JPH08187071A - Method for preserving food - Google Patents

Abstract

PURPOSE: To impart the preserving effect to food without getting its taste worse by adding a culture solution of Lactobacillus bifidus and the culture solution of Lactococcus lactis to the food. CONSTITUTION: This method for preserving food is to add a culture solution obtained by culturing microorganisms belonging to the genus Bifidobacterium in a liquid medium and the culture solution obtained by culturing nisin producing microorganisms belonging to Lactococcus lactis subsp. lactis to food preferably in a ratio of (3:7)-(7:3). The total amount to be added is at least 0.5wt.%, preferably >=1.0wt.% based on the food.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for preserving food. More specifically, the present invention relates to a culture obtained by culturing a liquid medium with a microorganism belonging to the genus Bifidobacterium (hereinafter sometimes referred to as Bifidobacterium) and a liquid medium for Lactococcus lactis subspecies. A method for preserving a food, which comprises adding a culture obtained by culturing a nisin-producing microorganism belonging to lactis (hereinafter sometimes referred to as lactis bacterium) to food.

In this specification, percentages are expressed by weight unless otherwise specified.

[0003]

Fermented foods using lactic acid bacteria or bifidobacteria have a flavor or a shelf life due to the effect of reducing the pH generated by the acid produced by the lactic acid bacterium or the bifidobacteria and producing an antibacterial substance depending on the strain. It is well known to be excellent in. In particular, among lactic acid-fermenting bacterial strains, lactis bacteria produce lactic acid from sugars by fermentation, and in particular produce the peptide antibacterial substance nisin having a high bacteriostatic effect against Gram-positive bacteria, so that the culture solution is a food product. It is known that it exerts a remarkable effect on improving the preservability.

On the other hand, since bifidobacteria produce lactic acid and acetic acid, which has a stronger bactericidal effect than lactic acid, by fermentation, the culture solution has a stronger bactericidal effect than that of the lactic acid-only bacterium.

Conventionally, a fermented seasoning obtained by single culture of bifidobacteria and a method for producing the same (Japanese Patent Laid-Open No. 6-38704), a lactic acid bacterium fermented preparation for food preservation containing sterile fermented milk prepared using bifidobacteria as an active ingredient (JP-A-64-
No. 30565), a method for preserving a grain powder processed food, characterized by adding sterilized and fermented milk prepared using bifidobacteria to a grain powder processed food (JP-A-6-12572).
No. 8), a food preservative containing a cell-removal medium after bifidobacteria single culture as an active ingredient (JP-A-6-46811), and utilization of a lactis mono-culture as a food additive (JP-A-5- No. 268975) and a method for preserving foods by mixing lactis with fresh foods or fermented foods (Japanese Patent Application Laid-Open No. 5-211859).

[0006] However, in these conventional techniques, preservatives derived from the synergistic effect of the antibacterial effect of nisin and the bactericidal effect of lactic acid and acetic acid, which are obtained by simultaneously adding a single culture of lactis and a single culture of bifidobacteria. There was no disclosure of a highly effective method for preserving foods, and there were no research reports.

[0007]

DISCLOSURE OF THE INVENTION In view of the above-mentioned prior art, the present inventors have earnestly studied a method for preserving foods that gives a preservative effect to foods without deteriorating the flavor of the foods, and as a result, bifidobacteria. It was found that the simultaneous addition of the culture solution of lactis and lactis produces a remarkable effect, and the present invention has been completed.

An object of the present invention is to provide a method for preserving a food which exhibits a high antiseptic effect derived from the synergistic effect of the antibacterial effect of nisin and the bactericidal effect of lactic acid / acetic acid by simultaneously adding a culture solution of bifidobacteria and lactis bacteria. To provide.

[0009]

Means for Solving the Problems The present invention for solving the above-mentioned problems includes a culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium and a Lactococcus lactis subspecies in the liquid medium. A method for preserving food, characterized in that the culture obtained by culturing a nisin-producing microorganism belonging to lactis is added to food.
A culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium and the addition of the culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis in a liquid medium are foods. To 0.5% (weight) or more,
Mixing ratio of the culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis in a liquid medium and a culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium, A culture obtained by culturing a microorganism belonging to the genus Bifidobacterium: Lactococcus lactis subspecies
The ratio of the culture obtained by culturing the nisin-producing microorganism belonging to Lactis is in the range of 3: 7 to 7: 3, and the culture is obtained by culturing the microorganism belonging to the genus Bifidobacterium in a liquid medium. Culture solution or a culture solution obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis, a sterilized culture solution,
Bacteria-free culture solution, a concentrate thereof, or a dried product thereof, a liquid medium containing milk and milk components as main components, and the liquid medium is at least one of a monosaccharide or an oligosaccharide. As a desirable embodiment, it contains various kinds of sugar sources and a nitrogen source selected from the group consisting of proteolytic products, peptone, yeast extract, meat extract, casamino acid and wort, or a mixture of two or more thereof. There is also.

Next, the method for storing food according to the present invention will be described in detail.

Bifidobacteria used in the present invention are Bifidobacteria longum (Bifidobacteria longum) derived from human intestinal tract.
obacterium longum), Bifidobacterium breve
(Bifidobacterium breve), Bifidobacterium bifidum, Bifidobacterium infanti
s), Bifidobacteria adressentis (Bifid
obacterium adolescentis), Bifidobacterium pseudocatenulatum
ulatum), Bifidobacterium catenulatum (B
ifidobacterium catenulatum) and the like, and one or more strains selected from the above, all of which are readily available.

[0012] Lactococcus lactis is a species of Lactococcus lactis.
tis ssp. lactis) and a nisin-producing strain, and examples thereof include ATCC11454 strain and NCDO497 strain. These strains are also easily available.

The liquid medium used in the present invention is a liquid medium containing milk and milk components as a main component, or a synthetic liquid medium generally composed of an aqueous solution of sugar source, nitrogen source, micronutrients, inorganic salts and the like. Is. In the case of milk and a liquid medium containing milk components as main components, yeast extract is required for rapid growth of Bifidobacterium, and glucose and yeast extract are required for rapid growth of Lactis.

In the case of the synthetic liquid medium, the sugar source contains at least one of monosaccharides such as glucose and galactose, and oligosaccharides such as lactose, sucrose and lactulose, and undegraded milk protein and soybean protein as nitrogen sources. Except for protein degradation products, peptone, yeast extract, fish meat extract, casamino acid, wort and the like. In addition, micronutrients include B group vitamins, sulfur-containing amino acids, nucleic acid components such as adenylic acid and guanylic acid, and inorganic salts include sodium phosphate, potassium phosphate, sodium chloride, calcium carbonate, ammonium sulfate, etc. are doing.

The pH of the medium satisfying these conditions is 6.0.
It is adjusted to ˜7.5, sterilized and cooled, and then inoculated with bifidobacteria and lactis bacillus in an amount of 0.1 to 5% of the amount of each medium.

As the culture temperature, a temperature suitable for the growth of each bacterium may be selected. Specifically, the amount of Bifidobacterium is 30
-45 ° C, preferably 33-41 ° C, and lactis bacteria 20-45 ° C, preferably 30-37 ° C.

The culture is carried out by allowing the bifidobacteria to stand still or 10 to 10.
While stirring at 100 rpm, the lactis bacteria are allowed to stand or stirred at 10 to 1000 rpm.

The culturing time is until the bifidobacteria reach the stationary growth phase, and the lactis bacteria are reached from the late logarithmic growth phase to the stationary growth phase. Specifically, it is 8 to 36 hours for bifidobacteria and 5 to 36 hours for lactis bacteria.

The obtained culture broth is directly sterilized by a method such as centrifugation, sterilized by heating, concentrated, or powdered by a method such as lyophilization. The culture is made by either method.

The cultures of Bifidobacteria and Lactis bacteria produced as described above are added to foods in the above proportions, but the total amount added is at least 0. 5%, preferably 1.
It is 0% or more, and can be used in combination with a known food preservative.

Next, the present invention will be described in detail by showing test examples. Test Example 1 This test was conducted to examine the effect of the present invention. 1) Preparation of sample A bifidobacteria culture (sample 1) and a lactis culture (sample 2) were prepared by the same method as in Example 1.

2) Test method 54.3% of strong flour (manufactured by Nippon Flour Milling Co., Ltd.), 3.5% of sugar (manufactured by Showa Sangyo Co., Ltd.), 1.4% skim milk powder (manufactured by Morinaga Milk Industry Co., Ltd.), salt (manufactured by Nippon Tobacco Co., Ltd.) ) 1.1%, butter (manufactured by Morinaga Milk Industry) 2.2%, raw yeast (manufactured by Oriental Yeast Co., Ltd.) 1.1%, water 35.3% and culture 1.1%. Bread was produced from the raw materials by a conventional method. In the above formulation, the culture means sample 1 alone, sample 2 alone, and an equal mixture of sample 1 and sample 2.

Place the produced bread on an aluminum tray,
It is covered with Saran wrap to prevent drying, and stored at room temperature for 3 weeks as shown in Table 1, the mold development on the surface of the bread during the storage period is visually observed according to the following evaluation criteria, and the change in flavor is determined by the following sensory test. Tested.

Evaluation of Mold Development The development of mold was evaluated according to the following criteria.

No mold is generated-Slightly mold is generated ± Mold is generated ＋ Marked mold is generated ++

Sensory test A panel of 10 men and women each had bread in their mouth except the surface, and the flavor was evaluated according to the following criteria, and the average value of the evaluations of 20 people was calculated.

Normal 0 Somewhat abnormal 1 There is abnormal 2 There is mold odor 3 There is strong mold odor 4

3) Test Results The results of this test are shown in Table 1. As is clear from Table 1, when the bifidobacterial culture or the lactis bacterial culture is added in the same amount as in the case of adding the bifidobacterial culture and the lactis bacterial culture, respectively, the shelf life of the bread is surely ensured. It was confirmed that it would be extended by 2 weeks. It should be noted that, although tests were carried out by changing the strain type and the liquid medium type, almost the same results were obtained.

[0029]

[Table 1] Test Example 2 This test was conducted to examine the effect of the culture obtained by culturing in another liquid medium. 1) Preparation of sample A bifidobacteria culture (sample 3) and a lactis culture (sample 4) were prepared by the same method as in Example 2.

2) Test method The test was carried out by the same method as in Test Example 1.

3) Test Results The results of this test are shown in Table 2. As is clear from Table 2, when the bifidobacterial culture or the lactis bacterial culture is added in equal amounts as compared with the case where the bifidobacterial culture and the lactis bacterial culture are added respectively, the storage stability of the bread is surely ensured. It was confirmed that it would be extended by 2 weeks. It should be noted that, although tests were carried out by changing the strain type and the liquid medium type, almost the same results were obtained.

[0032]

[Table 2] Test Example 3 This test was conducted to examine the mixing ratio of the bifidobacteria culture and the lactis culture. 1) Preparation of sample A bifidobacteria culture (sample 1) and a lactis culture (sample 2) were prepared by the same method as in Example 1.

2) Test method The test was carried out in the same manner as in Test Example 1 except that the mixing ratio of the bifidobacterium culture and the lactis culture was changed as shown in Table 3.

3) Test Results The results of this test are shown in Table 3. As is clear from Table 3, the most effective results were obtained when the mixing ratio of the bifidobacterium culture and the lactis culture was 3: 7 to 7: 3. It should be noted that, although tests were carried out by changing the strain type and the liquid medium type, almost the same results were obtained.

[0035]

[Table 3] Test Example 4 This test was conducted in order to investigate the addition rate of the mixture of the bifidobacteria culture and the lactis culture to the food. 1) Preparation of sample A bifidobacteria culture (sample 1) and a lactis culture (sample 2) were prepared by the same method as in Example 1, and mixed in equal amounts.

2) Test Method A test was conducted in the same manner as in Test Example 1 except that the addition ratio of the equal mixture of Sample 1 and Sample 2 was changed as shown in Table 4.

3) Test Results The results of this test are shown in Table 4. As is clear from Table 4, effective results were obtained when the addition ratio of the equal mixture of the bifidobacteria culture and the lactis culture was 0.5% or more, and particularly the addition ratio was 1.0%. In the above cases, the most effective result was obtained. It should be noted that, although tests were carried out by changing the strain type and the liquid medium type, almost the same results were obtained. However, when the culture was not freeze-dried, a test was conducted using 10 times the freeze-dried amount. As a result, when the addition rate was 5% or more, the same result as when the freeze-drying was obtained was obtained.

[0038]

[Table 4] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0039]

【Example】

Example 1 Yeast extract 1%, peptone (all manufactured by Difco) 1%,
The pH of 100 kg of liquid medium consisting of 2% glucose, 1% sodium chloride, 0.5% phosphate (all manufactured by Nacalai Tesque) and 94.5% water was adjusted to sodium hydroxide (manufactured by Nacalai Tesque). Adjust to 6.8 at 1 ℃ at 90 ℃
Sterilize for 5 minutes, cool to 37 ° C, and remove Bifidobacterium.
bacterium longum ATCC15707 strain) was inoculated and cultured at the same temperature for 16 hours with stirring at 30 rpm, and the culture solution was centrifuged to remove the bacterial cells.
It was sterilized for minutes and then freeze-dried by a conventional method to obtain about 5 kg of a powdered Bifidobacterium culture.

On the other hand, polypeptone 0.5%, phytonpeptone 0.5%, yeast extract 0.25%, meat extract (above Difco) 0.5%, ascorbic acid 0.05
%, Sodium B-glycerophosphate 1.9%, magnesium sulfate 0.025%, glucose (above Nacalai Tesque, Inc.) 1%, and water 95.275%. Adjusted to 7.2, sterilized at 90 ° C for 15 minutes, cooled to 37 ° C, inoculated with 1 kg of lactis bacterium (ATCC11454 strain), cultured at the same temperature for 16 hours with stirring at 100 rpm, and centrifuged the culture solution. The cells were separated to remove the cells, sterilized at 90 ° C. for 10 minutes, and freeze-dried by a conventional method to obtain about 5 kg of a powdery lactis culture.

An equal amount mixture of the powdery bifidobacteria culture and the powdery lactis culture was added to the raw material of bread by the same method as in Test Example 1 to prepare bread, and the result was 2 weeks at room temperature. I was able to save it without any abnormalities.

Example 2 100 kg of liquid medium consisting of 15% skimmed milk powder (made by Morinaga Milk Industry Co., Ltd.), 0.25% yeast extract (made by Difco) and 84.75% water was adjusted to pH 6. with sodium hydroxide. 8
Adjusted to 90 ℃, sterilized at 90 ℃ for 15 minutes, cooled to 37 ℃,
Bifidobacterium longum BB536 strain
2 kg was inoculated and statically cultivated at the same temperature for 24 hours, and the culture solution was freeze-dried by a conventional method to obtain about 11.5 kg of a powdery Bifidobacterium culture.

On the other hand, skim milk powder (made by Morinaga Milk Industry Co., Ltd.) 10%,
The pH of a liquid medium 100 kg having a composition of 0.25% yeast extract (manufactured by Difco), 1% glucose (manufactured by Nacalai Tesque) and 88.75% water was adjusted to 6.8 with sodium hydroxide, Sterilize at 90 ° C for 15 minutes, cool to 32 ° C, and add lactis (NCDO497 strain) to 1.5k
g, inoculated and cultivated at the same temperature for 24 hours and freeze-dried by a conventional method to give a powdery lactis culture product (about 1).
0.2 kg was obtained.

Raw Udon prepared by mixing an equal amount mixture of the powdered Bifidobacterium culture and the powdered Lactis culture was prepared as follows. Wheat flour (made by Nippon Flour Mills) 6
8.5%, salt (made by Japan Tobacco Co., Ltd.) 3.4%, water 27.
Of raw udon raw materials consisting of 5% and mixed culture 0.6%, first mix the raw materials except water, add water and knead well, extend to about 3 mm in diameter, and use polyethylene film to prevent drying. Encapsulate and in refrigerator (5-8 ° C)
As a result of storage at 1, it could be stored for 10 days without any problem in quality.

Example 3 1% meat extract (manufactured by Difco), 1.5% casein enzyme degradation product (manufactured by Morinaga Milk Industry), 3% lactose, 1% sodium chloride, phosphate (all manufactured by Nacalai Tesque) The pH of 10 kg of a liquid medium composed of 1% and water 82.5% was adjusted to 6.8 with sodium hydroxide, sterilized at 130 ° C for 2 seconds using a plate type sterilizer, and cooled to 37 ° C. Bifidobacterium breve ATCC15700
150 g of the strain) and cultured at the same temperature for 18 hours with stirring at 15 rpm, the culture solution is centrifuged to remove the cells, and the cells are sterilized at 130 ° C. for 2 seconds.
I got kg.

On the other hand, tryptone 2%, yeast extract (above Difco) 0.5%, gelatin 0.25%, dextrose 0.5%, lactose 0.5%, sucrose 0.5%, chloride P of 10 kg of liquid medium consisting of 0.4% sodium, 0.15% sodium acetate, 0.05% ascorbic acid (all manufactured by Nacalai Tesque, Inc.) and 95.15% water.
H was adjusted to 7.2 with sodium hydroxide, sterilized using a plate type sterilizer at 130 ° C. for 2 seconds, cooled to 33 ° C., and 200 g of lactis bacteria (NCDO497 strain) was inoculated at the same temperature. Cultivate for 18 hours with stirring at 200 rpm, centrifuge the culture solution to remove bacterial cells, and
It was sterilized for 2 seconds to obtain about 8 kg of a lactis culture.

An equal amount mixture of the bifidobacteria culture and the lactis culture was mixed with 10% of the amount of the powder to obtain 11%.
Was added to the raw material for bread in the same manner as in Test Example 1 except that the water content was reduced, and bread was produced. As a result, the bread could be stored at room temperature for 2 weeks without any abnormality.

Example 4 20 kg of liquid medium having the same composition as in Example 2 was adjusted to pH 6.8 with sodium hydroxide, sterilized using a plate sterilizer at 130 ° C. for 2 seconds, and brought to 37 ° C. After cooling, Bifidobacterium infantis ATCC15697
Strain) inoculated in an amount of 400 g and statically cultivated at the same temperature for 24 hours,
A culture solution was obtained. Sterilize this culture at 130 ° C for 2 seconds,
About 17 kg of a liquid Bifidobacterium culture was obtained.

On the other hand, a liquid medium 20 having the same composition as in Example 2
The pH of kg was adjusted to 6.8 with sodium hydroxide, sterilized at 130 ° C for 2 seconds using a plate type sterilizer, and 37 ° C.
And lactis bacteria (ATCC 11454 strain) to 3
00 g was inoculated and statically cultivated at the same temperature for 20 hours to obtain a culture solution. This culture solution was sterilized at 130 ° C for 2 seconds to obtain about 17 kg of a liquid lactis culture.

Except that an equal amount mixture of the Bifidobacterium culture and the lactis culture was made 6.0% corresponding to 10 times the amount of the powder, and the water content was reduced by 22.1% I. As a result of adding raw udon to the raw material by the same method as in Example 2 and making a raw udon as a trial, it was possible to store it in the refrigerator (5 to 8 ° C.) for 10 days without any quality problem.

[0051]

INDUSTRIAL APPLICABILITY As described in detail above, the present invention provides a culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium and Lactococcus lactis.
A culture obtained by culturing a nisin-producing microorganism belonging to Subspecies lactis is a method for preserving a food, which is characterized by adding to a food, and the effect exerted by the present invention is an antibacterial effect of nisin and lactic acid. The method for preserving foods having a high antiseptic effect derived from the synergistic effect of the bactericidal effect of acetic acid can be widely used for general foods without deteriorating the flavor of foods.

Claims (6)

[Claims] 1. A culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium, and a culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis in a liquid medium. To
A method for preserving food, which is characterized by being added to food. 2. A culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium, and a culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis in a liquid medium. The method for preserving food according to claim 1, wherein the addition of the above is carried out at a ratio of 0.5% (weight) or more to the food. 3. A culture obtained by culturing a microorganism belonging to the genus Bifidobacterium in a liquid medium and a culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis in a liquid medium. The mixture ratio of the cultures obtained by culturing the microorganisms belonging to the genus Bifidobacterium: the culture obtained by culturing the nisin-producing microorganisms belonging to Lactococcus lactis subspecies lactis is 3: 7. The method for preserving food according to claim 1 or 2, wherein the range is from 7 to 3: 3. 4. A culture solution obtained by culturing a liquid medium in which a microorganism belonging to the genus Bifidobacterium is cultivated, or a culture obtained by culturing a nisin-producing microorganism belonging to Lactococcus lactis subspecies lactis. A liquid, a sterilized culture liquid, a culture liquid from which bacterial cells have been removed, a concentrate thereof, or a dried product thereof.
The method for storing food described in. 5. The method for preserving food according to claim 1, wherein the liquid medium contains milk and milk components as main components. 6. The liquid medium comprises at least one sugar source of a monosaccharide or an oligosaccharide, a proteolytic product, peptone,
The method for preserving food according to any one of claims 1 to 4, which contains a nitrogen source selected from the group consisting of yeast extract, meat extract, casamino acid and wort, or a nitrogen source consisting of a mixture of two or more thereof.