DE1492662C3 - Process for protecting foodstuffs against deterioration or deterioration of a chemical nature - Google Patents

Description

food can be achieved in the packaged state.

This was all the more surprising as better results are obtained by using nitric oxide can than when using nitrogen with the same oxygen residual pressure in the. Gas mixture. the surprising technical progress of the process according to the invention is given below with reference to Comparative tests will be presented in detail.

Another property of the nitrogen oxide is that its protective effect against oxidation and the chemical reactions of the food is independent of the temperature, so that it works both at room temperature (20 to 40 ^° C.) and at low temperatures. This protective effect is also completely independent of the pressure.

The method according to the invention is characterized in that a protective gas atmosphere is used is, in the oxygen up to a partial pressure of less than 20% of the nitrogen oxyduldruckes next to the Nitrous oxide is present.

The saturation with nitric oxide can occur during the packaging of the food as well as during they are stored in silos or in airtight cells if the product is not sterilized must be subjected to such. B. in the case of butter or roasted coffee, or z. B. when transporting fruit and vegetables. The introduction of nitric oxide can be done in several ways be performed:

1. by removing the air from the container to a residual pressure of 110 mm Hg and Introduction of nitrogen oxide up to atmospheric or a slightly higher pressure;

2. by repeated washing with nitrogen oxide;

3. by displacing the oxygen with nitrogen or carbonic acid, which gas is then sucked off and is replaced by nitrogen oxide until atmospheric pressure is reached (this Working method is particularly suitable for coffee);

4. by saturation under pressure with nitric oxide until the partial oxygen pressure falls below the above Limits is brought.

The invention is explained in more detail using the following examples:

B e i s ρ ie 1 1

Nine samples of approximately 300 g were taken from a batch of coffee roasted the previous day and divided into three portions a), b), c) enclosed in airtight containers, but different were treated. Group a) with air removal up to an absolute pressure of 110 mm Hg and hermetically sealing the container; Group b) with lute removal up to an absolute pressure of 110 mm Hg and subsequent introduction of nitrogen up to an absolute pressure of 1.1 atmospheres and airtight seal of the container;

Group c) with air removal up to 110 mm Hg absolute pressure and subsequent introduction of Nitrogen oxide up to an absolute pressure of 1.1 atmospheres and airtight closure of the container. Each serving samples were taken after one and three months:

Of the samples after one month, the sample of group a) had a slightly rancid odor; the pattern of group b) the same odor; the pattern of group c) was unchanged.

From the samples after three months that had

under group a) a strong rancid odor; the pattern of group b) has the same odor; that

ίο pattern of group c) was still completely unchanged.

Groups a) and b) have been declared unsaleable by experts; with the patterns of group c) Coffee was made in the usual way and with a drink made from freshly roasted coffee compared without showing any difference in taste.

After seven months, the sample of the group a) had a strong rancid odor, which was also the case with the sample of group b) was noticeable, while the pattern of group c) still showed no difference in smell and taste also when comparing it with a freshly roasted coffee from the same coffee batch showed.

B e i s ρ i e 1 2

To check the harmlessness of the method according to the invention and the possibility of biological Rule out implementations were

39 hatching eggs divided into two groups; One group of 20 hatching eggs was placed in an airtight container filled with nitrogen oxide containing 10 percent by volume of oxygen. Saturation was achieved by introducing the nitrogen oxide-oxygen mixture three times and then releasing it again, first reaching a pressure of 1.5 atmospheres, which was then reduced to the final value of 1.1 atmospheres. The second group of 19 hatching eggs were left open in the same room; The room temperature varied between 18 and 2O ⁰ C. After 20 days, both groups eggs were hatched with the result that 12 eggs treated with nitrous oxide group of eggs against eggs of the non-treated group 9 escaped living chick. The chicks, which were kept under observation for 15 days, showed no difference between themselves in terms of vitality, liveliness and general behavior.

Example 3

In order to show the superiority of the use of nitrogen oxide in the presence of oxygen over the use of nitrogen, the following experiment was carried out: Peanut oil (quality DAB VII) with a peroxide value of 61 and an acidity was added to two bottles with a content of 500 ecm Oleic acids of 0.28% entered. A vacuum of 680 mm Hg was then applied to the bottles for 30 seconds. Then pure nitrogen was filled into the first bottle up to an internal pressure of 1 atm and pure nitrogen oxide was filled into the second bottle up to a pressure of 1 atm. The two containers were then placed in a refrigerator at +5 ⁰ C so that the oil could better saturate with the gases.

The containers were then taken out of the refrigerator

removed and stored in a thermostat at 40 ° C for 60 days. After 7, 15, 30 or Samples were taken for 60 days and examined for the peroxide value or for free acid. the . specimen stored in the same way under air are listed.

Due to the previous evacuation and refilling with nitrogen or nitrogen oxide, the

The results are summarized in the following table: each sample atmosphere has an oxygen content of represents, in which, for comparison, the values reached about 2.5%.

Table I.

Peroxide values

time
(d)

air

N ₂ + 2.5% O ₂ N ₂ O + 2.5% O ₂ acid number (%)
air

N ₂ + 2.5% O ₂

N ₂ O + 2.5% O ₂

61
67
73
83
106

61
65
71
76
82

61
62
63
65
66

0.2800
0.2850
0.2900
0.3000
0.3200

0.2800
0.2835
0.2880
0.2950
0.3100

0.2800
0.2825
0.2850
0.2901
0.3025

These values show that the protective effect of nitrogen oxide is considerably stronger than that of nitrogen in the presence of small amounts of oxygen.

Example 4

The influence of nitrogen on the one hand and nitrogen oxide on the other hand in the presence of small amounts of oxygen was examined on cheese. For this purpose, Parmesan cheese was grated and in pieces examined under different environmental conditions. The chemical composition of the original cheese (after sufficient aging) was as follows:

Water 31.80%

Albumin + casein 4.1.17%

Fatty substances 19.52%

Mineral salts 6.31%

The main difficulty with preserving grated Parmesan cheese is that that the fat components oxidize easily and that the cheese is highly exposed to the action of microorganisms can be subjected, whereby taste and aroma are impaired.

The experiments were once on grated cheese and the other time on cube-shaped pieces of carried out about 25 g weight.

The tests were carried out in white glass bottles. A total of four were different Experiments carried out, namely under normal atmosphere, i. H. Air, under vacuum (Residual pressure 80 mm Hg), under a nitrogen atmosphere with a residual oxygen content of 2.5% or under a nitrogen oxide atmosphere with a residual oxygen content of 2.5%. The latter two Gases were introduced according to the procedure of Example 7, i.e. the bottles with the cheese contents were first evacuated to a vacuum of 680 mm Hg and then the pure nitrogen or the Nitrogen oxide filled in. In each bottle there was either 100 g of grated cheese or 50 g of pieces of cheese weighed in. The vacuum was applied for 2 minutes. Each attempt was on a total of three Samples were carried out that were stored under different environmental conditions in order to avoid the different organoleptic characteristics of each group and each evolving over time To be able to assess the protection system.

The first group was stored in indirect light and 20 to 28 ° C, the second group without light, ie in the dark, at 20 to 28 ° C and the third group in the refrigerator at + 5 ° C, ie in the dark.
The results of these three groups are shown in Table II below. It should also be pointed out that the tests were discontinued after either severe mold formation had occurred or after the product had become so rancid that it could no longer be described as edible.

table II sample air vacuum N ₈ + 2.5% O ₂ N ₂ O + 2.5% O ₂ time (Comparison) (Comparison) (Comparison) (Invention) (d) Light; 20 to no mold no mold; 30th 28 ° C Smell and unchanged Taste light Smell and spoiled taste Darkness; strong mold, no mold, Mold on no mold, 30th 20 to 28 ° C rancid taste slightly sharper Surface of the unchanged and smell Taste, light Pieces; easy Smell and altered smell sharper taste Taste; easy altered smell

Table II (continued)

time
(d)

sample

air
(Comparison)

Vacuum (comparison) N ₂ + 2.5% O ₂
(Comparison)

N ₂ O + 2.5% O ₂ (invention)

30 refrigerator; Mold on the -

5 ° C surface of the

Pieces

90

90

90

Light; 20 to

28 ⁰ C

Darkness,
20 to 28 ° C

Fridge,

5 ° C

170 light, 20 to

28 ° C

170 darkness,

20 to 28 ° C

170 refrigerator,

5 ° C

no mold -

rancid, hotter
Taste, strong
rotten mold, rancid
Smell, sharp,
more depraved
taste

no mold, unchanged smell and taste

no mold, sweet smell and taste, but not sharp

no mold, unchanged smell and taste

no mold, unchanged smell and taste

no mold, slightly different smell and taste

no mold, slightly different smell and taste

no mold, slightly different smell and taste

From the results of this Table II it can be seen that only those under nitrogen oxydul in the presence of Samples stored at 2.5% oxygen were still edible after 170 days, while those below the usual Samples stored under conditions of preservation, namely in vacuum or under nitrogen, with 2.5% Residual oxygen, spoiled very quickly.

Example 5

The procedure of Example 1 was repeated with coffee beans and powder coffee, in this case Case a vacuum of 680 mm Hg was applied and then either nitrogen or nitric oxide was poured into the containers were introduced. In this way, a residual oxygen content of 2.5% was achieved in the atmosphere.

The bean-form samples were 30, 90 and 180 days, respectively, and those in the ground form 30, 75 or 150 days, and then partial samples were taken and made from 8 g of coffee, if necessary after grinding, a drink is made. The following ratings were made for the classification:

1 - natural smell, unchanged taste = excellent,

- strong smell, aromatic taste

= good,

3 - very strong smell, bitter taste = at the limit,

- changed smell, bitter

= old,

- Rancid smell, strange taste = not edible.

The results, compiled in Table III below, were obtained, which show that only the coffee treated with nitrogen oxide showed the rating 1, i.e. excellent, after 180 and 150 days, respectively.

table III N ₂ + 2.5% O ₂ N ₂ O + 2.5% O ₂ time Type of coffee 55 (d) 2 1 30th Beans 1 1 30th ground 2 1 90 Beans 1 1 60 75 ground 4th 1 180 Beans 3 1 150 ground

509 538/141

Claims (1)

ι 2 has leads. In the case of moist products, the Claim: Vacuum formation through the vapor pressure inside the number of preservable foods is limited, Process to protect food which is why this process is only for dry or almost against spoilage or deterioration of chemical 5 completely dried food is applicable, because Kind of by storing the food under otherwise would get the highest vacuum attainable a nitrogen oxide atmosphere as a protective gas atmosphere - before the air is in a sufficient atmosphere, d a you rch marked that dimensions can be removed. a protective gas atmosphere is used in which, in practice, the greatest possible amount of lei oxygen can be achieved up to a partial pressure of less io stung. The consequence is that not geals 20% of the nitrogen oxide pressure next to the stick - enough time spent to create the vacuum oxydul is present. so that the air out of the pores of the food is not completely removed, especially if it is is a very porous substance, such as. B. to 15 roasted coffee. On the other hand, the continued would Trying to achieve a real vacuum, too uneconomical Lead to processing costs. So there is still a great deal of harmfulness in the food Air back which it adversely affects when it is not The invention relates to a method for protecting 20 is kept frozen, which would lead to further high costs of food against spoilage or deterioration.
Another method used to preserve food under a nitrogen oxide atmosphere as a protective agent is to put it in a gas atmosphere. one with a chemically inert gas, e.g. B. Stick foods are two types of spoilage or 25 substance-filled space. This deterioration is exposed, namely by bacterial driving but with the same disadvantages as or by chemical influences. Storage under vacuum, because the chemical spoilage or deterioration of the air can never be fully displaced by a gas rests on the oxygen in the air and the reactions and the gas itself does not have the effect of the acid or the constituents of the food with one another. That can pick up matter. Chemical spoilage occurs in foods with foodstuffs. Furthermore, it is from the OE patent specification 41 196 adhere to substances with double bonds, e.g. high or the corresponding DT-PS 2 15 762 known, valuable fats, or with alcoholic, aldehydic foods can be preserved by adding them to see or ketonic groups, these are substances, a space is brought into its atmosphere which give the food its aroma. Typi- 35 from any one that is kept under overpressure See examples of spoilage are the rancidity of the gas and where nitric oxide powder is also used as butter and other fats that discolour fresh, which can be preserved or cured meat, the chicory taste, but products that are completely soft before storage Roasted coffee soon assumes that the dark is constantly unbroken. Here coloring of peeled potatoes and fruit and the 40 is nitrogen oxydul with the other gases, z. B. Air general canned taste of canned food. and oxygen, classified as absolutely equivalent. the The food industry has hitherto used this previously known preservation membrane for the holding effect or to combat the mentioned method can therefore only be based on the fat coating. Changes in the level of the chemical nature of the food Procedure applied. 45 making food is already done by others One method has been tried by adding antioxidants. This means was used to dantien, which are generally not used for human sterilization, namely as a bactericidal are harmful, but the character and taste of the means when applying a pressure of 30 to Change food. Another method is possible. ("Archive for Hygiene". Vol. 91 [1922], p. 1 ff. it says access to air by immersion in 50 and "Rivista ltaliana di Igiene" [1942], No. 7, p. 470). suitable substances such as B. liquid or liquidized From this work it can be seen that the use Fats, gelatine (especially to protect meat from nitrogen oxide as a bacteria killer only with were) to prevent. Pressure values between 28 and 50 atmospheres were possible. After a similar procedure the nitrogen oxydul for humans are completely increased Preserving fruit and vegetables in their "natural" state 55 is harmless, also because this gas desogened the same "Isotonic liquids" are used, the substances that are retained and exposed to the air immediately and from well water with a salt and / or sugar-free leaves. additional exist. It is also known from DT-AS 1105 696 or by immersion in fat or in isotonic from CH-PS 2 61 116 readyi, the sour liquids take all food the same 60 substance from an inert gas mixture, which to the Kon -Character on. In this process, the food is macerated and extracted in the packaged packaging. The purpose of this immersion grease and liquid level is not to be completely removed. In these cases, the weight of the goods is increased by about 40 to both publications, however, the use of 50% and therefore also influence the transport laughing gas or nitrogen oxide is not described above,
costs. The air trapped inside remains at 65. Surprisingly, it has now been found that such products also have an effect. Use of nitrogen oxide as an inert gas and not yet another method is the keeping of complete removal of the oxygen in an over-sub-vacuum, which, however, does not lead to any great success in technical progress in conservation.