JPH0783689B2 - Method for preparing natural flavor derived from lactic acid bacterium starter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for preparing a natural flavor derived from a lactic acid bacterium starter which is used to enhance the flavor of foods such as butter, margarine, cottage cheese, sour cream, and canday.

BACKGROUND ART Lactic acid bacteria have been conventionally used for producing various fermented dairy products, and also play an important role in a wide variety of food fields.

In recent years, various methods for enhancing the flavor of fermented milk, cottage cheese, sour cream, fermented butter cream, fermented butter and the like have been investigated with the diversification of palatability to foods.

Conventionally, lactic acid bacteria such as Streptococcus cremoris, Streptococcus diacetilactis, etc. produce diacetyl, which is a main flavor or aroma component of dairy products such as butter, and quenching. It is known that the addition of acid promotes the production of diacetyl.

On the other hand, the flavor in fermented dairy products is said to be formed by acetoin, acetaldehyde, acetic acid, propionic acid, carbon dioxide, etc. in addition to diacetyl, but the main components are diacetyl, acetoin and acetaldehyde. Diacetyl is particularly important in cottage cheese, fermented butter, etc., and acetaldehyde is regarded as an important flavor component in yogurt.

By the way, these flavors in fermented dairy products are:
What is produced by a lactic acid bacterium starter used in its production, the starter for the purpose of producing the flavor, Streptococcus diacetylase, known as aroma-producing bacteria such as diacetyl and acetoin, Leuconostoc cremoris, Leuconostoc・ Dextranicum, Lactobacillus plantarum,
Lactobacillus bulgaricus, Lactobacillus helveticus, Lactobacillus brevis and the like are used.

Incidentally, these lactic acid bacteria produce aroma components by using lactose or citric acid in milk and other culture media as a substrate.

However, even if the above-mentioned flavor-producing lactic acid bacterium is cultured, the production amount of diacetyl is 10 μg / ml or less. Therefore, in order to use it as a flavor, it is necessary to increase the production amount of diacetyl.

Regarding the enhancement of aroma components produced by lactic acid bacteria, a report by Toyoda [Dairy Science "Food Research" 34 (6), A221 (198)
5)], it is found that when both strains of Streptococcus diacetylachistis and Leuconostoc cremoris, which are fragrance-producing bacteria, are used together, the former strain alone produced about 1.5 to 2 ppm of diacetyl. However, it has been shown that diacetyl has reached 10 ppm.
Further, the same report, using both strains above, skim milk as a medium, inoculated with 0.3 wt% of sodium citrate added thereto, and culturing for 16 hours at 22 ℃, diacetyl 30ppm and It shows that an aromatic culture containing about 15 ppm of acetaldehyde was obtained.

However, Kamibe's report (milk co-operation material "Fermented milk flavor" vol.
28, No. 5, pp. 2 to 11 (1979)], the produced diacetyl becomes acetoin in an irreversible reaction by diacetyl reductase, as shown in the mechanism of production of odorous substances by diacetyl-producing bacteria. Also, since a part of acetoin is reduced to 2,3-butanediol, even a diacetyl-producing bacterium can produce more acetoin than diacetyl. Therefore, in order to prepare a flavor having a high diacetyl content from a lactic acid bacterium starter, it is necessary to convert acetoin produced by the lactic acid bacterium starter into diacetyl.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for advantageously preparing a natural flavor having a particularly high diacetyl content from a lactic acid bacterium starter. To do.

The present invention will be described in detail below.

Composition of the invention The composition of the present invention is characterized in that animal milk or whey to which citric acid or sodium citrate is added is inoculated with two kinds of lactic acid bacteria belonging to Streptococcus cremoris and Streptococcus diacetilactis. The resulting culture was further added with citric acid or citrate and stirred, and then the culture was subjected to steam distillation, and the distillate obtained was heated with an oxidizing agent. It is to obtain a natural flavor having an increased diacetyl content by post-distillation or immediately performing steam distillation by adding an oxidizing agent.

Means for Solving the Problems The present invention uses animal milk or whey added with citric acid or citrate as a medium for a lactic acid bacterium starter, and belongs to Streptococcus cremoris and Streptococcus diacetylactis as lactic acid bacteria. Two types of bacteria are used.

As the animal milk used as a raw material in the present invention, cow's milk is most preferable, but goat milk and other animal milks can also be used. These animal milks may be used as they are, but may be skim milk from which fat is removed, or powdered milk may be dissolved in water before use.

In the present invention, 0.5 to 1.0% by weight of citric acid or citrate is used.
The above-mentioned two kinds of lactic acid bacteria are inoculated into the animal milk or whey to which about a certain amount has been added, and the mixture is cultured at a temperature of about 22 ° C. for 16 to 17 hours to produce diacetyl, acetoin and acetaldehyde. The production of these aromatic substances is influenced by the amount of citric acid or citrate added. For example, after 17 hours of culture, the production of diacetyl is 0.5% by weight of sodium citrate.
It becomes maximum when added, and acetoin produces about 10 times the production amount of diacetyl, while acetaldehyde produces about 1/10 of diacetyl production, and the production amount decreases when the addition amount of sodium citrate increases. There is a tendency.

Further, when ascorbic acid or sodium ascorbate is added in the above culture, the production amount of diacetyl increases. In this case, it is appropriate that the amount of ascorbic acid or sodium ascorbate added be about 0.05% by weight with respect to the medium.

Next, the amount of lactic acid bacteria inoculated into the medium was 1.0% by weight of Streptococcus cremoris and Streptococcus
It is preferable for the production of diacetyl to inoculate each with 0.1% by weight of diacetylactis.

In the present invention, after the above culture, the production amount of diacetyl is increased by adding citric acid or citrate to the culture to adjust the citric acid concentration. The increase in the amount of diacetyl produced by adjusting the citric acid concentration in the culture is maximized by adjusting the citric acid concentration of the culture to 1.0% and adjusting the pH to 4.5 and stirring. Where the pH is 4.
The adjustment to 5 is due to the highest production of diacetyl by stirring. That is, culture according to the above
After 17 hours, the pH of the culture was adjusted to 4.1, 4.3, 4.
The changes in the production amount of diacetyl when the stirring was carried out for 3 hours after adjusting to 5, 4.7, 4.9 and 5.1 respectively are shown in the attached figure.

In addition, 200 ml of the culture was charged into a 500 ml flask and stirred at 180 rpm by a rotary shaker.

As can be seen, the increase in diacetyl production is maximized at pH 4.5. The figure also shows the effect of increasing the amount of diacetyl produced by stirring.

On the other hand, acetoin can significantly increase the production by culturing with an inoculum of Streptococcus diacetylachitis of 0.6% by weight, and then adjusting the citric acid concentration and pH as described above and stirring. You can For example, when the stirring is performed for 53 hours, the production amount of acetoin reaches about 5800 to 6000 μg / g.

Therefore, depending on whether it is intended to produce diacetyl as an aroma substance or acetoin,
It is advisable to select the above-mentioned culture conditions and stirring conditions of the culture solution.

When the citric acid solution is used for adjusting the pH, the production amount of the aroma substance is further increased. Next, Table 1 shows the results of examining the amount of aroma substances produced when 4N-HCl, edible lactic acid and citric acid solutions were used.

For example, for the purpose of producing diacetyl, inoculate the lactic acid bacterium starter at the above-mentioned ratio, add 0.2% by weight of 25% l-ascorbic acid solution, perform the culture at 22 ° C for 16 to 17 hours, and then quench. Acid soda was added to bring the culture to a citric acid concentration of 1%, and the pH was adjusted to 40% with a 40% citric acid solution.
When adjusting to 5 and stirring for 3 to 4 hours, diacetyl 1
A lactic acid bacteria culture containing 40 to 160 μg / g, acetoin 2100 to 2200 μg / g and acetaldehyde 5 to 12 μg / g is obtained.

Next, in the present invention, the lactic acid bacteria culture obtained as described above is steam-distilled. When the distillate obtained by this steam distillation is recovered, the boiling points of the respective aroma substances are different as shown below, and therefore the recovery rates thereof are also different.

Boiling point (° C) Diacetyl 87-89 Acetoin 142-148 Acetaldehyde 21 That is, about 90% of diacetyl is recovered from its boiling point, whereas acetoin has a high boiling point and only about 10% is recovered. Has a low boiling point and is easily volatilized, so about 50% is recovered.

For example, the lactic acid bacteria culture obtained as described above (diacetyl 140-160 μg / g, acetoin 2100-2200 μg
/ g, acetaldehyde 5 ~ 12μg / g) 100g steam distilling, diacetyl 1260 ~ 1440μg / g, acetoin 2
10 g of distillate containing 000 to 2100 μg / g and acetaldehyde 25 to 60 μg / g is recovered.

However, since the diacetyl content in this distillate is lower than the diacetyl content of the commercially available lactic acid bacterium flavors, the present invention converts the acetoin in the distillate into diacetyl to obtain the diacetyl content. Is significantly increased.

That is, in the present invention, by adding an oxidizing agent to the distillate obtained by the steam distillation and heating under a sealed condition and then distilling, or by adding the oxidizing agent and immediately performing steam distillation again, About 70% of acetoin in the distillate
It becomes possible to convert the above into diacetyl. In addition,
Diacetyl and acetaldehyde are not affected by the addition of the oxidizing agent, and the oxidizing agent is not mixed in the distillate obtained by the above distillation or steam distillation.

The oxidizing agent used here may be one that is recognized as a food additive, such as ferric chloride (FeCl ₃ ),
Examples include iron sulfate (FeSO ₄ ). Further, the oxidant is
Sulfuric acid is added to the distillate in advance and then added.

For example, after adding 0.7 ml of 10N-H ₂ SO ₄ to 5 g of distillate, a solution of 10 g of FeSO ₄ .7H ₂ O dissolved in 30 ml of 50% FeCl ₃ solution added 1.43 ml, After sealing and heating in boiling water for 30 minutes and then cooling, distillation is carried out or immediately steam distillation is carried out to convert acetoin in the distillate into diacetyl.

For example, the lactic acid bacteria culture (diacetyl 156.8 μg /
g, acetoin 5.843 μg / g, acetaldehyde 16.7 μg / g
(Containing) 100 g of the distillate obtained by steam distillation, the oxidant is added by the above and steam distillation is performed, diacetyl 15,413 μg / g, acetoin 2.153 μg / g, acetaldehyde 93.2 μg / g are contained. 100 g of distillate is obtained.
That is, a distillate having a very high diacetyl content (starter day stay rate) is obtained, and a product having such a diacetyl level is comparable to a flavor product with a formula commercially available from CHR.HANSEN'S LABORATORY.

By the way, the above-mentioned commercially available flavor is a mixture of various aroma substances obtained by a distillation method from a culture obtained by culturing reduced milk powder as a medium under special conditions, and is expensive. It is a product. However, the starter day stay rate obtained by the present invention has a very high diacetyl content of 90% or more in the aroma component contained therein, and moreover, since it can be efficiently prepared by using a specific lactic acid bacterium starter, a fermented dairy product is obtained. Initially, it is useful as a natural flavor for various food products.

The present invention will be specifically described below with reference to examples.

Example 1 15 parts by weight of whey powder and 1 part by weight of sodium citrate were dissolved in 84 parts by weight of water, and sterilized at a temperature of 90 ° C. for 60 minutes, and then 22 ° C.
The medium was cooled to a medium. To this medium, 0.2% by weight of a 25% ascorbic acid solution was added, and 1% by weight of Streptococcus cremoris SBT-1305 (Microtechnology Research Institute No. 9690),
Streptococcus diacetylactis SBT-1255 (Microtechnology Research Institute No. 9689) 0.1% by weight was inoculated, and at a temperature of 22 ° C, 17
Culture was carried out for a time.

After culturing, the resulting culture was adjusted to pH 4.5 with 40% citric acid solution.
After that, the mixture was stirred for 3 hours by a rotary shaker.

From the above, diacetyl 166.9 μg / g, acetoin 2091 μ
104 g of lactic acid bacteria culture containing g / g and 8.0 μg / g of acetaldehyde was obtained.

Next, 104 g of the lactic acid bacterium culture was steam distilled to obtain 100 g of a distillate. This distillate had the following fragrance composition.

Diacetyl 150.2 μg / g Acetoin 125 4.6 μg / g Acetaldehyde 4.8 μg / g To 100 g of the obtained distillate, 14 N of 10N-H ₂ SO ₄ was added, and then 5
28.6 ml of an oxidant solution prepared by dissolving 10 g of FeSO ₄ .7H ₂ O in 30 ml of 0% FeCl ₃ solution was subjected to steam distillation.

Distillate from the above distillation (starter day stay rate)
I got 10g.

The obtained starter day stay rate had the following fragrance component composition.

Diacetyl 5906.0 μg / g Acetoin 693.0 μg / g Acetaldehyde 36.8 μg / g The fragrance composition of CHR.HANSEN'S LABORATORY commercial flavor is shown below.

Diacetyl 14,000 μg / g Acetoin 1,100 μg / g Acetaldehyde 60 μg / g Example 2 In Example 1, Streptococcus cremoris SB
Inoculate 0.6% by weight of T-1255 (Microtechnology Research Institute No. 9689), and after the culture, add sodium citrate solution to the culture to make 1% by weight sodium citrate, and adjust the pH in the same manner. The starter day stay rate was the same as that described in Example 1 except that the stirring was performed for 53 hours.
I got 10g. The obtained starter day stay rate had the following fragrance component composition.

Diacetyl 15,413 μg / g acetoin 2,153 μg / g acetaldehyde 93.2 μg / g The composition of aroma components of the lactic acid bacteria culture obtained as described above was as follows.

Diacetyl 156.8 μg / g Acetoin 5.843 μg / g Acetaldehyde 16.7 μg / g

[Brief description of drawings]

The attached figure shows the relationship between the pH of the culture obtained by culturing the lactic acid bacterium starter and the amount of diacetyl produced.

Claims (1)

[Claims] 1. Animal milk or whey to which citric acid or a citrate is added, which belongs to Streptococcus cremoris and Streptococcus diacetylachistis 2.
Lactobacillus seeds were inoculated and cultivated, the obtained culture was further added with citric acid or citrate, stirred, and then the culture was subjected to steam distillation to oxidize the distillate obtained. A method for preparing a natural flavor having an increased diacetyl content, which comprises adding an agent and heating and then performing distillation, or adding an oxidizing agent and immediately performing steam distillation. (2) The method according to claim (1), wherein the culture is performed by adding ascorbic acid or sodium ascorbate.