JP6074799B2 - Lactic acid bacteria growth promoter and yogurt containing the same - Google Patents

Description

  The present invention relates to a lactic acid bacteria growth promoter and a yogurt containing the same.

  Yogurt fermented with lactic acid bacteria such as Bulgarian bacteria, acidophilus bacteria, thermophilus bacteria, bifidobacteria, etc. contains 10 million or more lactic acid bacteria per ml and may have many effects when ingested by humans. Are known. Specifically, by ingesting lactic acid bacteria, feed the good bacteria present in the intestine, and by increasing the number of good bacteria, the bad bacteria are reduced, the intestinal environment is adjusted, blood pressure and serum cholesterol Probiotic effects such as reduction and allergy symptoms such as hay fever are reduced.

  Yogurt food forms include plain yogurt fermented using milk as raw milk without adding anything, hard yogurt with gelatin, agar and other coagulants added, and the yogurt lump after fermentation breaks into semi-fluid Soft yogurt with fruit preparation in the form of a liquid, drinkable drink yogurt, frozen frozen yogurt, etc. As hard yogurt, agar is used for the purpose of preventing breakage during yogurt distribution and preparing a texture. On the other hand, in recent years, yogurt without adding a coagulant such as agar is increasing because the formation of yogurt curd has been improved by improving fermentation technology.

  Conventionally, yogurt using agar contains low-intensity agar in which molecules of the agar component are cut short (Patent Document 1), soy milk to which low-intensity agar is added, fermented with lactic acid bacteria (Patent Document 2), low A product produced by crushing a card using strength agar as a gelling agent (Patent Document 3) is known.

  By the way, the human stomach has a strong acidity, and the pH of the artificial gastric juice defined in the Japanese Pharmacopoeia is about 1.2. Thereby, many microorganisms that enter the living body from the oral cavity are sterilized. Lactic acid bacteria are known to be useful for humans, such as intestinal regulation and immunostimulatory action, and it is ideal that most of them reach the intestines when eating lactic acid bacteria products. Most will die.

  On the other hand, there are methods such as filling lactic acid bacteria into enteric-coated capsules or molding into tablets, but they are not suitable for eating as daily foods. Moreover, the product of lactic acid bacteria effective for the living body produced at the time of fermentation like yogurt or cheese cannot be obtained.

  Thus, Patent Documents 4 to 6 and the like show the development of lactic acid bacteria having acid resistance as probiotics. However, these are limited to one specific bacterial species and are not applicable to all lactic acid bacteria.

  Further, Patent Document 7 describes that lactic acid bacteria propagate in the voids by mixing porous dried okara with yogurt, and as a result, the lactic acid bacteria are hardly killed by gastric juice. However, since hemicellulose, which is a constituent of okara (soybean cell wall), is insoluble, when applied to acidic milk or the like, there is a disadvantage that it precipitates or becomes uncomfortable in texture.

JP-A-6-38691 (Claims 1 and 8) JP 2003-284520 A (Claims 1 and 4) JP 2009-82023 A (Claim 1, Claim 2) Special table 2009-539372 JP 2003-210105 A JP 2011-41499 A JP2011-120A

  The lactic acid bacteria contained in conventional yogurt are killed by gastric acid in the human body and reach the intestine almost dead, despite the fact that 10 million or more per 1 ml are contained as live bacteria at the time of manufacture. It will be. For this reason, the conventional yogurt has a problem that the effect of lactic acid bacteria as probiotics is not sufficiently exhibited. Therefore, there has been a demand for the development of a lactic acid bacteria growth promoter that can proliferate lactic acid bacteria remarkably and make it difficult to be killed by gastric acid and the like and can be added to yogurt.

  On the other hand, it is presumed that agar is not only a function of coagulation assistance but also a so-called prebiotic that agar, which is a dietary fiber, helps lactic acid bacteria, which are probiotics. For this reason, if agar is ingested with lactic acid bacteria, the effect of synbiotics by both can be expected. However, there is no literature specifically showing the prebiotics of agar. In addition, the agar added to the conventional yogurt as a use is merely added as a coagulation aid, and the effect as a prebiotic was not expected.

  Therefore, an object of the present invention is to provide a lactic acid bacterium growth promoter that significantly promotes the growth of lactic acid bacteria and also exhibits an effect as a prebiotic when ingested by humans, and a yogurt containing the same.

  In order to achieve the above object, as a result of earnest research on the combination of agar and yogurt without being constrained by the common knowledge of conventional knowledge, the present inventors have used a certain kind of agar together in the fermentation process of yogurt, The inventors have found that the effect of increasing lactic acid bacteria is enhanced, and have completed the present invention.

  That is, the present invention is a lactic acid bacteria growth promoter characterized by containing agar having a weight average molecular weight of 10,000 to 300,000 and a reducing sugar amount adjusted to 0.12 to 2.0.

  The molecular weight distribution (Mw / Mn) of the agar is preferably 15 or less. Further, the pH of the 1.5% by weight solution of the agar is preferably 4.0 to 5.8. Furthermore, it is preferable to improve the acid resistance of lactic acid bacteria under gastric juice conditions.

  Furthermore, the present invention is a yogurt containing the lactic acid bacterium growth promoter according to any one of the above and a lactic acid bacterium, wherein the content of the agar is 0.05 to 2.0% by weight. Yogurt.

  According to the present invention, an object of the present invention is to provide a lactic acid bacterium growth promoter that significantly promotes the growth of lactic acid bacteria and also exhibits an effect as a prebiotic when ingested by humans, and a yogurt containing the same. Is possible.

  Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited by the member, material, arrangement | positioning, etc. which are demonstrated below, These members etc. can be suitably changed in accordance with the meaning of this invention.

1. Lactic Acid Bacteria Growth Promoter The lactic acid bacteria growth promoter of the present invention is characterized in that it contains agar having a weight average molecular weight of 10,000 to 300,000 and a reducing sugar amount adjusted to 0.12 to 2.0. When the weight average molecular weight and the reducing sugar amount are out of the above ranges, not only the growth promoting effect of lactic acid bacteria is remarkably reduced, but also the growth of lactic acid bacteria is suppressed as compared with the case of culturing without adding agar. The weight average molecular weight of the agar is in the range of 10,000 to 300,000 as described above, and more preferably in the range of 15,000 to 290000. Further, the amount of reducing sugar in the agar is in the range of 0.12 to 2.0 as described above, and more preferably in the range of 0.14 to 1.9. In addition, the weight average molecular weight and the amount of reducing sugar in this invention can be defined as the value measured with the measuring method in the Example mentioned later.

  In the lactic acid bacterium growth promoter of the present invention, the molecular weight distribution (Mw / Mn) of agar is preferably 15 or less, more preferably 12 or less, and further preferably 10 or less. If the molecular weight distribution exceeds 15, the effect of promoting the growth of lactic acid bacteria tends to decrease. Furthermore, the lactic acid bacteria growth promoter of the present invention preferably has a pH in the range of 4.0 to 5.8 in a 1.5% by weight solution of agar. The pH here is a pH measured using agar after dehydration and drying described later. When this pH is out of the above range, the effect of promoting the growth of lactic acid bacteria tends to decrease. Hereinafter, the agar used in the present invention will be described.

(1) Agar The agar according to the present invention can be made from at least one or more seaweeds among the genus Genus, the genus Ogonori and the genus Obakusa. Commonly used seaweeds of the genus Tengusa, Ogonori and Obakusa can be used without limitation.

(2) Method for producing agar The agar according to the present invention is made from at least one seaweed of the genus Pleurotus, Ogonori genus and Ochrus genus, washed with water after alkali treatment, and optionally contains a buffer. After extraction with water and filtration, the filtrate can be cooled to gel, and the gelled product can be obtained by immersing the gel in water as necessary, followed by dehydration and drying. In this agar production method, agar molecules are cleaved without acid treatment, so that the amount of reducing sugar at the cleaved molecular ends is not excessively increased, and is within the range of 0.12-2.0 of the present invention. It can be. Hereinafter, the manufacturing method of agar is explained in full detail.

(A) Alkali treatment process First, the seaweed which is a raw material is alkali-treated. Specifically, seaweed as a raw material is immersed in a strong alkaline aqueous solution such as 0.5 to 20% by weight of NaOH or KOH at a temperature of 20 to 100 ° C. for 0.5 to 48 hours. Thereafter, the alkali adhered or penetrated into the seaweed as a raw material by the alkali treatment is washed with water to remove the alkali. The weight average molecular weight of the agar can be adjusted by the alkali treatment time. The weight average molecular weight can be increased by increasing the alkali treatment time, or the weight average molecular weight can be decreased by shortening the alkali treatment time. You can do it.

(B) Hot water extraction process Next, the agar component after alkali treatment is extracted with hot water. Specifically, agar components are extracted by hot water extraction for 1 to 3 hours using hot water adjusted to pH 4.0 to 7.0 and temperature 70 to 120 ° C. The weight average molecular weight of agar can be adjusted by the pH during hot water extraction. Increasing the pH increases the weight average molecular weight, or lowering the pH decreases the weight average molecular weight. Can be.

  Moreover, it is preferable to add a buffer to hot water for the purpose of reducing the pH fluctuation. Examples of such a buffering agent include weakly acidic and strongly alkaline salts, weakly alkaline salts, and combinations thereof, and combinations of weakly alkaline salts and weakly acidic salts. Sodium diphosphate, dibasic potassium phosphate, dipotassium phosphate, sodium polyphosphate, potassium polyphosphate, tribasic sodium phosphate, tribasic potassium phosphate, primary phosphate sodium, primary potassium phosphate, sodium metaphosphate And potassium metaphosphate, tetrasodium pyrophosphate, tetrapotassium pyrophosphate, sodium hydrogen pyrophosphate, potassium hydrogen pyrophosphate, sodium dihydrogen pyrophosphate and sodium citrate. The buffer may be added in such an amount that the pH of hot water does not fluctuate.

(C) Filtration process Next, the extract extracted above is filtered. Filtration can be performed, for example, by applying pressure with a filter press or the like. The filtration step is preferably performed at a temperature higher than the freezing point of the agar so that the agar does not gel. Specifically, the filtration step can be performed at 70 to 120 ° C.

(D) Gelation process Next, the filtrate obtained above is cooled and gelled. It is preferable to adjust the pH before gelation. Since the pH before gelation is almost the final pH as it is, in order to make the pH in the 1.5% by weight solution of the agar finally obtained within the range of 4.0 to 5.8 as described above. The pH before gelation is preferably in the range of 4.0 to 5.8. For pH adjustment, an acid such as acetic acid, hydrochloric acid or phosphoric acid, or an alkali such as sodium hydroxide can be used. The cooling temperature at the time of gelation is not higher than the freezing point of agar, and is usually 38 ° C. or lower, preferably about 33 ° C. or lower.

(E) Soaking step Next, in order to adjust the amount of reducing sugar and the molecular weight distribution, the obtained gelled product is immersed in water (hereinafter sometimes referred to as soaking). The immersion time is preferably 12 to 48 hours, although it depends on the target reducing sugar amount and molecular weight distribution. The water may be replaced at an appropriate time. By immersing the gelled product in water, low molecular weight components generated by hot water extraction can be eluted into the aqueous phase and removed from the gelled product. Thereby, low molecular weight agar is removed, and agar with a small amount of reducing sugar and a narrow molecular weight distribution can be obtained. The concentration of the gelled product during the immersion is preferably 0.2 to 2.0% by weight, and more preferably 0.4 to 1.2% by weight. If it is lower than 0.2% by weight, it is difficult to maintain the gel in the water soaking, and if it exceeds 2.0% by weight, it is difficult to remove the low molecular weight component. The concentration of the gelled product when immersed in water can be adjusted, for example, by adding water after hot water extraction.

(F) Dehydration / Drying Step Next, the gelled product obtained above is dehydrated and dried. Examples of the dehydration method include a method of freezing and thawing the gelled product and a method of dehydrating the gelled product, and a method of dehydrating the gelled product by pressing. Examples of the drying method include general drying methods. The moisture in the gelled product is preferably evaporated to an equilibrium moisture value (22% by weight or less) at which the agar is stabilized as a powder by drying.

  As described above, the agar contained in the lactic acid bacteria growth promoter can be obtained in the present invention. The obtained agar may be adjusted to powder or flakes using a pulverizer or the like.

2. Yogurt The lactic acid bacteria growth promoter of the present invention can be suitably used for lactic acid bacteria-containing foods, particularly yogurt. Hereinafter, the yogurt of the present invention will be described.

  Yogurt can be produced by mixing raw milk and the above-mentioned lactic acid bacteria growth promoter, adding lactic acid bacteria to this and performing lactic acid bacteria fermentation. Examples of the raw milk include raw milk such as cow milk and goat milk, skim milk powder, whole milk powder, fresh cream, and a mixture of two or more selected from these.

  The lactic acid bacterium is not particularly limited as long as it is used for normal yogurt. For example, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus helveticus, Lactobacillus bulgaricus, Lactobacillus gasseri, Lactobacillus Acidophilus, Lactobacillus salivarius salivarius, Lactobacillus gallinarum, Lactobacillus amylobolus, Lactobacillus brevis brevis, Lactobacillus fermentum, Lactobacillus mali, Lactobacillus delbrukki genus Lactobacillus genus Streptococcus Thermophilus, Streptococcus genus such as Streptococcus lactis, etc., Lactococcus lactis lactis, Lactococcus lactis cremolis etc. Bifidobacterium genus such as Coccus genus, Leuconostoc mesenteroides cremolith, Leuconostoc genus such as Leuconostoc lactis, Bifidobacterium breve, Bifidobacterium bifidum, Bifidobacterium longum etc. Known lactic acid strains such as can be used. In addition, these lactic acid bacteria can be used alone or in combination of two or more.

  The content of agar contained in the lactic acid bacteria growth promoter is preferably 0.05 to 2.0% by weight, preferably 0.1 to 1.5% by weight, based on the total amount of yogurt as the final product. Is more preferable. If the agar content is less than 0.05% by weight, the effect of promoting the growth of lactic acid bacteria contained in yogurt tends to be reduced, and the shape retention of yogurt tends to deteriorate. On the other hand, if the content of agar exceeds 2.0% by weight, the solid content becomes too much, and the texture of yogurt tends to deteriorate.

  During fermentation, a bulk starter may be made and added, or freeze-concentrated bacteria or freeze-dried concentrated bacteria can be added directly to the raw material milk. The addition amount of lactic acid bacteria can be appropriately adjusted according to the fermentation temperature and fermentation time. The fermentation temperature is usually 20 to 50 ° C., preferably 25 to 45 ° C., and the fermentation time is usually 3 to 48 hours, preferably 4 to 24 hours. After completion of fermentation, it is preferable to store in a cool dark place of 10 ° C. or less.

  Other components can be added to the yogurt of the present invention as long as the growth promoting effect is not inhibited. As such other components, for example, food materials such as gelatin, modified protein spheroids, various sugars and emulsifiers, thickeners, sweeteners, acidulants, fruit juices, and the like can be appropriately added. Specifically, sugar alcohols such as sucrose, isomerized sugar, sugars such as glucose, fructose, palatinose, trehalose, lactose, xylose, aspartame, sorbitol, xylitol, erythritol, lactitol, palatinit, reduced starch syrup, reduced maltose starch syrup, etc. And emulsifiers such as sucrose fatty acid ester, glycerin fatty acid ester and lecithin, acidulants such as citric acid, lactic acid and malic acid, and fruit juices such as lemon juice, orange juice and berry juice. In addition, vitamins such as vitamin A, vitamin B, vitamin C, vitamin D, and vitamin E, and minerals such as calcium, iron, manganese, and zinc can be used. These other components may be added to the raw milk or after fermentation.

  By using the lactic acid bacterium growth promoter of the present invention, an effect of remarkably growing lactic acid bacteria is exhibited. Specifically, as shown also in the examples described later, when lactic acid bacteria were cultured with the addition of agar, which is the lactic acid bacteria growth promoter of the present invention, 24 hours later than when no agar was added. The number of lactic acid bacteria increases by about 2 to 100 times. On the other hand, when the agar outside the numerical range of the present invention is added even in the same agar, the number of lactic acid bacteria after 24 hours is reduced as compared with the case of culturing without adding the agar. That is, by using agar included in the numerical range of the present invention, the effect of promoting the growth of lactic acid bacteria is remarkably improved as compared with the case where agar outside the numerical range is used.

By using the lactic acid bacteria growth promoter of the present invention, lactic acid bacteria can be proliferated remarkably. Agar can be dissolved in water or milk to form a three-dimensional matrix to immobilize the milk, which is one of the factors that promote the growth of lactic acid bacteria. That is, the formation of a matrix by agar promotes the growth of lactic acid bacteria by the following mechanism.
(1) A scaffold for growth of lactic acid bacteria can be formed and the growth can be facilitated. This scaffold immobilizes milk components, but by setting the weight-average molecular weight of the agar within the range of the present invention, the pores of the three-dimensional matrix have an appropriate size, so that the diffusion of milk components is moderate, and the lactic acid bacteria Is adequately fed. On the other hand, agar having a weight average molecular weight lower than that of the present invention has a weak matrix and is difficult to serve as a scaffold. In addition, agar having a weight average molecular weight higher than that of the present invention tends to be poor in growth because the matrix becomes too strong and the diffusion of milk components becomes extremely poor, making it difficult to supply sufficient nutrients to lactic acid bacteria.
(2) Bifidobacteria and the like produce growth factors themselves, but since the diffusion of the growth factors is inhibited by the three-dimensional matrix of agar, the growth factors easily act on the bacteria effectively.
(3) Milk convection is less likely to occur due to a three-dimensional matrix of agar, so anaerobic bacteria such as lactic acid bacteria increase in anaerobic degree and are likely to grow.

  The amount of reducing sugar is an index of the amount of low molecular agar. In other words, when agar is reduced in molecular weight, reducing sugar is generated at the end of the agar molecule. Low molecular weight agar (agar oligosaccharide) has bacteriostatic activity, and if there is a lot of reducing sugar, it is thought that the growth of lactic acid bacteria is inhibited. On the other hand, agar with less reducing sugar is considered to be less effective in promoting the growth of lactic acid bacteria because the agar molecules are long and the gel strength is too high.

  Further, as described above, the molecular weight distribution (Mw / Mn) of agar is preferably 15 or less. When the molecular weight distribution is wide, the amount of reducing sugar is increased, and the formed agar gel matrix contains a mixture of high and low molecules, so that the gel matrix is not uniform and a portion having a small lactic acid bacterium growth effect is formed.

  Moreover, the lactic acid bacteria growth promoter of this invention also exhibits the effect which relieve | moderates the bad influence with respect to lactic acid bacteria by a stomach acid in a human stomach environment. Furthermore, when the lactic acid bacteria growth promoter of the present invention is added and stored refrigerated, the number of viable bacteria can be maintained over a longer period than when no additives are added. This is because the fermentation of yogurt proceeds normally when stored refrigerated for a long period of time, and the pH is lowered by lactic acid, and the viable bacteria are reduced by deviating from the optimal environment of the bacteria. It is presumed that the environment of the optimum pH of the bacteria can be expanded by adding, and as a result, the number of viable bacteria can be kept large.

  Furthermore, by combining the agar contained in the lactic acid bacteria growth promoter of the present invention as prebiotics and the lactic acid bacteria as probiotics, the intestinal environment of humans can be further improved by synbiotics compared to yogurt without added agar. It becomes possible to be healthy. That is, the lactic acid bacteria growth promoter of the present invention has the effect of improving the intestinal environment as probiotics by proliferating lactic acid bacteria which are good bacteria as prebiotics. In addition, agar, which is a dietary fiber, is an indigestible polymer compound, and exerts an effect of regulating the intestine by itself and also has an effect of suppressing fat absorption in the intestine. Therefore, due to these synergistic effects, the yogurt of the present invention improves the human intestinal environment to a healthier state than conventional yogurt, thereby eliminating constipation and diarrhea, reducing stool odor and body odor, Effects such as preventing rough skin, preventing obesity, and improving immunity can be expected.

  The reason why the agar contained in the lactic acid bacteria growth promoter of the present invention exerts the gastric acid-resistant effect in the hardness of yogurt is presumed as follows. First, when agar having a weight average molecular weight of 10,000 or less is used, since the molecular chain of the polysaccharide constituting the agar is short, the three-dimensional network structure forming the gel is not strong and the gel is easily broken. Further, since the pores are partially formed in the network structure, gastric acid penetrates strongly into the gel, so that more lactic acid bacteria die upon contact with the gastric acid. When the use concentration of agar is increased, the gel becomes too strong, and the gel is not broken in the intestines, so that lactic acid bacteria are difficult to grow. When agar having a weight average molecular yield of 300,000 or more is used, the gel is strong and the network structure is firm because the molecular chain is long. For this reason, in order to obtain a yogurt-like hardness, the concentration of agar used must be lowered, and the entire mesh becomes large in pores, and the penetration of stomach acid into the gel becomes severe. If the concentration of agar used is increased in order to reduce the pores, the gel becomes too strong, and the gel is not broken in the intestines, making it difficult for lactic acid bacteria to grow.

  Further, when the molecular weight distribution (Mw / Mn) is 15 or less, it is difficult to form large pores that are partially formed in the network (the size of the pores in the network structure is uniform), and gastric acid penetration is delayed. In other words, by using the agar contained in the lactic acid bacteria growth promoter of the present invention, the permeation of gastric acid is suppressed by the uniform three-dimensional matrix (uniform network structure) of the agar, and the gel is broken by peristalsis in the intestine. As a result, lactic acid bacteria are released and can proliferate.

  Furthermore, the lactic acid bacteria in yogurt produced using the agar contained in the lactic acid bacteria growth promoter of the present invention, when passing through the stomach and reaching the intestine (artificial intestinal fluid), grow better than those using no agar. It has been found. This is because even if the same viable bacteria do not use agar, the damage caused by the gastric juice is large and the moribund state is used, while those using agar are less damaged by the gastric juice for the above reasons and thus proliferate well. In the present invention, “improving acid resistance under gastric juice conditions” means that the bacteria after incubation for 120 minutes with artificial gastric fluid at pH 1.2 when agar is added compared to when agar is not added. Means good survival.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

1. Production of lactic acid bacteria growth promoter (agar) (Examples 1-6, Comparative Examples 1-14)
(1) Example 1: Agar 1 (low reducing sugar (molecular weight 280,000), pH 5.5, narrow molecular weight distribution)
1 kg of dried ogonori (made in Chile) was immersed in 20 kg of 5% NaOH solution at 90 ° C. for 2 hours. The NaOH solution was removed and washed thoroughly with water to remove alkali. This ogonori was put into 20 kg of water, and 6 g of dibasic sodium phosphate and an acetic acid solution were added thereto as a buffering agent to adjust the pH to 6.3, followed by extraction at 97 ° C. for 2 hours. This solution was filtered, and the filtrate whose pH was adjusted to 5.5 was cooled and gelled. The same amount of water was added to the gelled product (agar concentration: 0.8%), and the mixture was left for 18 hours to be immersed in water. Thereafter, the gelled product was taken out and subjected to compression dehydration, and then dried at 90 ° C. and pulverized to obtain agar (agar 1). The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.74.

(2) Example 2: Agar 2 (low reducing sugar (molecular weight 280,000), pH 7.2, narrow molecular weight distribution)
Agar 2 was obtained in the same manner as Agar 1 except that the pH of the filtrate was adjusted to 7.2 after extraction. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.22.

(3) Example 3: Agar 3 (in reducing sugar (molecular weight 150,000), pH 5.5, narrow molecular weight distribution)
1 kg of dried ogonori (from Chile) was immersed in 20 kg of 5% NaOH solution at 90 ° C. for 1 hour. The NaOH solution was removed and washed thoroughly with water to remove alkali. This ogonori was put into 20 kg of water, and 6 g of dibasic sodium phosphate and an acetic acid solution were added thereto as a buffering agent to adjust the pH to 6.0, followed by extraction at 97 ° C. for 2 hours. This solution was filtered, and the filtrate whose pH was adjusted to 5.5 was cooled and gelled. The same amount of water was added to the gelled product (agar concentration: 0.8%), and the mixture was left for 18 hours to be immersed in water. Thereafter, the gelled product was taken out, and after press dehydration, it was dried at 90 ° C. and pulverized to obtain agar (agar 3). The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.65.

(4) Example 4: Agar 4 (in reducing sugar (molecular weight 150,000), pH 7.2, narrow molecular weight distribution)
Agar 4 was obtained in the same manner as Agar 3 except that the pH of the filtrate was adjusted to 7.2 after extraction. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.15.

(5) Example 5: Agar 5 (Many reducing sugars (molecular weight 15,000), pH 5.5, narrow molecular weight distribution)
1 kg of dried ogonori (from Chile) was immersed in 20 kg of 5% NaOH solution at 90 ° C. for 1 hour. The NaOH solution was removed and washed thoroughly with water to remove alkali. This ogonori was put in 20 kg of water, and 6 g of dibasic sodium phosphate and an acetic acid solution were added thereto as a buffering agent to adjust the pH to 4.3, followed by extraction at 97 ° C. for 2 hours. This solution was filtered to adjust the pH to 5.5, and then placed in 80% ethanol for gelation. 500 g of water was added to the resulting gelled product, and left for 18 hours for immersion. Then, after taking out a deposit and performing press dehydration, it dried at 90 degreeC and grind | pulverized and obtained agar (agar 5). The pH of this 1.5% wt. Agar solution at 80 ° C. was 5.61.

(6) Example 6: Agar 6 (Many reducing sugars (molecular weight 15,000), pH 7.2, narrow molecular weight distribution)
Agar 6 was obtained in the same manner as Agar 5 except that the pH of the filtrate was adjusted to 7.2 after extraction. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 6.90.

(7) Comparative Example 1: Agar 7 (reducing sugar minimal (molecular weight 380,000), pH 5.5, narrow molecular weight distribution)
1 kg of dried ogonori (made in Chile) was immersed in 20 kg of 5% NaOH solution at 90 ° C. for 3 hours. The NaOH solution was removed and washed thoroughly with water to remove alkali. This ogonori was placed in 20 kg of water, and 6 g of dibasic sodium phosphate as a buffer and an acetic acid solution were added thereto to adjust the pH to 7.0, followed by extraction at 97 ° C. for 2 hours. This solution was filtered, and the filtrate whose pH was adjusted to 5.5 was cooled and gelled. The same amount of water was added to the gelled product (agar concentration: 0.8%), and the mixture was left for 18 hours to be immersed in water. Thereafter, the gelled product was taken out, and after pressing and dehydrating, it was dried at 90 ° C. and pulverized to obtain agar (agar 7). The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.64.

(8) Comparative Example 2: Agar 8 (Minimum reducing sugar (molecular weight 380,000), pH 7.2, narrow molecular weight distribution)
Agar 8 was obtained in the same manner as Agar 7 except that the pH of the filtrate was adjusted to 7.2 after extraction. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.05.

(9) Comparative Example 3: Agar 9 (reducing sugar minimal (molecular weight 380,000), pH 5.5, wide molecular weight distribution)
Extraction was performed without adding a buffering agent, and agar 9 was obtained in the same manner as agar 7, except that the gelled product was not soaked in water. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.60.

(10) Comparative Example 4: Agar 10 (reducing sugar minimal (molecular weight 380,000), pH 7.2, wide molecular weight distribution)
Extraction was performed without adding a buffer, and the pH of the filtrate was adjusted to 7.2 after extraction, and the agar 10 was obtained in the same manner as the agar 7 except that the gelled product was not soaked in water. It was. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.00.

(11) Comparative Example 5: Agar 11 (Many reducing sugars (molecular weight 280,000), pH 5.5, broad molecular weight distribution)
Extraction was performed without adding a buffering agent, and agar 11 was obtained in the same manner as Agar 1 except that the gelled product was not soaked in water. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.65.

(12) Comparative Example 6: Agar 12 (Many reducing sugars (molecular weight 280,000), pH 7.2, wide molecular weight distribution)
Extraction was performed without adding a buffer, and the agar 12 was obtained in the same manner as the agar 1 except that the pH of the filtrate was adjusted to 7.2 after the extraction and the gelled product was not soaked in water. It was. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.10.

(13) Comparative Example 7: Agar 13 (Many reducing sugars (molecular weight 150,000), pH 5.5, broad molecular weight distribution)
Extraction was performed without adding a buffering agent, and agar 13 was obtained in the same manner as agar 3 except that the gelled product was not soaked in water. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.60.

(14) Comparative Example 8: Agar 14 (Many reducing sugars (molecular weight 150,000), pH 7.2, wide molecular weight distribution)
Extraction was performed without adding a buffer, and the pH of the filtrate was adjusted to 7.2 after extraction, and the agar 14 was obtained in the same manner as the agar 3 except that the gelled product was not soaked in water. It was. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 7.10.

(15) Comparative Example 9: Agar 15 (Many reducing sugars (molecular weight 15,000), pH 5.5, broad molecular weight distribution)
Extraction was performed without adding a buffer, and agar 15 was obtained in the same manner as agar 5 except that the gelled product was not soaked in water. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.57.

(16) Comparative Example 10: Agar 16 (Many reducing sugars (molecular weight 15,000), pH 7.2, wide molecular weight distribution)
Extraction was performed without adding a buffer, and the pH of the filtrate was adjusted to 7.2 after extraction, and the agar 16 was obtained in the same manner as the agar 5 except that the gelled product was not soaked in water. It was. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 6.85.

(17) Comparative Example 11: Agar 17 (reducing sugar excess (molecular weight 5,000), pH 5.5, narrow molecular weight distribution)
1 kg of dried ogonori (from Chile) was immersed in 20 kg of 5% NaOH solution at 90 ° C. for 1 hour. The NaOH solution was removed and washed thoroughly with water to remove alkali. This ogonori was put in 20 kg of water, and 6 g of dibasic sodium phosphate and an acetic acid solution were added thereto as a buffering agent to adjust the pH to 4.0, followed by extraction at 97 ° C. for 2 hours. This solution was filtered to adjust the pH to 5.5, and then placed in 80% ethanol for gelation. 500 g of water was added to the resulting gelled product, and left for 18 hours for immersion. Then, after taking out a deposit and performing press dehydration, it dried at 90 degreeC and grind | pulverized and obtained agar (agar 17). The pH of this 1.5% wt. Solution of agar at 80 ° C. was 5.56.

(18) Comparative Example 12: Agar 18 (reducing sugar excess (molecular weight 5,000), pH 7.2, narrow molecular weight distribution)
Agar 18 was obtained in the same manner as Agar 17 except that the pH of the filtrate was adjusted to 7.2 after extraction. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 6.85.

(19) Comparative Example 13: Agar 19 (reducing sugar excess (molecular weight 5,000), pH 5.5, broad molecular weight distribution)
Extraction was performed without adding a buffer, and agar 19 was obtained in the same manner as agar 17 except that the gelled product was not soaked in water. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 5.52.

(20) Comparative Example 14: Agar 20 (reducing sugar excess (molecular weight 5,000), pH 7.2, wide molecular weight distribution)
Extraction was performed without adding a buffer, and the pH of the filtrate was adjusted to 7.2 after extraction, and the agar 20 was obtained in the same manner as the agar 17 except that the gelled product was not soaked in water. It was. The pH at 80 ° C. of a 1.5% by weight solution of this agar was 6.80.

(21) Measurement of physical properties of agar after dehydration and drying (a) Weight average molecular weight (Mw);
It measured according to GPC method by HPLC. Specifically, 0.3 g of agar was dissolved in 200 mL of distilled water (97 ° C., 3 minutes) and measured using a column (TOSOH TSK-GEL for HPLC, TSK-GEL GMPWXL).
(B) Reducing sugar amount (%);
0.01 g of agar was dispersed in 100 g of water, heated at 110 ° C. for 5 minutes, and the amount of reducing sugar was measured by the Park-Johnson method for the dissolved solution in which the agar was dissolved. The calibration curve was prepared using galactose.
(C) pH;
1.5 g of agar was dispersed in 100 g of ion-exchanged water and dissolved by heating at 110 ° C. for 5 minutes. The pH of this solution (corrected with ion-exchanged water so that the final agar concentration was 1.5% by weight) was measured at 80 ° C.
(D) molecular weight distribution (Mw / Mn);
It calculated | required by the weight average molecular weight / number average molecular weight. (The closer to 1, the narrower the molecular weight distribution) Mn was also determined by the HPLC method in the same manner as Mw.
(E) Elution rate when immersed in water (%);
100 g of water when the same amount of water (water soaked) was added to the gelled product was immersed in the gelled product, taken out, evaporated to dryness, and the solid content eluted from the gelled product was measured. Separately from this, 100 g of the gelled product obtained before soaking was dried at 100 ° C. to remove water, and the amount of agar in the gel was measured. The elution rate was determined by the following formula.
Elution rate (%) at the time of water immersion = (weight of solid content evaporated to dryness / agar amount in 100 g of gel before water immersion) × 100

  Based on the above, the addition of a buffer during extraction and the removal of low molecular weight components by adding soaked water to the gelled product may have a relatively low reducing sugar amount and a narrow molecular weight distribution. Recognize.

2. Preparation of Yogurt and Confirmation of Proliferation Effect of Lactic Acid Bacteria Lactic acid bacteria used were obtained from JAPAN COLLECTION OF MICROORGANISM (JCM) and BIOLOGICAL RESOURCE CENTER, NITE (NBRC).
(1) Preparation of yogurt 1
After dissolving 0.5 g of the agar (agar 1-20) prepared above with 21.8 g of boiling water at 95 ° C. for 5 minutes, add 10 g of granulated sugar, 65 g of milk and 2.7 g of skim milk powder, and further boil and heat for 1 minute. After dissolving and cooling to 45 ° C., Lactobacillus delbrueckii subsp. bulgaricus JCM 1002 strain was added 140000000 cfu, mixed, and allowed to stand at 37 ° C. for 12 hours and 24 hours (Examples 1-1 to 6-1 and Comparative Examples 1-1 to 14-1). In addition, in a system without agar (Comparative Example 15-1), 10 g of granulated sugar, 65 g of milk and 2.7 g of skim milk powder were added to 22.3 g of boiling water at 95 ° C., and the mixture was dissolved by boiling for 1 minute. After cooling to Lactobacillus delbrueckii subsp. bulgaricus JCM 1002 strain was added 140000000 cfu, mixed, and allowed to stand at 37 ° C. for 12 hours and 24 hours.

  The cultured yogurt is suspended and diluted in a phosphate buffer (pH 7.2), seeded on a BCP-added plate count agar (Nissui Pharmaceutical, Tokyo) prepared on a sterile petri dish, and maintained at 37 ° C. under aerobic conditions. Then, after standing for 72 hours, the number of colonies formed was counted to determine the number of bacteria. The results are shown in Table 2.

  From the results shown in Table 2, when comparing agars (for example, agar 1, 3, and 5) having different weight average molecular weights and reducing sugar amounts, and having substantially the same pH and molecular weight distribution, the smaller the weight average molecular weight, the larger the reducing sugar amount. It can be seen that the number increases. However, in the agar 7 having a large weight average molecular weight and a small amount of reducing sugar, and the agar 17 having a small weight average molecular weight and a large amount of reducing sugar, it can be seen that the number of bacteria is reduced as compared with the case of no addition.

  Furthermore, when comparing agars having substantially the same weight average molecular weight and reducing sugar amount (for example, agars 1 and 2), yogurt prepared by adding agar having a slightly acidic pH and a narrower molecular weight distribution, It was found that the number of bacteria increased markedly.

  From the above, in agars 1 to 6 in which the weight average molecular weight is 10,000 to 300,000 and the amount of reducing sugar is adjusted to 0.12 to 2.0, the physical properties of the agar are outside the above range (agar 7 to 20). ) And those with no agar added, the number of bacteria increased remarkably, and further, the proliferation effect increased as the weight average molecular weight decreased and the reducing sugar amount increased. In addition, as the pH of a 1.5% by weight solution of agar is 4.0 to 5.8, or as the agar having a narrow molecular weight distribution with a molecular weight distribution (Mw / Mn) of 15 or less, the growth effect of lactic acid bacteria is higher. I understood it.

(2) Preparation of yogurt 2
Streptococcus thermophilus JCM17883 was added as a starter and mixed with 140000000 cfu, and the number of bacteria was measured after preparing yogurt in the same manner as in “(1) Preparation of yogurt 1”. The results are shown in Table 3.

  From the above, Lactobacillus delbrueckii subsp. Similarly to the case of yogurt prepared by adding bulgaricus JCM 1002 strain, when it was prepared by adding Streptococcus thermophilus JCM17834 strain, the weight average molecular weight was 10,000 to 300,000 and the amount of reducing sugar was 0.12 to In agars 1 to 6 adjusted to 2.0, the number of bacteria is remarkably increased as compared to those having physical properties of agar outside the above range and those having no agar added, and the weight average molecular weight is small and reduced. It was found that the growth effect increases as the amount of sugar increases. Further, as the pH of a 1.5% by weight solution of agar is 4.0 to 5.8, or as agar having a narrow molecular weight distribution with a molecular weight distribution (Mw / Mn) of 15 or less, the growth effect of lactic acid bacteria is increased. I found it expensive.

(3) Preparation of yogurt 3
As a starter, Bifidobacterium longum subsp. longum JCM1217 strain was prepared in the same manner as in “(1) Preparation of yogurt 1” except that 15000000 cfu was added and mixed. The cultured yogurt is suspended and diluted in a phosphate buffer (pH 7.2), seeded on a TOS propionate agar medium (Yakult Pharmaceutical Co., Ltd., Tokyo) prepared on a sterile petri dish, and anaerobic at 37 ° C. Then, after standing for 72 hours, the number of colonies formed was counted to determine the number of bacteria. The results are shown in Table 4.

  From the above, Lactobacillus delbrueckii subsp. bulgaricus JCM 1002 and Streptococcus thermophilus JCM17834 were added in the same manner as yoghurt prepared by adding Bifidobacterium longum subsp. Even when the longum JCM1217 strain is added and prepared, agar 1 to 6 having a weight average molecular weight of 10,000 to 300,000 and a reducing sugar amount of 0.12 to 2.0 have a physical property value of agar. It was found that the number of bacteria was significantly increased compared to those outside the above range and those not added with agar, and that the proliferation effect was increased as the weight average molecular weight was decreased and the reducing sugar amount was increased. In addition, as the pH of a 1.5% by weight solution of agar is 4.0 to 5.8, or as the agar having a narrow molecular weight distribution with a molecular weight distribution (Mw / Mn) of 15 or less, the growth effect of lactic acid bacteria is higher. I understood it.

3. Preservation test The yogurt prepared in “(3) Preparation of yogurt 3” and cultured for 24 hours was allowed to stand at 4 ° C. for 3 days and 7 days. The yogurt after standing was suspended and diluted in a phosphate buffer (pH 7.2), and seeded on a TOS propionic acid agar medium (Yakult Pharmaceutical Co., Ltd., Tokyo) prepared on a sterile petri dish. After leaving still at 72 ° C. for 72 hours, the number of colonies formed was counted to determine the number of bacteria. The results are shown in Table 5.

  From the results of Table 5, when comparing agars having different weight average molecular weights and reducing sugar amounts and substantially the same pH and molecular weight distribution (for example, agar 1, 3, 5), the weight average molecular weight is smaller and the reducing sugar amount is larger. It can be seen that there are many residual lactic acid bacteria after long-term storage at ℃. In addition, when comparing agars having substantially the same weight average molecular weight and reducing sugar amount (for example, agars 1 and 2), agar with a slightly acidic pH and a narrower molecular weight distribution is a residual lactic acid bacterium when stored at 4 ° C for a long time. It turns out that there are many numbers.

  From the above, when agars 1 to 6 having a weight average molecular weight of 10,000 to 300,000 and a reducing sugar amount adjusted to 0.12 to 2.0 are stored at 4 ° C. for a long time as compared with those without addition of agar It was found that the number of the remaining viable bacteria was higher and the preservation effect was higher as the weight average molecular weight was smaller and the reducing sugar amount was larger. Further, as the pH of a 1.5% by weight solution of agar is 4.0 to 5.8 or agar having a narrow molecular weight distribution with a molecular weight distribution (Mw / Mn) of 15 or less, the preservation effect of lactic acid bacteria is higher. I understood it.

4). Intestinal assumption test To the yoghurt prepared in the above “(3) Preparation of yoghurt 3”, an equal amount of the second solution of the local disintegration test was added and allowed to stand at 37 ° C. for 6 hours, 12 hours and 24 hours. The yogurt after standing was suspended and diluted in a phosphate buffer (pH 7.2), and seeded on a TOS propionic acid agar medium (Yakult Pharmaceutical Co., Ltd., Tokyo) prepared on a sterile petri dish. After leaving still at 72 ° C. for 72 hours, the number of colonies formed was counted to determine the number of bacteria. The results are shown in Table 6.

  From the results in Table 6, when comparing agars (for example, agar 1, 3, and 5) having different weight average molecular weights and reducing sugar amounts and substantially the same pH and molecular weight distribution, the smaller the weight average molecular weight is, the larger the reducing sugar amount is. It can be seen that the number of bacteria when stored in the second liquid of the disintegration test is large. In addition, when comparing agars with almost the same weight average molecular weight and reducing sugar amount (for example, agars 1 and 2), agar with a slightly acidic pH and a narrower molecular weight distribution is stored in the second solution of the local decay test. It can be seen that the number of bacteria is large.

  That is, in the agars 1 to 6 in which the weight average molecular weight is 10,000 to 300,000 and the amount of reducing sugar is adjusted to 0.12 to 2.0, the lactic acid bacteria in the intestinal environment are compared to those in which no agar is added. It has been found that the proliferation effect is higher, and that the proliferation effect increases as the weight average molecular weight decreases and the amount of reducing sugar increases. In addition, as the pH of a 1.5% by weight solution of agar is 4.0 to 5.8, or as agar having a narrow molecular weight distribution with a molecular weight distribution (Mw / Mn) of 15 or less, the expected environment in the intestine of lactic acid bacteria is increased. It was found that the growth effect of lactic acid bacteria underneath was high.

5. Artificial gastric juice treatment test Agar 1-6 (Examples 1-6, respectively) and Agar 7, 11, 17 (Comparative Examples 1, 5, 11 respectively) The acid resistance test was carried out with the yogurt (cultured for 24 hours) prepared in “Preparation 2” and “Preparation 3 of yogurt”. The test method was as follows: 200 g of the prepared yogurt was uniformly cut into 5 mm squares, and the yogurt cut into 250 g of JP 1st liquid (artificial gastric fluid, pH 1.2) was added, and the dissolution tester (JP, paddle method, 50 rpm) , 37 ° C.). Sampling was performed at 0 minutes, 30 minutes, 60 minutes, 90 minutes, and 120 minutes, and the number of bacteria was measured. The results are shown in Tables 7-9.

  Table 7 shows the changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of the yogurt (Lactobacillus delbrueckii subsp. Bulgaricus JCM1002) prepared in “Preparation of yogurt 1”. From the result of this table | surface, it turned out that the yogurt of Examples 1-6 to 6-6 has acid resistance.

  Table 8 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of the yogurt (Streptococcus thermophilus JCM17834) produced in “Preparation of yogurt 2”. Also from the result of this table | surface, it turned out that the yogurt of Examples 1-7 to 6-7 has acid resistance.

  Table 9 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of the yogurt (Bifidobacterium longum subsp. Longum JCM1217 strain) prepared in “Preparation of yogurt 3”. Also from the result of this table | surface, it turned out that the yogurt of Examples 1-8 to 6-8 has acid resistance.

6). Artificial gastric juice treatment test with additional lactic acid bacteria Using agar 1-6 (Examples 1-6, respectively) and agar 7, 11, 17 (respectively Comparative Examples 1, 5, 11), the following lactic acid bacteria were used: Other than the above, the yogurt was prepared in the same manner as in “2. Preparation of yogurt and confirmation of lactic acid bacteria growth effect”, and the test with the artificial gastric juice and the test with the artificial intestinal fluid were conducted in the same manner as the above “5. went. The result was shown to 10-16.
Additional lactic acid bacteria 1: Lactobacillus delbrueckii subsp. bulgaricus NBRC 13953
Additional lactic acid bacteria 2: Lactobacillus casei NBRC 15883
Additional lactic acid bacteria 3: Lactobacillus acidophilus NBRC 13951
Additional lactic acid bacteria 4: Lactobacillus lactis subsp. lactis NBRC 10093
Additional lactic acid bacteria 5: Streptococcus thermophilus NBRC 13957
Additional lactic acid bacteria 6: Bifidobacterium bifidum NBRC 100015

  Table 10 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Lactobacillus delbrueckii subsp. Bulgaricus NBRC 13953). From the result of this table | surface, it turned out that the yogurt of Examples 1-9-6-9 has acid resistance.

  Table 11 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Lactobacillus casei NBRC 15883). From the result of this table | surface, it turned out that the yogurt of Examples 1-10 to 6-10 has acid resistance.

  Table 12 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Lactobacillus acidophilus NBRC 13951). From the results of this table, it was found that the yogurts of Examples 1-11 to 6-11 had acid resistance.

  Table 13 shows the changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Lactobacillus lactis subsp. Lactis NBRC 10093). From the result of this table | surface, it turned out that the yogurt of Examples 1-12-6-12 has acid resistance.

  Table 14 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Streptococcus thermophilus NBRC 13957). From the result of this table | surface, it turned out that the yogurt of Examples 1-13 to 6-1 has acid resistance.

  Table 15 shows changes in the artificial gastric juice treatment time and the number of lactic acid bacteria of yogurt (Bifidobacterium bifidum NBRC 100015). From the result of this table | surface, it turned out that the yogurt of Examples 1-14 to 6-14 has acid resistance. As described above, yogurt using any of the additional lactic acid bacteria 1 to 6 was acid resistant.

7). Artificial Intestinal Fluid Treatment Test For yogurt treated with artificial gastric fluid for 120 minutes in the above “5. Artificial gastric fluid treatment test”, the yogurt was sampled so that the number of viable bacteria was 1.0 × 10 ² , and 5% by weight of defatted The mixture was added to 500 mL of Japanese Pharmacopoeia second solution (artificial intestinal fluid, pH 6.8) containing milk powder, and allowed to stand at 37 ° C. for 12 hours for cultivation. The viable cell count was measured for this culture solution. The results are shown in Tables 16-18.

  Table 16 shows changes in artificial intestinal fluid treatment time and the number of lactic acid bacteria of yogurt (Lactobacillus delbrueckii subsp. Bulgaricus JCM1002). From the result of this table | surface, it turned out that the yogurt of Examples 1-15-1-6-15 has acid resistance, and the proliferation in artificial intestinal fluid is quick.

  Table 17 shows changes in the artificial intestinal fluid treatment time and the number of lactic acid bacteria of yogurt (Streptococcus thermophilus JCM17834). From the result of this table | surface, it turned out that the yogurt of Examples 1-16 to 6-16 has acid resistance, and the proliferation in artificial intestinal fluid is quick.

  Table 18 shows changes in artificial intestinal fluid treatment time and the number of lactic acid bacteria of yogurt (Bifidobacterium longum subsp. Longum JCM1217 strain). From the result of this table | surface, it turned out that the yogurt of Examples 1-17 to 6-17 has acid resistance, and the proliferation in an artificial intestinal fluid is quick.

Claims (5)

  A lactic acid bacteria growth promoter, comprising agar having a weight average molecular weight of 10,000 to 300,000 and a reducing sugar amount of 0.12 to 2.0.   The lactic acid bacteria growth promoter according to claim 1, wherein the molecular weight distribution (Mw / Mn) of the agar is 15 or less.   The lactic acid bacteria growth promoter according to claim 1 or 2, wherein the pH of the 1.5 wt% solution of the agar is 4.0 to 5.8.   The lactic acid bacterium growth promoter according to any one of claims 1 to 3, which improves acid resistance of lactic acid bacteria under gastric juice conditions.   A yogurt containing the lactic acid bacteria growth promoter according to any one of claims 1 to 4 and a lactic acid bacterium, wherein the agar content is 0.05 to 2.0% by weight.