JP3379923B2 - Production method of fermented milk food - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fermented dairy foods and fermented dairy foods. More specifically, fermented dairy materials are fermented with lactic acid bacteria to produce fermented milk, which is commonly called yogurt. The target is a fermented dairy food, also called a yogurt dessert, which is produced by mixing solid foods, and a method for producing the same.

[0002]

Fermented milk (yogurt) is produced by fermenting raw material milk by lactic acid bacteria by adding lactic acid bacteria to the raw material milk and storing it in an appropriate temperature environment for a certain period of time. Fermented dairy foods, also called yogurt desserts, are known in which small pieces of fruit or jelly are added to fermented milk to give it a taste that cannot be obtained by itself.

In order to improve the texture of fermented milk and enhance its shape retention property, agar, gelatin, starch, gums and the like have been added to fermented milk as a thickener and a stabilizer. . As an industrial method for producing fermented milk, the mixed raw material mixed with raw milk and lactic acid bacteria is filled into a retail packaging container such as a cup-shaped synthetic resin molded product, a glass bottle, and a paper container, and then this packaging container is used. Fermentation proceeds as it is to make fermented milk in the packaging container (post-fermentation type) and after putting the mixed raw material in a large tank etc. and fermenting,
A method (pre-fermentation type) of filling the manufactured fermented milk into the above-mentioned retail packaging container is generally adopted.

It is general to employ a post-fermentation method for hard yogurt (solid yogurt) and a pre-fermentation method for soft yogurt (stirred yogurt). JP-A-11
No. 32673, a high acyl gellan gum was added as a thickener to a dessert product containing fermented milk and cream cheese produced in advance as a dessert product manufacturing technique using fermented milk as one of the raw materials. A technique for filling a container in a state is described. It is said that the use of high-acyl gellan gum improves the filling property when filling a dessert product into a container. However, in this technique, fermented milk obtained by fermentation in advance is blended in a dessert product together with high acyl gellan gum, and high acyl gellan gum is not blended at all in the production stage of fermented milk itself.

[0005]

When producing solid foods such as fruits and jellies added to fermented milk, there is a problem that the above-mentioned post-fermentation type production method is difficult to employ. In the post-fermentation type, a mixed material is mixed with a solid substance such as fruit and the like is filled in a packaging container and then fermented.
The raw material milk before fermentation is liquid, and the mixed raw material is also liquid with relatively low viscosity. Therefore, the solid matter may sink to the bottom or float on the liquid surface in the liquid mixed raw material, resulting in a product in which the solid matter is unevenly distributed only on the bottom or surface of the fermented milk solidified by fermentation. To be When such a fermented milk food is eaten, for example, at first, there is no difference from fermented milk only, and at the end, only solid substances such as fruits are eaten. With this, it is not possible to enjoy the combination of the texture and the taste of the fermented milk and the solid matter.

To solve this problem, it is considered that a thickener is added to the mixed raw material to increase the viscosity of the mixed raw material and the solid matter is evenly dispersed in the mixed raw material in a floating state. . However, among the thickeners for food, when gellan gum, locust bean gum, guar gum, etc. are used, at the time of addition to the mixed raw material before fermentation, the solid matter can be dispersed in the mixed raw material. In the fermentation process, there is a problem that milk solids are separated or aggregated. Further, the fermentation is not sufficiently carried out, the viscosity of the mixed raw material is lowered, and the solid substance sinks to the bottom of the mixed raw material or floats on the surface. It can be presumed that such a phenomenon is caused by some reaction between the protein constituting the raw milk and the polysaccharide such as gellan gum.

When agar or gelatin is used as a thickener, the above-mentioned problems of separation and aggregation are unlikely to occur, but since the gelling temperature of agar and gelatin is low, the fermentation temperature is 40%.
At temperatures near ℃, sufficient agar and gelatin viscosities are not obtained, and solids sink to the bottom of the mixed raw materials or float on the liquid surface, so the purpose is to disperse solids in the mixed raw materials. Cannot be demonstrated.

In the pre-fermentation type production method described above, after producing fermented milk, a thickening agent such as gelatin or gums is mixed with a solid substance and mixed with stirring to obtain a thickened fermented milk. Filling the container in a state in which the solid matter is stably dispersed can avoid the problems of separation and aggregation during fermentation. However, in this case, the fermented milk once produced is blended with a solid substance and a thickener that have been sterilized in advance,
Furthermore, the work of aseptically stirring and mixing is difficult, and the workability is not very good.

An object of the present invention is to efficiently produce fermented dairy foods in which solids such as fruits are stably dispersed.

[0010]

[Mixed raw materials]

Basically, the same materials as the mixed raw materials in a normal fermented dairy food can be used in combination.

The main raw material is raw milk. In addition to normal liquid whole milk, skim milk, milk powder, fresh cream, etc. are also used. Usually, the blending amount of the raw material milk with respect to the mixed raw material is determined so that the non-fat milk solid content is 8% or more with respect to the whole fermented milk food produced. Depending on the amount of solids to be blended,
It is preferable to adjust the non-fat milk solid content in the milk raw material so that the milk solid content is 8% or more with respect to the entire fermented dairy food product finally obtained.

As the lactic acid bacteria, the same fungi or starters as those used for ordinary fermented milk are used. Sweeteners such as sugar, flavors, and colorings are also included. Can be mixed with fruit syrup, juice, honey, etc. Examples of solid foods that can be used include finely cut fruit pulp and vegetables such as pears, mandarin oranges, and nata de coco, pulp syrup, nuts, chocolate, and jelly.

The mixed raw material may be subjected to a sterilization step before the fermentation step. As the sterilization step, the same means as in ordinary food production is adopted. In order to improve the texture and the like of the fermented milk, polysaccharides such as agar, gelatin, LM pectin, starch and the like which have a thickening or texture improving property can be added. However, since the stable dispersion of the solid food is performed by the native gellan gum, the polysaccharide blended here does not have to be involved in the stable dispersion of the solid food during fermentation. As these polysaccharides, materials that do not easily cause problems such as separation and aggregation during fermentation are used. The blending amount of the polysaccharide varies depending on the material used, but is usually preferably 0.05 to 1.5% by weight.

[Native Gellan Gum] Gellan gum is a high molecular polysaccharide produced by a specific microorganism (Pseudomonas elodea). However, gellan gum which has been generally used conventionally is recovered after deacylation treatment of the culture of the above microorganism. This deacylation treatment has been performed in order to adjust the gellan gum such as gelling temperature and gel strength when used as a gelling agent, a thickening agent, etc., within a range that is easy to use.

On the other hand, the native gellan gum used in the present invention is obtained by directly recovering the culture of the above-mentioned microorganism without deacylation. Its chemical structure is also described in JP-A No. 11-32673.
It is also called high-acyl gellan gum because it contains more acyl groups than conventional normal gellan gum. Native gellan gum has a gelling temperature of about 70 ° C,
It is much higher than the normal gellan gum of about 30 ° C. It also forms a softer gel than gellan gum. Further, when the concentration is made low, complete gelation does not occur even at low temperature, and thixotropic properties are exhibited. Due to this thixotropic property, the solid food can be stably dispersed in the liquid of the mixed raw material. Thixotropy is
It is expressed in a wide range from around the gelling temperature to around the fermentation temperature of fermented milk.

The blending amount of native gellan gum varies depending on the type and blending of raw materials such as raw milk and solid food to be used and the required function, but usually 0.04 to 0.16% by weight based on the mixed raw materials. Blend it. If the compounding amount is small, effects such as stable dispersion of solid foods cannot be achieved,
If the blending amount is too large, the native gellan gum causes gelation and loses fluidity, and the viscosity of the mixed raw material becomes too high, which makes it difficult to disperse the solid food.

[Post-fermentation type manufacturing process] The following processes
A fermented dairy food product can be produced via (a) and (b). Step (a): Filling a packaging container with a mixed raw material containing raw milk, lactic acid bacteria, native gellan gum, and solid foods Step (b): Fermenting the mixed raw material in the packaging container, the mixed raw materials are thoroughly stirred and mixed. Then, it is preferable to fill the solid food after it is stably dispersed in the mixed raw material.

As the packaging container, an ordinary distribution or retail packaging container can be used. For example, a cup-shaped container made of synthetic resin can be used. A paper container or a container made of a composite material of paper and synthetic resin can also be used. Containers made of glass, pottery, or metal can also be used. After the mixed material is filled in the packaging container, the packaging container can be covered and the inside of the container can be sealed. Even in the sealed state, there is no problem in the next fermentation process. By hermetically sealing, it is possible to prevent various bacteria and foreign substances from entering the container.

As a means for sealing the packaging container, a lid member made of the same material as the container can be attached by means such as fitting or screwing. A film- or sheet-like lid material can be adhered to the opening of the packaging container. For the fermentation process, the same equipment and processing conditions as those for producing normal fermented milk can be adopted. Although it depends on the conditions such as the blending of the mixed raw materials and the type of lactic acid bacteria, it is usually 20 to 45
Fermentation is carried out at a temperature of 6 to 24 hours.

After the fermentation is sufficiently carried out, the fermentation can be stopped by rapid cooling or the like. About 5 ° C. is adopted as the cooling temperature. The post-fermentation type manufacturing method described above does not require special equipment such as a fermentation tank. Conventional production equipment that is conventionally used for producing so-called plain yogurt containing no solid matter can be used as it is. Therefore, the equipment cost is low, the workability is good, and the method is suitable for industrial production.

[Production process of pre-fermentation type]
A fermented dairy food product can be produced through (f) to (j). Step (f): A mixed raw material containing raw milk, native gellan gum and solid food is prepared. Step (g): Sterilize the mixed raw materials. Step (h): Add lactic acid bacteria to the sterilized mixed raw material. Step (i): Ferment a mixed raw material containing lactic acid bacteria. Step (j): A fermented mixed raw material is filled in a packaging container.

The preparation of the mixed raw materials is basically the same as the above-mentioned post-fermentation type production conditions. First step (f)
Does not include only lactic acid bacteria in the mixed raw materials. The specific treatment conditions of the sterilization step may be the same as those for normal fermented milk production.
The lactic acid bacterium is blended after the sterilization step until the environment does not adversely affect the lactic acid bacterium. For example, when high temperature heating is performed in the sterilization step, the lactic acid bacteria are blended after the mixed raw materials are cooled to some extent.

The mixed raw material mixed with lactic acid bacteria is fermented in a state of being stored in a fermentation tank or the like. The fermentation conditions may be the same as the post-fermentation type described above. Before performing the fermentation process,
It is preferable that the mixed raw materials are sufficiently stirred and mixed to uniformly disperse the solid food product. This keeps the solids uniformly dispersed during fermentation.

The fermented dairy food product produced after fermentation is
Fill in packaging for distribution or retail. As the packaging container, the same one as in the post-fermentation type manufacturing method described above can be used. However, since the packaging container is not fermented as it is, it is not necessary to select the packaging container in consideration of the problem of fermentation. In the above-mentioned pre-fermentation type manufacturing method, the mixed raw material containing all the ingredients such as solid foods and native gellan gum excluding lactic acid bacteria can be sterilized all at once, so that the sterilization step can be simplified.

[Fermented Milk Food] In the fermented milk food obtained by the production method of the present invention, solid food is dispersed in the fermented milk obtained by fermenting the raw material milk without uneven distribution. Dispersion without uneven distribution does not have to be a completely uniform dispersion state, but it is possible to clearly distinguish between the place where solid food does not exist at all in the fermented milk and the place where solid matter solidifies. It means not in a state.

[Source Material Layer] As the fermented dairy food, it is also possible to provide a fermented dairy food having a structure in which a main body portion made of fermented milk produced from the mixed raw material and a source material layer are laminated. The source material layer is composed of fruit jam, marmalade, caramel, syrup, cream and the like.

In the case of the post-fermentation type production method described above,
After the mixed raw material is filled in the packaging container, the source material can be supplied thereon to form the source material layer. Since the native gellan gum is blended with the mixed raw material to retain its shape, even if the source materials are supplied onto the mixed raw material layer, they will not be mixed with each other. The mixed raw material layer can be fermented in a state where the source material layer is laminated on the mixed raw material layer.

In the case of the above-mentioned pre-fermentation type production method, after the fermented milk produced from the mixed raw material is filled in the container, the source material may be supplied thereon to form the source material layer.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The results of evaluating the performance of the present invention will be shown below. [Example 1] A fermented milk food was produced with the following formulation.

[0030]

[Table 1] Composition% by weight ────────────────── Skim milk powder 10 Sugar 7 Stabilizer See Table 2 below Nata de coco pulp 20 Lactic acid bacteria Appropriate amount of water Remaining amount ───── ───────────── Total 100 Skim milk powder, sugar and stabilizer are mixed in powder, dispersed in water and heated at 90 ° C for 10 minutes to dissolve and sterilize the solution. The mixture was cooled to 42 ° C with stirring. Lactic acid bacteria and nata de coco pulp were added thereto and stirred to evenly disperse the nata de coco pulp in the mixed raw material.

After filling and sealing the mixed raw material in a container,
Fermentation was carried out for 7 hours in an incubator adjusted to 42 ° C. After 7 hours, the fermentation was stopped by cooling to 5 ° C. The evaluation results of the obtained fermented milk food are shown below.

[0032]

[Table 2] ────────────────────────────────── Stabilizer type Performance rating Addition% Fermentation Post-treatment state Dispersion of pulp Texture ────────────────────────────────── Native gellan gum No separation or agglomeration Uniform dispersion Very good 0.08 Gellan gum 0.1 Completely aggregated all settled --- Locust bean gum Completely aggregated --- 0.3 Guar gum 0.3 Completely aggregated ----- Gelatin 0.5 Slightly Aggregation All settling Rough agar 0.5 Slightly aggregated All settling Agar 1.0 Slightly aggregated All settling Hard, grainy LM Pectin A 0.3 No separation or aggregation All settling Rough LM pectin B 0.3 Fully aggregated All settling --- HM pectin 0.3 Completely flocculated All settled --- Processed starch 2.0 No separation or flocculation Generally dispersed Heavy and pasty ──────────────────────────── As a result of the above, it was agar, gelatin, modified starch and a part of LM pectin that did not cause an agglutination reaction during fermentation. However, the pulp of agar, gelatin, and LM pectin precipitated, and the processed starch had a bad texture.

When nata de coco was used as the pulp, the acidity of nata de coco facilitated aggregation, and agar and gelatin slightly aggregated. However, it can be seen that native gellan gum has an advantage that aggregation is unlikely to occur even in a certain acidic environment. [Example 2] By changing the compounding amount of native gellan gum,
The performance was evaluated.

[0034]

[Table 3] Weight% ─────────────────── Skim milk powder 10 Sugar 7 Native gellan gum 0 to 0.18 Nata de coco pulp 20 Lactic acid bacteria Proper amount of water Remaining amount ──── ────────────── Total 100 Fermented dairy foods were produced through the same steps as in Example 1. The evaluation results of the obtained fermented milk food are shown below.

[0035]

[Table 4] ──────────────────────────────── Native gellan gum Workability during production Addition amount after fermentation% Fruit pulp Dispersion state of ──────────────────────────────── 0 The pulp settles during filling, sedimentation, uniform filling is difficult ───── ─────────────────────────── 0.02 Good sedimentation 0.04 Good Almost no sedimentation 0.06 Good Uniform dispersion 0.08 Good Uniform Dispersion 0.10 Good Uniform dispersion 0.12 Good Uniform dispersion 0.14 Good Uniform dispersion 0.16 High viscosity during cooling-Mixing of pulp is difficult ──────────────── ──────────────── In addition, when native gellan gum is not added, the pulp completely settles and agglomeration / separation occurs. Alive When the amount of native gellan gum added exceeds 0.16%, the thickening of the mixed raw material is remarkable when cooled, and it shows a rice cake-like physical property at the stage of cooling to 42 ° C, and it is extremely difficult to mix the pulp uniformly. It is had.

When native gellan gum was added in an appropriate amount, the fermented dairy food product after fermentation was in a state where the pulp, which was a solid, was uniformly dispersed. [Example 3] Based on the results of Examples 1 and 2, specific examples of fermented dairy foods that are considered to be practically preferable are shown.

[0037]

[Table 5] Composition% by weight ──────────────────── Whole milk powder 11.00 Skim milk powder 2.80 Sugar 9.00 Agar * 1 0.10 Gelatin * 2 0.50 Native gellan gum * 3 0.08 Nata de coco pulp 20.00 Lactic acid bacteria Appropriate amount of water Remaining amount ──────────────────── Total 100.00 * 1: AG -7 (product name, manufactured by Nitta Gelatin Co., Ltd.) * 2: FYB-150S (product name, manufactured by Nitta Gelatin Co., Ltd.) * 3: Kercogel LT-100 (product name, manufactured by Dainippon Pharmaceutical Co., Ltd.) Nata de Coco Fruit Meat Disperse the raw materials excluding lactic acid bacteria and water, and
After stirring and heating to 0 ℃, 150kg / cm ² (about 14.7
Homogenization treatment was performed at (MPa). Next, using a plate sterilizer, instantaneous sterilization was performed under the conditions of 130 ° C. for 4 seconds and then cooled to 42 ° C. In this mixed raw material,
Separately sterilized 5 to 10 mm square nata de coco pulp and lactic acid bacteria were added and sufficiently stirred. The pulp was in a state of being uniformly dispersed in the mixed raw material. This dispersion was filled and sealed in a container. Each container was fermented in a fermentation chamber at 42 ° C for 7 hours. After the fermentation was completed, the fermentation was stopped by cooling to 5 ° C.

As a result, the fermented milk food obtained was a hard yogurt food in which the nata de coco pulp was uniformly dispersed in the fermented milk and the texture was good.

[0039]

The method for producing a fermented dairy food product according to the present invention comprises fermenting a mixed raw material in a state of mixing native gellan gum into a mixed raw material containing raw milk, lactic acid bacteria and solid food to produce a fermented dairy food. It is possible to maintain a state in which the solid food is uniformly dispersed in the mixed raw material during fermentation, and the fermented milk food produced has the solid food uniformly dispersed in the fermented milk, and has an excellent taste. It becomes a thing.

Moreover, even if the native gellan gum is present in the mixed raw material at the time of fermentation, it does not cause the problem of separating or agglomerating the raw material milk and does not inhibit the fermentation.

Claims (6)

(57) [Claims] 1. A method for producing a fermented dairy food, which comprises fermenting a mixed raw material containing unfermented raw material milk, lactic acid bacteria, native gellan gum, and a solid food. 2. The method for producing a fermented dairy food according to claim 1, wherein the native gellan gum is blended in an amount of 0.04 to 0.16% by weight based on the whole mixed raw material. 3. At least one material selected from the group consisting of agar, gelatin, LM pectin, and starch is added in an amount of 0.05 to 1.5% by weight based on the total weight of the mixed raw material. Or the method for producing a fermented dairy food according to 2. 4. The method for producing a fermented dairy food according to claim 1, wherein a packaging container is filled with a mixed raw material containing unfermented raw material milk, lactic acid bacteria, native gellan gum, and solid food. a)
And a step (b) of fermenting the mixed raw material in the packaging container. 5. The step (a) according to claim 4, wherein the mixed raw material and the source material are sequentially filled in a packaging container, and the mixed raw material layer and the source material layer are separately arranged in the packaging container. Method for producing fermented dairy food. 6. The method for producing a fermented dairy food according to any one of claims 1 to 3, wherein a step (f) of preparing a mixed raw material containing unfermented raw material milk, native gellan gum, and a solid food is mixed. Step (g) of sterilizing the raw materials, step (h) of blending the sterilized mixed raw material with lactic acid bacteria, step (i) of fermenting the mixed raw material containing the lactic acid bacteria, and the fermented mixed raw material in a packaging container. A method for producing a fermented dairy food, which comprises the step (j) of filling .