softer than salty softer than salty more salty than sweet more salty than sweet only very salty, not sweet

Table 6

Effect of chloride salts on the bursting pressure of high-moisture cellulose fiber sausage casings, without soaking

Salt

Envelope sample

Type

Amount (% of cellulose)

Burst pressure (mm of mercury)

IIA IIE IIH IIJ IVA IVB

None NaCl NaCl CaCl2 NaCl None

0 9.4 - 18.1 16.5 4.9 0

530 534 515 522 771 745

This example demonstrates the migration or transfer to the exterior surface in an envelope of a saturated solution of sodium chloride applied internally. In the first 20 s after application of the salt solution, only the mild taste of glycerol could be detected on the outer surface of the envelope. Between 30 and 80 s after application, the salt could be detected in the presence of a very marked sweet taste of glycerol. Between 80 and 120 seconds after application, the salty taste was stronger than the sweet taste of glycerol. After 150 s of application, the salty taste was so strong that the sweet taste of glycerol could no longer be detected. After 180 s, the salty taste was even stronger. After more than 180 s, the envelope was cut so as to taste the internal surface and the external surface. Both the inner surface and the outer surface had identical very strong salty flavors which masked the sweet taste of glycerol.

Thus, salt applied to the inner surface of an envelope is easily detected on the outer surface of the envelope and could thus prevent any growth of mold on both surfaces of the envelope.

Example VI:

This example illustrates that the incorporation of chloride salts into a cellulose sausage envelope, fibrous, with a high moisture content, has no detrimental effect on the burst strength of the envelope.

During the manufacture of envelopes of fibrous cellulose sausages, a thorough washing is carried out on the envelope before drying it. One of the purposes of this washing is to remove the sulfate salts from the gel shell. Before the existence of this invention, such salts had been considered by experts to be probable factors contributing to reducing the resistance of the envelope. This example illustrates that no undesirable reduction in resistance results from the incorporation of chloride salts as antimycotic agents in envelopes of fibrous sausages, made of cellulose with high moisture content, which can be stuffed without being soaked before stuffing in the water or any other form of additional wetland.

In preparing this example, fibrous envelopes of Examples II and IV were selected to measure the burst pressure. The envelopes were inflated with air and the pressure was recorded when the envelopes burst. The results are shown in Table 6 below.

(Table at the top of the next column)

The EU, UH, IIJ and IVA envelopes, which contain chloride salts, have burst pressures which are not significantly different from those of the IIA and IVB control envelopes which, themselves, do not contain chloride salts. The almost identical burst pressures observed indicate that the chloride salts have no detrimental effect on the strength of the envelopes. Test samples did not show any signs of shell breakage due to the presence of chloride salts.

Example VII:

This example illustrates that the preservation and protection against deterioration by molds of fibrous envelopes, of high moisture content, without soaking, are obtained when an antimycotic solution of chlorine salts is added directly to the bore of the rubberized cover. "Effective storage is achieved despite observed non-uniform application of the antimycotic salt solution. The direct addition of an antimycotic agent to the rubberized envelope contrasts with the conventional method of addition by uniform soaking of the solution on the envelope before rubberization, and thus constitutes an alternative for applying the invention.

30

In the preparation of envelopes for this example, rubberized lengths of 6 in of fibrous, tubular, cellulose, rubberized size 8 sausage envelopes, having a maximum packing diameter of 4.76 in (12.1 cm) , a moisture content of 12% of the total weight of the envelope and a glycerol content of 29.5% of the cellulose of the envelope were used. To prepare envelopes of various moisture and chloride content, the test solutions were added to the bores of the rubberized envelopes. The addition was made as uniformly as possible over all the lengths of the rubberized envelope and the envelope was rotated along its longitudinal axis after addition to allow the solution to soak in the envelope as uniformly as possible . With all these precautions, however, it was noted that the solution tended to remain in pockets in folds of rubber.

After a balancing period of four weeks in a plastic bag, the envelope samples were inoculated with mold cultures, subdivided, stored at 35 ° C and observed to detect visible mold growth, as described 50 in Example II, above.

It was observed that the mold growth results in this example, as illustrated in Table 7 below, are comparable and correspond to those reported in Example II where a salt solution was applied uniformly to the surface of the vessel. -55 lops before rubberizing. Envelope A sample, which had no antimycotic salt added, showed visible mold growth due to its high water activity of 0.89. Sample B, which also had no added salt, showed no mold growth due to its lower water activity of 0.84. The 60 envelope samples C to G contained antimycotic salt and showed no mold growth due to their low water activities. The non-uniform addition observed of the antimycotic salt solution by direct addition to the bore of the rubberized casing had no influence on the interpretation of the results of growth of molds, as regards the activity. water from the envelopes. Thus, the non-uniform addition of a solution of chloride salts does not prevent the chloride salt from acting as an antimycotic agent for the shell without soaking.

9

654268

Table 7

Storage of envelopes without soaking by adding a solution of sodium chloride salts to the bore of a rubberized envelope

Envelope variables

Envelope sample

Humidity (% of total)

Glycerol (% of cellulose)

Salts of sodium chlorides (% of cellulose)

Calculated water activity

Visible mold growth after 13 months at 35 ° C

A B C D E F G

34.0 24.0 34.0 24.0 34.0 24.0 34.0

29.5 29.5 29.5 29.5 29.5 29.5 29.5

0 0 5.9

2.4 9.8

4.5 14.4

0.89 0.84 0.83 0.80 0.79 0.78 0.76

+

Example VIII:

This example concerned the re-examination of the envelopes of Example II, which were examined for mold growth after storage for 3 months at 35 ° C, then at subsequent periods, 6, 8 and 10 months. Table 8 below illustrates the list of

Table 8 shows that chloride salts prevent or delay damage or deterioration by molds of envelopes of fibrous sausages, made of cellulose, with high humidity. Generally, a delay of deterioration by mold occurred with envelopes containing chloride salts, having a water activity, Aw, of 0.83 and more. Envelopes containing a salt with values, Aw, of 0.81 and less were kept for the entire 10 month storage period. Envelope A in Table 8 showed no visible mold growth after 3 months of storage, because no chloride salt was added as an antimycotic agent. An antimycotic chloride salt added to envelope B reduced the water activity, Aw, and reduced it to 0.86 and delayed the presence of visible mold growth until the eighth month of the storage period. An antimycotic in the form of a chloride salt added to the D envelope reduced Aw even further to 0.83 and also delayed the presence of visible mold growth up to 8 months of storage. Envelope C, with an antimycotic salt added to give a value, Aw, of 0.84, showed no visible mold growth after 10 months of storage, although envelope D with a value, Aw, of less than 0 , 83 showed visible mold growth. This indicates that a value, Aw, of 0.84 is close enough to the minimum value allowing the prevention of visible mold growth. Envelopes E to I showed no visible mold growth, even after 10 months of storage, at

identical envelope samples from Table 2, Example II,

all the other values entered in table 2 being the same for this example as for example II, with the visible results of growth of molds noted for the additional time periods and reproduced for the time period at origin of 3 months.

because of the sufficient addition of an antimycotic in the form of a chloride salt to reduce the value, Aw, to 0.81 or less.

Example IX:

This example demonstrates that a water activity of an envelope not exceeding about 0.75 is preferable when a long period of storage is required under commercial conditions, with fluctuating temperatures. This example also relates to the re-examination of the envelopes described in Examples II and VIII.

The growth of mold visible to the naked eye was unexpectedly discovered after 12 months of storage in envelopes 55 with antimycotic salts with a water activity value as low as 0.73 (sample I). These envelopes were stored, not inoculated, in a storage chamber having ambient temperatures fluctuating in a range between about 65 to 80 ° F (about 18 to 27 ° C). Storage at 35 ° C at constant temperature of sampled 60 tons from the same series of envelopes did not show any growth of molds until a water activity of 0.83 was reached (sample D). It is conceivable that temperature fluctuations caused migration or transfer of moisture vapor from the hottest regions of the envelope to the colder regions, thereby increasing the water activity ■ d '' a region of the envelope sufficient to allow mold growth. The growth results of molds appear in detail in Table 9.

Table 8

Periodic observations on the growth of molds on envelopes of fibrous sausages, in cellulose, of high moisture content preserved with chloride salts

Calculated water activity (A „)

3 'visible growth of mold to

Envelope sample

No salt added

Salt added

3 months

6 months

8 months

10 months

A B C D E F G H I J

0.91 0.90 0.89 0.90 0.90 0.89 0.89 0.91 0.90 0.90

0.91 0.86 0.84 0.83 0.81 0.80 0.78 0.77 0.73 0.79

+

+

111111 + 1 ++

111111 + 1 ++

"'at 35 ° C

+ = visible mold growth - = no visible mold growth

The preferred embodiment of the invention consists in using approximately 2 to 10% concentration of sodium chloride by weight of cellulose in the envelope, in combination with a moisture content in the envelope of approximately 20 to 25 % of the total weight of the envelope, to adjust these parameters to reach a final calculated water activity in the envelope, A „, of about 0.75 or less.

The foregoing description and examples, as well as the included experimental data, illustrate that the chloride salts are effective antimycotic agents in fibrous, cellulose, large sausage wraps, and can be successfully used to substitute large amounts of expensive softeners, used until now. The use of chloride salts as antimycotic agents rather than the current use of known softeners, such as propylene glycol, not only has an economic advantage for envelope producers and consumers but, in some countries, particularly In some European countries, this use solves the problem of controlling or banning the use of polyol softeners. Food legislation in some 25 countries strictly controls the use of polyol softeners and in some European countries the use of propylene glycol softener is not allowed in the package of food products. In some cases, the amount of glycerol allowed is so low that it is not possible to rely on it for the preservative effect of fibrous cellulose envelopes with a high moisture content.

These are the problems solved, the advantages presented, the new and advantageous features of this invention. The foregoing description of the invention is for illustrative purposes only and should therefore not be interpreted with a restrictive meaning.

654 268 10

Table 9

Observations on the growth of molds carried out on envelopes of sausages, fibrous, of great humidity, preserved with salts of chlorides

Envelope sample

Glycerol (% cellulose)

Humidity (% of total weight)

Chloride salt

Calculated water activity (A „)

Visible mold growth b)

Type

Amount (% of cellulose)

if no salt is added

when salt is added

after 12 months after 4 months

AT

29.0

42.7

No

0

0.91

0.91

vs)

+

B

27.0

33.3

NaCl

4.4

0.90

0.86

+

+

VS

30.8

32.3

NaCl

4.1

0.89

0.84

-

-

D

28.5

39.4

NaCl

7.9

0.90

0.83

+

-

E

29.7

38.4

NaCl

9.4

0.90

0.81

+

-

F

30.6

33.6

NaCl

8.4

0.89

0.80

+

-

G

30.6

31.7

NaCl

8.8

0.89

0.78

_

-

H

25.1

39.1

NaCl

18.1

0.91

0.77

-

-

I

28.8

32.8

NaCl

18.1

0.90

0.73

+

-

b) stored envelopes, not inoculated, at fluctuating room temperature c) no observations made

1 drawing sheet

Claims (21)

654,268 2 1. Large envelope, tubular, made of cellulosic material, for food products, prehumidified to a degree which makes it possible to stuff the envelope without having to add additional moisture before stuffing the stuffing, having a salt content chloride chosen from the group consisting of sodium chloride, magnesium chloride, ammonium chloride, calcium chloride and potassium chloride, in a concentration expressed as a percentage by weight of the cellulose in the shell, able to maintain the activity of the water in the envelope no more than 0.81. 2. The envelope of claim 1, wherein the chloride salt is sodium chloride in a concentration of 2 to 22.6% by weight of the cellulose in the envelope. 3. The envelope of claim 1, wherein the chloride salt is magnesium chloride in a concentration of 2.9 to 22.0% by weight of the cellulose in the envelope. 4. The envelope of claim 1, wherein the chloride salt is ammonium chloride in a concentration of 3.1 to 33.0% by weight of the cellulose in the envelope. 5. The envelope of claim 1, wherein the chloride salt is calcium chloride in a concentration of 4.1 to 35.9% by weight of the cellulose in the envelope. 6. The envelope of claim 1, wherein the chloride salt is potassium chloride in a concentration of 2.6 to 68.7% by weight of the cellulose in the envelope. 7. The envelope of claim 1, wherein the moisture content is not more than 40% of the total weight of the envelope. 8. The envelope of claim 7, wherein the chloride salt is sodium chloride in a concentration of 2 to 22.6% by weight of the cellulose in the envelope. 9. The envelope of claim 7, wherein the chloride salt is magnesium chloride in a concentration of 2.9 to 22.0% by weight of the cellulose in the envelope. 10. The envelope of claim 7, wherein the chloride salt is ammonium chloride in a concentration of 3.1 to 33.0% by weight of the cellulose in the envelope. 11. The envelope of claim 7, wherein the chloride salt is calcium chloride in a concentration of 4.1 to 35.9% by weight of the cellulose in the envelope. 12. The envelope of claim 7, wherein the chloride salt is potassium chloride in a concentration of 2.6 to 68.7% by weight of the cellulose in the envelope. 13. The envelope of claim 1, wherein the activity of the water in the envelope is maintained at a value not greater than 0.75. 14. The envelope of claim 1, wherein a fibrous support sheet is embedded in its walls. 15. Method for manufacturing a food envelope according to claim 1, characterized by the following steps: Addition of moisture in a cellulose envelope to obtain 20 to 40% humidity in the envelope relative to the total weight of said envelope, and Addition of a chloride salt chosen from the group consisting of: 2.0 to 22.6% NaCl 2.9 to 22.0% MgCI2 3.1 to 33.2% NH4C1 4.1 to 35.9% CaCl2 2.6 to 68.7% KCl in a concentration expressed as a percentage by weight of the cellulose in the envelope, capable of maintaining the activity of the water in the envelope not more than 0.81. 16. The method of claim 15, wherein the activity of the water in the envelope is maintained at a value not exceeding 0.75. 17. Method according to one of claims 15 or 16, wherein a fibrous support sheet is embedded in the walls of the envelope. 18. The method of claim 15, wherein the moisture is added to the envelope to obtain a total moisture content of 20 to 25% of the total weight of the envelope, and wherein sodium chloride is added in proportions of 2 to 10% by weight of the cellulose in the 5 veloppe. 19. Use of an envelope according to claim 1, for the manufacture of a food product enclosed or wrapped in said envelope, consisting in choosing such an envelope containing - from 20 to 40% humidity relative to the total weight of the envelope, and A chloride salt selected from the group consisting of sodium chloride, magnesium chloride, ammonium chloride, calcium chloride, potassium chloride in a concentration expressed as a percentage by weight of the cellulose in 15 the envelope, capable of maintaining the activity of the water in the envelope at a value not greater than 0.81 and of stuffing or stuffing this envelope with a food product without additional addition of moisture to the envelope by soaking before stuffing. 20. Use according to claim 19, in which the activity of the water in the envelope is maintained at a value not exceeding 0.75. 21. Use according to one of claims 19 or 20, wherein a fibrous support sheet is embedded in the walls of the envelope.