JPH0365134B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention has been made to prevent the number and vitality of lactic acid bacteria from decreasing even when a lactic acid bacteria culture (hereinafter referred to as a starter) used for producing fermented milk, lactic acid bacteria drinks, cheese, etc. is stored under refrigeration. This invention relates to a method for producing a starter.

Even if the starter produced according to the present invention is stored for a long period of time, the vitality of lactic acid bacteria and the number of bacteria will not decrease. Therefore, the starter can be produced in bulk for several weeks and stored refrigerated as needed. It is economical because it can be used in small quantities, and it brings revolutionary changes to the manufacturing methods of various fermented products.

Generally, a starter is produced by inoculating and culturing lactic acid bacteria into sterilized skim milk, etc., but since refrigerated storage reduces the pressure and number of lactic acid bacteria, it is used immediately after culturing.

Figures 1 and 2 show the decrease in the number of bacteria and the decrease in activity when the starter obtained by inoculating various lactic acid bacteria into sterilized skim milk and culturing was stored at 5°C.

All measurements were taken by the present inventors, and FIG. 1 shows the number of viable bacteria and activity (acid production amount) measured after storing Lactobacillus bulgaricus starter at 5° C. for up to 21 days. a indicates the number of viable bacteria during storage at 5°C, and b indicates the amount of acid produced during storage at 5°C.

Moreover, FIG. 2 is a diagram in which the Streptococcus cremoris starter was stored at 5° C. for up to 21 days, and the number of viable bacteria and activity (acid production amount) were measured. c indicates the number of viable bacteria during storage at 5°C, and d indicates the amount of acid produced during storage at 5°C.

In Figures 1 and 2, activity refers to sterilized skim milk.
This is the titration amount (ml) of 0.1 ^N NaOH required to inoculate 100 ml with 2 ml of starter and neutralize 9 ml after 5 hours of culture.

As is clear from FIGS. 1 and 2, if the conventional skim milk culture starter is stored as it is, the number of viable bacteria and activity will decrease considerably, and it can be seen that it cannot be stored for a long period of time.

However, it is clear that if the starter can be stored for a long period of time, it will be extremely advantageous for the production of fermented products such as concentrated mass production and timely distribution of the starter.

As a result of intensive research on the refrigerated storage stability of starter, the present inventors discovered that, when inoculating lactic acid bacteria, a small amount of an edible emulsifier containing oleic acid as a main component was added to the culture medium to preserve the starter under refrigerated storage. Furthermore, sodium L-ascorbate, L-cysteine, etc. may be added singly or in combination to the starter or its concentrated product immediately after culturing, and nitrogen gas and/or carbon dioxide gas may be further enclosed in the starter. They also learned that by deaerating it, its refrigerated storage stability can be significantly improved.

The present invention was completed based on these findings,
Adding one or more types of glycerin oleate, sucrose oleate, sorbitan oleate, or propylene glycol oleate to the starter medium,
Inoculating and culturing lactic acid bacteria, adding sodium ascorbate and/or L-cysteine to the obtained culture or its concentration, and enclosing nitrogen gas and/or carbon dioxide gas, or deaerating it. This is a method for producing a starter with a characteristic long shelf life.

In the present invention, one or more of glycerin olefinic acid ester, sucrose oleic acid ester, sorbitan oleic acid ester, or propylene glycol oleic acid ester is added to the culture medium, and sodium ascorbic acid is added to the culture or a concentration thereof. It was possible to preserve the starter for a long period of time only by combining the three treatments of adding L-cysteine and/or enclosing nitrogen gas and/or carbon dioxide gas, or deaerating it. .

When producing the starter of the present invention, the raw materials are mainly skimmed milk, reduced skim milk or whey dissolved at a concentration of about 10%, and either as is or with the addition of nutrients such as yeast extract, glycerin oleate, sucrose oleate,
Approximately 0.01 to 0.5% of one or more of sorbitan oleate or propylene glycol oleate is added, sterilized at a high temperature of 110°C or higher, and lactic acid bacteria are inoculated and cultured.

As the starter lactic acid bacteria in this case, various lactic acid bacteria such as Lactobacillus, Streptococcus, and Leuconostoccus are used depending on the desired product.

Cultivation conditions vary slightly depending on the bacterial species, but 35-45℃
A starter can be obtained by statically culturing at 25°C for about 5 hours or at 25°C for about 16 to 24 hours.

In the present invention, approximately 0.01 to 0.5% of sodium ascorbate and/or L-cysteine is added to the obtained starter or its concentrate, and then nitrogen gas and/or carbon dioxide gas is enclosed or degassed. Perform the processing to do.

Nitrogen gas and/or carbon dioxide gas may be vented through the starter to sufficiently replace the air, and then sealed. For degassing, use a vacuum pump to reduce the pressure in the pressure container containing the starter until it becomes almost vacuum.
Just seal it.

The starter obtained by the method of the present invention is
Even if it is refrigerated for up to 21 days, the number of bacteria does not decrease, and the activity (acid production) does not decrease, which is an excellent effect.

Next, test examples and examples of the present invention will be shown.

Test Example 1 Skim milk with 0.1% yeast extract added and 0.05% of each edible emulsifier, or a control without the addition, was sterilized at 121°C for 15 minutes, and skim milk culture solution of Lactobacillus bulegaricus ATCC 11842 was added to it. 1% was added and cultured for 5 hours at 40°C. The resulting culture solution was stored at 5°C for 21 days, and changes in the number of viable bacteria were observed during that time.

The results are shown in FIG.

In Figure 3, e is the addition of 0.05% sorbitan monooleate, f is the addition of 0.05% propylene glycol oleate, and g is 0.05.
Addition of % diglycerol monooleate,
h indicates the case of addition of 0.05% sucrose oleate, and i indicates the case of no addition as a control.

From FIG. 3, it can be seen that the addition of each edible emulsifier resulted in slightly better shelf life than the control, but the number of bacteria tended to decrease.

Test Example 2 Changes in activity were measured in the same manner as Test Example 1.
(The activity was determined in the same manner as in Figures 1 and 2.) The results are shown in Figure 4. e to i mean the same additives in the same amounts as in Test Example 1.

From FIG. 4, it can be seen that the activity also tends to decrease with the addition of each emulsifier used alone.

Test example 3 Streptococcus as a lactic acid bacterium
Test example 1 except for using cremoris ATCC9596
Changes in the number of viable bacteria were observed in the same manner as above.

The results are shown in FIG. In FIG. 5, e to i indicate the same materials and additives as in Test Example 1.

Test Example 4 Changes in activity were measured in the same manner as Test Example 3.
(The activity was determined in the same manner as in Figures 1 and 2.) The results are shown in Figure 6.

Test example 5 0.1% yeast extract was added to skim milk, and 0.05% yeast extract was added to this.
% of sorbitan monooleate to which Lactobacillus
bulgaricus ATCC 11842 was added at 1%, and cultured for 5 hours at 40° C. to obtain a culture solution.

The obtained culture solution with and without each additive, and with and without each treatment,
Each sample was stored at 5°C for up to 21 days, and changes in the number of viable bacteria were observed during that time.

The results are shown in FIG. In Figure 7, j is added with 0.05% L-sodium ascorbate and 0.05% L-cysteine and filled with nitrogen gas, k is added with 0.05% sodium ascorbate and 0.05% L-cysteine. and filled with carbon dioxide gas, l is filled with nitrogen gas without additives, m is filled with carbon dioxide gas without additives, and n is without additives and untreated. , respectively.

From FIG. 7, it can be seen that the number of viable bacteria hardly decreased when the culture solution was stored by adding sodium ascorbic acid and L-cysteine and aerated with nitrogen gas or carbon dioxide gas.

Test Example 6 Changes in activity were measured in the same manner as Test Example 5.
(The activity was determined in the same manner as in Figures 1 and 2.) The results are shown in Figure 8. j to n mean the same additives and the same treatments as in Test Example 5.

Test example 7 Streptococcus as a lactic acid bacterium
Test example 5 except for using cremoris ATCC9596
Changes in the number of viable bacteria were observed in the same manner as above.

The results are shown in FIG. In FIG. 9, j to n represent the same additives and the same treatments as in Test Example 5.

Test Example 8 Changes in activity were measured in the same manner as Test Example 5.
(The activity was determined in the same manner as in Figures 1 and 2.) The results are shown in Figure 10. j~n are test example 5
The same additives mean the same treatment.

Example 1 0.1% yeast extract and 0.05% sorbitan oleate are added to skim milk and sterilized at 120°C for 15 minutes. This includes Lactobacillus bulgaricus
Inoculate ATCC1842 and culture at 42°C for 5 hours to obtain lactic acid bacteria starter. Add 0.05% sodium L-ascorbate to this starter, and
Ventilate with N ₂ gas. The bacterial count and activity when this product was stored at 10°C are as follows.Both the activity and bacterial count did not decrease even after 14 days of storage, making it an excellent starter for yogurt production.

At the start of storage 7 days at 10°C 14 days at 10°C Bacterial count 7.1×10 ⁸ 7.0×10 ⁸ 7.0×10 ⁸ Activity 8.8 8.5 8.6 Example 2 A 10% aqueous solution of whey powder was prepared and 0.05% of commercially available proteolytic oxygen was added. In addition, hold at 50°C for 3 hours to decompose proteins. 0.1% yeast extract and 0.1% sucrose oleate were added and sterilized at 121°C for 10 minutes, followed by Streptococcus cremoris.
ATCC9596 was inoculated and cultured at 25°C for 18 hours to obtain lactic acid bacteria starter. 0.05% sodium L-ascorbate was added to this starter, and the starter was stored at 5°C under nitrogen gas. The number of bacteria after storage was as follows.The number of bacteria after storage for 21 days hardly decreased, making it an excellent starter for cheese production.

At the start of storage 5℃ 10 days 5℃ 20 days 5℃ 21
Number of bacteria per day 1.6×10 ⁹ 1.5×10 ⁹ 1.6×10 ⁹ 1.6×10 ⁹ Example 3 Prepare 10% skim milk powder and protease 0.05
% and stored at 50°C for 3.5 hours to degrade the protein. 0.1% propylene glycol oleate was added and sterilized at 120°C for 15 minutes. This was inoculated with Lactobacillus acidraphyllus ATCC11506 and cultured at 37°C for 16 hours to obtain a lactic acid bacteria starter. Add 0.03% of sodium L-ascorbate and 0.02% of L-cysteine to this starter,
Furthermore, nitrogen gas and carbon dioxide gas were mixed and sealed, and then stored at 5°C. The number of bacteria at this time was as follows, and the number of bacteria did not decrease even after storage for 3 months, making it an excellent lactic acid bacteria starter for lactic acid bacteria drinks.

At the start of storage 5℃ 1 month 5℃ 2 months 5
℃ 3 months Bacteria count 8.0×10 ⁸ 7.9×10 ⁸ 7.9×10 ⁸ 7.7×10 ⁸ Example 4 Glyceric acid monooleate ester in skim milk
0.03% and sorbitan oleate 0.08% were added and sterilized at 120°C for 15 minutes. This was inoculated with Streptococcus thermophilus FERM P-7025 and cultured at 42°C for 5 hours to obtain a lactic acid bacteria starter. To this starter were added 0.02% sodium L-ascorbate and 0.05% L-cysteine, and the starter was sealed with nitrogen gas and stored at 7°C. The number of bacteria after storage was as follows, and the number of bacteria did not decrease even after 21 days of storage, making it an excellent starter for yogurt production.

At the start of storage 7℃ 10 days 7℃ 14 days 7℃ 21
Number of bacteria per day 2.3×10 ⁹ 2.3×10 ⁹ 2.2×10 ⁹ 2.1×10 ⁹

[Brief explanation of drawings]

Figure 1 shows changes in the number of viable bacteria and activity of Lactobacillus bulgaricus starter, and Figure 2 shows
Figures 3, 5, and 7 are diagrams showing changes in the number of viable bacteria and activity of Streptococcus cremoris starter.
9 and 9 are diagrams showing changes in the number of viable bacteria in each test example, and FIGS. 4, 6, 8, and 10 are diagrams showing changes in activity in each test example.

Claims (1)

[Claims] 1 Add one or more of glycerin oleate, sucrose oleate, sorbitan oleate, or propylene glycol oleate to a starter medium, inoculate and culture lactic acid bacteria, and culture the resulting culture or A method for producing a starter with good shelf life, which comprises adding sodium ascorbate and/or L-cysteine to the concentrate, and enclosing or deaerating nitrogen gas and/or carbon dioxide gas.