DK176482B1 - Fish silage and product for preventing gas formation in fish silage - Google Patents

Description

DK 176482 B1

The present invention relates to a fish silage having improved storage properties and a product for preventing gas formation in fish silage.

During the production and transport of fish silage, there is occasionally extreme gas formation in the silage. Due to the properties of the silage (oil and water), this results in large bubbles ("boiling") and foaming, which creates serious handling problems.

WO 01/06869 relates to a method and a material for inhibiting gas formation in fish silage, where an effective amount of an agent that inhibits microbial growth is added to the fish silage. A preferred embodiment of the process relates to the addition of sodium benzoate, and a preferred material of the invention is a fish silage fluid comprising sodium benzoate.

The effect of sodium benzoate is not sufficient to inhibit "boiling" sufficiently to keep it at an acceptable level, and it will therefore be of interest to develop a formulation capable of sufficiently inhibiting gas formation and its consequences. It will also be of interest to develop an effective foam inhibitor, either in combination with the gas inhibitor composition or a separate agent.

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The main object of the invention was to provide a fish silage which would not have problems with gas formation and foaming during storage for a longer period of time.

Another object was to obtain a product that would effectively prevent gas formation in fish silage.

It was a further purpose that the product should also prevent foaming in fish silage.

These and other objects of the invention were achieved with the fish silage and product as described below. The invention is further characterized by the claims.

Several factors can cause gas formation ("boiling") in fish silage, for example, microbial activity with resulting gas formation, CO 2 evolution from fish bones which are dissolved in acid or by enzymatic reactions.

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Provided that "boiling" is primarily caused by microorganisms, it must be possible to provoke "boiling" in fresh silage by inoculating 1-50% by weight of "boiling" silage or a newly boiled silage. This is because the microorganisms from the "boiling" silage would thereby regenerate and rapidly multiply under the right conditions and cause "boiling" in the fresh silage. In this way, the inventors were able to investigate the effect of certain selected formulations that were supposed to inhibit "boiling" in fish silage. During the tests, it was found that formulations comprising various forms of sulfite and possibly also nitrite and benzoate effectively inhibited "boiling" in the silage. Forms of sulfite that can be used are 10 sulfite, disulfite (metabisulfite) and bisulfite. Cations could be sodium, potassium, magnesium, calcium or ammonium. The most preferred cations would be sodium and potassium. A fish silage comprising 0.05-3% by weight of the formulations that inhibited "boiling" proved to be effective. When a foam inhibitor was added either alone or in combination with the "boiling" inhibition formulations, the foam of the fish silage layer was also significantly reduced. Foam inhibitors include surfactants that reduce the surface tension so that the foam bubbles burst.

The present invention will comprise, in its extreme scope, a fish silage comprising 0.05-3% by weight of a gas-preventing formulation comprising sulfite and / or disulfite and optionally nitrite and / or benzoate. The fish silage will include 0, 05 - 0.20 wt% sulfite and / or disulfite and / or bisulfite, 0 - 0.05 wt% nitrite and 0 - 0.50 wt% benzoate. The fish silage may also include a foam inhibitor in an amount of 0.0005-0.02% by weight.

The invention also includes a product for preventing gas formation in fish silage, wherein said product comprises from 2 to 50% by weight of sulfite and / or disulfite and / or bisulfite, 0 to 1% by weight of nitrite, 0 to 25% by weight of benzoate , 0-1% w / w foam inhibitor, the remainder being water.

The invention is further explained in the following figures and examples.

FIG. Figure 1 shows gas formation in an experiment in which different formulations were tested.

FIG. 2 shows gas formation at various concentrations of formulations.

FIG. 3 shows gas formation at optimized concentrations of the various formulations.

35 3 DK 176482 B1

FIG. 4 shows gas formation in a particular formulation at different pH values.

Test system 5

It was necessary to have a reliable test system for establishing "boiling" at various pH values and temperatures. Fish silage from cold storage and fish silage that had previously been "boiling" were mixed in glass bottles. The fish silage glass bottles were sealed tightly with a cork stopper with a valve, and a tube was connected to the valve and placed in a measuring flask filled with water and placed with the opening downwards in a beaker. The gas formation in the glass bottles was measured by reading the height of the water column. The test system was used in Examples 1-5. All tests were performed at room temperature.

EXAMPLE 1

Example 1 relates to tests of various formulations suitable for inhibiting gas formation. The test system as described above was used. Portions of 250 g of "boiling" silage were used in each glass bottle. The pH of the silage was 3.8 - 3.9.

The following different formulations were tested.

B5 - The benziloxesis of 76-77% by weight propionic acid, 23% by weight benzoic acid, 0-1% by weight water was added to the silage at doses of 0.5% by weight.

B6 - "Nutriox" consisting of 45% by weight calcium nitrate, 55% by weight water was added to the silage at a dose of 1.0% by weight.

B7 - Sodium benzoate consisting of 26 wt% sodium benzoate, 74 wt% water was added to the silage at a dose of 1.0 wt%.

B8 - Nitrite consisting of 25 wt% sodium nitrite, 75 wt% water was added to the silage at a dose of 0.5 wt%.

B9 - Sulfite consisting of 10 wt% sodium nitrite, 90 wt% water was added to the silage at a dose of 2 wt%.

4 GB 176482 B1 B10 - Control without addition.

The gas volumes generated were recorded at start, after 15 min, 30 min, 45 min, 60 min, 100 min, 160 min, 265 min and 390 min. 1 shows the gas formation in the various 5 fish silages. At the end of the test, the pH was measured in all glass bottles and ranged from 3.8 - 4.0. Figure 1 shows that gas formation increased rapidly when the formulations including Benziloxessens (B5), "Nutriox" (B6) and sodium benzoate (B7) were added. Gas formation was significantly inhibited when the formulations of the invention including sulfite (B9) or nitrite (B8) were added to the silage.

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Example 1 shows that there is a significant prevention of gas formation in the silage with the formulations including sulfite or nitrite.

EXAMPLE 2 15

Example 2 relates to tests of various formulations. The same test system as described above was used.

Two silos, one "boiling" and one fresh, were mixed in a 1: 1 ratio. The pH was 3.2 and 4.8, respectively. 400 g of silage was added to each glass bottle. The following concentrations of formulations were added to each bottle: C1 - Benziloxessence, dose 1% by weight.

C2 - sodium benzoate, dose 2% by weight.

C3 - "Nutriox", dose 2% by weight.

C4 - sulphite, dose 2% by weight.

C11 control without addition.

C12 - nitrite, dose 0.25% by weight.

The gas volumes were recorded at start, after 15 min, 30 min, 90 min, 135 min, 195 min and 840 min. Figure 2 shows the gas formation in the silage comprising the various formulations. At the end of the test, the pH was measured in all glass bottles and ranged from 3.5 - 3.7. Figure 2 also shows that addition of sulfite (C4) gave the lowest gas formation and that addition of nitrite (C 12) also effectively inhibited gas formation. The other 35 formulations tested did not adequately prevent gas formation in the silage.

5 DK 176482 B1

Example 2 shows that the addition of formulations comprising sulfite or nitrite has an inhibitory effect on "boiling" at the concentrations tested.

EXAMPLE 3 5

Example 3 relates to tests with optimized concentrations of selected formulations.

The same test system as described above was used.

Fresh silage (not "cooked" and stored in a refrigerator overnight) and "boiling" ensilage (directly from a boat) were mixed in a 2: 1 ratio. The pH was 4.1. Portions of 400 g were transferred to the glass bottles and the following formulations were added: D1 - Benziloxessence, dose 1% by weight.

D2 - Benziloxescence, dose 1% by weight.

D3 - nitrite, dose 0.3% by weight.

D4 - nitrite, dose 0.3 wt%, D5 - sulfite, dose 2 wt%.

D6 - sulfite, dose 2% by weight ..

D7 - a formulation consisting of 15 wt% sodium benzoate, 1.5 wt% sodium nitrite, 6 wt% sodium sulfite, 78.5 wt% water, dose 1.6 wt%.

D8 formulation and dosage as in D7.

D9 control without addition.

D11 - control without addition.

The gas volumes generated were recorded at start, after 15 min, 35 min, 60 min, 90 min, 120 min, 150 min, 180 min, 340 min, 550 min, 710 min and 1270 min. The pH was measured in the bottles at the end of the test. The pH values for the various formulations were 2.1-4.8.

FIG. 3 shows the gas formation in the silage. As can be seen in the figure, gas formation was kept at a low level for an extended storage period when sulfite (D5, D6) or nitrite (D3, D4) or a mixture of sulfite, nitrite and benzoate (D7, D8) was added silage.

Example 3 shows that formulations comprising sulfite or nitrite or a mixture comprising sulfite, nitrite and benzoate inhibit the "boiling" of the fish silage.

EXAMPLE 4

Example 4 relates to testing of a foam inhibitor.

5 "boiling" silos in 150 g portions were transferred to 4 test tubes. To each tube, different concentrations of a foam inhibitor and Benziloxes sens were added. The foam inhibitor tested was the commercial product Antraphon NE4582.

For practical reasons, the test was performed using Benziloxessence as a 10 gas inhibition formulation, but the results of foaming are believed to be similar for other formulations of the invention.

K1 - 0.1% by weight Benziloxessence with foam inhibitor (10 ppm final concentration).

K2 - 0.3% by weight Benziloxessence with foam inhibitor (30 ppm final concentration).

K3 - 1.0% by weight Benziloxessence with foam inhibitor (100 ppm final concentration).

K4 control without addition.

A continuous visual inspection was performed and a significant reduction of the foam was observed in the 100 ppm foam inhibitor tube (K3). The reduction was 20 smaller in K1 and K2, and K4 showed the most foaming.

EXAMPLE 5

Example 5 relates to tests of a particular formulation (H) consisting of 8 wt% sodium sulfite, 10 wt% sodium benzoate, 2 wt% sodium nitrite and 80 wt% water in a number of samples from silage batches reported to "boil".

The same test system as previously described was used. Silage samples of approx.

500 g was divided into two equal subsamples. To one of the sub-samples, 1.25% by weight of the above formulation was added, while no additions to the second sub-test (control) were made. The gas formation from the two subsamples was monitored during incubation at room temperature for 24 hours.

Figure 4 shows the gas formation from untreated samples (controls) compared to that of their counterpart treated with the formulation during incubation in test system for 24 hours. The pH at the start of the test is shown in Table 1. The pH ranged in the range 3.1 - 5.1.

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Table 1

Silage sample H2 H3 H6 H8 H9 H10 H14 H16 pH 47 3 ^ 9 3 ^ 4 3? L 3 ^ 2 3 $ 4 ^ 6

Example 5 shows that the addition of formulations comprising sulfite, nitrite and benzoate reduces or eliminates silage gas formation over a wide range of pH values.

As can be seen from the above, the inventors have succeeded in producing an improved silage which is possible to store for a longer period without the problems of gas formation and "boiling". As shown by the above examples, the silage 10 and the product of the invention are substantially better than known silages and products in terms of gas formation and "boiling". The foam in the silage is also reduced.

Claims (6)

Fish silage, characterized in that the silage comprises 0.05 to 3% by weight of a formulation which prevents gas formation comprising sulfite and / or disulfite 5 and / or bisulfite and optionally nitrite and / or benzoate. Fish silage according to claim 1, characterized in that the silage comprises 0.05 - 0.20 wt% sulfite and / or disulfite and / or bisulfite, 0 - 0.05 wt% nitrite. 0 - 0.50% by weight benzoate. 10 Fish silage according to claim 1, characterized in that the silage also comprises a foam inhibitor. Fish silage according to claim 3, characterized in that the content of foam inhibitor 15 is 0.0005 - 0.02% by weight. Product for the prevention of gas formation in fish silage, characterized in that the product comprises 2 - 50% by weight sulphite and / or disulphite and / or bisulphite, 0-10% by weight nitrite, 0-25% by weight benzoate, 0 - 1% by weight foam inhibitor, the remainder being water. 20 DK 176482 B1 o to h— oo o ί— CD CD DO OQ CQ CD I f \ ί + \ O! -, -, -, -, -, -, -, -, -, - (- O LO \ i: -¾ \ ji \ VV o V ii 'O ^ :: ------------ ^ f- o ooooooooooo OaOCO ^ frCslOCOtD' ^ fCM (| lu) if | 8uuepsE9 DK 176482 B1 t - CM T— CM CO 'Cf i— OOOOOO + t + + + t ________ o _ oo \\ Λ IT-I o \ \ \ - o \ \ \ \\ \ i "\ \ \ io \\ \ sc \ \ V o> \ \ V —o \ \ \ o \ Λ «+ ~ w <► 4 -------— OOOOOOOOO OLOOLOOLOOLO Tf CO CO CM CM τ— ί— {July) asiauuBpsBø DK 176482 B1 r- in η μ- m to i— οοσίτ— QQQQQQQQQCl \ M * Μ Μ IIO _____ o \ I 1 IIJ-I \ \ \ ω 00 \\ \ r Jo \\. \ \ o ^ IL vi -V Jli -3 I 111 \ 1 O \ v \ —O xA 4 -¾ i il »M ^ ooooooooooo C500000C3000 oosooi ^ comri-cocsiT— (| iu) 9S | øllUBpSBØ DK 176482 B1" 55 x> "O ε ω co oi— ^ <D * = = C 2 ro Έ, Ό 0 ® 1 S CO] ir. j..v ...... 5E 8 0 ....... ......... ir fwiSwSiiSi: *: = ro I cn - o I 05 ~ s Γ IIJ .... .... Γ ........ I .......... q5 -go I ¥ a IL * · '“**" ^ Λ'ι'-νΛ'ι4 / - a> -> s l_ CO Q_.,.;. ·. ·.,. · ^ ·. ·.,.,.;.; Λ;.;., Ιν ^ [1: ¾¾ S ooooooooo oooooooo CD- ^ CNJOOOCO- ^ CM (| UU) eS | 9UUEpSBØ