Blueberry jam-containing yogurt

Abstract

To provide blueberry jam-containing yogurt that imparts richness of milk of plain yogurt, and a milk original flavor and a thickness feeling in addition to refreshing acidity of blueberry jam and a natural flavor and a proper pulp feeling originated from blueberry, is harmonized in the flavor and palate feeling, and has the integrated feeling of blueberry jam and plain yogurt.SOLUTION: Blueberry jam-containing yogurt contains 10-25 wt.% of blueberry jam with an acid degree (in terms of citric acid) of 0.35-0.54%, and 90-75 wt.% of plain yogurt in the entire blueberry jam-containing yogurt. The blueberry jam-containing yogurt is such that: 23-40 wt.% of blueberry, and 0.3-0.65 wt.% of lemon juice in terms of a solid content are contained in the entire blueberry jam, and the content of blueberry which passes through a 15 mm mesh sieve and does not pass a 5 mm mesh sieve is 10-20 wt.% in the blueberry.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a yogurt containing blueberry jam and a method for producing the same. [Background technology]

[0002] With the diversification of food in recent years, yogurt has attracted attention for its health benefits, but more recently there has been a growing tendency to place emphasis on the "palatability" of yogurt, that is, enjoying the taste and texture of the yogurt itself.

[0003] In the above circumstances, fruit-infused yogurts containing various fruits or combining plain yogurt with fruit sauce or fruit jam are on the market, but from the viewpoint of flavor and texture, the combination of these with plain yogurt is not necessarily optimal.

[0004] Patent Document 1 describes a two-layered fermented milk product (Examples 1-3) in which 98 g of concentrated fermented milk with a protein concentration of 10% and a viscosity of 4000 cp (4 Pa s) is filled into a plastic cup, the surface is smoothed, and then 42 g of blueberry sauce with a Brix value of 26, which has been prepared by blending 21.2% blueberry pulp, 0.8% LM pectin with an esterification degree of 35, 19.2% sugar, and 0.045% stevia in advance, is filled. However, this patent relates to a technology for maintaining a clear interface between the concentrated fermented milk layer and the blueberry sauce layer, and the obtained two-layered fermented milk product does not have a well-balanced flavor and texture of the blueberry jam and plain yogurt when eaten, and the two are not felt as one. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-050533 A Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, we have studied the optimal combination of plain yogurt and blueberry jam from the viewpoints of flavor and texture.The object of the present invention is to provide a yogurt with blueberry jam that, when eaten together with blueberry jam, provides the refreshing sourness and natural flavor and moderate fruitiness of blueberries of blueberry jam, as well as the richness, flavor, and thickness of milk of plain yogurt, and further has a well-balanced flavor and texture, providing a sense of unity between blueberry jam and plain yogurt. [Means for solving the problem]

[0007] As a result of intensive research by the inventors to solve the above problems, it has been found that in a blueberry jam-containing yogurt containing blueberry jam and plain yogurt, the blueberry jam has a specific acidity, a specific Brix and a specific hardness, contains specific amounts of blueberries and lemon juice, and has a content of blueberries of a specific size within a specific range, the plain yogurt is a fermented raw material mix of the plain yogurt, has a specific content of raw milk and / or milk and ash in the entire raw material mix of the plain yogurt, has a specific weight ratio of minerals in the ash within a specific range, and has a specific content of curd of the plain yogurt. The inventors have found that by preparing yogurt with blueberry jam having a diameter and viscosity within specific ranges and containing specific amounts of the blueberry jam and the plain yogurt, when the plain yogurt and blueberry jam are eaten together, it is possible to obtain yogurt with blueberry jam that has a refreshing acidity and natural blueberry flavor and moderate fruitiness of the blueberry jam as well as the rich milkiness, original milk flavor and thick texture of the plain yogurt, and that has a well-balanced flavor and texture and a sense of unity between the blueberry jam and the plain yogurt. This has led to the completion of the present invention.

[0008] That is, a first aspect of the present invention is a yogurt containing blueberry jam, the blueberry jam containing 10 to 25% by weight of blueberry jam having an acidity (calculated as citric acid) of 0.35 to 0.54% in the entire blueberry jam-containing yogurt, and 90 to 75% by weight of plain yogurt, the blueberry jam contains 23 to 40% by weight of blueberries and 0.3 to 0.65% by weight of lemon juice in terms of solids, the content of blueberries that pass through a sieve with 15 mm openings but do not pass through a sieve with 5 mm openings is 10 to 20% by weight, the blueberry jam has a Brix of 45 to 55% and a hardness at 25° C. ( The present invention relates to a yogurt with blueberry jam, the plain yogurt having a compressive strength (maximum load at compression) of 0.9 to 1.6 N, the plain yogurt being obtained by fermenting a raw material mix for plain yogurt in which the raw milk and / or cow's milk content is 60 to 97% by weight, the ash content is 0.85 to 1.25% by weight, and the (Ca+P) / (K+Mg+Na) (mineral content weight ratio) in the ash content is 1 to 1.25, the plain yogurt having a median curd diameter of 5 to 70 μm and a viscosity of 20 to 60 Pa s at 10° C. using a No. 4 rotor in a BH type viscometer at a rotation speed of 2 rpm. A preferred embodiment relates to the yogurt with blueberry jam, the blueberry jam containing 0.8 to 1.3% by weight of pectin and 40 to 50% by weight of sugar. More preferably, the present invention relates to the yogurt with blueberry jam, wherein the Ca content in the total sugar in the blueberry jam is 0.002 to 0.005% by weight and the K content is 0.01 to 0.02% by weight. Another preferred embodiment relates to the yogurt with blueberry jam, wherein the milk solid content in the total raw material mix of the plain yogurt is 14.5 to 18% by weight and the milk protein content is 4.5 to 6.5% by weight.The second aspect of the present invention is a method for producing yogurt with blueberry jam, which contains blueberry jam and plain yogurt, the method comprising the steps of: filling a container with 10 to 25 parts by weight of the blueberry jam and 90 to 75 parts by weight of the plain yogurt; the plain yogurt has a viscosity of 20 to 60 Pa s at 10°C when a BH type viscometer is used with a No. 4 rotor at a rotation speed of 2 rpm; and the blueberry jam is mixed with blueberries and water so that the total content of blueberries in the blueberry jam is 23 to 40% by weight and that the content of blueberries that pass through a sieve with a mesh size of 15 mm but do not pass through a sieve with a mesh size of 5 mm is 10 to 20% by weight; concentrating the mixed raw material mixture by maintaining it at 65 to 85°C under reduced pressure conditions of a gauge pressure of 0.02 to 0.1 MPa; and adding lemon juice to the concentrated raw material mixture in an amount of 0.3 to 0.6 in terms of solid content based on the total content of the blueberry jam. the raw material mix having a raw milk content of 60 to 97% by weight and an ash content of 0.85 to 1.25% by weight, and a (Ca+P) / (K+Mg+Na) (weight ratio of minerals) in the ash content adjusted to 1 to 1.25, is combined with a lactic acid bacteria starter, and fermented at a temperature of 36 to 42°C until the pH reaches 4.1 to 4.85, and pulverized the curd obtained by the fermentation so as to have a median diameter of 5 to 70 μm. Effect of the Invention

[0009] According to the present invention, when plain yogurt and blueberry jam are eaten together, it is possible to provide yogurt with blueberry jam, which has the refreshing sourness and natural flavor and moderate fruitiness of blueberries of the blueberry jam, as well as the rich milkiness, flavor and thick texture of the plain yogurt, and which has a well-balanced flavor and texture and gives a sense of unity between the blueberry jam and the plain yogurt. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in more detail below. The yogurt with blueberry jam of the present invention contains specific amounts of a specific blueberry jam and a specific plain yogurt.

[0011] [Blueberry Jam] The blueberry jam is a product obtained by heating blueberries together with lemon juice until they become jelly. In order to adjust the Brix and hardness of the blueberry jam, sugars and gelling agents may be added before heating, and acidulants, preservatives, flavorings, colorants, etc. may be added either before or after heating, as necessary. Blueberries are a general term for shrubs classified in the genus Vaccinium, section Cyanococus, family Ericaceae, and their fruits (berries). Among them, wild blueberries, which have a strong flavor and strong sourness, are preferred.

[0012] The acidity of the blueberry jam is preferably 0.35 to 0.54%, more preferably 0.42 to 0.51%, and even more preferably 0.43 to 0.5%. If the acidity is lower than 0.35%, the acidity may be weak, resulting in a loss of flavor harmony with plain yogurt, the jam may become soft and water may be released during storage, or the jam may be prone to dripping during filling during yogurt production, resulting in poor productivity. If the acidity is higher than 0.54%, the acidity may be strong, resulting in a loss of refreshing acidity, resulting in a loss of flavor harmony with plain yogurt, the jam may become hard and flavor release may become poor, or the jam may become difficult to mix with plain yogurt. Note that a "refreshing acidity" is a moderate, good, or favorable acidity, whereas a "too strong acidity" is an excessively unpleasant acidity.

[0013] The acidity mentioned above means the acidity converted into citric acid, and can be measured by neutralization titration using a sample made by grinding the jam pulp in a blender. Specifically, it can be measured by the following method. Approximately 5 g of the sample is placed in a beaker, diluted approximately twice with distilled water, and two drops of phenolphthalein solution are added as an indicator. Titrate with 0.1 mol / L aqueous sodium hydroxide solution using a burette. Calculate the acidity from the amount (ml) used for titration using the following formula. Since the organic acid in blueberry pulp and lemon juice is mainly citric acid, the citric acid coefficient is used as the calculation coefficient. Acidity (%) = ((titer volume (ml) x F x 0.0064) / sample volume (g)) x 100 F: Factor of 0.1 mol / L sodium hydroxide solution 0.0064: Citric acid factor

[0014] The blueberry jam has a Brix of preferably 45 to 55%, more preferably 46 to 54%, and even more preferably 48 to 52%. If the Brix is ​​out of the above range, the refreshing taste and sourness of the blueberry jam may be difficult to feel, or the harmony of flavor and texture may be lost when the blueberry jam is eaten with plain yogurt, resulting in a loss of unity.

[0015] The Brix can be measured by measuring the temperature of blueberry jam at 20° C. using a sugar refractometer (Atago Co., Ltd., “RX-5000”).

[0016] The blueberry jam has a hardness (maximum load when compressed) at 25° C. of preferably 0.9 to 1.6 N, more preferably 0.9 to 1.5 N, and even more preferably 0.9 to 1.4 N. If the hardness is outside the above range, the original natural flavor and texture preferable for blueberry jam may not be obtained, or the harmony of flavors and textures may be lost when the blueberry jam is eaten with plain yogurt, resulting in a loss of unity.

[0017] The hardness at 25° C. can be measured by using a rheometer (Sun Scientific "CR-200D", plunger: disk-shaped, diameter 40 mm) for blueberry jam adjusted to 25° C.

[0018] The content of blueberries in the whole blueberry jam is preferably 23 to 40% by weight, more preferably 26 to 40% by weight, and even more preferably 30 to 40% by weight. If the content of blueberries is less than 23% by weight, the natural flavor of blueberries may not be felt. If the content of blueberries is more than 40% by weight, the sourness of the blueberry jam may be felt too strongly, losing its refreshing sourness, or when the blueberry jam is eaten with plain yogurt, the harmony of flavor and texture may be lost, resulting in a loss of unity.

[0019] It is preferable to cut the surface of the blueberries to some extent in advance using a silent cutter, etc. This allows the blueberry jam to have a natural blueberry flavor and a moderate fruit texture.

[0020] Specifically, the size of the blueberry jam with the surface cut is preferably 10 to 20% by weight, more preferably 12 to 18% by weight, and even more preferably 14 to 18% by weight, of the blueberries that pass through a sieve with a mesh size of 15 mm and do not pass through a sieve with a mesh size of 5 mm. If the content is less than 10% by weight, the texture of the blueberries may not be felt. If the content exceeds 20% by weight, the harmony of flavor and texture may be lost when the blueberry jam is eaten with plain yogurt, resulting in a loss of unity. The details of the measurement method are described in the Examples section. As the sieve, a test sieve specified in "JIS Z 8801-1:2019" may be used.

[0021] The lemon juice is a liquid obtained by squeezing lemon fruit, and at least one type selected from the group consisting of straight juice, concentrated juice, and reconstituted juice from concentrate can be used.

[0022] The content of the lemon juice is preferably 0.3 to 0.65% by weight, more preferably 0.45 to 0.65% by weight, and even more preferably 0.5 to 0.6% by weight, calculated as solid content in the entire blueberry jam. If the content is less than 0.3% by weight, calculated as solid content, the refreshing sourness may be insufficient. If the content is more than 0.65% by weight, the sourness may be felt too strongly, and the refreshing sourness may be lost. When the blueberry jam is eaten with plain yogurt, the harmony of flavor and texture may be lost, and the sense of unity may be lost. Note that acidulants and fruit juices other than lemon juice may be contained in the entire blueberry jam in a range of 0.15% by weight or less, calculated as solid content, as long as they do not impair the effects of the present invention.

[0023] Examples of the acidulant include citric acid, malic acid, tartaric acid, lactic acid, phosphoric acid, and salts of these acids (e.g., sodium salts). Examples of the fruit juice include citrus fruits such as yuzu, sudachi, lime, mandarin orange, grapefruit, kabosu, bitter orange, and orange. At least one selected from each of these groups can be used.

[0024] From the viewpoint of flavor and texture, it is preferable to add pectin to the blueberry jam. The pectin is a thickening polysaccharide that exists in many plants such as fruits and vegetables, and is mainly composed of polygalacturonic acid in which galacturonic acid, which is a component of plant tissue or a component of the intermediate layer, is bonded by α-1,4 bonding. The galacturonic acid that constitutes pectin is partially methyl esterified, and it is divided into LM (low methoxyl) pectin and HM (high methoxyl) pectin depending on the degree of esterification. HM pectin generally refers to one having an esterification degree of 50% or more. The pectin that can be used in the present invention may be either HM pectin or LM pectin, or a mixture thereof.

[0025] The content of pectin in the blueberry jam is preferably 0.8 to 1.3% by weight, more preferably 0.8 to 1.2% by weight, and even more preferably 0.8 to 1.1% by weight. By setting the content within the above range, the flavor and texture can be more harmoniously improved when eaten with plain yogurt.

[0026] From the viewpoint of flavor and texture, it is preferable to add sugar to the blueberry jam. Examples of the sugar include molasses sugar such as cane sugar and brown sugar; refined sugar such as white sugar, brown sugar, granulated sugar, white bicarbonate sugar, powdered sugar, granulated sugar, and liquid sugar; and the like, and at least one type selected from these groups can be used. Among them, sugar with a Ca content of 0.002 to 0.005 wt % and a K content of 0.01 to 0.02 wt % in the total sugar is more preferable. This is to obtain blueberry jam with a gentle and refreshing sweetness. The Ca and K contents can be easily adjusted if the sugar is derived from an organic raw material (for example, cane sugar such as organic sugar).

[0027] The Ca and K contents in the whole sugar can be measured by atomic absorption spectrometry or ICP (inductively coupled plasma) atomic emission spectrometry.

[0028] The sugar content in the blueberry jam is preferably 40 to 50% by weight, more preferably 40 to 48% by weight, and even more preferably 40 to 45% by weight. By keeping the content within this range, the flavor and texture can be more harmoniously combined when eaten with plain yogurt.

[0029] The blueberry jam may also contain, as appropriate, sugars other than sugar, gelling agents other than pectin, preservatives, flavorings, colorings, and the like, as long as the effects of the invention are not impaired.

[0030] The sugars other than sugar are not particularly limited, and examples thereof include sugars and sugar alcohols such as glucose, fructose, sucrose, maltose, enzyme-saccharified starch syrup, reduced starch syrup, isomerized liquid sugar, sucrose-bound starch syrup, reduced sugar, reduced palatinose, sorbitol, lactose, reduced lactose, L-arabinose, trehalose, xylose, xylitol, maltitol, erythritol, mannitol, fructooligosaccharides, soybean oligosaccharides, galactooligosaccharides, lactoferrotigosaccharides, xylooligosaccharides, raffinose, lactulose, palatinose, and palatinose oligosaccharides, as well as natural sweeteners such as honey and maple sugar. At least one selected from these groups can be used.

[0031] Examples of gelling agents other than pectin include locust bean gum, gellan gum, xanthan gum, carrageenan, guar gum, tara gum, sodium alginate, agar, gelatin, starches, celluloses, etc., and at least one selected from this group can be used.

[0032] The preservative may be at least one selected from the group consisting of sorbic acid and its salts, benzoic acid and its salts, sulfurous acid and its derivatives, natamycin, nisin, calcium propionate, etc. From the viewpoint of flavor, it is preferable not to add a preservative.

[0033] The flavoring agent may be a natural or synthetic blueberry flavor, etc. From the viewpoint of flavor, it is preferable not to add a flavoring agent.

[0034] The colours include blueberry colour, red radish colour, strawberry colour, plum colour, cranberry colour, blackberry colour, raspberry colour, red beet colour and purple corn colour.

[0035] [plain yogurt] In this disclosure, the plain yogurt is a fermented milk defined in the Ministerial Ordinance on Milk, etc., which is a paste made by fermenting milk or milk containing an equivalent or greater amount of non-fat milk solids with lactic acid bacteria, and a raw material mix made by mixing the milk, etc. with sugars and the like and not containing flavoring materials, which is fermented with lactic acid bacteria to make a paste. Here, the raw material mix refers to a mixture of raw materials other than lactic acid bacteria before fermentation of yogurt.

[0036] The milk referred to above includes raw milk, cow's milk, special milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, raw buffalo milk, adjusted milk, low-fat milk, non-fat milk, and processed milk. The raw milk referred to above is cow's milk as it is, and the cow's milk referred to above is cow's milk that is sold for the purpose of direct consumption or for use in the manufacture or processing of foods made from it. The special milk referred to above is milk that is sold as special milk, and among "milk," standards for specific manufacturing methods are established (as stipulated in the Ministry of Health and Welfare Ordinance No. 52 of December 27, 1951, "Ministry Ordinance on the Compositional Standards of Milk and Dairy Products").

[0037] The plain yogurt is obtained by fermenting a raw material mix for plain yogurt, and the raw material mix contains a specific amount of raw milk and / or cow's milk and a specific amount of ash in the entire raw material mix, and the weight ratio of minerals in the ash falls within a specific range. The plain yogurt has a median diameter of curd and a viscosity at 10°C that fall within specific ranges.

[0038] The content of the raw milk and / or cow's milk in the entire raw material mix is ​​preferably 60 to 97% by weight, more preferably 75 to 97% by weight, and even more preferably 85 to 97% by weight. If the content is less than 60% by weight, the original flavor of milk may be insufficient. If the content is more than 97% by weight, it may be difficult to obtain a thick texture.

[0039] The type of raw milk and / or cow's milk used is not particularly limited, but from the viewpoint of enhancing the inherent flavor of milk, the protein reduction value of the raw milk and / or cow's milk is preferably 2 to 9, and more preferably 4 to 9.

[0040] Raw milk and milk may be used alone or in combination, but using raw milk alone is preferred because it is possible to obtain plain yogurt with a more original milk flavor without losing the richness of the milk during the pasteurization process, etc. When using a mixture of raw milk and milk, the mixing ratio is not particularly limited, but it is preferred that the protein reduction value of the mixture of raw milk and milk is within the above range.

[0041] The protein reducing value can be measured by a known method, for example, the method described in "Testing Methods for Dairy Products: Commentary, edited by the Pharmaceutical Society of Japan" (Kanbara Publishing Co., Ltd., p. 131, published March 20, 1984).

[0042] The ash content (ash amount) is preferably 0.85 to 1.25% by weight, more preferably 0.9 to 1.2% by weight, and even more preferably 0.9 to 1.1% by weight, based on the total raw material mix of plain yogurt. If the ash amount is less than 0.85% by weight, the richness of the milk may be insufficient, and if it is more than 1.25% by weight, an unpleasant taste such as acridness caused by minerals may be felt.

[0043] The ash content refers to the total amount of ash contained in the entire raw material mix. Examples of metal components contained in the ash include monovalent metals such as alkali metals (e.g., sodium, potassium, etc.), alkaline earth metals (e.g., calcium, magnesium, etc.), and polyvalent metals such as iron, zinc, copper, and aluminum.

[0044] The ash content in the entire raw material mix of plain yogurt can be measured by a known method, for example, the magnesium acetate addition ashing method, the direct ashing method, or the sulfuric acid addition ashing method.

[0045] The ash content can be appropriately adjusted depending on the type and amount of raw milk and / or cow's milk used as raw materials, and other raw materials. Examples of other raw materials include milk other than raw milk and cow's milk, dairy products, milk protein sources, and mineral sources.

[0046] Examples of the raw milk and milk other than cow's milk include raw goat's milk, pasteurized goat's milk, raw sheep's milk, raw buffalo milk, ingredient-adjusted milk, low-fat milk, non-fat milk, and processed milk.

[0047] Examples of the dairy products include whey, desalted whey, whey powder (including desalted whey powder), whole milk powder, skim milk powder, whole fat concentrated milk, skim concentrated milk, sweetened condensed milk, sweetened condensed skim milk, unsweetened condensed milk, unsweetened condensed skim milk, cream, cultured cream, butter, cultured butter, buttermilk, buttermilk powder, and the like.

[0048] Examples of the milk protein source include milk protein concentrate (MPC), milk protein isolate (MPI), highly purified milk protein (TMP), whey protein concentrate (WPC), whey protein isolate (WPI), calcium caseinate, sodium caseinate, potassium caseinate, magnesium caseinate, acid casein, rennet casein, casein peptides, and the like.

[0049] Examples of the mineral source include lye, whey minerals, and various metal components.

[0050] The weight ratio of the mineral content in the ash content is preferably 1 to 1.25, more preferably 1 to 1.2, and even more preferably 1 to 1.1. If the weight ratio of the mineral content is less than 1, an unpleasant taste such as acridness may be felt, or the richness of the milk may be insufficient. If the weight ratio of the mineral content is higher than 1.25, the richness of the milk may be insufficient.

[0051] The mineral weight ratio refers to the weight ratio of the content of minerals consisting of calcium (Ca) and phosphorus (P) to the content of minerals consisting of potassium (K), magnesium (Mg) and sodium (Na), and is specifically calculated by the following formula. Mineral weight ratio = (Ca+P) content / (K+Mg+Na) content

[0052] The content of each of the minerals in the entire raw material mix of the plain yogurt can be measured by absorptiometry, atomic absorption spectrometry, or ICP (inductively coupled plasma) atomic emission spectrometry.

[0053] From the viewpoint of obtaining rich milk, the mineral content weight ratio is preferably adjusted using milk-derived raw materials, i.e., raw milk and / or cow's milk, milk other than raw milk and cow's milk, dairy products, milk protein sources, whey minerals, etc. The milk-derived raw materials may have a biased mineral composition because the minerals of the raw milk are partially removed during a concentration process such as membrane concentration in the production process, and the mineral content weight ratio can be adjusted by using these raw materials.

[0054] Examples of the milk-derived raw materials include dairy products such as skim milk, skim concentrated milk, skim milk powder and concentrated milk; milk protein sources such as milk protein concentrate (MPC), milk protein isolate (MPI), high-purity milk protein (TMP), whey protein concentrate (WPC) and whey protein isolate (WPI); milk-derived mineral sources such as whey minerals; and lactose. Among them, it is more preferable to use at least one selected from the group consisting of skim milk, skim concentrated milk, skim milk powder, milk protein isolate (MPC), milk protein isolate (MPI), high-purity milk protein (TMP), whey protein isolate (WPC) and whey protein isolate (WPI), and it is even more preferable to use at least one selected from the group consisting of skim milk, skim concentrated milk and skim milk powder, and at least one selected from the group consisting of milk protein isolate (MPC), milk protein isolate (MPI) and high-purity milk protein (TMP).

[0055] The "skim milk" refers to raw milk, cow's milk, special cow's milk, or raw buffalo milk from which the milk fat has been removed. In the present invention, low-fat milk and non-fat milk are considered to be included in skim milk. The "concentrated skim milk" refers to raw milk, cow's milk, special cow's milk, or raw buffalo milk from which the milk fat has been removed and then concentrated. The "skim milk powder" refers to raw milk, cow's milk, special cow's milk, or raw buffalo milk from which the milk fat has been removed (i.e., skim milk) from which almost all of the water has been removed and the product has been made into a powder form.

[0056] The types of the skim milk, skim concentrated milk, and skim milk powder are not particularly limited, but the content of at least one selected from the group consisting of skim milk, skim concentrated milk, and skim milk powder is preferably 1 to 7 wt %, more preferably 2 to 6 wt %, and even more preferably 3 to 5 wt %, in terms of dry weight, of the entire raw material mix of plain yogurt, since this allows for relatively easy adjustment of the ash content and weight ratio of minerals.

[0057] The ash content and mineral content weight ratio can be relatively easily adjusted by the content of at least one selected from the group consisting of milk protein concentrate (MPC), milk protein isolate (MPI), and highly purified milk protein (TMP), and therefore the content of each component is preferably 0.2 to 2.5% by dry weight, more preferably 0.3 to 2% by weight, and even more preferably 0.4 to 1% by weight, in the entire raw material mix of plain yogurt. The dry weight of each component can be measured by a normal pressure heating drying method.

[0058] The plain yogurt of the present invention preferably has a milk solid content of 14.5 to 18% by weight, more preferably 14.5 to 17% by weight, and even more preferably 14.5 to 16% by weight, based on the entire raw material mix of the plain yogurt. When the milk solid content is 14.5% by weight or more, the richness of the milk is felt more strongly than when the milk solid content is less than 14.5% by weight. When the milk solid content is 18% by weight or less, the thickening feeling is felt more strongly than when the milk solid content is more than 18% by weight.

[0059] The content of milk solids refers to the total amount of milk fat and non-fat milk solids. The contents of milk fat and non-fat milk solids can be measured based on the "Quantitative Method for Quantitative Analysis of Milk Fat in Cow's Milk, Special Cow's Milk, Pasteurized Goat's Milk, Low-Fat Cow's Milk, Non-Fat Cow's Milk, and Processed Milk" (in other words, the Roese-Gottlieb Method) and "Quantitative Method for Quantitative Analysis of Non-Fat Milk Solids in Milk and Dairy Products", which are quantitative methods described in the Ministry of Health, Labor and Welfare Ordinance No. 52 of Japan, "Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products, etc."

[0060] In the entire raw material mix of the plain yogurt, the milk protein content is preferably 4.5 to 6.5% by weight, more preferably 4.5 to 6% by weight, and even more preferably 4.6 to 5.5% by weight. When the milk protein content is 4.5% by weight or more, the richness and thickening of the milk are felt more strongly than when it is less than 4.5% by weight. When it is 6.5% by weight or less, the thickening is felt more strongly than when it is more than 6.5% by weight. Here, the milk protein content refers to the total amount of all milk-derived proteins contained in the entire raw material mix of the plain yogurt. The milk protein content in the entire raw material mix of the plain yogurt can be measured by a known method, for example, by a combustion method.

[0061] In order to adjust the amount of milk protein, a raw material serving as a milk protein source can be blended into the entire raw material mix of plain yogurt. The milk protein source may be the same as the milk protein source used to adjust the ash content, and examples of the milk protein source include milk protein concentrate (MPC), milk protein isolate (MPI), highly purified milk protein (TMP), whey protein concentrate (WPC), whey protein isolate (WPI), calcium caseinate, sodium caseinate, potassium caseinate, magnesium caseinate, acid casein, rennet casein, casein peptide, etc.

[0062] The proportion of whey protein in the milk protein contained in the entire raw material mix of plain yogurt is preferably 18 to 25% by weight, more preferably 18 to 23% by weight, and even more preferably 19 to 21% by weight, from the viewpoint of better flavor and smooth texture.

[0063] The ratio of whey protein to milk protein in the entire raw material mix of plain yogurt can be derived as a theoretical value calculated from the protein content of each raw material and the ratio of whey protein to the above proteins.

[0064] From the viewpoint of the original flavor and viscosity of milk, the milk fat content in the entire raw material mix of plain yogurt is preferably 3 to 5% by weight, more preferably 3 to 4.5% by weight, and even more preferably 3 to 4% by weight. Here, the milk fat content refers to the total amount of milk fat contained in the entire raw material mix of plain yogurt, and refers to the total amount of all milk fats contained in the raw material mix of plain yogurt described above. The milk fat content in the entire raw material mix of plain yogurt can be measured by a known method, for example, by the Roese-Gottlieb method.

[0065] The entire raw material mix of the plain yogurt may contain optional ingredients other than raw milk, milk, and ingredients that are mixed as necessary to adjust the ash content and the weight ratio of minerals in the ash, so long as the effects of the present invention are not adversely affected. Examples of the optional ingredients include sugars, stabilizers, oils and fats, emulsifiers, flavorings, antioxidants, etc.

[0066] Examples of sugars that can be contained in the raw material mix of the plain yogurt include white sugar, granulated sugar, powdered sugar, glucose, fructose, sucrose, maltose, enzyme-saccharified starch syrup, reduced starch syrup, isomerized liquid sugar, sucrose-bound starch syrup, reduced sugar, reduced palatinose, sorbitol, reduced lactose, L-arabinose, trehalose, xylose, xylitol, maltitol, erythritol, mannitol, fructooligosaccharides, soybean oligosaccharides, galactooligosaccharides, lactofructose oligosaccharides, xylooligosaccharides, raffinose, lactulose, palatinose oligosaccharides, and other sugars and sugar alcohols, as well as natural sweeteners such as honey and maple sugar. The content of the sugars is preferably 10% by weight or less, more preferably 5% by weight or less, even more preferably 3% by weight or less, and particularly preferably none, in the entire raw material mix of the plain yogurt.

[0067] Examples of stabilizers that may be included in the raw material mix of the plain yogurt include pectin, gum arabic, carrageenan, alginic acids (alginic acid, alginate), guar gum, tara gum, locust bean gum, tamarind seed gum, psyllium seed gum, water-soluble soybean polysaccharides, thickening polysaccharides such as glucomannan, gellan gum, xanthan gum, pullulan, curdlan, cellulose, carboxymethylcellulose salt, methylcellulose, chitin, chitosan, and gelatin; raw starches such as tapioca starch, potato starch, corn starch, waxy corn starch, wheat starch, and rice starch; and processed starches and dextrins obtained by subjecting the raw starches to pregelatinization, etherification, esterification, acetylation, crosslinking, oxidation, and the like. The content of the stabilizer is preferably 2% by weight or less, more preferably 1% by weight or less, even more preferably 0.5% by weight or less, and particularly preferably none is contained in the entire raw material mix of the plain yogurt.

[0068] Examples of fats and oils that can be contained in the plain yogurt include various animal and vegetable fats and oils such as soybean oil, cottonseed oil, corn oil, safflower oil, olive oil, palm oil, rapeseed oil, rice bran oil, coconut oil, palm kernel oil, lard, and fish oil, as well as processed fats and oils such as hardened oils, fractionated oils, and interesterified oils thereof. The content of the fats and oils is preferably 3% by weight or less, more preferably 2% by weight or less, and even more preferably 1% by weight or less, based on the total raw material mix of the plain yogurt, and is particularly preferably zero.

[0069] Examples of emulsifiers that may be contained in the plain yogurt include monoglycerides, monoglyceride derivatives bound to organic acids, sucrose fatty acid esters, polyglycerol fatty acid esters, propylene glycol fatty acid esters, polyglycerol condensed ricinoleic acid esters, calcium stearoyl lactylate, sodium stearoyl lactylate, etc. The content of the emulsifier is preferably 1% by weight or less, more preferably 0.5% by weight or less, even more preferably 0.2% by weight or less, and particularly preferably zero, based on the total weight of the raw material mix of the plain yogurt.

[0070] Examples of flavorings that can be contained in the plain yogurt include yogurt flavor, milk flavor, vanilla flavor, and mixtures thereof, etc. The content of the flavoring is preferably 0.5% by weight or less, more preferably 0.3% by weight or less, and even more preferably 0.2% by weight or less, based on the total raw material mix of the plain yogurt, and is particularly preferably zero.

[0071] Examples of antioxidants that may be contained in the plain yogurt include vitamin A, carotenoids, vitamin C, vitamin E, selenium, flavonoids, polyphenols, lycopene, lutein, lignans, etc. The content of the antioxidant is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, and even more preferably 0.05% by weight or less, based on the total raw material mix of the plain yogurt.

[0072] The median diameter of the plain yogurt curd is preferably 5 to 70 μm, more preferably 10 to 60 μm, and even more preferably 10 to 50 μm. If the median diameter is smaller than 5 μm, the richness of the milk may be insufficient, and if it is larger than 70 μm, the thickening may be insufficient. The median diameter of the plain yogurt curd can be measured using a laser diffraction / scattering particle size distribution analyzer LA-960V2 (manufactured by Horiba, Ltd.) using water as a dispersion medium.

[0073] The plain yogurt preferably has a viscosity of 20 to 60 Pa·s, more preferably 23 to 60 Pa·s, and even more preferably 25 to 55 Pa·s, as measured at 10°C using a BH type viscometer with a No. 4 rotor at a rotation speed of 2 rpm. If the viscosity is lower than 20 Pa·s, the richness and thick texture of the milk may be insufficient. If the viscosity is higher than 60 Pa·s, the richness of the milk may be insufficient.

[0074] The plain yogurt of the present invention is a fermented product of a raw material mix having the specific composition as described above, and the median diameter and viscosity of the curd fall within the above ranges, thereby enabling the plain yogurt to satisfy all of the inherent milk flavor, milk richness, and thick texture.

[0075] [Yogurt with blueberry jam] The blueberry jam-containing yogurt of the present invention preferably contains 10 to 25% by weight of the blueberry jam and 90 to 75% by weight of the plain yogurt in the entire blueberry jam-containing yogurt. If the content of each component is outside the above range, the harmony of flavor and texture may be lost when the blueberry jam and the plain yogurt are eaten together, resulting in a loss of unity. Furthermore, it is more preferable that the blueberry jam contains 12 to 25% by weight and 88 to 75% by weight of plain yogurt, even more preferable that the blueberry jam contains 12 to 22% by weight and 88 to 78% by weight of plain yogurt, and particularly preferable that the blueberry jam contains 14 to 20% by weight and 86 to 80% by weight of plain yogurt.

[0076] Ingredients other than blueberry jam and yogurt may be included as long as they do not impair the effects of the present invention. The amount of such ingredients added is preferably 3 parts by weight or less, more preferably 1 part by weight or less, and even more preferably none is added.

[0077] The method for producing yogurt containing blueberry jam of the present invention is exemplified below. The blueberry jam can be produced through a step of mixing ingredients, a step of concentrating, a step of adjusting acidity, a step of heating, and a step of cooling. The plain yogurt can be produced through a step of fermenting ingredients and a step of grinding. And the yogurt containing blueberry jam can be produced through a step of filling the blueberry jam and the plain yogurt into a container. Specifically, it is as follows.

[0078] [How to make blueberry jam] (Raw material mixing process) The above-mentioned blueberry jam ingredients (blueberries, water, and other optional ingredients as required) are all mixed together to obtain a jam ingredient mixture.

[0079] As described above, before mixing with other raw materials, the blueberries are preferably cut to some extent on the surface with a cutting device such as a dicer or silent cutter, more preferably a silent cutter. As described above, the blueberries are appropriately cut so that the content of blueberries that pass through a sieve with 15 mm openings but do not pass through a sieve with 5 mm openings is 10 to 20% by weight.

[0080] The content of blueberries in the jam ingredient mixture may be set taking into consideration the content of blueberries in the entire blueberry jam as described above and the degree of concentration in the concentration step described next.

[0081] (concentration process) The jam ingredient mixture obtained in the mixing step is placed in a device capable of heating and stirring under reduced pressure, and then is kept at 65 to 85°C under reduced pressure conditions and concentrated to a predetermined weight to obtain a concentrated ingredient mixture. The temperature during the concentration is preferably 65 to 85°C, more preferably 67 to 83°C. The reduced pressure condition may be a gauge pressure of 0.02 to 0.1 MPa.

[0082] (Acidity adjustment process) Lemon juice is added to the concentrated raw material mixture obtained in the concentration step so that the amount is 0.3 to 0.65% by weight in terms of solid content based on the total weight of the blueberry jam, and the acidity (as calculated as citric acid) is adjusted to 0.35 to 0.54%, thereby obtaining a raw material mixture with an adjusted acidity. When flavorings and colorants are added, they are preferably added in this step from the viewpoint of suppressing deterioration of flavor and color tone.

[0083] (Heating process) The raw material mixture after the acidity adjustment obtained in the acidity adjustment step is heated to 70 to 95°C to obtain a raw material mixture after heat treatment. The heat treatment temperature is more preferably 75 to 92°C, and even more preferably 80 to 90°C. The holding time at the heat treatment temperature may be approximately 1 to 5 minutes. If the heat treatment temperature is lower than 70°C or the holding time is shorter than 1 minute, the hygienic shelf life may decrease. If the heat treatment temperature is higher than 95°C or the holding time is longer than 5 minutes, the flavor may deteriorate.

[0084] (cooling process) The blueberry jam of the present invention can be obtained by cooling the heat-treated raw material mixture obtained in the heating step to 0 to 50° C. If the cooling temperature is lower than 0° C., freezing may occur and water may be separated, and if it is higher than 50° C., the flavor may deteriorate. The cooling temperature is preferably 15 to 35° C., and more preferably 15 to 25° C.

[0085] Alternatively, the raw material mixture after the heat treatment obtained in the heating step may be packed in a sealed container such as a pillow package, and then cooled. This method makes it easy to store and transport the produced blueberry jam. Thereafter, the sealed container is opened to take out the blueberry jam, which is then packed into a container together with plain yogurt.

[0086] [How to make plain yogurt] (Raw material heat treatment process) The raw materials for the plain yogurt described above (raw milk and / or cow's milk, raw materials blended as necessary to adjust the ash content and the weight ratio of minerals in the ash, and other optional ingredients blended as necessary) are mixed and dissolved to obtain a raw material mix. The raw milk and / or cow's milk content, ash content, and mineral weight ratio in the raw material mix may be adjusted as described above.

[0087] The raw material may or may not require a heat treatment step, but from the viewpoint of obtaining plain yogurt that has the richness and viscosity of milk, it is preferable to heat treat the raw material mix.

[0088] The heat treatment conditions are, for example, 80 to 98°C, preferably 85 to 95°C, and 1 to 50 minutes, preferably 5 to 20 minutes. The heat treatment method is, for example, to heat the raw material mix using a device used for heat sterilization until the temperature reaches the temperature, and then place the raw material mix in a device capable of heating and maintaining the temperature and maintain the temperature for a predetermined period of time. This sterilizes the raw material mix.

[0089] The device used for the heat treatment is not particularly limited as long as it is a heating device for performing heat sterilization of milk, and can be appropriately selected, but in consideration of productivity, a flow path type sterilization device is preferable. Examples of such sterilization devices include, but are not limited to, a plate type sterilization device, a tube type sterilization device, a spin injection type sterilization device, a Joule type sterilization device, etc. In addition, examples of devices that can heat and maintain temperature include, but are not limited to, containers and tanks with a jacket that can keep the temperature.

[0090] Prior to the heat treatment, a known homogenization treatment may be carried out in order to make the fat globules contained in the raw milk uniform in diameter and stabilize the quality. In this case, a device such as a homogenizer, a microfluidizer, or a colloid mill may be used. Such a homogenization treatment may also be carried out after the heat treatment.

[0091] (Fermentation process) A lactic acid bacteria starter is added to the raw material mix after the heat treatment, and fermentation is carried out until the pH reaches 4.1 to 4.85, thereby obtaining a raw material mix after a fermentation step. The pH is preferably 4.2 to 4.8, and more preferably 4.2 to 4.7.

[0092] The temperature of the raw material mix during fermentation is preferably 36 to 42° C., more preferably 38 to 42° C. The temperature of the raw material mix after the heat treatment is preferably adjusted to 36 to 42° C., more preferably 38 to 42° C., before the lactic acid bacteria starter is added.

[0093] The fermentation step can also be carried out in two stages. For example, the raw material mix can be fermented to a certain degree (primary fermentation) at a temperature of 36 to 42°C, and then cooled to 15 to 25°C, and secondary fermentation can be carried out under the same temperature conditions (15 to 25°C). By carrying out the secondary fermentation, larger curds are regenerated, improving the richness and viscosity of the milk in the plain yogurt. The temperature condition during the secondary fermentation is preferably 15 to 19°C.

[0094] When the secondary fermentation is carried out, from the viewpoint of further improving the richness and viscosity of the milk in the plain yogurt, it is preferably carried out until the pH of the raw material mix reaches 4.2 to 4.75, more preferably 4.2 to 4.6, and even more preferably 4.3 to 4.6.

[0095] The lactic acid bacteria starter is not particularly limited, and known lactic acid bacteria starters can be used, such as lactic acid bacteria belonging to Lactococcus, Streptococcus, Pediococcus, and Leuconostoc, lactic acid bacteria belonging to Lactobacillus, and Bifidobacterium, etc. Specific examples include Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, and Bifidobacterium lactis.

[0096] The amount of the lactic acid bacteria starter to be added is not particularly limited, and may be an amount normally used in the preparation of yogurt. For example, 0.00001 to 5 parts by weight may be added per 100 parts by weight of the raw material mix, and the approximate amount is 0.00001 to 0.05 parts by weight for the freeze-dried type and 0.01 to 5 parts by weight for the fermented liquid type.

[0097] (Crushing process) The curd of the raw material mix after fermentation obtained in the fermentation step is pulverized to a median diameter of 5 to 70 μm.

[0098] The curds can be crushed by a known method, specifically, a method using a mesh filter, a method by stirring in a tank, etc. From the viewpoint of simplicity and uniformity of the curd size, a method using a mesh filter is preferred.

[0099] The mesh size of the mesh filter used is, for example, preferably 10 to 100 mesh, more preferably 20 to 90 mesh, and further preferably 30 to 70 mesh.

[0100] The pressure condition when passing through the mesh filter is, for example, preferably 0.01 to 0.45 MPa, more preferably 0.05 to 0.45 MPa, and further preferably 0.1 to 0.4 MPa.

[0101] By the above-mentioned manufacturing method, plain yogurt having a curd median diameter of 5 to 70 μm and a viscosity measured at 10° C. of 20 to 60 Pa·s can be easily obtained.

[0102] [How to make yogurt with blueberry jam] (filling process) Yogurt containing blueberry jam can be produced by filling a container with 10 to 25 parts by weight of the blueberry jam and 90 to 75 parts by weight of the plain yogurt. Either the blueberry jam or the plain yogurt may be filled first into the container. Alternatively, the two may be filled simultaneously.

[0103] According to the method for producing yogurt with blueberry jam described above, the plain yogurt has the original milk flavor, richness, and viscosity of milk, and the blueberry jam has a refreshing acidity and the original natural flavor of blueberries with a moderate fruity texture, so that when these are eaten together, the flavors and textures are well harmonious, and it is possible to provide yogurt with blueberry jam that has a sense of unity between the blueberry jam and the plain yogurt. EXAMPLES

[0104] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are by weight.

[0105] The raw materials used in the examples and comparative examples are as follows. 1) “Jinpakuto P” manufactured by Nippon Seito Co., Ltd. 2) "Organic Crystal Sugar" made by Usina Sao Francisco SA 3) Sansho Co., Ltd. "LM-102AS-J" (LM Pectin) 4) "Lemon Concentrate" (solids: 42%) manufactured by Yuzan Co., Ltd. 5) "Raw milk" produced by Betsukai Wellness Farm Co., Ltd. (Milk fat content: 3.7%, milk protein content: 3.2%, protein reduction value: 4.4) 6) Kaneka skim milk powder (milk fat content: 1.0%, milk protein content: 34.0%, water content: 3.8%) 7) Glanbia Nutritionals "MPC80 SOLMIKO" (Milk fat: 1.5%, milk protein: 80.5%, moisture: 4.2%) 8) Meiji Co., Ltd. "Meiji Tokachi Fresh Cream 47" (milk fat content: 47.0%, milk protein content: 1.0%) 9) "Lactose HILMAR FINE GRAIND" by HILMAR CHEESE CO. 10) Danisco "YO-MIX207"

[0106] <Measurement of the amount of blueberries in blueberry jam that pass through a sieve with a 15 mm opening but not a sieve with a 5 mm opening> The content of blueberries that passed through a sieve with 15 mm openings but did not pass through a sieve with 5 mm openings in the blueberry jams produced in the Examples and Comparative Examples was evaluated by the following method.

[0107] First, the weight (Z) of the blueberry jam (total amount in the container) was measured, and then the entire amount was passed through a sieve with square meshes of 5 mm and washed with warm water at 40°C. Blueberries that did not pass through the 5 mm mesh sieve were collected, and the weight (X) of the blueberries after wiping off the surface moisture was measured.

[0108] Next, the blueberries that did not pass through the 5 mm sieve were placed on a 15 mm square sieve and washed with 40°C warm water to recover the blueberries that did not pass through the 15 mm sieve, and the weight (Y) was measured after wiping off the surface moisture.

[0109] The content was then calculated using the following formula. Content (wt%) of blueberries in blueberry jam that pass through a 15 mm sieve but not a 5 mm sieve = {(XY) / Z)} × 100

[0110] <Measurement of Ca and K content in total sugar in blueberry jam> The Ca and K contents in the total sugar in blueberry jam were measured by ICP (inductively coupled plasma) atomic emission spectrometry.

[0111] <Measurement of acidity (citric acid equivalent) of blueberry jam> The acidity means the acidity converted into citric acid, and was measured by neutralization titration using blueberry jam that had been put into a blender to break down the pulp into small pieces as a sample. Specifically, the procedure is as follows. Approximately 5 g of the sample was placed in a beaker and diluted approximately twice with distilled water, and two drops of phenolphthalein solution were added as an indicator. A burette was used to titrate with 0.1 mol / L aqueous sodium hydroxide solution. The acidity was calculated from the amount (ml) used in the titration using the following formula. Since the organic acid in blueberry pulp and lemon juice is mainly citric acid, the citric acid coefficient was used as the calculation coefficient. Acidity (%) = ((titer volume (ml) x F x 0.0064) / sample volume (g)) x 100 F: Factor of 0.1 mol / L sodium hydroxide solution 0.0064: Citric acid factor

[0112] <Measurement of Brix of blueberry jam> The Brix was measured using a sugar refractometer (Atago Co., Ltd. "RX-5000") for blueberry jam adjusted to 20°C.

[0113] <Measurement of hardness (maximum load when compressed) of blueberry jam> The hardness at 25°C was measured using a rheometer (Sun Scientific "CR-200D", plunger: disk-shaped, diameter 40 mm) for blueberry jam adjusted to 25°C.

[0114] <Measurement of median diameter of plain yogurt curd> The median diameter was measured using a laser diffraction / scattering type particle size distribution measuring device "LA-960V2" (manufactured by Horiba, Ltd.) using water as a dispersion medium.

[0115] <Measurement of viscosity of plain yogurt> The viscosity at 10°C was measured in a conventional manner using a BH type viscometer with a No. 4 rotor at a rotation speed of 2 rpm while maintaining the sample at 10°C.

[0116] <Measurement of protein reducing value> The protein reducing value of raw milk and / or cow's milk was measured according to the method described in "Testing Methods for Dairy Products: Commentary, edited by the Pharmaceutical Society of Japan" (Kanbara Publishing Co., Ltd., p. 131, published March 20, 1984).

[0117] <Composition analysis of raw material mix for plain yogurt> The contents of milk solids, milk protein, ash, and milk fat were analyzed according to the general nutritional analysis method for dairy products as follows. Milk solids: Measured based on the quantitative methods described in the Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products, namely "Method for Quantitative Analysis of Milk Fat in Cow's Milk, Special Cow's Milk, Pasteurized Goat's Milk, Low-fat Milk, Non-fat Milk and Processed Milk" (Roese-Gottlieb method) and "Method for Quantitative Analysis of Non-fat Milk Solids in Milk and Dairy Products." Milk proteins: combustion method Ash content: Direct ashing method Milk fat: Roese-Gottlieb process The mineral weight ratio (Ca+P) / (K+Mg+Na) in the ash of the raw material mix for plain yogurt was calculated using ICP (inductively coupled plasma) atomic emission spectrometry. The proportion of whey protein in milk protein was calculated from the protein content in each raw material and the proportion of whey protein in the above protein.

[0118] <Sensory evaluation of blueberry jam> Ten experienced panelists tasted each of the blueberry jams obtained in the production examples, which had been adjusted to 10°C, and conducted a sensory evaluation of each jam from the standpoints of refreshing acidity, natural blueberry flavor, and texture, and the average scores are shown in each table as the sensory evaluation score. The evaluation criteria were as follows:

[0119] (Clean acidity) 5 points: Better than the blueberry jam in Example 1, with a strong refreshing sour taste 4 points: Equivalent to the blueberry jam in Production Example 1, with a refreshing sour taste 3 points: Slightly inferior to the blueberry jam in Example 1, but has a refreshing sour taste. 2 points: Worse than the blueberry jam of Production Example 1, it is difficult to feel a refreshing sourness. 1 point: Much worse than the blueberry jam in Example 1, lacking a refreshing sour taste

[0120] (Blueberry's natural flavor) 5 points: Better than blueberry jam from Production Example 1, with a stronger natural flavor 4 points: Equivalent to blueberry jam from Production Example 1, with a fully preserved natural flavor 3 points: Slightly inferior to the blueberry jam in Example 1, but the original natural flavor can be felt. 2 points: Worse than the blueberry jam of Production Example 1, and it is difficult to feel the original natural flavor. 1 point: Much worse than the blueberry jam in Example 1, with no natural flavor.

[0121] (fruit feel) 5 points: Better than the blueberry jam in Example 1, with a strong fruity texture 4 points: Equivalent to blueberry jam in Production Example 1, with a good fruity texture 3 points: Slightly inferior to the blueberry jam in Example 1, but the texture of the fruit can be felt. 2 points: Worse than the blueberry jam of Production Example 1, with little or too much fruitiness. 1 point: Much worse than the blueberry jam of Production Example 1, with no fruit texture at all or too much fruit texture

[0122] <Sensory evaluation of plain yogurt> Ten experienced panelists tasted each of the plain yogurts obtained in the production examples, which had been adjusted to 10°C, and conducted a sensory evaluation of each one from the standpoints of the original milk flavor, milk richness, and viscosity. The average scores are shown in each table as the sensory evaluation scores. The evaluation criteria were as follows:

[0123] (Original milk flavor) 5 points: Better than the plain yogurt of Example 16, with a strong milk flavor 4 points: Equivalent to the plain yogurt of Production Example 16, with a full milk flavor 3 points: Slightly inferior to the plain yogurt of Example 16, but the original milk flavor can be felt. 2 points: Worse than the plain yogurt of Production Example 16, and the original milk flavor is difficult to feel. 1 point: Much worse than the plain yogurt in Example 16, with no inherent milk flavor.

[0124] (Milk richness) 5 points: Better than the plain yogurt of Example 16, with a strong milky richness. 4 points: Equivalent to the plain yogurt of Production Example 16, with a rich milk flavor. 3 points: Slightly inferior to the plain yogurt of Production Example 16, but the richness of the milk can be felt. 2 points: Worse than the plain yogurt of Production Example 16, the richness of the milk is hard to feel. 1 point: Much worse than the plain yogurt in Example 16, and the richness of the milk is not felt.

[0125] (Thickness) 5 points: Better than the plain yogurt in Example 16, with a strong sense of thickness 4 points: Equivalent to the plain yogurt in Example 16, with a good sense of thickness 3 points: Slightly inferior to the plain yogurt of Production Example 16, but has a thick texture 2 points: Worse than the plain yogurt of Production Example 16, and the feeling of thickness is hard to feel. 1 point: Much worse than the plain yogurt in Example 16, with no sense of thickness

[0126] <Sensory evaluation of yogurt with blueberry jam> A sensory evaluation was conducted by having 10 experienced panelists eat the yogurt containing blueberry jam obtained in the Examples and Comparative Examples, which had been adjusted to 10°C, after which the panelists stirred the whole with a spoon five times so that the blueberry jam and the plain yogurt were mixed together, and the average of the scores was regarded as the sensory evaluation. The evaluation criteria were as follows:

[0127] (A harmonious blend of blueberry jam and plain yogurt in flavor and texture) 5 points: Better than the yogurt with blueberry jam in Example 1, the flavor and texture of the blueberry jam and plain yogurt are well balanced and the taste is very tasty. 4 points: The taste is equivalent to the yogurt with blueberry jam in Example 1, and the flavor and texture of the blueberry jam and plain yogurt are well balanced and delicious. 3 points: Slightly inferior to the yogurt with blueberry jam in Example 1, but the flavor and texture of the blueberry jam and plain yogurt are in harmony and oneness. 2 points: Worse than the yogurt with blueberry jam in Example 1, the flavor and texture of the blueberry jam and plain yogurt are not in harmony with each other, and there is no sense of unity. 1 point: Much worse than the yogurt with blueberry jam in Example 1. The flavor and texture of the blueberry jam and plain yogurt are not in harmony with each other at all, and there is no sense of unity at all.

[0128] (Production Example 1) Preparation of blueberry jam According to the formulation in Table 1, 30.0 parts by weight of blueberries (variety: wild blueberry) cut with a silent cutter, 30 parts by weight of water, 44.85 parts by weight of sugar, and 1.05 parts by weight of pectin were put into a heating mixer. After sealing the heating mixer, the mixture was heated to 75°C and held at that temperature while stirring under reduced pressure of 0.05 MPa (gauge pressure), and when concentrated to a predetermined weight, the pressure was returned to normal, 1.2 parts by weight of lemon juice was added, the mixture was heated to 88°C and held for 3 minutes, and then cooled to 25°C to obtain 100 parts by weight of blueberry jam. The acidity, Brix, and hardness of the obtained blueberry jam, as well as the evaluation results of the refreshing acidity, natural flavor of blueberries, and pulp texture are shown in Table 1.

[0129] [Table 1]

[0130] (Production Example 2) Preparation of blueberry jam A blueberry jam was obtained in the same manner as in Production Example 1, except that the white sugar was changed to organic sugar according to the formulation in Table 1. The acidity, Brix, hardness, refreshing acidity, natural blueberry flavor, and pulp texture of the obtained blueberry jam are shown in Table 1.

[0131] (Production Examples 3 to 7) Preparation of blueberry jam Blueberry jam was obtained in the same manner as in Production Example 1, except that the amounts of blueberries and white sugar were changed to 23.0 parts by weight and 50.0 parts by weight (Production Example 3), 39.0 parts by weight and 40.0 parts by weight (Production Example 4), 20.0 parts by weight and 50.0 parts by weight (Production Example 5), 45.0 parts by weight and 38.0 parts by weight (Production Example 6), or 23.0 parts by weight and 55.0 parts by weight (Production Example 7) according to the formulation in Table 1, and the total amount was adjusted with water. The acidity, Brix, hardness, refreshing acidity, natural flavor of blueberries, and pulp texture of the obtained blueberry jam were evaluated, and the results are shown in Table 1.

[0132] (Production Examples 8 to 11) Preparation of Blueberry Jam Blueberry jam was obtained in the same manner as in Production Example 2, except that the content of pectin was changed according to the formulation in Table 2, the total amount was adjusted with water, and the cutting time with the silent cutter was adjusted to change the content of blueberries that passed through a sieve with a mesh size of 15 mm but not through a sieve with a mesh size of 5 mm. Table 2 shows the evaluation results of the acidity, Brix, hardness, refreshing acidity, original natural flavor of blueberries, and pulp texture of the obtained blueberry jam.

[0133] [Table 2]

[0134] (Production Examples 12 to 15) Preparation of Blueberry Jam Blueberry jam was obtained in the same manner as in Production Example 2, except that the content of concentrated lemon juice was changed according to the formulation in Table 2, the total amount was adjusted with water, and the cutting time with the silent cutter was adjusted to change the content of blueberries that passed through a sieve with a mesh size of 15 mm but not through a sieve with a mesh size of 5 mm. Table 2 shows the evaluation results of the acidity, Brix, hardness, refreshing acidity, original natural flavor of blueberries, and pulp texture of the obtained blueberry jam.

[0135] (Production Example 16) Preparation of plain yogurt According to the formulation in Table 3, 85.0 parts by weight of raw milk was mixed with 4.2 parts by weight of skim milk powder, 1.0 part by weight of MPC, and 9.8 parts by weight of water, and dissolved to prepare a raw material mix for yogurt.

[0136] These were preheated to 60°C, homogenized at a pressure of 3.5 / 17 MPa using a high-pressure homogenizer, heated to 90°C using a plate-type heat exchanger, and heated in a jacketed tank at 90°C for 10 minutes. Then, cooled to 40°C, 0.0014 parts by weight of lactic acid bacteria starter (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus acidophilus, Bifidobacterium lactis) was added, and fermentation was performed until the pH reached 4.5. The fermented yogurt raw material mix was passed through a 60-mesh filter at a pressure of 0.22 MPa to crush the curd, then filled into a retail container and cooled to 8°C in a refrigerated warehouse to obtain plain yogurt. The viscosity, median diameter of the curd, and the evaluation results of the original milk flavor, richness of the milk, and thickness of the obtained plain yogurt are shown in Table 3.

[0137] [Table 3]

[0138] (Production Example 17) Preparation of plain yogurt Plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 60.0 parts by weight, the skim milk powder was changed from 4.2 parts by weight to 8.5 parts by weight, the MPC was changed from 1.0 parts by weight to 1.5 parts by weight, and the water was changed from 9.8 parts by weight to 28.2 parts by weight in accordance with the formulation in Table 3, and 1.8 parts by weight of fresh cream was added and dissolved to prepare a yogurt mix. Table 3 shows the evaluation results of the viscosity, median diameter of the curd, the original milk flavor, the richness of the milk, and the thickening feel of the obtained plain yogurt.

[0139] (Production Example 18) Preparation of plain yogurt Plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 95.6 parts by weight, the skim milk powder was changed from 4.2 parts by weight to 3.9 parts by weight, and the MPC was changed from 1.0 part by weight to 0.5 parts by weight according to the formulation in Table 3, and no water was added. The viscosity, median diameter of the curd, and the evaluation results of the original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0140] (Production Example 19) Preparation of plain yogurt According to the formulation in Table 3, the raw milk was changed from 85.0 parts by weight to 97.0 parts by weight, the skim milk powder was changed from 4.2 parts by weight to 2.0 parts by weight, the MPC was left at 1.0 part by weight, and no water was added, so plain yogurt was obtained in the same manner as in Production Example 16. The evaluation results of the viscosity, median diameter of the curd, original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0141] (Production Example 20) Preparation of plain yogurt The fermented yogurt mix obtained by fermenting in the same manner as in Production Example 16 under the production conditions in Table 3 was stirred for 90 minutes at a stirring speed of 0.35 revolutions / second in a tank equipped with paddle-type stirring blades to crush the curds, and then filled into retail containers and cooled to 8°C in a refrigerated warehouse to obtain plain yogurt. The evaluation results of the viscosity, median diameter of the curds, original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0142] (Production Example 21) Preparation of plain yogurt Plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 40.0 parts by weight, the skim milk powder was changed from 4.2 parts by weight to 7.0 parts by weight, and the water was changed from 9.8 parts by weight to 45.5 parts by weight, the MPC was left unchanged at 1.0 part by weight, and 4.5 parts by weight of fresh cream and 2.0 parts by weight of lactose were added according to the formulation in Table 3. The viscosity, median diameter of the curd, and the evaluation results of the original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0143] (Production Example 22) Preparation of plain yogurt According to the formulation in Table 1, plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 100.0 parts by weight, and skim milk powder, MPC, and water were not added. The evaluation results of the viscosity, curd median diameter, original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0144] (Production Example 23) Preparation of plain yogurt Plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 95.0 parts by weight, and the skim milk powder was changed from 4.2 parts by weight to 5.0 parts by weight according to the formulation in Table 3, and MPC and water were not added. The viscosity, median diameter of the curd, and the evaluation results of the original milk flavor, milk richness, and thickening feel of the obtained plain yogurt are shown in Table 3.

[0145] (Production Example 24) Preparation of plain yogurt Plain yogurt was obtained in the same manner as in Production Example 16, except that the raw milk was changed from 85.0 parts by weight to 97.0 parts by weight, and the MPC was changed from 1.0 part by weight to 3.0 parts by weight according to the formulation in Table 3, and skim milk powder and water were not added. Table 3 shows the evaluation results of the viscosity, median diameter of curd, original milk flavor, milk richness, and thickening feel of the obtained plain yogurt.

[0146] Example 1: Preparation of yogurt with blueberry jam According to the formulation in Table 4, 18 g of blueberry jam of Production Example 1 was filled, and then 82 g of plain yogurt of Production Example 16 was filled on top of that, and cooled to 8° C. in a refrigerated warehouse to obtain yogurt with blueberry jam. The evaluation results of the obtained yogurt with blueberry jam for the harmonious and unified flavor and texture of the blueberry jam and plain yogurt are shown in Table 4.

[0147] [Table 4]

[0148] (Examples 2 to 8, Comparative Examples 1 to 7) Preparation of yogurt with blueberry jam Yogurt containing blueberry jam was obtained in the same manner as in Example 1, except that the blueberry jam of Production Example 1 was changed to blueberry jam of Production Example 2 (Example 2), Production Example 3 (Example 3), Production Example 4 (Example 4), Production Example 8 (Example 5), Production Example 9 (Example 6), Production Example 12 (Example 7), Production Example 13 (Example 8), Production Example 5 (Comparative Example 1), Production Example 6 (Comparative Example 2), Production Example 7 (Comparative Example 3), Production Example 10 (Comparative Example 4), Production Example 11 (Comparative Example 5), Production Example 14 (Comparative Example 6), or Production Example 15 (Comparative Example 7) according to the composition of Table 4. The evaluation results of the unity of the flavor and texture of the blueberry jam and plain yogurt of the obtained yogurt containing blueberry jam are shown in Table 4.

[0149] As is clear from Table 4, the blueberry jam-containing yogurts (Examples 1 to 8) each contained 23 to 40% by weight of blueberries and 0.30 to 0.65% by weight of lemon juice calculated as solids, and the content of blueberries that passed through a sieve with 15 mm openings but not a sieve with 5 mm openings was 10 to 20% by weight, and the blueberry jam had an acidity of 0.35 to 0.54%, a Brix of 45 to 55%, and a hardness at 25°C (maximum load when compressed) of 0.9 to 1.6 N. All of these yogurts had a refreshing acidity, a natural blueberry flavor, and a moderate fruit texture, as well as a rich milky flavor and a milky taste, and had a well-balanced flavor and texture, with a sense of unity between the blueberry jam and the plain yogurt, and were evaluated as being favorable.

[0150] On the other hand, in the yogurt with blueberry jam (Comparative Example 1) containing blueberry jam with a low content of 20.0% by weight, a low content of 9.0% by weight of blueberries that passed through a sieve with 15 mm openings but not a sieve with 5 mm openings, and a low hardness (maximum load when compressed) of 0.8 N at 25°C, the refreshing acidity of the blueberry jam and the natural flavor and texture of the blueberries were difficult to taste, and the harmony between the blueberry jam and the plain yogurt was lost, resulting in a lack of unity.

[0151] In addition, in the yogurt with blueberry jam (Comparative Example 2) containing blueberry jam with a high blueberry content of 45.0% by weight, the refreshing acidity of the blueberry jam was weak and the texture of the blueberry pulp was too strong, disrupting the harmony between the blueberry jam and the plain yogurt and resulting in no sense of unity.

[0152] In addition, in the yogurt with blueberry jam (Comparative Example 3) containing blueberry jam with a low content of 8.9% by weight of blueberries that passed through a sieve with 15 mm openings but not a sieve with 5 mm openings, a high Brix of 60%, and a high hardness at 25°C (maximum load when compressed) of 1.7 N, the refreshing acidity of the blueberry jam and the natural flavor and texture of the blueberries were difficult to taste, and the harmony between the blueberry jam and the plain yogurt was lost, resulting in a lack of unity.

[0153] In addition, in the yogurt with blueberry jam (Comparative Example 4), which contained a high content of blueberries (21.0% by weight) that passed through a sieve with 15 mm openings but not a sieve with 5 mm openings and contained blueberry jam with a low hardness (maximum load when compressed) of 0.7 N at 25°C, the blueberry jam was too soft, disrupting the harmony between the blueberry jam and the plain yogurt, and no sense of unity was felt.

[0154] In addition, the yogurt with blueberry jam (Comparative Example 5) contained blueberry jam with a low content of 9.0% by weight, which was a blueberry that passed through a sieve with 15 mm openings but not a sieve with 5 mm openings, and had a high hardness (maximum load when compressed) of 1.8 N at 25°C. The refreshing acidity of the blueberry jam was weak, and it was difficult to feel the texture of the blueberry pulp. The harmony between the blueberry jam and the plain yogurt was lost, and no sense of unity was felt.

[0155] In addition, in the yogurt with blueberry jam (Comparative Example 6), which contained only 0.29% by weight of lemon juice in terms of solid content and low acidity of 0.28% blueberry jam, the refreshing sourness of the blueberry jam was weak, and the harmony between the blueberry jam and the plain yogurt was lost, and no sense of unity was felt. Also, syneresis was observed in the blueberry jam.

[0156] Furthermore, in the yogurt with blueberry jam (Comparative Example 7), which contained a high amount of lemon juice (0.67% by weight calculated as solid content) in the entire blueberry jam and blueberry jam with a high acidity of 0.60%, the sourness of the blueberry jam was strong, compromising the refreshing sourness and destroying the harmony between the blueberry jam and the plain yogurt, resulting in no sense of unity.

[0157] (Examples 9 to 12, Comparative Examples 8 to 11) Preparation of yogurt with blueberry jam Yogurt containing blueberry jam was obtained in the same manner as in Example 1, except that the plain yogurt of Production Example 16 was changed to Production Example 17 (Example 9), Production Example 18 (Example 10), Production Example 19 (Example 11), Production Example 20 (Example 12), Production Example 21 (Comparative Example 8), Production Example 22 (Comparative Example 9), Production Example 23 (Comparative Example 10), or Production Example 24 (Comparative Example 11) in accordance with the formulation in Table 5. The evaluation results of the obtained yogurt containing blueberry jam for the harmonious and united flavor and texture of the blueberry jam and plain yogurt are shown in Table 5.

[0158] [Table 5]

[0159] As is clear from Table 5, the blueberry jam-containing yogurt (Examples 1, 9 to 12) containing plain yogurt having a raw milk content of 60 to 97% by weight, an ash content of 0.85 to 1.25% by weight, a mineral weight ratio (Ca+P) / (K+Mg+Na) in the ash content of 1 to 1.25, a median diameter of the plain yogurt curd of 5 to 70 μm, and a viscosity of 20 to 60 Pa s at 10° C. using a No. 4 rotor in a BH type viscometer at a rotation speed of 2 rpm all had a refreshing acidity, a natural blueberry flavor, and a moderate fruit texture, as well as a rich milk flavor and a milky taste. The flavors and textures were well-balanced, and the blueberry jam and plain yogurt were united, resulting in favorable evaluation results.

[0160] On the other hand, in the yogurt with blueberry jam (Comparative Example 8) which used plain yogurt with a low raw milk content of 40% by weight in the entire raw material mix of the plain yogurt, the original milk flavor of the plain yogurt was weak, the harmony between the blueberry jam and the plain yogurt was lost, and no sense of unity was felt.

[0161] In addition, in the yogurt with blueberry jam (Comparative Example 9), which used plain yogurt with a high raw milk content of 100% by weight, a low ash content of 0.70% by weight, and a low viscosity of 5 Pa s at 10°C, the plain yogurt was not very rich in milk and had a low viscosity of 5 Pa s, and the harmony between the blueberry jam and the plain yogurt was lost, resulting in a lack of unity.

[0162] In addition, in the yogurt with blueberry jam (Comparative Example 10) which used plain yogurt with a low (Ca+P) / (K+Mg+Na) (mineral weight ratio) in the ash of 0.95 in the entire raw material mix of plain yogurt, the richness of the milk in the plain yogurt was felt to be weak, the harmony between the blueberry jam and the plain yogurt was lost, and no sense of unity was felt.

[0163] Furthermore, in the yogurt with blueberry jam (Comparative Example 11) which used plain yogurt with a high (Ca+P) / (K+Mg+Na) (mineral content weight ratio) in the ash of 1.45 in the entire raw material mix of the plain yogurt, the richness of the milk in the plain yogurt was weak, the plain yogurt had a bitter taste, and the harmony between the blueberry jam and the plain yogurt was lost, resulting in no sense of unity.

[0164] (Examples 13 to 40) Preparation of yogurt with blueberry jam Yogurt containing blueberry jam was obtained in the same manner as in Example 1, except that the blueberry jam and plain yogurt used in Example 1 were changed according to the formulation in Table 6. The evaluation results of the harmonious and unified flavor and texture of the blueberry jam and plain yogurt in the obtained yogurt containing blueberry jam are shown in Table 6.

[0165] [Table 6]

[0166] As is clear from Table 6, the blueberry jam contains 23 to 40% by weight of blueberries and 0.30 to 0.65% by weight of lemon juice in terms of solid content, the content of blueberries that pass through a sieve with a mesh size of 15 mm but not a sieve with a mesh size of 5 mm is 10 to 20% by weight, the acidity is 0.35 to 0.54%, the Brix is ​​45 to 55%, and the hardness at 25°C (maximum load when compressed) is 0.9 to 1.6N. The raw material mix for blueberry jam and plain yogurt contains 60 to 97% by weight of raw milk and 0.85 to 1.25% by weight of ash, and the (Ca+P) / (K+Mg+Na) (mineral) content of the ash is 0.01 to 0.02% by weight. The blueberry jam-containing yogurt (Examples 13 to 40) containing plain yogurt having a curd content ratio (weight ratio) of 1 to 1.25, a median diameter of the plain yogurt curd of 5 to 70 μm, and a viscosity of 20 to 60 Pa s at 10° C. when measured at a rotation speed of 2 rpm using a No. 4 rotor in a BH type viscometer, all had the refreshing acidity of the blueberry jam, the natural flavor of blueberries, and a moderate texture of fruit pulp, as well as the rich milkiness, original flavor and thick texture of the plain yogurt, and a well-balanced flavor and texture, giving a sense of unity between the blueberry jam and the plain yogurt, and were favorably evaluated.

[0167] (Examples 41 to 42, Comparative Examples 12 to 13) Preparation of yogurt with blueberry jam Yogurt with blueberry jam was obtained in the same manner as in Example 1, except that the 18% by weight of blueberry jam and 82% by weight of plain yogurt in the entire blueberry jam-containing yogurt were changed to 25% by weight and 75% by weight (Example 41), 10% by weight and 90% by weight (Example 42), 28% by weight and 72% by weight (Comparative Example 12), or 8% by weight and 92% by weight (Comparative Example 13), respectively, according to the formulation in Table 7. The evaluation results of the harmonious and united flavor and texture of the blueberry jam and plain yogurt in the obtained blueberry jam-containing yogurt are shown in Table 4.

[0168] [Table 7]

[0169] As is clear from Table 7, all of the blueberry jam-containing yogurts (Examples 1, 41, and 42) in which the blueberry jam was in the range of 10 to 25% by weight and the plain yogurt was in the range of 90 to 75% by weight had a sense of unity between the blueberry jam and the plain yogurt, and were evaluated as having good results.

[0170] On the other hand, in yogurt with blueberry jam, which had a high content of 28% by weight of blueberry jam and low content of plain yogurt, which was 72% by weight (Comparative Example 12), and in yogurt with low content of blueberry jam, which was 8% by weight, and high content of plain yogurt, which was 92% by weight (Comparative Example 13), the harmony between the blueberry jam and the plain yogurt was not good, and no sense of unity was felt.

Claims

1. Yogurt with blueberry jam in whole A yogurt containing blueberry jam, the yogurt containing blueberry jam being 10 to 25% by weight and having an acidity (as calculated as citric acid) of 0.35 to 0.54% and 90 to 75% by weight of plain yogurt, the blueberry jam contains 23 to 40% by weight of blueberries and 0.3 to 0.65% by weight of lemon juice calculated as solid content in the whole blueberry jam, and the content of blueberries passing through a sieve having a mesh size of 15 mm but not passing through a sieve having a mesh size of 5 mm is 10 to 20% by weight of the blueberries, The blueberry jam has a Brix of 45 to 55% and a hardness (maximum compression load) at 25° C. of 0.9 to 1.6 N; The plain yogurt is a fermented raw material mix of plain yogurt, in which the raw milk and / or cow's milk content is 60 to 97% by weight, the ash content is 0.85 to 1.25% by weight, and the (Ca+P) / (K+Mg+Na) (mineral content weight ratio) in the ash content is 1 to 1.

25. The plain yogurt has a curd median diameter of 5 to 70 μm and a viscosity of 20 to 60 Pa s at 10° C. when measured using a BH type viscometer with a No. 4 rotor at a rotation speed of 2 rpm. Yogurt with blueberry jam.

2. 2. The yogurt with blueberry jam according to claim 1, wherein the blueberry jam contains 0.8 to 1.3% by weight of pectin and 40 to 50% by weight of sugar based on the total weight of the blueberry jam.

3. 3. The yogurt with blueberry jam according to claim 2, wherein the Ca content in the total sugar in the blueberry jam is 0.002 to 0.005% by weight and the K content is 0.01 to 0.02% by weight.

4. The blueberry jam-containing yogurt according to any one of claims 1 to 3, wherein the milk solid content is 14.5 to 18% by weight and the milk protein content is 4.5 to 6.5% by weight in the entire raw material mix of the plain yogurt.

5. A method for producing blueberry jam-containing yogurt, comprising: Filling a container with 10 to 25 parts by weight of the blueberry jam and 90 to 75 parts by weight of the plain yogurt; The plain yogurt has a viscosity of 20 to 60 Pa s at 10°C when measured using a BH type viscometer with a No. 4 rotor at a rotation speed of 2 rpm; The blueberry jam is a step of mixing blueberries and water so that the content of blueberries in the entire blueberry jam is 23 to 40% by weight and the content of blueberries that pass through a sieve having a mesh size of 15 mm but not a sieve having a mesh size of 5 mm is 10 to 20% by weight; A step of concentrating the mixed raw material mixture by maintaining it at 65 to 85° C. under reduced pressure conditions of a gauge pressure of 0.02 to 0.1 MPa; adding lemon juice to the concentrated raw material mixture in an amount equivalent to 0.3 to 0.65% by weight of the total blueberry jam in terms of solid content, and adjusting the acidity (in terms of citric acid) to 0.35 to 0.54%; heating the raw material mixture after the acidity adjustment to a temperature of 70 to 95° C. and maintaining said temperature for 1 to 5 minutes; and cooling the heated raw material mixture to a temperature of 0 to 50° C. The plain yogurt is A process of combining the raw material mix of the plain yogurt, which has a raw milk and / or cow's milk content of 60 to 97% by weight, an ash content of 0.85 to 1.25% by weight, and a mineral content weight ratio (Ca+P) / (K+Mg+Na) of 1 to 1.25 in the ash, with a lactic acid bacteria starter and fermenting the mixture at a temperature of 36 to 42° C. until the pH reaches 4.1 to 4.85; and crushing the curd obtained by the fermentation to a median diameter of 5 to 70 μm. How to make yogurt with blueberry jam.

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