Yeast-containing beverage and method for improving flavor of yeast-containing beverage

Abstract

The present invention provides a directly drinkable, yeast-containing beverage in which the characteristic yeast smell and bitterness of a yeast material is reduced.　Provided is a yeast-containing beverage including a yeast extract residue or a cell wall lytic enzyme decomposition product thereof, wherein the vanillin content is 0.1 ppm or more. The characteristic yeast smell and bitterness unique to yeast are significantly reduced in this beverage, and the sweetness and deliciousness thereof are also improved. Therefore, as a yeast-containing beverage, this beverage is more suitable for direct drinking than conventional products.

Description

Yeast-containing beverage and method for improving flavor of yeast-containing beverage

[0001] The present invention relates to a yeast-containing beverage containing yeast extract cell residue or a cell wall-lytic enzymatic hydrolyzate thereof, and vanillin, a method for producing the same, and a method for improving the flavor of a yeast-containing beverage, which includes blending vanillin.

[0002] In recent years, in order to avoid milk-derived allergens, there has been an increasing demand for low-fat or fat-free foods due to dietary and health-conscious trends, as well as an increasing demand for vegan diets, and as a result, beverages made from plant ingredients such as oats, soybeans, and almonds instead of dairy ingredients have been attracting more attention. However, these plant ingredients are usually more expensive than milk and are known to contain allergens.

[0003] In addition to such plant materials, beverages using yeast materials have also been reported. For example, the present applicant has reported the use of a composition containing a cell wall-lytic enzyme hydrolyzed residue (yeast extract cell residue) after yeast extract production as a food or beverage (see, for example, Patent Document 1).

[0004] International Publication No. 2022 / 185762

[0005] However, yeast materials have a characteristic yeast odor and bitter taste, and therefore, when used at a concentration of about 5% for the purpose of protein supplementation, there is a problem that the strong yeast odor and bitter taste make them unsuitable for direct consumption.

[0006] As a result of extensive research to solve the above problems, the present inventors have discovered that in a yeast-containing beverage containing yeast extract cell body residue or a cell wall-lytic enzyme hydrolysate thereof, by setting the content of said residue or said hydrolysate within a specified range and setting the vanillin content to 0.1 ppm or more, the characteristic yeast odor and bitterness can be reduced, and further, the sweetness and palatability can be improved, making it possible to provide the resulting yeast-containing beverage for direct consumption, thereby completing the present invention.

[0007] The gist of the present invention is as follows. [1] A yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or a cell wall-lytic enzymatic hydrolysate thereof, and 0.1 ppm or more of vanillin, relative to the total mass of the beverage. [2] A yeast-containing beverage according to [1], which contains 0.1 to 200 ppm of vanillin. [3] A yeast-containing beverage according to [1] or [2], which further contains sugars and salts. [4] A yeast-containing beverage according to any of [1] to [3], which further contains 0.1% by mass or more of sugars and 0.005% by mass or more of salt, relative to the total mass of the beverage. [5] A yeast-containing beverage according to any of [1] to [4], which further contains 0.1 to 30% by mass of oils and fats, relative to the total mass of the beverage. [6] A yeast-containing beverage according to any of [1] to [5], in which the residue is a water-insoluble fraction after hot water extraction of yeast. [7] The yeast-containing beverage according to any one of [1] to [5], wherein the degradation product is a glucanase degradation product of yeast extract cell residue. [8] The yeast-containing beverage according to any one of [1] to [7], which is a milk substitute beverage. [9] A method for producing a yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or a degradation product thereof with a cell wall-lytic enzyme, and 0.1 ppm or more of vanillin, based on the total mass of the beverage, the method comprising mixing a suspension of yeast extract cell residue or a degradation product thereof with a cell wall-lytic enzyme with vanillin.

[10] A method for improving the flavor of a yeast-containing beverage, comprising blending 0.1 ppm or more of vanillin into a yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or a degradation product thereof with a cell wall-lytic enzyme.

[0008] According to the present invention, a yeast-containing beverage can be provided using inexpensive and easily available yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate as a raw material. The yeast-containing beverage of the present invention contains 0.1 ppm or more of vanillin together with the yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate, thereby significantly reducing the characteristic yeast odor (a grassy odor derived from yeast) and bitterness (a bitter taste that irritates the tongue) that are unique to yeast, and also improving sweetness (a sweet taste like sugar) and overall palatability (a well-balanced aroma that makes the beverage taste delicious). This allows the beverage to be provided as a yeast-containing beverage suitable for direct consumption. Therefore, the yeast-containing beverage of the present invention allows for easier intake of yeast-derived proteins, dietary fiber, and other nutrients.

[0009] The present invention provides a yeast-containing beverage containing yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof, and vanillin, wherein the amount of yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof is preferably 1 to 20% by mass relative to the total mass of the beverage, and the amount of vanillin is 0.1 ppm or more.

[0010] One embodiment of the present invention provides a yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue and 0.1 ppm or more of vanillin, based on the total mass of the beverage.

[0011] The term "yeast extract cell residue" as used herein includes yeast cell walls and is not particularly limited as long as it is the residue (insoluble fraction) of yeast cells obtained after subjecting yeast to an extraction treatment and removing the extract. Specifically, it refers to the yeast cells that are generated as a residue after subjecting yeast to a known extraction treatment such as autolysis (protease treatment), hot water treatment, acid treatment, alkali treatment, and / or mechanical disruption, and removing the supernatant (soluble fraction (yeast extract)) separated by centrifugation or the like. The yeast extract cell residue is preferably the residue (water-insoluble fraction) of yeast cells after hot water extraction of yeast. The yeast extract cell residue (water-insoluble fraction) of the present invention preferably has a soluble solid content of less than 5% by mass based on its dry mass. The solubility of the soluble solids refers to their solubility in water, and the soluble solids are calculated as the proportion (mass%) of the dry mass of the yeast extract cell residue. The soluble solids content of the yeast extract cell residue according to the present invention can be measured, for example, according to the method described in Test Example 4 of Japanese Patent No. 7519036 (Patent Application No. 2023-119306). Furthermore, the "dry mass of yeast extract cell residue" used herein refers to the mass of the yeast extract cell residue after drying the yeast extract cell residue by a known method. The drying method is not particularly limited, and known drying methods can be used, such as atmospheric heat drying, vacuum drying, spray drying, and freeze drying. For example, the soluble solids content can be obtained by drying a sample in an atmospheric heat dryer at 105°C for 5 hours and then weighing the residue.

[0012] Yeast extract cell residue is composed of proteins, lipids, ash, dietary fiber, and the like. The protein content is, for example, 20% to 60% by mass based on the dry mass of the yeast extract cell residue. The lipid content is, for example, 1% to 10% by mass based on the dry mass of the yeast extract cell residue. The ash content is, for example, 0% to 10% by mass based on the dry mass of the yeast extract cell residue. The dietary fiber content is, for example, 10% to 60% by mass based on the dry mass of the yeast extract cell residue. In addition to general nutritional components, yeast extract cell residue also contains components such as β-glucan and α-mannan, which have been reported to have physiological functions. β-glucan is a polysaccharide formed by the polymerization of D-glucose via β-1,3 and β-1,6 bonds, and is classified as dietary fiber because it is a resistant component in food that cannot be digested by human digestive enzymes. α-Mannan is a polysaccharide formed by the polymerization of D-mannose via α-1,6, α-1,2, or α-1,3 bonds. It is classified as dietary fiber because it is an indigestible food component that cannot be digested by human digestive enzymes. The β-glucan content is, for example, 10% to 40% by mass relative to the dry mass of the yeast extract cell residue. The α-mannan content is, for example, 10% to 40% by mass relative to the dry mass of the yeast extract cell residue. The content of each component can be measured by known analytical methods. The protein content can be determined, for example, by measuring the nitrogen content using the Kjeldahl method and multiplying the nitrogen content by a conversion factor of 6.25. The lipid content can be quantified, for example, by acid hydrolysis. The ash content can be quantified by direct ashing. The dietary fiber content can be quantified, for example, by the Prosky method (enzyme-gravimetric method) or high-performance liquid chromatography (enzyme-HPLC method). The α-mannan content can be measured, for example, by quantifying the amount of mannose produced by hydrolyzing mannan, and the β-glucan content can be measured, for example, using a (1-3), (1-4)-β-glucan measurement kit (Megazyme).

[0013] If the total amount of free amino acids (particularly glutamic acid), organic acids, and linear saturated aliphatic aldehydes in the yeast cell residue (water-insoluble fraction) obtained in this manner is equal to or greater than the predetermined amount described below, appropriate purification and washing procedures can be carried out as necessary to obtain a yeast extract cell residue in which the total amount of free amino acids (particularly glutamic acid), organic acids, and linear saturated aliphatic aldehydes is less than the predetermined amount described below. Examples of such purification and washing procedures include repeated extraction and separation procedures and increasing the amount of washing water.

[0014] The yeast is not particularly limited as long as it is applicable to the food industry, and examples thereof include yeast for beer production, yeast for bread production, and yeast for sake production. Alternatively, the yeast is not limited to these, and examples thereof include those belonging to genera such as Saccharomyces, Saccharomycodes, Rhodotorula, Endomycopsis, Nematospora, Brettanomyces, Candida, and Torulopsis. Of these, Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces bayanus, and Candida utilis are preferred. These may be used alone or in combination of two or more types.

[0015] The yeast extract cell residue according to the present invention is preferably one in which the total amount of free glutamic acid is reduced to less than a predetermined amount, since this reduces the characteristic flavor specific to yeast. Specifically, the total amount of free glutamic acid contained in the yeast extract cell residue according to the present invention is preferably less than 0.5% by mass, more preferably less than 0.4% by mass, and even more preferably less than 0.3% by mass, based on the dry mass of the residue.

[0016] Furthermore, the yeast extract cell residue according to the present invention is preferably one in which not only the amount of free glutamic acid but also the total amount of free amino acids has been reduced to less than a predetermined amount. Specifically, the total amount of free amino acids contained in the yeast extract cell residue according to the present invention is preferably less than 1% by mass, more preferably less than 0.8% by mass, and even more preferably less than 0.5% by mass, based on the dry mass of the residue.

[0017] In the present invention, the "total amount of free amino acids" refers to the sum of the amounts of histidine (His), asparagine (Asn), serine (Ser), glutamine (Gln), arginine (Arg), glycine (Gly), aspartic acid (Asp), glutamic acid (Glu), threonine (Thr), alanine (Ala), γ-aminobutyric acid (GABA), proline (Pro), cysteine ​​(Cys), lysine (Lys), tyrosine (Tyr), methionine (Met), valine (Val), isoleucine (Ile), leucine (Leu), phenylalanine (Phe), and tryptophan (Trp), and can be calculated, for example, from the measured values ​​obtained by UPLC analysis (labeling method). The free amino acids may be in the L-, D-, or DL-configuration, but are preferably in the L-configuration. The total amount of free amino acids contained in the yeast extract cell residue can be measured by UPLC analysis (labeling method) according to the method described in Test Example 3 of Japanese Patent No. 7519036 (Patent Application No. 2023-119306), for example.

[0018] Amino acids are also known to contribute to bitterness, sweetness, and the like. Therefore, the yeast extract cell residue of the present invention preferably has the total amount of free amino acids known to impart bitterness and / or sweetness reduced to less than a predetermined amount. Therefore, for example, in the yeast extract cell residue of the present invention, the total amount of free amino acids known to impart bitterness, phenylalanine, tyrosine, arginine, isoleucine, leucine, valine, methionine, and lysine, is preferably less than 0.07% by mass, more preferably less than 0.05% by mass, and even more preferably less than 0.03% by mass, based on the dry mass of the residue. Furthermore, the total amount of free amino acids known to impart sweetness, alanine and proline, is preferably less than 0.2% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.05% by mass, based on the dry mass of the residue. By controlling the total amount of free amino acids in the yeast extract cell residue according to the present invention, as well as the total amount of free amino acids known to impart bitterness or sweetness, it is expected that the characteristic flavor specific to yeast can be further reduced.

[0019] The yeast extract cell residue of the present invention is also preferably one in which the total amount of organic acids has been reduced to less than a predetermined amount. Specifically, the organic acids contained in the yeast extract cell residue of the present invention are typically phosphoric acid and citric acid, and the phosphoric acid content is preferably less than 0.1% by mass, more preferably less than 0.05% by mass, based on the dry mass of the residue. Furthermore, the citric acid content is preferably less than 0.03% by mass, more preferably less than 0.02% by mass, based on the dry mass of the residue. By controlling the total amount of organic acids in the yeast extract cell residue of the present invention, it is expected that the characteristic flavor unique to yeast can be further reduced.

[0020] Furthermore, the yeast extract cell residue of the present invention preferably has the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms, reduced to a predetermined amount or less. Straight-chain saturated aliphatic aldehydes are known to have citrus aromas, grassy aromas, and the aroma of oxidized fats and oils. Alcohols such as octanol and nonanol and 2-pentylfuran are known to have floral and sweet fruity aromas, but they have also been reported to be present in oxidized oil products. Saturated straight-chain aliphatic aldehydes are known to exhibit unpleasant aromas when present at high concentrations. Long-carbon straight-chain aliphatic aldehydes are less volatile than short-carbon saturated straight-chain aliphatic aldehydes, and the impression of the aroma varies depending on the carbon number. Butanal, which has four carbon atoms, and pentanal, which has five carbon atoms, have a sweet-and-sour, burnt, pungent odor, while hexanal, which has six carbon atoms, is said to contribute to the grassy aroma of soybeans. Heptanal, which has 7 carbon atoms, octanal, which has 8 carbon atoms, and nonanal, which has 9 carbon atoms, have a grassy smell as well as an oily smell and a smell that is emitted when fats and oils are oxidized. Decanal, which has 10 carbon atoms, has an oily smell as well as a citrus-like smell.

[0021] Specifically, since the characteristic aroma specific to yeast is reduced, the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the yeast extract cell residue according to the present invention, is preferably 3.8 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing the "yeast odor," "deteriorated oil odor," and "grassy odor," it is more preferably 3.5 ppm or less, even more preferably 3.0 ppm or less, and particularly preferably 2.0 ppm or less. The lower limit of the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the yeast extract cell residue according to the present invention, based on the dry mass of the residue is not particularly limited, and they do not necessarily need to be detected, but if they are detected, it is generally 0.03 ppm or more.

[0022] Specifically, the heptanal content of the yeast extract cell residue according to the present invention is preferably 1.50 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing the "yeast odor," "oil-deterioration odor," and "grassy odor," it is more preferably 1.40 ppm or less, even more preferably 1.25 ppm or less, and particularly preferably 1.00 ppm or less. Furthermore, the octanal content of the yeast extract cell residue according to the present invention is preferably 0.37 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing the "yeast odor," "oil-deterioration odor," and "grassy odor," it is more preferably 0.35 ppm or less, even more preferably 0.30 ppm or less, and particularly preferably 0.20 ppm or less. Furthermore, the nonanal content of the yeast extract cell residue according to the present invention is preferably 2.02 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing "yeast odor," "oil deterioration odor," and "grassy odor," it is more preferably 1.80 ppm or less, even more preferably 1.50 ppm or less, and particularly preferably 1.00 ppm or less. The lower limit of the content of heptanal, octanal, and nonanal, which are linear saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the yeast extract cell residue according to the present invention, based on the dry mass of the residue is not particularly limited, and they do not necessarily need to be detected, but if detected, they are generally 0.01 ppm or more. The content of each aldehyde contained in the yeast extract cell residue can be calculated from the respective measured values ​​obtained by known methods such as gas chromatography (GC) and liquid chromatography (LC).

[0023] In the present invention, "vanillin" is not particularly limited as long as it is vanillin (4-hydroxy-3-methoxybenzaldehyde) or a natural or synthetic flavoring containing vanillin as a main component. Vanillin or a flavoring containing vanillin as a main component is available from reagent suppliers as an additive for food or pharmaceutical use.

[0024] The yeast-containing beverage of the present invention containing yeast extract cell residue and vanillin may be a cloudy white liquid containing yeast extract cell residue and vanillin at appropriate concentrations in an appropriate medium (preferably water). The concentration of the yeast extract cell residue in the beverage of the present invention is 1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 3 to 8% by mass, expressed as the dry mass of the yeast extract cell residue relative to the total mass of the beverage. Incorporating a larger amount of yeast extract cell residue into the yeast-containing beverage allows for more efficient intake of yeast-derived proteins, dietary fiber, and other nutrients, but increasing the amount increases the viscosity of the yeast-containing beverage. A blending amount of yeast extract cell residue within the above range can provide a beverage that allows for efficient intake of yeast-derived proteins, dietary fiber, and other nutrients while maintaining the desirable mouthfeel of a yeast-containing beverage. The vanillin concentration in the beverage of the present invention is 0.1 ppm or more, preferably 0.5 ppm or more, and more preferably 1.0 ppm or more, relative to the total mass of the beverage. The upper limit of the vanillin concentration in the beverage of the present invention is not particularly limited, but is preferably 500 ppm or less, more preferably 400 ppm or less, even more preferably 300 ppm or less, and particularly preferably 200 ppm or less, in order to maintain a good balance of aroma and flavor that is perceived as delicious as a beverage. The concentration range of vanillin in the beverage of the present invention is, for example, 0.1 to 500 ppm, 0.1 to 300 ppm, 0.1 to 200 ppm, 1.0 to 500 ppm, 1.0 to 300 ppm, or 1.0 to 200 ppm. Flavorings are usually used to add aroma to foods and enhance their deliciousness, and the inventors have found that by incorporating vanillin, among other flavorings, within the above-mentioned range, the aroma and flavor derived from the yeast material can be significantly improved. The reason for this is not clear, but it is thought that the characteristic yeasty smell and bitterness derived from the yeast material are effectively masked by the sweet aroma unique to vanillin, and that the balance of these and the sweetness resulting from the sweet aroma unique to vanillin is good, resulting in improved flavor.

[0025] In the beverage of the present invention, the ratio of vanillin to yeast extract cell residue (by mass) is preferably in the range of 0.0000005:1 to 0.05:1, more preferably 0.000002:1 to 0.02:1, even more preferably 0.00002:1 to 0.01:1, and particularly preferably 0.0002:1 to 0.005:1.

[0026] Another embodiment of the present invention provides a yeast-containing beverage containing, relative to the total mass of the beverage, 1 to 20% by mass of a cell wall-lytic enzymatic hydrolyzate of yeast extract cell residue and 0.1 ppm or more of vanillin. The terms "yeast extract cell residue" and "vanillin" are as defined above. As used herein, the "dry mass of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell residue" refers to the mass of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell residue after drying the cell wall-lytic enzymatic hydrolyzate of yeast extract cell residue using a known method. The drying method is not particularly limited, and known drying methods can be used, including atmospheric heat drying, vacuum drying, spray drying, and freeze drying. For example, the dry mass can be obtained by drying a sample in an atmospheric heat dryer at 105°C for 5 hours and weighing the residue.

[0027] The cell wall-lytic enzyme digestion product of the present invention is preferably one in which the total amount of free glutamic acid is reduced to less than a predetermined amount, specifically, the total amount of free glutamic acid contained in the cell wall-lytic enzyme digestion product of the present invention is preferably less than 0.4% by mass, more preferably less than 0.3% by mass, and even more preferably less than 0.1% by mass, based on the dry mass of the digestion product.

[0028] Furthermore, the cell wall-lytic enzyme decomposition product according to the present invention is preferably one in which not only the amount of free glutamic acid but also the total amount of free amino acids has been reduced to less than a predetermined amount. Specifically, the total amount of free amino acids contained in the cell wall-lytic enzyme decomposition product according to the present invention is preferably less than 1% by mass, more preferably less than 0.5% by mass, and even more preferably less than 0.3% by mass, based on the dry mass of the decomposition product.

[0029] In addition, in the cell wall-lytic enzyme hydrolysate of the present invention, the total amount of free amino acids known to impart bitterness, phenylalanine, tyrosine, arginine, isoleucine, leucine, valine, methionine, and lysine, is preferably less than 0.1% by mass, more preferably less than 0.07% by mass, and even more preferably less than 0.05% by mass, based on the dry mass of the hydrolysate. Furthermore, the total amount of free amino acids known to impart sweetness, alanine and proline, is preferably less than 0.2% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.05% by mass, based on the dry mass of the hydrolysate. By controlling the total amount of free amino acids and the total amount of free amino acids known to impart bitterness or sweetness, the characteristic flavor specific to yeast can be further reduced.

[0030] The cell wall-lytic enzyme hydrolysate of the present invention is also preferably one in which the total amount of organic acids has been reduced to less than a predetermined amount. Specifically, the organic acids contained in the cell wall-lytic enzyme hydrolysate of the present invention are typically phosphoric acid and citric acid, and the phosphoric acid content is preferably less than 0.20% by mass, more preferably less than 0.15% by mass, and even more preferably less than 0.10% by mass, based on the dry mass of the hydrolysate. Furthermore, the citric acid content is preferably less than 0.02% by mass, more preferably less than 0.01% by mass, based on the dry mass of the hydrolysate. By controlling the total amount of organic acids in the cell wall-lytic enzyme hydrolysate of the present invention, further reduction of the characteristic flavor unique to yeast can be expected.

[0031] Furthermore, the cell wall-lytic enzyme hydrolyzed product of the yeast extract cell residue according to the present invention is preferably one in which the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the residue, has been reduced to a predetermined amount or less. Specifically, the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the yeast extract cell residue according to the present invention, is preferably 3.8 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing the "yeast odor," "odor of deteriorated oils and fats," and "grassy odor," is more preferably 3.5 ppm or less, even more preferably 3.0 ppm or less, and particularly preferably 2.0 ppm or less. The lower limit of the total amount of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the yeast extract cell residue according to the present invention, is not particularly limited relative to the dry mass of the residue, and they do not necessarily have to be detected, but if they are detected, they are generally 0.03 ppm or more.

[0032] Specifically, the heptanal content of the residue of the cell wall-lytic enzyme hydrolyzed product of the yeast extract cell residue according to the present invention is preferably 1.50 ppm or less, based on the dry mass of the residue, more preferably 1.40 ppm or less, even more preferably 1.25 ppm or less, and particularly preferably 1.00 ppm or less, from the viewpoint of the effect of reducing the "yeast odor," "oil deterioration odor," and "grassy odor."Furthermore, the octanal content of the residue is preferably 0.37 ppm or less, based on the dry mass of the residue, and from the viewpoint of the effect of reducing the "yeast odor," "oil deterioration odor," and "grassy odor," more preferably 0.35 ppm or less, even more preferably 0.30 ppm or less, and particularly preferably 0.20 ppm or less. Furthermore, the content of nonanal contained in the residue is preferably 2.02 ppm or less based on the dry mass of the residue, and from the viewpoint of the effect of reducing "yeast odor," "oil deterioration odor," and "grassy odor," it is more preferably 1.80 ppm or less, even more preferably 1.50 ppm or less, and particularly preferably 1.00 ppm or less. The lower limit of the content of heptanal, octanal, and nonanal, which are straight-chain saturated aliphatic aldehydes having 7 to 9 carbon atoms contained in the cell wall-lytic enzyme hydrolyzed product of yeast extract cell residue according to the present invention, based on the dry mass of the residue is not particularly limited, and they do not necessarily need to be detected, but if detected, they are generally 0.01 ppm or more. The content of each aldehyde contained in the residue can be calculated from the respective measured values ​​obtained by known methods such as gas chromatography (GC) and liquid chromatography (LC).

[0033] As used herein, the term "cell wall-lytic enzyme" refers to an enzyme or combination of enzymes capable of partially or completely degrading yeast cell walls. Cell wall-lytic enzymes preferably have endoactivity, and more preferably have only endoactivity. Cell wall-lytic enzymes preferably have low, almost no, or no protease activity (i.e., no protease activity). Alternatively, when using a cell wall-lytic enzyme with protease activity, or when an enzyme with protease activity is coexisting, it is preferable to use it under conditions (e.g., pH, temperature, etc.) that suppress the protease activity.

[0034] The cell wall lytic enzyme may be, for example, a naturally occurring enzyme, a commercially available enzyme, or an enzyme obtained by a method using genetic engineering or the like.

[0035] Examples of cell wall lytic enzymes include, but are not limited to, glucanases, mannanases, etc. Glucanases (preferably glucanases having endoactivity (preferably only endoactivity) and / or no protease activity) are, for example, glucanases having β-1,3, β-1,4, and / or β-1,6 activity, preferably glucanases derived from the genus Streptomyces or Talaromyces, more preferably glucanases derived from the genus Streptomyces, even more preferably glucanases derived from Streptomyces and having β-1,3, β-1,4, and / or β-1,6 activity, and even more preferably glucanases derived from Streptomyces and having β-1,3, β-1,4, and / or β-1,6 activity. and endo activity (preferably only endo activity), and even more preferably, a glucanase derived from Streptomyces that has β-1,3, β-1,4, and / or β-1,6 activity, endo activity, and no protease activity (e.g., Denatzyme GEL-L1 / R manufactured by Nagasevita Co., Ltd.), and even more preferably, a glucanase derived from Streptomyces that has β-1,3, β-1,4, and / or β-1,6 activity, endo activity, and no protease activity.

[0036] In one embodiment of the present invention, the cell wall lytic enzyme is a glucanase.

[0037] In one embodiment of the invention, the cell wall lytic enzyme is a glucanase having β-1,3, β-1,4, and / or β-1,6 activity.

[0038] In one embodiment of the present invention, the cell wall lytic enzyme is a glucanase derived from Streptomyces.

[0039] In one preferred embodiment of the present invention, the cell wall lytic enzyme is a glucanase derived from Streptomyces and having β-1,3, β-1,4, and / or β-1,6 activity.

[0040] In one embodiment of the present invention, the cell wall lytic enzyme is a glucanase having endoactivity (preferably having only endoactivity).

[0041] In a preferred embodiment of the present invention, the cell wall-lytic enzyme is a glucanase derived from Streptomyces and having β-1,3, β-1,4, and / or β-1,6 activity and endo activity (preferably, having only endo activity).

[0042] In one embodiment of the present invention, the cell wall-lytic enzyme is a glucanase that does not have protease activity.

[0043] In a preferred embodiment of the present invention, the cell wall-lytic enzyme is a glucanase derived from Streptomyces, having β-1,3, β-1,4, and / or β-1,6 activity, endo activity (preferably, only endo activity), and no protease activity.

[0044] As used herein, the term "cell wall-lytic enzyme hydrolysate" refers to a substance obtained by hydrolyzing yeast extract cell residue with a cell wall-lytic enzyme, specifically, a substance obtained by hydrolyzing yeast cell walls contained in the yeast extract cell residue with a cell wall-lytic enzyme.

[0045] The cell wall-lytic enzyme hydrolysate of yeast extract cell body residue is composed of proteins, lipids, ash, dietary fiber, etc. The protein content is, for example, 20% to 60% by mass, based on the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. The lipid content is, for example, 1% to 10% by mass, based on the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. The ash content is, for example, 0% to 10% by mass, based on the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. The dietary fiber content is, for example, 10% to 60% by mass, based on the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. In addition to general nutritional components, the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue also contains components such as β-glucan and α-mannan, which have been reported to have physiological functions. β-Glucan is a polysaccharide in which D-glucose is polymerized via β-1,3 and β-1,6 bonds, and is classified as dietary fiber because it is an indigestible food component that is not digested by human digestive enzymes. α-Mannan is a polysaccharide in which D-mannose is polymerized via α-1,6, α-1,2, or α-1,3 bonds, and is classified as dietary fiber because it is an indigestible food component that is not digested by human digestive enzymes. The β-glucan content varies depending on the exoactivity of glucanases contained in cell wall-lytic enzymes, but is typically 0% to 40% by mass relative to the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. The α-mannan content is typically 10% to 40% by mass relative to the dry mass of the cell wall-lytic enzyme hydrolysate of yeast extract cell body residue. The content of each component can be measured by known analytical methods, as described above.

[0046] Methods for obtaining a "cell wall-lytic enzyme hydrolysate" include, but are not limited to, methods known to those skilled in the art, methods described in the Examples, or a method comprising the following: (a) treating yeast extract cell body residue with a cell wall-lytic enzyme, and (b) recovering the treated product obtained in (a), or methods similar thereto.

[0047] In another embodiment of the present invention, the degradation product is obtained by a method comprising the following steps: (a) treating yeast extract cell residue with a cell wall-lytic enzyme (preferably glucanase) at 40 to 60°C for 1 to 24 hours; and (b) recovering the treated product obtained in (a).

[0048] The "yeast extract cell residue" in (a) above is as described above, and is preferably the residue of yeast cells (water-insoluble fraction) after hot water extraction of yeast, and preferably a yeast extract cell residue having a soluble solid content of less than 5% by mass relative to the dry mass thereof.

[0049] The "cell wall-lytic enzyme" in (a) above is as described above, and is preferably glucanase.

[0050] The "treatment" in (a) above is not particularly limited as long as the conditions are such that the cell wall-lytic enzyme can decompose the yeast cell walls contained in the yeast extract cell residue, and can be appropriately changed depending on the origin of the yeast cell walls, the type and / or amount of the cell wall-lytic enzyme, the desired properties, and the like. The treatment is typically carried out in a desired solvent (e.g., water). For example, the treatment is carried out using a suspension of the yeast extract cell residue in a solvent (e.g., water). If necessary, the suspension may be subjected to a sterilization treatment (e.g., heat sterilization, filtration sterilization, etc.). The treatment of the yeast extract cell residue with the cell wall-lytic enzyme can be carried out, for example, at a temperature above 0°C but below 100°C (preferably 10 to 70°C, more preferably 25 to 65°C, even more preferably 40 to 60°C), for 0.5 to 120 hours (preferably 0.5 to 60 hours, more preferably 1 to 24 hours, even more preferably 3 to 24 hours, particularly preferably 12 to 24 hours), and at a pH of 1 to 12 (preferably 2 to 10, more preferably 3 to 8, even more preferably 4 to 6). After the above treatment, the cell wall-lytic enzyme may be inactivated, if necessary, by high-temperature treatment, acid or alkali treatment, or the like.

[0051] In (b) above, the treated product obtained in (a) may be used as is, including the residue (insoluble fraction), as a "cell wall-lytic enzymatic degradation product of yeast extract cell body residue," or, if necessary, may be further purified (e.g., HPLC, ultrafiltration, etc.), concentrated (e.g., air drying, vacuum filtration, etc.), sterilized (e.g., heat sterilization, filtration sterilization, etc.), dried (e.g., air drying, heating, vacuum, spray drying, freeze drying, etc.) and used as a "cell wall-lytic enzymatic degradation product of yeast extract cell body residue." The conditions for these steps can be adjusted as appropriate by those skilled in the art.

[0052] The yeast-containing beverage of the present invention, which contains a cell wall-lytic enzymatic hydrolyzate of yeast extract cell cell residue and vanillin, may be a cloudy liquid containing the hydrolyzate and vanillin at appropriate concentrations in an appropriate medium (preferably water). The concentration of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell cell residue in the beverage of the present invention is 1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 3 to 8% by mass, expressed as the dry mass of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell cell residue relative to the total mass of the beverage. Incorporation of a larger amount of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell cell residue in a yeast-containing beverage allows for efficient intake of more yeast-derived proteins, dietary fiber, and other nutrients, but increasing the amount increases the viscosity of the yeast-containing beverage. When the amount of the cell wall-lytic enzymatic hydrolyzate of yeast extract cell cell residue in the above-described range is within the above range, a beverage can be provided that allows efficient intake of yeast-derived proteins, dietary fiber, and other nutrients while maintaining the desirable mouthfeel of a yeast-containing beverage. The concentration of vanillin in the beverage of the present invention is 0.1 ppm or more, preferably 0.5 ppm or more, and more preferably 1.0 ppm or more, based on the total mass of the beverage. While there are no particular limitations on the upper limit of the vanillin concentration in the beverage of the present invention, it is preferably 500 ppm or less, more preferably 400 ppm or less, even more preferably 300 ppm or less, and particularly preferably 200 ppm or less, in order to maintain a good balance of aroma and flavor that is perceived as delicious in the beverage. The concentration of vanillin in the beverage of the present invention may range, for example, from 0.1 to 500 ppm, 0.1 to 300 ppm, 0.1 to 200 ppm, 1.0 to 500 ppm, 1.0 to 300 ppm, or 1.0 to 200 ppm. Flavorings are typically used to impart aroma to foods and enhance their deliciousness. The present inventors have found that the aroma and flavor derived from the yeast material can be significantly improved by incorporating vanillin, among other flavorings, within the above-mentioned range. The reason for this is not clear, but it is thought that the characteristic yeasty smell and bitterness derived from the yeast material are effectively masked by the sweet aroma unique to vanillin, and that the balance of these and the sweetness resulting from the sweet aroma unique to vanillin is good, resulting in improved flavor.

[0053] In the beverage of the present invention, the ratio (by mass) of vanillin to cell wall-lytic enzymatic hydrolysate of yeast extract cell residue is preferably in the range of 0.0000005:1 to 0.05:1, more preferably 0.000002:1 to 0.02:1, even more preferably 0.00002:1 to 0.01:1, and particularly preferably 0.0002:1 to 0.005:1.

[0054] The yeast-containing beverage of the present invention can contain a suitable medium (preferably water) in addition to the yeast extract cell residue or its cell wall-lytic enzymatic hydrolyzate and vanillin. The amount of medium (preferably water) in the yeast-containing beverage is generally 30 to 99% by mass, preferably 40 to 98% by mass, more preferably 40 to 97% by mass, even more preferably 40 to 95% by mass, and particularly preferably 45 to 93% by mass, based on the mass of the yeast-containing beverage. From the perspective of improving the drinkability of the beverage, it is preferable to increase the amount of medium (preferably water) in the yeast-containing beverage; specifically, the lower limit of the above-mentioned range of the amount can be changed to 50%, 60%, 70%, or 80% by mass.

[0055] Furthermore, the yeast-containing beverage of the present invention preferably further contains fats and oils. The "fat and oil" used herein is not limited to vegetable fats and oils, animal fats and oils, or processed fats and oils, such as edible safflower oil, edible grape oil, edible soybean oil, edible sunflower oil, edible corn oil, edible cottonseed oil, sesame oil, edible rapeseed oil, edible rice bran oil, edible peanut oil, edible olive oil, edible palm oil, edible palm olein, edible palm stearin, edible palm kernel oil, edible coconut oil, edible blended oil, flavored edible oil, beef tallow, lard, chicken oil, fish oil, milk fat, hydrogenated fats and oils produced by microorganisms such as yeast.

[0056] The amount of fat or oil contained in the yeast-containing beverage of the present invention is not particularly limited, but is preferably 0.1 to 30% by mass, more preferably 0.1 to 10% by mass, even more preferably 0.1 to 5% by mass, and particularly preferably 1 to 5% by mass, relative to the total mass of the beverage. By adjusting the amount within these ranges, the beverage can maintain a good balance of flavor while enhancing the milk-like mellowness, richness, and lingering aftertaste. In the beverage of the present invention, the ratio of fat or oil to yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate (by mass) is preferably 0.005:1 to 30:1, more preferably 0.01:1 to 10:1, even more preferably 0.1:1 to 5:1, even more preferably 0.1:1 to 2.5:1, and particularly preferably 0.1:1 to 1:1. When the blending amounts of the medium (preferably water) and fat or oil are within the above ranges, the yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate and fat or oil can be homogeneously dispersed in the medium, resulting in a beverage with a good palate feel.

[0057] The method for producing the yeast-containing beverage of the present invention is not particularly limited, and can be carried out by mixing a yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof with vanillin (and, if necessary, with a fat or oil or other optional components described below) by any method. For example, the beverage can be produced by mixing and emulsifying a predetermined amount of a yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof, water, and optionally a fat or oil using an appropriate stirrer (e.g., a homomixer, a homogenizer, etc.) to obtain a base liquid (emulsion), and then adding vanillin.

[0058] In yet another embodiment of the present invention, there is provided a yeast-containing beverage containing, relative to the total mass of the beverage, 1 to 20% by mass of yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof, 0.1 ppm or more of vanillin, sugars and salts. In yet another embodiment of the present invention, there is provided a yeast-containing beverage containing, relative to the total mass of the beverage, 1 to 20% by mass of yeast extract cell body residue or a cell wall-lytic enzymatic hydrolysate thereof, 0.1 ppm or more of vanillin, 0.1 to 30% by mass of oils and fats, sugars and salts.

[0059] "Sugars" as used herein include, but are not limited to, monosaccharides such as glucose (grape sugar) and fructose (fruit sugar), and disaccharides such as sucrose (cane sugar), lactose (milk sugar), and maltose (malt sugar). The sugar is preferably sucrose or a sucrose-based material that is available for consumption and is not particularly limited. The source of sucrose may be cane sugar, beet sugar, etc., and the purity of the sucrose may be granulated sugar, brown sugar, white sugar, medium-sized white sugar, etc. "Salt" as used herein is not particularly limited to sodium chloride or a sucrose-based material that is available for consumption and is not particularly limited. The salt may be rock salt, solar salt, or smelt salt, and may have a purity of special grade salt, table salt, regular salt, white salt, etc.

[0060] The amount of sugars contained in the yeast-containing beverage of the present invention is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.1 to 10% by mass, even more preferably 0.5 to 7% by mass, and particularly preferably 0.5 to 5% by mass, relative to the total mass of the beverage. By adjusting the amount within these ranges, the beverage can maintain a well-balanced milk-like taste. The yeast extract cell residue or its cell wall-lytic enzyme hydrolysate according to the present invention may contain no sugars or very small amounts of sugars, but this does not substantially affect the above amounts. The amount (concentration) of sugars contained in the yeast-containing beverage of the present invention is a value calculated based on the amount added to the beverage of the present invention. The amount of salt contained in the yeast-containing beverage of the present invention is not particularly limited, but is preferably 0.005% by mass or more, more preferably 0.005 to 0.5% by mass, even more preferably 0.005 to 0.3% by mass, and particularly preferably 0.01 to 0.3% by mass, relative to the total mass of the beverage. By setting the amount of salt contained in the yeast-containing beverage within this range in the presence of the above-mentioned amount of sugars, the beverage can maintain a well-balanced milk-like taste. Note that the yeast extract cell residue or its cell wall-lytic enzyme hydrolyzate according to the present invention may contain no salt or a very small amount of salt, but this does not substantially affect the above amount. Therefore, the amount (concentration) of salt contained in the yeast-containing beverage in the present invention is a value calculated based on the amount added to the beverage of the present invention.

[0061] In the beverage of the present invention, the ratio (by mass) of sugars to yeast extract cell residue or its cell wall-lytic enzymatic decomposition product is preferably in the range of 0.005:1 to 10:1, more preferably 0.01:1 to 5:1, even more preferably 0.02:1 to 2:1, and particularly preferably 0.1:1 to 1.5:1.

[0062] In the beverage of the present invention, the ratio (by mass) of salt to yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate is preferably in the range of 0.00025:1 to 0.5:1, more preferably 0.0005:1 to 0.2:1, even more preferably 0.001:1 to 0.1:1, and particularly preferably 0.001:1 to 0.05:1. In the beverage of the present invention, the ratio (by mass) of sugar to salt is preferably in the range of 0.2:1 to 2000:1, more preferably 1:1 to 1000:1, even more preferably 10:1 to 500:1, and particularly preferably 50:1 to 500:1. By adjusting the ratio within these ranges, the beverage can maintain a well-balanced milk-like taste.

[0063] In yet another embodiment of the present invention, the yeast-containing beverage of the present invention is provided as a milk substitute beverage (e.g., yeast milk). In the present invention, the term "dairy substitute beverage" refers to a beverage that can be used in place of milk consumed by humans (typically, cow's milk). Human milk is a cloudy liquid secreted from the mammary glands of mammals that contains nutrients such as water, protein, lipids, carbohydrates, vitamins, and minerals and has a unique milky flavor. A milk substitute beverage refers to a liquid consumed that possesses one or more of these characteristics. Milk substitute beverages are generally produced from plant materials such as soybeans, almonds, oats, rice, and coconuts, and contain plant-derived proteins and lipids, as well as dietary fiber that is rarely found in milk. These plant-based beverages may be used alone, in combination, or mixed with animal-derived milk. The milk substitute beverage of the present invention can also be used in place of milk substitute beverages produced from such known plant materials. When used as a milk substitute beverage, fats or oils are preferably blended. In a milk substitute beverage, the more fat or oil blended, the more richness, satisfaction, and smoothness of the drink can be achieved. On the other hand, if the blending amount is too large, it can have undesirable effects such as reducing the drinkability of the milk substitute beverage and increasing the energy intake too much. However, if the blending amount of fat or oil is within the above-mentioned range, it is possible to make a drink that is easy to drink and allows for a moderate energy intake while imparting richness, satisfaction, and smoothness to the milk substitute beverage.

[0064] The milk substitute beverage of the present invention can be a new milk substitute beverage made primarily from yeast, which contains a protein as the main ingredient, a moderate amount of fat, and has a milk-like appearance. If no animal-derived ingredients are used as ingredients, it can be a beverage suitable for vegetarians and vegans who avoid consuming animal products. If fats and oils produced using microorganisms are used as ingredients, it can be a new milk substitute beverage that does not use either animals or plants. The yeast-containing beverage of the present invention can be used as a milk substitute during cooking, and can be used in foods such as gratin and sweets.

[0065] The yeast-containing beverage of the present invention may further contain additives such as, but not limited to, excipients, lubricants, binders, disintegrants, pH adjusters, solvents, solubilizers, suspending agents, buffers, preservatives, antioxidants, colorants, sweeteners, surfactants, flavorings, etc. These additives may be, for example, known additives for foods or pharmaceuticals, and the amounts used may be adjusted as appropriate by those skilled in the art depending on the purpose.

[0066] In another embodiment of the present invention, there is provided a method for improving the flavor of a yeast-containing beverage, which comprises blending 0.1 ppm or more of vanillin to a yeast-containing beverage containing a yeast extract cell residue or a cell wall-lytic enzymatic hydrolysate thereof. The above-mentioned explanation for the embodiment of the yeast-containing beverage containing a yeast extract cell residue or a cell wall-lytic enzymatic hydrolysate thereof can be similarly applied to these embodiments of the present invention.

[0067] The present invention will be described in more detail below using examples, but these examples are not intended to limit the scope of the present invention in any way.

[0068] [Examples 1 to 10, Comparative Examples 1 and 2] The raw materials shown in Table 1 below were added, pre-emulsified (8,000 rpm, 10 minutes) using a PRIMIX homogenizer MARK II 2.5 (manufactured by Primix Corporation), and emulsified three times at 220 bar using a homogenizer (homogenizer L-100-H2-CH, manufactured by Sanwa Engineering Co., Ltd.) to obtain a base liquid. Two types of base liquids were prepared using yeast materials A and B, which will be described later, as the yeast materials. Vanillin was then added to the base liquid to obtain the concentration shown in Table 2, and yeast-containing beverages (Examples 1 to 10, Comparative Examples 1 and 2) were obtained as test samples.

[0069]

[0070]

[0071] [Preparation of Yeast Material A (Yeast Material Derived from Baker's Yeast)] Yeast material A derived from baker's yeast was prepared in the same manner as in Example 2 of Japanese Patent No. 7519036 (Patent Application No. 2023-119306). Dried yeast (Hyper Yeast HG-DY, manufactured by Asahi Group Foods Co., Ltd.) was extracted with hot water, and the heavy liquid (insoluble fraction) obtained by separating the yeast extract using a nozzle-type continuous centrifuge was sterilized at 125°C for 40 seconds and spray-dried to obtain a yeast extract cell residue. The resulting aqueous suspension of the yeast extract cell residue (solid content 16%) was subjected to solid-liquid separation while adding water using three nozzle-type continuous centrifuges arranged in series, to obtain a heavy liquid from which soluble components had been removed. The resulting heavy liquid was sterilized at 125°C for 40 seconds. After sterilization, the heavy liquid was adjusted to conditions of 50°C and pH 5.3, and 0.2% by mass of glucanase (Denazyme GEL-L1 / R, manufactured by Nagasevita Co., Ltd.) based on the dry mass was added, followed by treatment at 50°C for 18 hours. The treated product was treated at 125°C for 40 seconds to sterilize and inactivate the glucanase, and a cell wall-lytic enzyme decomposition product was obtained as yeast material A by spray drying.

[0072] [Preparation of Yeast Material B (Beer Yeast-Derived Yeast Material)] Beer yeast was extracted with hot water, centrifuged, and the resulting water-insoluble fraction was dried to obtain a yeast extract cell residue. An aqueous suspension of the resulting yeast extract cell residue (16% solids content) was sterilized in an autoclave (121°C, 15 minutes). 0.2% by mass of glucanase (Denazyme GEL-L1 / R, manufactured by Nagasevita Co., Ltd.) based on the dry mass of the yeast extract cell residue was added to the sterilized suspension at 50°C and pH 5.3, and the mixture was treated at 50°C for 24 hours. The treated product was then heated to approximately 80°C to inactivate the glucanase, sterilized in an autoclave (121°C, 15 minutes), and spray-dried to obtain a cell wall-lytic enzyme hydrolyzate as yeast material B.

[0073] [Examples 11 to 18] The following test samples were prepared to confirm the effect on beverages of changing the concentration by adding sugars and salt to the base liquid. The liquids were prepared in the same manner as in Examples 3 and 8, except that sugar (Cup Brand Granulated Sugar, manufactured by Nisshin Sugar Co., Ltd.) and salt (Hakata Salt, manufactured by Hakata Salt Co., Ltd.) were added to two types of base liquids using yeast materials A and B, respectively, as shown in Table 3. These liquids were obtained as yeast-containing beverages of Examples 11 to 14 and Examples 15 to 18, respectively.

[0074]

[0075] <Sensory evaluation of yeast-containing beverages> The yeast-containing beverages of Examples 1 to 18 and Comparative Examples 1 and 2 were evaluated by a panel of five experts on a seven-point scale based on the following evaluation criteria for yeast odor (a grassy odor derived from yeast), bitterness (a bitter taste that irritates the tongue), sweetness (a sweet taste like sugar), and palatability (a well-balanced flavor and aroma that makes the beverage taste delicious). In each test example, the base liquid was used as a control sample. The evaluation results are the average of the five expert panels.

[0076] [Evaluation criteria] <Yeast odor> 7: No yeast odor at all 6: Less yeast odor than "7", but less yeast odor than the control 5: Slightly less yeast odor than the control 4: Same as the control 3: Slightly more yeast odor than the control 2: Not as bad as "1", but more yeast odor than the control 1: Strong yeast odor in the mouth <Bitterness> 7: No bitterness at all 6: Not as bad as "7", but less bitter than the control 5: Slightly less bitter than the control 4: Same as the control 3: Slightly more bitter than the control 2: Not as bad as "1", but more bitter than the control 1: Stronger bitterness than the control <Sweetness> 7: Stronger sweetness than the control 6: Not as bad as "7", but more sweet than the control 5: Slightly sweeter than the control 4: Same as the control 3: Slightly less sweet than the control 2: Not as bad as "1", but less sweet than the control 1: No sweetness at all <Palatability (overall evaluation)> 7: Very delicious 6: Not as tasty as "7", but tastier than the control 5: Slightly tastier than the control 4: About the same as the control 3: Slightly less tasty than the control 2: Not as tasty as "1", but less tasty than the control 1: Less tasty than the control

[0077] [Overall Evaluation] Furthermore, based on the evaluation results of the four items described above, the [overall evaluation] was evaluated on a four-point scale of ◎, ◯, △, × according to the following criteria: ◎: All ratings of "yeast odor," "bitterness," "sweetness," and "taste (overall evaluation)" are 5.5 or higher ○: All ratings of "yeast odor," "bitterness," "sweetness," and "taste (overall evaluation)" are 5.0 or higher △: All ratings of "yeast odor," "bitterness," and "sweetness" are 4.5 or higher ×: Any of the ratings of "yeast odor," "bitterness," and "sweetness" is less than 4.5

[0078] Test Example 1: Evaluation of yeast-containing beverages with different vanillin concentrations (ppm) (Examples 1 to 10, Comparative Examples 1 and 2) A liquid prepared by adding vanillin at the concentration shown in Table 2 to the base liquid shown in Table 1 using yeast material A or B was used to prepare a yeast-containing beverage test sample (Examples 1 to 10, Comparative Examples 1 and 2), and a sensory evaluation was carried out for each test sample as described above. The results of the sensory evaluation are shown in Tables 4 and 5 below. The test samples of Examples 1 and 6, which contained 0.1 ppm of vanillin, showed significantly higher scores than Comparative Examples 1 and 2, which contained 0.05 ppm of vanillin, in the evaluation scores for yeast odor (a grassy odor derived from yeast), bitterness (a bitter taste that irritates the tongue), sweetness (a sweet taste like sugar), and palatability (a well-balanced aroma that makes the beverage taste delicious) (significant difference was found by t-test (p<0.05)). The test samples of Examples 2 to 5 and 7 to 10 showed values ​​equivalent to or higher than those of Examples 1 and 6, respectively, in the evaluation points of yeast odor (a grassy odor derived from yeast), bitterness (a bitter taste that irritates the tongue), sweetness (a sweet taste like sugar), and deliciousness (a well-balanced flavor and aroma that makes the beverage taste delicious), and also showed values ​​significantly higher than those of Comparative Examples 1 and 2, respectively (significant difference in t-test (p<0.05)).

[0079]

[0080]

[0081] Test Example 2: Evaluation of yeast-containing beverages with a vanillin concentration of 100 ppm and different sugar and salt concentrations (Examples 11 to 18) The test samples of Examples 11 to 18 were subjected to sensory evaluation as described above. The results of the sensory evaluation are shown in Tables 6 and 7 below. Examples 12 to 14 and 16 to 18, which contained 0.1% by mass or more of added sugar and 0.01% by mass or more of added salt, tended to show higher values ​​than Examples 3 and 8, which contained no added sugar or salt, in the evaluation of yeast odor (a grassy odor derived from yeast), bitterness (a bitter taste that irritates the tongue), sweetness (a sweet taste like sugar), and palatability (a well-balanced aroma that is perceived as a delicious beverage).

[0082]

[0083]

[0084] [Preparation of Yeast Material C (Yeast Material Derived from Baker's Yeast)] Dried yeast (Hyper Yeast HG-DY, manufactured by Asahi Group Foods Co., Ltd.) was extracted with hot water, and the heavy liquid (insoluble fraction) obtained by separating the yeast extract using a nozzle-type continuous centrifuge was sterilized at 125°C for 40 seconds and spray-dried to obtain a yeast extract cell residue. An aqueous suspension of the obtained yeast extract cell residue (solid content 16%) was subjected to solid-liquid separation while adding water using three nozzle-type continuous centrifuges arranged in series, to obtain a heavy liquid from which soluble components had been removed. The obtained heavy liquid was sterilized at 125°C for 40 seconds and spray-dried to obtain the yeast extract cell residue as yeast material C.

[0085] [Preparation of yeast material D (yeast material derived from brewer's yeast)] Brewer's yeast was extracted with hot water, centrifuged, and the resulting water-insoluble fraction was dried to obtain a yeast extract cell residue. An aqueous suspension of the obtained yeast extract cell residue (solid content 16%) was sterilized in an autoclave (121°C, 15 minutes) and spray-dried to obtain a yeast extract cell residue as yeast material D.

[0086] Test Example 3 A yeast-containing beverage (Example 19) was obtained as a test sample by using the base liquid in Table 1, except that yeast material C was used as the yeast material, and vanillin was added to the base liquid so that the vanillin concentration was 100 ppm. A yeast-containing beverage (Example 20) was also obtained as a test sample by using the base liquid in Table 1, except that yeast material D was used as the yeast material, and vanillin was added to the base liquid so that the vanillin concentration was 100 ppm. Each sample was subjected to sensory evaluation as described above. The sensory evaluation results are shown in Table 8 below. In Examples 19 and 20, in which yeast extract cell cell residue was used instead of the cell wall-lytic enzyme hydrolysate as the yeast material, the addition of vanillin improved the yeast odor (a grassy odor derived from yeast), bitterness (a bitter taste that irritates the tongue), sweetness (a sweet taste like sugar), and palatability (a well-balanced flavor and aroma that is perceived as a delicious beverage) compared to the control sample (base liquid) without vanillin.

[0087]

[0088] The yeast-containing beverage of the present invention contains 1 to 20% by mass of yeast extract cell residue or its cell wall-lytic enzymatic hydrolysate together with 0.1 ppm or more of vanillin, thereby significantly reducing the characteristic yeast odor (a grassy odor derived from yeast) and bitterness (a bitter taste that irritates the tongue) that are unique to yeast, and further improving sweetness (a sweet taste like sugar) and overall palatability (a well-balanced aroma that makes the beverage taste delicious), making it possible to provide a yeast-containing beverage that is suitable for direct consumption. Therefore, yeast-derived proteins, dietary fiber, and other nutrients can be more easily ingested via the yeast-containing beverage of the present invention.

Claims

1. A yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or its cell wall-lysing enzyme degradation product and 0.1 ppm or more of vanillin based on the total mass of the beverage.

2. The yeast-containing beverage according to claim 1, containing 0.1 to 200 ppm of vanillin.

3. The yeast-containing beverage according to claim 1, further containing saccharides and salts.

4. The yeast-containing beverage according to claim 3, containing 0.1% by mass or more of saccharides and 0.005% by mass or more of salts based on the total mass of the beverage.

5. The yeast-containing beverage according to claim 1, further containing 0.1 to 30% by mass of oil and fat based on the total mass of the beverage.

6. The yeast-containing beverage according to claim 1, wherein the residue is a water-insoluble fraction after hot water extraction of yeast.

7. The yeast-containing beverage according to claim 1, wherein the degradation product is a glucanase degradation product of yeast extract cell residue.

8. The yeast-containing beverage according to any one of claims 1 to 7, which is a milk substitute beverage.

9. A method for producing a yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or its cell wall-lysing enzyme degradation product and 0.1 ppm or more of vanillin based on the total mass of the beverage, the method comprising mixing a suspension of yeast extract cell residue or its cell wall-lysing enzyme degradation product and vanillin.

10. A method for improving the flavor of a yeast-containing beverage, comprising blending 0.1 ppm or more of vanillin into a yeast-containing beverage containing 1 to 20% by mass of yeast extract cell residue or its cell wall-lysing enzyme degradation product.

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