Food materials for masking vegetable protein odors

Abstract

To provide a composition that can mask or reduce plant protein odors, or strange flavors of plant protein such as a green smell, and a method therefor.SOLUTION: A yeast material with the content of free amino acids of 5% or less and the content of nucleotides of 3% or less, or yeast cells thereof, or the yeast cells from which yeast extract has been extracted, is treated with a cell wall digesting enzyme and then subjected to a heating process, so that the plant protein odors can be masked.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a yeast material having a specific component, or a material which reduces off-flavors of soy protein and the like, obtained by acting a specific enzyme on yeast cells or cultured yeast cells. [Background technology]

[0002] Yeast contains a wealth of flavorful and nutritious components, such as nucleic acids, amino acids, and peptides, and its extract, yeast extract, is used in a wide range of applications, including as a natural seasoning, health food, and culture medium for microorganisms. As a method for producing yeast extract, various methods are known that differ depending on the enzymes and media used for extraction, and examples thereof include Patent Documents 1 to 3.

[0003] On the other hand, methods using yeast cells as they are are also known, for example, as disclosed in Patent Document 4 or Patent Document 5.

[0004] In recent years, the market for vegetable proteins has expanded due to their health and nutritional value, but vegetable proteins have a unique flavor, such as a grassy smell, and reducing this has been a challenge. For example, Patent Document 6 describes that sucralose has the effect of masking the odor of protein ingredients derived from soy protein, wheat protein, etc., but sucralose itself has a sweet taste. In addition, seasonings containing yeast extract can suppress the odor of vegetable protein due to their own taste-imparting effect, but the taste-imparting effect of yeast extract can sometimes impart flavor to foods. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-252894, [Patent Document 2] Japanese Patent Application Publication No. 6-113789 [Patent Document 3] Japanese Patent Application Publication No. 9-56361 [Patent Document 4] JP 2019-030339 A [Patent Document 5] International Publication WO2018 / 034204 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide a composition that can mask or reduce the odor of vegetable protein and the grassy and other off-flavorful flavors that vegetable protein has, and a method for doing so. [Means for solving the problem]

[0007] As a result of extensive research, the inventors have discovered that the vegetable protein odor can be masked by applying a cell wall-lytic enzyme to a yeast material containing specific components, or to yeast cells not yet extracted with yeast extract, or to yeast cells after yeast extract extraction, and then subjecting the resulting mixture to a heating process.

[0008] That is, the present invention is as follows. (1) A yeast material for reducing off-flavors of vegetable protein, having a free amino acid content of 5% or less and a nucleotide content of 3% or less. (2) A method for producing a yeast material according to claim 1, characterized in that a cell wall-lytic enzyme is allowed to act on yeast cells after extraction with yeast extract or on yeast cells before extraction with yeast extract. (3) The method for producing a yeast material according to (2) above, wherein the yeast cell is Candida utilis or Saccharomyces cerevisiae. (4) A method for reducing the off-flavor of vegetable protein by adding the yeast material described in (1) above to food or beverage. Effect of the Invention

[0009] According to the present invention, the yeast material can reduce the unpleasant odor and off-flavor of vegetable protein without imparting a taste such as umami to the food to which it is added, as compared to yeast extract. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be specifically described below.

[0011] The yeast material of the present invention is a yeast extract having a free amino acid content of 5% by mass or less and a nucleotide content of 3% by mass or less. The free amino acid content is preferably 4% by mass or less, more preferably 3.5% by mass or less. The nucleotide content is preferably 2% by mass or less, and it is particularly preferable that the nucleotide content is below the detection limit. The mononucleotide and RNA content is preferably less than 5% by mass. The free amino acid content, nucleotide content, and RNA content are measured according to the methods described in the specification of the present application.

[0012] The enzyme material of the present invention can be produced by the following method. The yeast referred to in the present invention is a yeast mainly used as a raw material for yeast extract, and any yeast that is used as a raw material for yeast extract can be used. Specific examples include Saccharomyces cerevisiae and Candida utilis.

[0013] The yeast used as the raw material of the present invention can be yeast cells obtained by a culture method used for normal yeast extract production. To obtain the composition of the present invention, it is preferable to prepare the yeast cells after adjusting them so that the content of free amino acids and nucleotides is below a specific amount. As a simple adjustment method, the yeast cells (yeast residue) after normal yeast extract extraction is used. Specifically, the yeast cells after yeast extract extraction are the residues left after yeast extract is removed by extracting yeast with hot water, alkaline solution, autolysis, mechanical crushing, cell wall lytic enzyme, proteolytic enzyme, ribonuclease, or deaminase. An example is "KR yeast" manufactured by Mitsubishi Corporation Life Sciences Co., Ltd. Such residues generally contain glucan, mannan, protein, and lipid as main components, but it is presumed that structurally, glucan and mannan are firmly bound to other components as a complex, and even if protease is directly applied to the residues, there is almost no reaction. In cases where yeast residue is not used as the raw material, the free amino acid and nucleotide contents may be adjusted to the values ​​of the present invention during the production process of the yeast material of the present invention, for example, before or after the enzyme treatment described below. The adjustment method may be any method that is adopted by those skilled in the art.

[0014] The process for obtaining the yeast material of the present invention is not particularly limited, but it is preferable to first add water to the above-mentioned yeast cells to adjust the concentration to about 5 to 20%, suspend the cells, add a cell wall-lytic enzyme, and allow it to act at 30°C or higher for 1 to 6 hours.

[0015] The cell wall lytic enzyme to be added here includes glucanase and mannanase, but in the present invention, "Denazyme GEL" manufactured by Nagase & Co., Ltd. is the most preferable cell wall lytic enzyme. "Sumizyme TG" manufactured by Shin Nippon Chemical Industry Co., Ltd. is an enzyme preparation having glucanase activity and protease activity, and an enzyme preparation containing such a protease can also be used.

[0016] Following the reaction with the cell wall-lysing enzyme, heat treatment is carried out at a temperature of 50°C or higher, preferably 50 to 100°C, more preferably 70 to 100°C, for 5 minutes or more, preferably 5 to 20 minutes. Then, after a heating step at 110°C or higher for 5 seconds or more, preferably 5 to 30 seconds, the product is obtained by drying treatment. The drying method is not particularly limited, and freeze-drying method, spray-drying method, drum-drying method, etc. are adopted. Also, it may be directly added to food and drink products without going through the drying process.

[0017] The yeast material of the present invention may be yeast extract obtained by extracting the extract by solid-liquid separation treatment, or may be in a state containing cells without solid-liquid separation treatment. The yeast material of the present invention may contain other components such as stabilizers and preservatives.

[0018] The yeast material etc. obtained in this way can mask the plant-derived protein odor by adding it to foods containing plant protein. Examples of foods containing plant protein include grains such as wheat, rice, potatoes, corn, or beans such as soybeans, or grain-derived foods such as soy-derived foods and soy protein materials, and vegetables such as broccoli. The yeast material of the present invention added to these foods can be added in any amount. Usually, by adding 0.01 to 1% by mass, the effects of the present invention can be obtained.

[0019] In the present invention, the nucleotide content can be measured under the following HPLC conditions. After measuring the nucleotide standard under the following conditions to obtain the retention time and area, the sample is measured, and the nucleotide content in the sample is calculated based on the area ratio. <HPLC conditions> · Column: MCL GEL CDR10 (4.6 mm × 250 mm), manufactured by Mitsubishi Chemical · Mobile phase: 2M acetic acid - ammonium acetate (pH 3.3) · Flow rate: 1.0 mL / min · Temperature: 60°C · Detection wavelength: 260 nm

[0020] In the present invention, the free amino acid content was measured by diluting the sample with 0.02-N-HCL and using an amino acid analyzer (Hitachi high-speed amino acid analyzer L-8800).

[0021] In the present invention, the RNA content was measured by HPLC using a sample dissolved in ultrapure water. The column used was Asahipak HPLC column GS-320H, and the eluent was 0.1M sodium phosphate buffer. The detection wavelength was 260 nm. EXAMPLES

[0022] The present invention will now be described in detail with reference to examples. <Example 1> In the method for producing Candida utilis yeast extract described in Example 3 of JP 2002-101846 A, after extract extraction, the cell residue removed by centrifugation was obtained and used as the raw yeast cell. 1 kg of this yeast cell was suspended in water to a concentration of 10%, and then the temperature was adjusted to 40°C and pH 4.5. 3 g of a cell wall lytic enzyme (Nagase ChemteX Corporation's "Denazyme GEL") was added and allowed to act for 5 hours, followed by heating at 70°C for 20 minutes, and then further heating at 125°C for 10 seconds, followed by drying in a drum dryer (Katsuragi Kogyo Co., Ltd.). The free amino acid content was 1.5%, and the nucleotide content was 0%.

[0023] <Example 2> Before drying as described in Example 1, the extract was collected by centrifugation, concentrated, and then spray-dried to obtain 32 g of dry powder. The free amino acid content was 2.3%, and the nucleotide content was 0%.

[0024] <Example 3> The same procedure as in Example 1 was repeated, except that 3 g of "Sumizyme TG" manufactured by Shin Nippon Chemical Industry Co., Ltd. was added and allowed to react for 5 hours in the same manner as in Example 1. The free amino acid content was 2.6%, and the nucleotide content was 0%.

[0025] <Example 4> The extract was collected by centrifugation before drying as described in Example 3, and the collected extract was concentrated and then spray-dried to obtain 39 g of dry powder. The free amino acid content was 3.2%, and the nucleotide content was 0%.

[0026] <Comparative Example 1> 30 g of dry powder was obtained by the Candida utilis yeast extract production method described in Example 3 of JP 2002-101846 A. The free amino acid content was 12.0%, and the nucleotide content was 0%.

[0027] <Example 5> 1 g of Fuji Oil's "Fujipro-F", a vegetable protein material, was dissolved in 99 g of water, and 0.05 g of each of Mitsubishi Corporation Life Sciences' "Ajilex NH" (free amino acid 0.2% by mass, nucleotide content 0.1% by mass, RNA 30.4% by mass), "Aromild" (free amino acid content 8.5% by mass, nucleotide content 35.5%) and "Ajitop" (free amino acid content 28.1% by mass, nucleotide content 2.4%) were added as examples 1 to 4, comparative example 1, comparative example 2, and reference example, and a sensory evaluation was performed by four highly skilled experts. For comparison, a sensory evaluation was also performed on a sample without the yeast material added. The results are shown in Table 1.

[0028] [Table 1] [Industrial Applicability]

[0029] The yeast material obtained by the production method of the present invention can be used as a food product by masking the off-flavor of vegetable protein without imparting any flavor.

Claims

1. A method for producing a yeast material, comprising the steps of: allowing a cell wall-lytic enzyme to act on yeast cells after yeast extract extraction or on yeast cells before yeast extract extraction; subjecting the cells to a heat treatment at 50-100°C for 5-20 minutes after the enzyme reaction; and then heating at 110°C or higher for 5-30 seconds; wherein the yeast cells are Candida utilis, the cell wall-lytic enzyme is glucanase, and the yeast material for reducing vegetable protein off-flavors has a free amino acid content of 5% or less and a nucleotide content of 3% or less.

2. A method for producing a yeast material as described in claim 1, characterized in that a protease is further used as the cell wall-decomposing enzyme.

3. A method for reducing the off-flavor of vegetable protein by adding the yeast material according to claim 1 or 2 to food or drink.

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