JP2604301C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a yeast extract composition having an improved taste, and more particularly, to a method for producing a 5′-nucleotide having a taste and freeing it. and amino acids both a manufacturing process of yeast extract composition having a high content. BACKGROUND OF THE INVENTION [0002] Yeast extract, in addition to having excellent taste like a meat extract, has a complex taste that is not present in chemical seasonings such as sodium glutamate. In other words, it has an unpleasant taste such as umami, sourness, karatami, bitterness, and sweetness, and thus has been widely used as a food material. In addition, various types of yeast extract compositions have been developed and marketed by recent improvements in enzyme utilization technology and separation and purification technology. [0003] Amino acids, peptides, 5'-nucleotides, carbohydrates, organic acids, and the like are known as taste components of yeast extract compositions. Among them, amino acids and peptides are particularly important as components that bring out the unpleasant taste peculiar to the yeast extract composition, and 5′-nucleotide is a component that brings out the umami. The yeast extract composition is usually produced by an autolysis method, an enzymatic decomposition method, or the like. [0004] In the autolysis method, the content of free amino acids can be increased by the action of protease in yeast cells, but only extremely low 5'-nucleotide content can be obtained by the action of coexisting ribonuclease, phosphatase and the like. Was.
In order to increase the 5'-nucleotide content, a method of controlling the pH during autolysis is known (see Japanese Patent Application Laid-Open No. 55-92772). However, even in these methods, the solid content yield is 50%. The 5'-nucleotide content described above was still low and was not fully satisfactory. In the enzymatic decomposition method, yeast cells are heated in advance to deactivate all enzymes possessed by yeast, and then 5′-phosphodiesterase, 5′-adenylate deaminase, protease and the like are added. A method for increasing the content of 5,5'-nucleotides is known (see JP-A-62-201595). In this method, the content of tasteful 5'-nucleotides can be increased to about 4% and a high oligopeptide content can be obtained, but on the other hand, protease sufficiently acts because the yeast protein is denatured by heating. However, there is a problem that the content of free amino acids, which is indispensable for extracting the characteristic flavor of yeast extract, is small. [0006] As described above, in the conventionally known simple autolysis method and enzymatic decomposition method, the free amino acid content is large but the tasteable 5'-nucleotide content is low, or the tasteable 5'-nucleotide content is low. Although it was large, only those having a low free amino acid content could be obtained, and it was not possible to obtain a yeast extract composition having high free amino acid content and 5'-nucleotide content, and having excellent flavor and especially good umami. Therefore, since the yeast extract composition does not have the expected characteristic of having an unpleasant taste, there is a problem that the type and amount of food to be used are restricted. Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that a yeast having a limited temperature and pH within a specific range in combination with a cell wall lysing enzyme is used. After performing digestion, increasing the solid content yield, and increasing the amount of free amino acids without decomposing the high-molecular-weight RNA, the reaction solution is heated under a certain condition to inactivate the enzyme, and 5'-nucleotide is further added. Of 5'-phosphodiesterase and 5'-adenylate deaminase, which produce the yeast, and found that the yeast extract composition thus obtained is excellent in both taste and unpleasant taste. Was completed. The temperature and pH at the time of autolysis in the present invention are intended to increase the free amino acid content and to suppress the degradation of RNA, and to incorporate a heating step after the autolysis reaction in the subsequent enzyme reaction step. Therefore, it is a very important factor in suppressing the degradation of tasteful 5'-nucleotides. Hereinafter, the present invention will be described in more detail. The yeast used in the present invention is not particularly limited as long as it is edible, and yeasts generally used in the food industry such as brewer's yeast, baker's yeast, alcoholic yeast, and sake yeast can be used. Examples of such yeasts include Saccharomyces cerevisiae (IFO 1954, IFO 0309, IAM 4274), Candida utilis (IFO 0619, ATCC 15239), Torulopsis nodaensis (IFO 1942), Torulopsis stellata (IFO).
O 1953), Hansenula anomala (IFO 1150) and the like. Next, the cell wall lysing enzyme used in the present invention may be any one containing glucanase and mannanase and having sufficient activity to lyse the yeast cell wall. Is YL-5 (manufactured by Amano Pharmaceutical Co., Ltd.),
Tuncase (manufactured by Daiwa Kasei Co., Ltd.) and kitalase (manufactured by Kumiai Chemical Co., Ltd.). At this time, the protease may act to decompose the protein in the cell wall to facilitate lysis. After suspending the yeast at an appropriate concentration of about 10 to 15%, the cell wall lysing enzyme is added. The amount of the cell wall lysing enzyme varies depending on the level of the enzyme activity, but is usually about 0.3-3%. Regarding the reaction pH and the reaction temperature, it is necessary to suppress the degradation of the high-molecular RNA and to increase the production of free amino acids. Outside this range, it is difficult to increase the free amino acid content. When the temperature is below this range, the content of free amino acids increases, but RNA degradation is observed. On the other hand, when the temperature exceeds 65 ° C., the degradation of RNA disappears, but the free amino acid content is extremely reduced. After the digestion under the above conditions is performed for about 10 to 20 hours, the enzyme is heated at 80 to 120 ° C., preferably 90 to 100 ° C., to deactivate the intracellular enzymes. A heating time of about 10 minutes is sufficient. Subsequently, 5'-phosphodiesterase and 5'-adenylate deaminase are added to generate 5'-nucleotides. The amount of the enzyme added, the enzyme reaction temperature, and the pH are not particularly limited, and may be performed under the minimum conditions for each enzyme. The reaction solution is heated to 90 ° C. to inactivate the enzyme, and then centrifuged to concentrate the supernatant and collect the extract. Although the extract can be used as it is, it may be dried by a method such as spray drying if necessary. The yeast extract thus obtained contains both 5'-inosinic acid and 5'-guanylic acid in an amount of 1-5% based on the solid content and 12% or more of free amino acids, and thus has an excellent taste and strong taste. It has a bitter taste and can be used more widely as a food material than conventional products. Further, since the solid content yield is 50% or more, it is very economically advantageous. EXAMPLES Specific examples will be described below. Example 1 Saccharomyces cerevisiae (IFO 1954) was cultured using a 5% molasses medium, and after collecting and washing, 1000 ml of a yeast slurry (cell concentration: 15%) was prepared.
After adjusting the pH to 6, the cell wall lysing enzyme (trade name: YL-5 [manufactured by Amano Pharmaceutical Co., Ltd.])
Was added and reacted at 55 ° C. for 18 hours. Thereafter, the mixture was heated at 90 ° C. for 10 minutes to inactivate the intracellular enzymes, then cooled to 70 ° C., and 5′-phosphodiesterase ｛was added.
Product name: Add nuclease “Amano” (manufactured by Amano Pharmaceutical Co., Ltd.)｝ 0.3 g and pH
After the preparation to 5, the mixture was reacted for 10 hours. Subsequently, 0.2 g of 5'-adenylate deaminase {trade name: deamizyme (manufactured by Amano Pharmaceutical Co., Ltd.)} was added to adjust the pH to 5, and then 1
At 0 o'clock, the reaction was performed. After the reaction, the mixture was treated by a conventional method to obtain 113 g of a yeast extract composition. The contents of 5′-inosinic acid, 5′-guanylic acid, and free amino acids in the yeast extract composition were determined using a high performance liquid chromatograph. The content of 5'-inosinic acid, 5'-guanylic acid and free amino acid in the yeast extract composition produced by autolysis at pH 6,40 ° C using brewer's yeast was 0.1% and 0.1%, respectively. % And 30%. The content of 5'-inosinic acid, 5'-guanylic acid and free amino acid in the yeast extract composition produced by the enzymatic method using brewer's yeast which had been inactivated by heating in advance was 2.1% and 2.2%, respectively. % And 8%. Next, these three items were evaluated by conducting a sensory test on two points of umami and savory intensity. A 0.5% solution of each yeast extract composition was prepared and maintained at 60 ° C., and a sensory test was performed by 10 panelists to compare the performance. Table 1 shows the results. As is clear from Table 1, the method according to the present invention is based on the autolysis method and the enzyme.
It was found that both the umami taste and the unpleasant taste strength were superior to those obtained by the elemental decomposition method . [0016] Example 2 Candida utilis (IFO 0619) was cultured in a 5% molasses medium, and after collecting and washing cells, 1000 ml of a yeast slurry (cell concentration: 15%) was prepared. p
After H was adjusted to 6.5, 1.8 g of a cell wall lysing enzyme (trade name: Tunicase [manufactured by Daiwa Kasei Co., Ltd.]) was added and reacted at 55 ° C. for 18 hours. Then 95 ℃, 10
After heating for a minute to inactivate the intracellular enzymes, the mixture is cooled to 70 ° C and nuclease is used.
180 mg of nuclease "Amano" (manufactured by Amano Pharmaceutical Co., Ltd.) was added and reacted for 9 hours. Thereafter, the temperature was lowered to 45 ° C., and the protease was trade name: Amano P [Amano Pharmaceutical (
1.8 g, 5'-adenylate deaminase {trade name: deamizyme [
200 mg, manufactured by Amano Pharmaceutical Co., Ltd.] and reacted for 10 hours. After cooling, the mixture was treated by a conventional method to obtain 121 g of a yeast extract composition. Each content of 5′-inosinic acid, 5′-guanylic acid, and free amino acid in this yeast extract composition was determined using a high performance liquid chromatograph. The content of 5'-inosinic acid, 5'-guanylic acid, and free amino acid in the yeast extract composition produced by autolysis at pH 6,40 ° C using brewer's yeast was 0.1% and 0.1%, respectively. % And 30%. The content of 5'-inosinic acid, 5'-guanylic acid and free amino acid in a yeast extract composition produced by an enzymatic method using beer yeast previously inactivated by heating was 2.1% and 2.2%, respectively. % And 8%. Next, these three items were evaluated by conducting a sensory test on two points of umami and savory intensity. A 0.5% solution of each yeast extract composition was prepared and maintained at 60 ° C., and a sensory test was performed by 10 panelists to compare the performance. Table 2 shows the results. As is clear from Table 2, the method according to the present invention is based on the autolysis method and the enzyme.
It was found that both the umami taste and the unpleasant taste strength were superior to those obtained by the elemental decomposition method . [0020] EFFECTS OF THE INVENTION According to the present invention, a yeast extract composition having a strong umami and a strong savory intensity, which has never existed before, can be obtained. ,amount to use,
It can impart a savory taste, especially umami, to foods whose use has been restricted.

Claims (1)

[Claims] After all inactivation, 5′-phosphodiesterase and 5′-adenylate deamidation A method for producing a yeast extract composition, comprising: