JP7285161B2 - Method for producing fermented milk and method for suppressing syneresis of fermented milk - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing fermented milk and a method for suppressing syneresis of fermented milk.

Usually, the heat treatment conditions for the raw material liquid when producing fermented milk are (i) 30 minutes at a temperature of 85 ° C., (ii) 10 minutes to 5 minutes at a temperature of 90 to 95 ° C., and (iii) at a temperature of 120 ° C. 5 to 3 seconds is generally known (Non-Patent Document 1).

"Latest food processing course Milk and its processing" First edition, published by Kenpakusha, 1987, page 282.

Fermented milk containing various effective ingredients has been developed as health consciousness increases.
The present inventors have found that syneresis tends to occur when fermented milk is produced by a method of fermenting a raw material solution to which indigestible dextrin, which is a water-soluble dietary fiber, is added.
INDUSTRIAL APPLICABILITY The present invention provides a method for producing fermented milk that hardly causes syneresis while containing indigestible dextrin, and a method for suppressing syneresis of fermented milk.

As a result of intensive research, the present inventors have found that when a raw material solution containing a milk raw material and an indigestible dextrin is heat-treated, browning (coloration) tends to occur after heat treatment, syneresis after fermentation tends to occur when browning occurs, The inventors have found that syneresis after fermentation can be suppressed by adjusting the heat treatment conditions to control the degree of browning, leading to the present invention.

The present invention has the following aspects.
[1] A method of obtaining fermented milk by subjecting a raw material liquid containing a milk raw material and an indigestible dextrin to heat treatment at a heating temperature of 80° C. or higher and a holding time of 1 minute or longer, and then adding lactic acid bacteria and fermenting the mixture. , where b1 is the b* value in the CIE L*a*b* color system of the raw material liquid before the heat treatment, and b2 is the b* value of the raw material liquid when the lactic acid bacteria are added, b2/b1 A method for producing fermented milk, wherein the heat treatment is performed so that the ratio of is 1.95 or less.
[2] The production method of [1], wherein the content of the indigestible dextrin is 2.5 to 7% by mass with respect to the total mass of the raw material liquid.
[3] The production method of [1] or [2], wherein the non-fat milk solid content is 8% by mass or more with respect to the total mass of the raw material liquid.
[4] The production method according to any one of [1] to [3], wherein the heat treatment has a heating temperature of 80 to 96°C and a holding time of 1 to 10 minutes.
[5] A method of suppressing syneresis of fermented milk fermented by adding lactic acid bacteria after subjecting a raw material liquid containing a milk raw material and an indigestible dextrin to a heat treatment at a heating temperature of 80° C. or higher and a holding time of 1 minute or longer. When b1 is the b* value in the CIE L*a*b* color system of the raw material liquid before the heat treatment, and b2 is the b* value of the raw material liquid when the lactic acid bacteria are added, A method for suppressing syneresis of fermented milk, wherein the heat treatment is performed so that the ratio of b2/b1 is 1.95 or less.

ADVANTAGE OF THE INVENTION According to this invention, the fermented milk which syneresis does not produce easily can be manufactured, while containing an indigestible dextrin.

In the present specification, the numerical range represented by "~" means a numerical range with the lower and upper limits of the numbers before and after ~.
In this specification, the b* value in the CIE L*a*b* color system is the chromaticity ( a* value, b* value, L* value). In the CIE L*a*b* color system, the L* axis is a lightness axis that represents brightness, with values close to 0 representing black and values close to 100 representing white. The a* axis represents green to red, with minus representing green and plus representing red. The b* axis represents blue to yellow, minus blue and plus yellow.

Fermented milk includes stirring type fermented milk and stationary type fermented milk depending on the difference in production method. Stirred fermented milk (also called pre-fermented fermented milk) is made by fermenting fermented milk raw materials in a tank or the like, stirring and pulverizing the formed curd to make it fluid, and packing it into product containers (containers for eating and drinking). ).
Stationary fermented milk (also called post-fermented fermented milk) is fermented after filling the fermented milk raw material in a product container (container for eating and drinking), and the curd formed in the container is marketed without stirring. The final product is fermented milk (curd) in a solid state that does not have fluidity.
The method for producing fermented milk according to the present embodiment can be applied to stationary fermented milk or stirred fermented milk.

<Indigestible dextrin>
The indigestible dextrin used in this embodiment is a type of water-soluble dietary fiber obtained from starch. The term "indigestible" means that it is difficult to be digested by human digestive enzymes.
For example, roasted dextrin obtained by acidifying (adding mineral acid) and/or heating plant-derived starch such as corn, wheat, barley, rice, beans, potatoes (potato, sweet potato), tapioca, etc. It is a water-soluble dietary fiber that is optionally desalted and decolored after being enzymatically treated with α-amylase and/or glucoamylase according to the requirements, and has indigestibility.

Indigestible dextrin is a low-calorie, low-fat food material, and has physiologically active effects such as intestinal regulation, blood sugar elevation suppression, serum cholesterol lowering, intestinal environment improvement, and triglyceride lowering. (For example, Reference Document 1 (Japanese Unexamined Patent Application Publication No. 2001-252064), Reference Document 2 (Japanese Unexamined Patent Application Publication No. 04-1591765, etc.).
References 1 and 2, for example, can be referred to for methods for producing indigestible dextrin. The plant-derived starch that is the raw material for the indigestible dextrin is not particularly limited, but corn starch is particularly suitable. Mineral acids for acidification include, for example, hydrochloric acid, nitric acid, sulfuric acid and the like, among which hydrochloric acid is preferred.

For indigestible dextrin, high-performance liquid chromatography, which is a dietary fiber analysis method described in Eishin No. 13 dated April 26, 1999 ("Methods for analyzing nutritional components, etc. in nutrition labeling standards") Dextrin containing indigestible components as measured by (enzyme-HPLC method), preferably dextrin containing 85 to 95% by weight of indigestible components.
For the sake of convenience, the indigestible dextrin used in the present embodiment also includes reduced products of indigestible dextrin produced by hydrogenation.
Indigestible dextrin and its reduced product (reduced indigestible dextrin) are commercially available in the form of powder, fine granules, granules, etc. Any form can be used.

<Method for producing fermented milk>
[Preparation of raw material solution]
In the method for producing fermented milk of the present embodiment, lactic acid bacteria are added to the raw material liquid and fermented to produce fermented milk.
First, a raw material liquid containing milk raw materials and indigestible dextrin is prepared. Specifically, a raw material liquid is obtained by mixing water with milk raw materials, indigestible dextrin, and other ingredients as necessary.
In the present specification, the raw material liquid means a liquid from mixing at least a dairy raw material and one or more raw materials other than the dairy raw material to adding lactic acid bacteria.

The dairy raw material is a milk-derived raw material, and known dairy raw materials used in the production of fermented milk can be used. Examples include cow's milk, buffalo milk, sheep's milk, goat's milk, horse's milk, skimmed milk, skimmed concentrated milk, skimmed milk powder, concentrated milk, whole milk powder, cream, butter, buttermilk, condensed milk, and milk proteins. One type of these may be used, or two or more types may be mixed and used.
The content of the milk raw material is preferably 8% by mass or more, preferably 12% by mass or less, more preferably 8 to 10% by mass of non-fat milk solids relative to the total mass of the raw material liquid. When it is at least the lower limit of the above range, moderate milky taste is exhibited, and good flavor is likely to be obtained. If it is equal to or less than the upper limit, aggregation of milk protein due to heat sterilization is likely to be suppressed.

The content of the indigestible dextrin is preferably 2.5-7% by mass, more preferably 3-6% by mass, relative to the total mass of the raw material solution. When the content is at least the lower limit of the above range, a physiological effect can be expected, and when it is at most the upper limit, a favorable flavor is likely to be obtained.

The raw material liquid contains water in addition to the milk raw material and the indigestible dextrin. Furthermore, other components can be included within a range that does not impair the effects of the present invention.
Other ingredients include, for example, rare sugars, fructose, psicose, allose, lactulose, sugars such as sucrose, low-calorie sweeteners, casein hydrolysates, vegetable fats, stabilizers (agar, gelatin, pectin, etc.), and flavors. , a pH adjuster, and the like.
Rare sugars generally refer to monosaccharides and sugar alcohols that are less abundant in nature.
Low-calorie sweeteners include aspartame, acesulfame K, sucralose (also known as 4,1′,6′-trichlorogalactosucrose), stevia sweetener, saccharin, sodium saccharinate, licorice extract, and the like.

The pH of the raw material liquid at 25° C. is preferably 6.4 to 6.9, more preferably 6.5 to 6.7. When the pH of the raw material liquid is within the above range, aggregation is less likely to occur when the raw material liquid is heated.

[Heat treatment]
The raw material liquid is heat-treated one or more times before adding the lactic acid bacteria.
The heat treatment in this specification means a treatment with a heating temperature of 80° C. or higher and a holding time of 1 minute or longer. Holding time means the time during which a given heating temperature is maintained. The holding time does not include the temperature rising time and the temperature falling time to the predetermined heating temperature.
When the raw material liquid is heat-treated at a heating temperature of 80° C. or higher and a holding time of 1 minute or longer, browning (coloring) tends to occur after the heat treatment, and syneresis tends to occur after fermentation, so the application of the present invention is effective. big.

In this embodiment, the heat treatment may be performed twice or more. For example, the temperature may be lowered after being held at a first heating temperature of 80° C. or higher for 1 minute or longer, then held at a second heating temperature of 80° C. or higher for 1 minute or longer, and then lowered. The first heating temperature and the second heating temperature may be the same or different. At least one heat treatment is preferably a heat sterilization treatment.
If the heating temperature of the heat treatment is too high, or if the holding time is too long, it is not preferable in that fermentation delay and syneresis tend to occur. For example, the upper limit of the heating temperature is preferably 96°C or lower, more preferably 90°C or lower. The upper limit of the retention time is preferably 10 minutes or less.
The lower limit of the heating temperature for the heat treatment is 80°C or higher, but 85°C or higher is preferable from the viewpoint of formation of the texture of the fermented milk.

In this embodiment, the heating temperature and holding time of the heat treatment are such that the ratio of b2/b1 is 1, where b1 is the b* value of the raw material solution before heat treatment and b2 is the b* value of the raw material solution when lactic acid bacteria are added. 0.95 or less.
In the present specification, the term "at the time of addition of lactic acid bacteria" is a concept including immediately before adding lactic acid bacteria, simultaneously with addition, and immediately after addition.
When browning (coloring) occurs due to heat treatment of the raw material liquid, b2 becomes larger than b1. If the heating temperature is the same, the longer the holding time, the larger the b2/b1 ratio tends to be. If the holding time is the same, the ratio of b2/b1 tends to increase as the heating temperature increases.
When the ratio of b2/b1 is 1.95 or less, the effect of suppressing water separation is excellent. The ratio b2/b1 is preferably 1.8 or less, more preferably 1.6 or less. The lower limit of the ratio b2/b1 is greater than 1 and is not particularly limited. Practically, 1.1 or more is preferable.

The value of b2 is preferably 1-8, more preferably 3-7. When it is at least the lower limit of the above range, it is easy to obtain a favorable milk flavor, and when it is at most the upper limit, it is easy to suppress fermentation delay and syneresis.
The value of b1 varies depending on the composition of the raw material liquid. It also varies depending on the raw material lot.

In this embodiment, the raw material liquid before addition of the lactic acid bacteria may be subjected to one or more heat treatments, and if necessary, may be subjected to one or more heat treatments other than the heat treatments. Another heat treatment may be performed before or after the heat treatment.
For example, even if the heating temperature is 80° C. or higher, a heating step in which the holding time is less than 1 minute is another heat treatment. If the heating temperature is less than 80° C., even if the holding time is 1 minute or more, it is another heat treatment. Other heat treatments are less prone to browning (coloration) after treatment.
For example, as another heat treatment, heat sterilization treatment may be performed at a heating temperature of 90° C. or higher for a holding time of less than 1 minute.

It is preferable that the raw material liquid, which has been subjected to the heat treatment and, if necessary, other heat treatments, is cooled to the fermentation temperature in the next fermentation step. Alternatively, after heat treatment or other heat treatment, it is preferable to cool to 10° C. or less when storing in a tank or the like.

[fermentation]
Lactic acid bacteria are added to the heat-treated raw material liquid, and the mixture is fermented at a predetermined fermentation temperature to obtain fermented milk. Curd is formed by fermentation.
As lactic acid bacteria, known lactic acid bacteria can be used in the production of fermented milk. one of the lactic acid starters commonly used in the production of fermented milk, such as L. bulgaricus, L. lactis, S. thermophilus, or It is preferable to use two or more kinds.
The amount of lactic acid bacteria to be added can be appropriately adjusted within a normal range.

Since acid is produced in fermentation by lactic acid bacteria, the pH of the raw material solution after the start of fermentation decreases over time. The final pH in the fermentation process is preferably 4.2 to 4.8.
The fermentation temperature is preferably 35 to 43°C, for example. The fermentation time is preferably 7 hours or less, more preferably 6 hours or less. If the fermentation time exceeds 7 hours, it is not preferable in terms of production efficiency.
When the pH reaches the target value (ultimate pH), it is cooled to 10°C or less to obtain fermented milk. The fermentation process is completed when the temperature is cooled to 10°C or less.

When producing static fermented milk, after adding lactic acid bacteria to the raw material liquid, the product container (container for eating and drinking) is filled and fermented.
When producing stirred fermented milk, after adding lactic acid bacteria to the raw material solution, it is fermented, for example, in a tank, the resulting curd is stirred and pulverized, and if necessary, a stabilizer solution or food other than curd Mix with materials and fill product containers (containers for eating and drinking). Examples of food materials other than fermented milk include pulp, sauce, jelly, and the like. The stirred fermented milk may be a solid type to be scooped up with a spoon or the like, or may be a drinkable type.

The method for producing fermented milk according to the present embodiment can produce fermented milk with little syneresis while containing indigestible dextrin, whether it is static fermented milk or stirred fermented milk. When the syneresis is small, changes in appearance and flavor during storage are suppressed.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.
<Measurement method>
The b* value of the raw material liquid was measured using a color difference meter (product name: Color Reader CR-13, manufactured by Konica Minolta Japan, Inc.). Specifically, after adjusting the temperature of the raw material solution to 10° C., it was filled in a light-shielding cup, and the measuring part of a color reader was applied vertically to measure the chromaticity.

<raw materials>
Skimmed concentrated milk: manufactured by Morinaga Milk Industry Co., Ltd.
Cream: Made by Morinaga Milk Industry Co., Ltd.
Casein hydrolyzate: The casein hydrolyzate obtained in Preparation Example 1 below.
Indigestible dextrin: Matsutani chemical industry product name Fibersol 2.
Sucralose: manufactured by San-Ei Gen FFI.
Rare sugar-containing syrup: Matsutani Chemical Industry Co., Ltd. product name Rare Sugar Sweet, containing 31% by mass of D-fructose, 44% by mass of D-glucose, 6% by mass of D-psicose, and 4% by mass of D-allose.
Lactulose-containing syrup: Milk oligosaccharide MLS (R)-50, product name of Morinaga Milk Industry Co., Ltd., containing 50% by mass of lactulose.
Agar: Agar UP-6, product name of San-Ei Gen FFI.
Fragrance: Yogurt flavor, manufactured by San-Ei Gen FFI.
Lactic acid bacteria starter: DANISCO product name YO-MIX (R), a mixed culture of Streptococcus thermophilus (S. thermophilus) and Lactobacillus delbrueckii subsp. bulgaricus (L. delbrueckii subsp. bulgaricus).
Pectin: SM-MN-2779, product name of San-Ei Gen FFI.

[Preparation Example 1]
Add 900 mg of water to 100 mg of commercially available casein (derived from milk, manufactured by New Zealand Dairy Board) and disperse well, add sodium hydroxide to adjust the pH of the solution to 7.0, completely dissolve the casein, and adjust the concentration to An approximately 10% casein aqueous solution was prepared. The resulting aqueous casein solution was heat sterilized at 85°C for 10 minutes, adjusted to 50°C, and added with sodium hydroxide to adjust the pH to 9.0. A 4 mg (manufactured by Amano Enzyme) was added to initiate the hydrolysis reaction. After 8 hours, the enzyme was deactivated by heating at 80°C for 6 minutes to stop the enzymatic reaction, and the mixture was cooled to 10°C.
The resulting hydrolyzate was ultrafiltered with an ultrafiltration membrane (manufactured by Nippon Pall Co., Ltd.) having a molecular weight cutoff of 1000, concentrated and freeze-dried to obtain 85 mg of casein hydrolyzate.

[Test Examples 1 to 4]
In order to investigate the cause of browning (coloration) and syneresis of fermented milk when a raw material solution containing milk raw materials and indigestible dextrin was heat-treated, solid fermented milk (still yogurt) was prepared with the formulation shown in Table 1. manufactured.
Test Examples 1 and 2 are examples in which the indigestible dextrin is blended, and Test Examples 3 and 4 are examples in which the indigestible dextrin is not blended.

First, raw materials other than the lactic acid bacteria starter were mixed in a mixer to prepare a raw material liquid (70° C.). Then, it was heated and homogenized by a homogenizer (temperature: 85°C, 2 seconds, pressure: 20 MPa). The raw material liquid (85°C) after homogenization was heat sterilized at 90°C for 10 minutes, and then cooled to 42°C.
Immediately after adding the lactic acid bacteria starter to the cooled raw material liquid, the mixture was filled into a container and kept at 40° C. for fermentation. When the pH reached 4.6, the fermentation was terminated by cooling below 10°C.
The fermentation time is defined as the time from the addition of the lactic acid bacteria starter to the end of fermentation (the same shall apply hereinafter). Table 1 shows the fermentation time for each example.
The obtained stationary yogurt was stored at 10° C. for 3 days, and then visually observed to check for browning and syneresis. Table 1 shows the results.

As shown in the results of Table 1, Test Examples 1 and 2 had longer fermentation times than Test Examples 3 and 4, and the fermented milk was clearly browned. Moreover, in Test Examples 1 and 2, there was a gap between the inner wall of the container and the solid fermented milk, and syneresis occurred remarkably.
From the results of Test Examples 1 to 4, it was found that indigestible dextrin causes fermentation delay and syneresis.

[Examples 1 to 11]
A stationary yogurt was produced by the same procedure as in Test Example 1 with the formulation shown in Table 2. However, the conditions for heat sterilization were changed as shown in Table 3.
In addition, after homogenization, the b* value (b1) of the raw material solution before heat sterilization (85 ° C. was adjusted to 10 ° C.), and the raw material solution when adding the lactic acid bacteria starter (40 ° C. to 10 ° C. The b* value (b2) of the adjusted temperature (°C) was measured, and the ratio of b2/b1 was calculated. Table 3 shows the results.

Evaluation (1) Fermentation delay suppression property Table 3 shows the fermentation time. Fermentation delay inhibition was evaluated according to the following criteria.
O: Fermentation time is 7 hours or less.
x: Fermentation time exceeds 7 hours.
(2) Syneresis suppression property After storing the obtained stationary yogurt at 10 ° C. for 3 days, the inside of the container opening was visually observed from above, and a gap was formed between the inner wall of the container and the solid fermented milk. The total length R in the circumferential direction was measured. The ratio (unit: %) of the total length R in the circumferential direction was calculated with respect to the entire circumference of the opening of the container, and was taken as the degree of wall surface peeling. The syneresis suppression property was evaluated according to the following criteria. Table 3 shows the results.
A: The degree of peeling from the wall surface is 0%.
◯: The degree of peeling from the wall surface is more than 0% and 20% or less.
x: The degree of peeling from the wall surface is more than 20%.

[Examples 12 and 13]
Static yogurt was produced by changing the heat treatment conditions.
In the formulation shown in Table 2, raw materials other than the lactic acid bacteria starter were mixed in a mixer to prepare a raw material solution (70° C.). Then, it was heated and homogenized by a homogenizer (temperature: 80°C, 2 seconds, pressure: 20 MPa).
In Example 12, the raw material liquid (80°C) after homogenization was subjected to heat sterilization (1) at 97°C for 17 minutes, and then cooled to 10°C. Then, after heat sterilization treatment (2) was performed at 90°C for 10 seconds, it was cooled to 40°C.
In Example 13, the raw material liquid (80°C) after homogenization was subjected to heat sterilization treatment (1) at 96°C for 5 minutes, and then cooled to 10°C. Then, after heat sterilization treatment (2) was performed at 90°C for 10 seconds, it was cooled to 40°C.
In Examples 12 and 13, after the lactic acid bacteria starter was added to the cooled raw material liquid, the mixture was filled in a container and kept at 40° C. for fermentation. When the pH reached 4.6, the fermentation was terminated by cooling below 10°C.
Table 4 shows the fermentation time for each example. Fermentation delay inhibition and syneresis inhibition were evaluated by the methods described above. Table 4 shows the results.

[Examples 14 and 15]
Static yogurt was produced by changing the heat treatment conditions.
In the formulation shown in Table 2, raw materials other than the lactic acid bacteria starter were mixed in a mixer to prepare a raw material solution (70° C.). Then, it was heated and homogenized by a homogenizer (temperature: 80°C, 2 seconds, pressure: 20 MPa).
In Example 14, the raw material liquid (80°C) after homogenization was subjected to heat sterilization (1) at 85°C for 6 minutes, and then cooled to 10°C. Then, after heat sterilization treatment (2) was performed at 90°C for 5 seconds, it was cooled to 40°C.
In Example 15, the raw material liquid (80°C) after homogenization was subjected to heat sterilization (1) at 85°C for 6 minutes, and then cooled to 5°C. Then, after heat sterilization treatment (2) was performed at 85°C for 60 minutes, it was cooled to 40°C. That is, heat treatment at 85° C. or higher for 1 minute or longer was performed twice.
In Examples 14 and 15, after the lactic acid bacteria starter was added to the raw material liquid after cooling, it was filled in a container and kept at 40° C. for fermentation. When the pH reached 4.6, the fermentation was terminated by cooling below 10°C.
Table 4 shows the fermentation time for each example. Fermentation delay inhibition and syneresis inhibition were evaluated by the methods described above. Table 4 shows the results.

[Example 16]
In this example, a stirring type fermented milk (yoghurt drink) was produced.
A raw material solution (70° C.) was prepared by mixing raw materials other than the lactic acid bacteria starter in a mixer according to the composition of the raw material solution shown in Table 5. Then, it was heated and homogenized by a homogenizer (temperature: 85°C, pressure: 20 MPa for 2 seconds). The raw material solution (85 ° C.) after homogenization was subjected to heat sterilization (1) at 80 ° C. for 6 minutes, and then heat sterilization (2) at 121 ° C. for 2 seconds. After that, it was cooled to 40°C.
After adding the lactic acid bacteria starter to the cooled raw material liquid, the mixture was kept at 40° C. in a tank and fermented until the pH reached 4.6, and then cooled to 5° C. to complete the fermentation. After this, a previously prepared pectin solution (5° C.) was added and mixed while stirring to break up the fermented milk. A mixture of crushed fermented milk and pectin solution was filled in a container to obtain a yogurt drink.
Table 6 shows the fermentation time of this example and the results of evaluation of the fermentation delay suppression property based on the above criteria.

After the obtained yogurt drink was allowed to stand at 10° C. for 8 days, the mass of syneresis (supernatant portion) generated in the yogurt in the container was measured. The syneresis rate (unit: % by mass) with respect to the total mass of the yogurt drink was defined as the amount of syneresis. The syneresis suppression property was evaluated according to the following criteria. Table 6 shows the results.
◯: The amount of separation of water is 20% by mass or less.
x: The amount of syneresis generated is more than 20% by mass.

As shown in the results of Tables 3, 4, and 6, when the ratio of b2/b1 was 1.95 or less, fermented milk containing indigestible dextrin and hardly causing syneresis was obtained.

Claims (5)

A method of obtaining fermented milk by subjecting a raw material liquid containing a milk raw material and an indigestible dextrin to a heat treatment at a heating temperature of 80° C. or higher and a holding time of 1 minute or longer, and then adding lactic acid bacteria and fermenting the mixture.
If b1 is the b* value in the CIE L*a*b* color system of the raw material solution before the heat treatment, and b2 is the b* value of the raw material solution when the lactic acid bacteria are added, b2/b1 A method for producing fermented milk, wherein the heat treatment is performed so that the ratio is 1.95 or less. The production method according to claim 1, wherein the content of the indigestible dextrin is 2.5 to 7% by mass with respect to the total mass of the raw material liquid. The production method according to claim 1 or 2, wherein the non-fat milk solid content is 8% by mass or more with respect to the total mass of the raw material liquid. The production method according to any one of claims 1 to 3, wherein the heat treatment has a heating temperature of 80 to 96°C and a holding time of 1 to 10 minutes. A method for suppressing syneresis of fermented milk obtained by subjecting a raw material liquid containing a milk raw material and an indigestible dextrin to a heat treatment at a heating temperature of 80° C. or higher and a holding time of 1 minute or longer, and then adding lactic acid bacteria and fermenting it. ,
If b1 is the b* value in the CIE L*a*b* color system of the raw material solution before the heat treatment, and b2 is the b* value of the raw material solution when the lactic acid bacteria are added, b2/b1 A method for suppressing syneresis of fermented milk, wherein the heat treatment is performed so that the ratio is 1.95 or less.