Coffee yoghourt and preparation method thereof

Abstract

The invention provides coffee yoghourt and a preparation method thereof. The acidity of the coffee yogurt is 72-95 DEG T, the viscosity is 100-400 mPa.s, the water retention rate is 35-43%, the chlorogenic acid content is 0.011-0.058 g / 100 g, the protein content is 3.04-4.05 g / 100 g, the fat content is 3.8-5.4 g / 100 g, and the coffee yogurt has the characteristics of strong coffee fragrance and milk fragrance, weak bad acid bitter taste of coffee, moderate acidity, low viscosity, high stability and the like.

Description

Technical Field

[0001] The present invention relates to a coffee yogurt, and particularly to a coffee yogurt and a preparation method thereof, belonging to the food field. Background Art

[0002] Coffee is one of the world's three major beverages, with the effects of refreshing the mind, promoting urination, and strengthening the spleen. Most of the aromatic substances in coffee beans are volatile. During the roasting process, the aromatic substances volatilize, enabling us to smell the pleasant coffee aroma. However, the acidic, bitter, and astringent components in coffee beans do not volatilize. When coffee is brewed, these acidic, bitter, and astringent components dissolve in water, making us taste sour, bitter, and astringent, which constitutes the unique flavor of coffee.

[0003] As a convenient and easy-to-eat food, yogurt meets the needs of consumers in the modern fast-paced life. Its sour and sweet taste is loved by people, and the market development prospect is very broad. On the basis of basically solidifying milk sources and strains and having similar processes, how to make the product more distinctive, and flavor innovation has become the key to differentiation. Among them, the combination of coffee and yogurt is an attempt at flavor innovation.

[0004] However, the acidic, bitter, and astringent bad tastes of coffee do not match the sour and sweet taste of yogurt, and the inappropriate mixing of coffee extract or coffee powder with yogurt will cause a certain degree of flocculation of the protein in yogurt, reducing the stability of the product. Therefore, a coffee yogurt that retains the aroma of coffee, the milk aroma and taste of yogurt, removes the acidic, bitter, and astringent bad tastes of coffee, and has high stability is expected to fill the market gap. Summary of the Invention

[0005] The present invention provides a coffee yogurt, which has a moderate acidity, appropriate viscosity, and good taste; it has a relatively high chlorogenic acid content, high protein content, rich nutrition, and good product stability.

[0006] The present invention also provides a preparation method of the coffee yogurt, which is simple to operate and suitable for industrial production.

[0007] The present invention provides a coffee yogurt, the acidity of which is 72-95°T, the viscosity is 100-400 mPa·s, the water holding rate is 28-43%, the chlorogenic acid content is 0.011-0.058 g / 100 g, the protein content is 3.04-4.05 g / 100 g, and the fat content is 3.8-5.4 g / 100 g.

[0008] The coffee yogurt as described above has raw materials including a coffee liquid base material and a yogurt base material;

[0009] Among them, the content of chlorogenic acid in the coffee liquid base material is 0.08 - 0.29 g / 100 g; the content of protein in the yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g; the volume ratio of the coffee liquid base material to the yogurt base material is (10 - 20):(80 - 90).

[0010] The coffee yogurt as described above, wherein the coffee liquid base material is prepared by a method including the following process: adding a first fermentation strain to a raw material system including coffee beans and sugar solution for fermentation, and terminating the fermentation when the content of chlorogenic acid in the coffee beans reaches 5.5 - 8.5 g / 100 g, grinding the fermented coffee beans and then mixing them with water to obtain the coffee liquid base material;

[0011] Among them, the mass ratio of the fermented coffee beans to water is (1.5 - 3.5):(96.5 - 98.5).

[0012] The coffee yogurt as described above, wherein the first fermentation strain is three of Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Streptococcus thermophilus, Lactobacillus bulgaricus, Pediococcus acidilactici, and Lactobacillus acidophilus.

[0013] The coffee yogurt as described above, wherein the sugar solution is at least one of glucose, fructose, or sucrose aqueous solution.

[0014] The coffee yogurt as described above, wherein the yogurt base material is prepared by a method including the following process: filtering and concentrating the raw milk to obtain concentrated raw milk with a protein content of 3.8 - 4.5 g / 100 g and a fat content of 4.5 - 6.0 g / 100 g, and then adding a second fermentation strain to the raw material system including the concentrated raw milk for fermentation, and stopping the fermentation when the acidity reaches 72 - 80 °T to obtain the yogurt base material.

[0015] The coffee yogurt as described above, wherein the raw materials of the coffee yogurt further include jam.

[0016] The coffee yogurt as described above, wherein the addition amount of the jam is 5 - 10 g / 100 g.

[0017] The present invention also provides a preparation method of the coffee yogurt described in any one of the above, including the following steps:

[0018] Mixing the coffee liquid base material and the yogurt base material, and homogenizing to obtain the coffee yogurt;

[0019] Among them, the content of chlorogenic acid in the coffee liquid base material is 0.08 - 0.29 g / 100 g; the content of protein in the yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g; the volume ratio of the coffee liquid base material to the yogurt base material is (10 - 20):(80 - 90).

[0020] The preparation method as described above, wherein, it further includes mixing jam and the coffee yogurt.

[0021] The present invention provides a coffee yogurt, which has a moderate acidity, appropriate viscosity, good taste, and is suitable for direct drinking; it has a relatively high content of chlorogenic acid, enabling the product to have functions such as antiviral, antibacterial, antioxidant, and blood pressure lowering; it has a high protein content, is rich in nutrition, has good water retention during the shelf life, and good product stability; this coffee yogurt combines the advantages of coffee and yogurt, removes the sour, bitter, and astringent taste of coffee, retains the aroma of coffee, and at the same time has the rich milk fragrance and mellow taste of yogurt; it can not only meet the emotional value of consumers, but also ensure the nutritional value of the product, and is expected to fill the market gap. Specific embodiments

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] The first aspect of the present invention provides a coffee yogurt, the acidity of which is 72 - 95 °T, the viscosity is 100 - 400 mPa·s, the water retention rate is 28 - 43%, the content of chlorogenic acid is 0.011 - 0.058 g / 100 g, the content of protein is 3.04 - 4.05 g / 100 g, and the fat content is 3.8 - 5.4 g / 100 g.

[0024] Chlorogenic acid is an important non-volatile substance in coffee beans and is one of the important factors affecting the quality and flavor of coffee. Chlorogenic acid has functions such as antiviral, antibacterial, antioxidant, and blood pressure lowering, can prevent diseases such as cardiovascular diseases, type 2 diabetes, and Alzheimer's disease, and products rich in chlorogenic acid also have the above effects beneficial to human health; generally, the content of chlorogenic acid in green coffee beans is very high, about between 6.7% and 12%, while most of the chlorogenic acid in roasted coffee beans will dissolve or decompose from the coffee beans, and at this time the chlorogenic acid content is reduced to 2.7% - 3.1% of the coffee bean quality; chlorogenic acid itself has no bitterness, but it will decompose into "chlorogenic acid lactone" and "phenyl lindane" when heated during the roasting process, and these two are generally considered to be the main sources of the bitter taste of coffee, ultimately resulting in the roasted coffee having a strong bitter taste and presenting an uncomfortable sour-bitter taste. And within the shelf life, the chlorogenic acid content in the coffee beans of the present invention is 5.5 - 8.5 g / 100 g, and its content is relatively high, which means that less chlorogenic acid dissolves or decomposes, that is, less "chlorogenic acid lactone" and "phenyl lindane" are generated, and ultimately makes the coffee yogurt not only contain a relatively high content of chlorogenic acid, retain the aroma and health value of coffee, but also remove the strong sour-bitter taste of traditional roasted coffee.

[0025] Acidity is an important indicator reflecting the quality of coffee yogurt, mainly brought by chlorogenic acid, citric acid, malic acid, quinic acid, acetic acid, tartaric acid in coffee and lactic acid in yogurt. Within the shelf life, the acidity of the coffee yogurt of the present invention is 72 - 95 °T, and the acidity is moderate. On the basis of removing the bad sour-bitter taste of traditional roasted coffee, the above coffee yogurt presents a pleasant sour taste.

[0026] Viscosity is also an important indicator reflecting the quality of coffee yogurt. It is a reflection of the changes in milk components during fermentation, storage and transportation. Appropriate viscosity can prevent the product from showing the phenomenon of water separation and stratification, and make the product have a good tissue state and appearance. Within the shelf life, the viscosity of the coffee yogurt of the present invention is 100 - 400 mPa·s, and the water holding rate is 28 - 43%. This coffee yogurt is in a liquid state with good fluidity, suitable for direct drinking, has a high water holding rate within the shelf life, and good stability, avoiding the problem of water separation and stratification.

[0027] The protein content of the above coffee yogurt within the shelf life is 3.04 - 4.05 g / 100 g, and the protein content is relatively high, being rich in nutrition.

[0028] Fat is the main source of the milk aroma and mellow taste of coffee yogurt. The fat content of the above coffee yogurt within the shelf life is 3.8 - 5.4 g / 100 g, making this coffee yogurt have a rich milk aroma and a mellow taste.

[0029] In summary, the coffee yogurt of the present invention combines the advantages of coffee and yogurt, removes the unpleasant sour, bitter and astringent taste of coffee while retaining the aroma of coffee, has a rich milk flavor and mellow taste of yogurt; has a moderate acidity, presenting a pleasant sour taste; has a moderate viscosity and is in a liquid state with good fluidity, suitable for direct drinking, has good water retention and stability within the shelf life; has a high protein content and is rich in nutrition; has a relatively high chlorogenic acid content, making this coffee yogurt have functions such as antiviral, antibacterial, antioxidant, blood pressure lowering, etc., and can prevent diseases such as cardiovascular diseases, type 2 diabetes, and Alzheimer's disease, which is beneficial to human health.

[0030] In some embodiments, the raw materials of the above-mentioned coffee yogurt include a coffee liquid base material and a yogurt base material;

[0031] Among them, the content of chlorogenic acid in the coffee liquid base material is 0.08 - 0.29 g / 100 g; the protein content in the yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g; the volume ratio of the above-mentioned coffee liquid base material to the yogurt base material is (10 - 20):(80 - 90).

[0032] Because the coffee flavor is relatively domineering and easily overwhelms other flavors, and when the content of chlorogenic acid in the above-mentioned coffee liquid base material is 0.08 - 0.29 g / 100 g, at this time, the unpleasant sour, bitter and astringent taste of the coffee liquid base material is weaker, and the coffee flavor is improved; the coffee aroma is rich; the chlorogenic acid content is relatively high, and the health value is relatively high. The protein content in the above-mentioned yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g. This yogurt base material is rich in nutrition, has a strong milk flavor and a mellow taste. After mixing the above two according to the volume ratio of (10 - 20):(80 - 90), the prepared coffee yogurt combines the advantages of coffee and yogurt, not only removes the strong sour, bitter and astringent taste of coffee while retaining the aroma of coffee, but also has a rich milk flavor and a mellow taste of yogurt. The coffee flavor and the yogurt flavor complement each other and match appropriately; this coffee yogurt also has characteristics such as regulating the balance of intestinal flora, high protein, simple formula, high nutritional value, appropriate sour-sweet ratio, and being easily accepted by the public.

[0033] In some embodiments, the above-mentioned coffee liquid base material is prepared by a method including the following process: adding a first fermentation strain to a raw material system including coffee beans and sugar solution for fermentation, and terminating the fermentation when the content of chlorogenic acid in the coffee beans reaches 5.5 - 8.5 g / 100 g, grinding the fermented coffee beans and then mixing them with water to obtain the coffee liquid base material;

[0034] Among them, the mass ratio of the fermented coffee beans to water is (1.5 - 3.5):(96.5 - 98.5).

[0035] It is understandable that, in order to improve the quality of coffee yogurt, high-quality coffee beans are preferably selected for preparing the above-mentioned coffee liquid base material.

[0036] The above raw material system including coffee beans and sugar solution is obtained by adding coffee beans to the sugar solution so that the sugar solution submerges the coffee beans.

[0037] Since chlorogenic acid is easily soluble in water, during the process of processing coffee beans with water, chlorogenic acid is easily dissolved out from the coffee beans, reducing the content of chlorogenic acid in the coffee beans. The fermentation effect of the above-mentioned first fermentation strain on coffee beans can avoid or minimize the dissolution of chlorogenic acid from coffee beans, so that the fermented coffee beans contain a higher content of chlorogenic acid, and thus the final product coffee yogurt also has a higher pharmacological and health value. At the same time, the above fermentation effect can also increase the types and content of organic acids in coffee beans, which helps to inhibit the degradation of chlorogenic acid during the preparation of coffee yogurt, thereby avoiding or minimizing the generation of unpleasant taste sensations such as sourness, bitterness, and astringency in coffee. In addition, the above fermentation effect can also reduce the caffeine content in coffee beans, and thus the caffeine content in coffee yogurt is also reduced accordingly, which is beneficial to reducing the potential health risks brought by caffeine.

[0038] During the fermentation process, when the chlorogenic acid content in the coffee beans reaches 5.5 - 8.5 g / 100 g, the fermentation can be terminated to obtain the fermented coffee beans. At this time, the content of chlorogenic acid and other organic acids in the fermented coffee beans is relatively high, and the degradation process of chlorogenic acid is effectively inhibited, ultimately avoiding or minimizing the bitterness of the fermented coffee beans. In addition, the caffeine content in the fermented coffee beans is less, which is beneficial to human health.

[0039] After the fermentation is completed, the obtained fermented coffee beans are washed clean, dried and ground to obtain fermented coffee powder. Then, the fermented coffee powder is mixed with water at a mass ratio of (1.5 - 3.5):(96.5 - 98.5) to obtain the above-mentioned coffee liquid base material with a chlorogenic acid content of 0.08 - 0.29 g / 100 g.

[0040] Preferably, the above coffee powder and water are mixed at a mass ratio of 2:98, which is beneficial to achieving a better degree of aroma and flavor of the coffee liquid base material.

[0041] Furthermore, when the temperature of the above water is 65 - 70 °C, the aroma of coffee can be better stimulated, making the coffee flavor of the coffee liquid base material more prominent, which is beneficial to further optimizing the coffee flavor of the final product coffee yogurt.

[0042] It is understandable that, in order to enable the above-mentioned fermented coffee powder and water to be fully mixed evenly and make the aroma and flavor of coffee more fully emitted, the mixing time can be set to 20 min.

[0043] In order to improve the smooth taste and stability of the above coffee liquid base, the above coffee liquid base can be subjected to air pressure homogenization and sterilization treatment.

[0044] The coffee liquid base obtained after the above sterilization treatment is cooled and then directly used for preparing coffee yogurt or refrigerated for standby.

[0045] The present invention does not particularly limit the conditions of the above air pressure homogenization; the conditions of the above sterilization treatment can be sterilization at 95±2°C for 300 s; the temperature of the above cooling treatment can be 4-6°C.

[0046] In some embodiments, the above first fermentation strains include three of Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Streptococcus thermophilus, Lactobacillus bulgaricus, Pediococcus acidilactici, and Lactobacillus acidophilus, which can effectively reduce the dissolution of chlorogenic acid in coffee beans and inhibit the degradation of chlorogenic acid, so that the content of chlorogenic acid in coffee beans after fermentation remains at a relatively high level.

[0047] The inoculation amount of the above first fermentation strains is generally 0.06%-0.15% of the mass of coffee beans, and at this time, the fermentation effect of coffee beans is better.

[0048] The present invention does not limit the mass ratio and viable count of various bacteria in the above first fermentation strains, and the parameters commonly used in the art can be adopted.

[0049] In order to further improve the viability of the above first fermentation strains and thus improve the fermentation effect of coffee beans, the above fermentation can be carried out at a constant temperature of 37-42°C for 48-72 h, and the chlorogenic acid content can generally reach the above range of 5.5-8.5 g / 100 g; in addition, in order to make the coffee beans ferment fully and further optimize the fermentation effect of coffee beans, stirring can be carried out once every 12 h after 24 h of the start of fermentation.

[0050] The above sugar solution is at least one of glucose, fructose or sucrose aqueous solution. Glucose, fructose or sucrose can all be utilized by the above first fermentation strains to provide carbon source and energy for the first fermentation strains.

[0051] It can be understood that the mass percentage of sugar in the above sugar solution can be 0.05%-0.1%, and at this time, the sugar solution is suitable for the survival of the first fermentation strains and is beneficial to improving the fermentation viability of the first fermentation strains.

[0052] In some embodiments, the above yogurt base is prepared by a method including the following process: the raw milk is filtered and concentrated to obtain concentrated raw milk with a protein content of 3.8-4.5 g / 100 g and a fat content of 4.5-6.0 g / 100 g, and then a second fermentation strain is added to the raw material system including the concentrated raw milk for fermentation, and the fermentation is stopped after the acidity reaches 72-80°T to obtain the above yogurt base.

[0053] The above raw milk includes at least one of raw cow milk, raw goat milk, pure milk, pure goat milk, and reconstituted milk.

[0054] The above filtration and concentration refer to using an RO membrane (i.e., a reverse osmosis membrane) to perform reverse osmosis on the raw milk, removing part of the water and mineral ions to increase the protein and fat content in the raw milk, thereby enhancing the milk flavor of the yogurt base material.

[0055] The present invention does not particularly limit the type of the above second fermentation strain, and common strains used in yogurt fermentation in the art can be used. For example, the above second fermentation strain includes Streptococcus thermophilus and Lactobacillus bulgaricus, and further may include at least one of Lactobacillus plantarum and Bifidobacterium lactis.

[0056] The present invention does not particularly limit the addition amount of the above second fermentation strain, and the commonly used addition amount in the art can be adopted.

[0057] The present invention does not particularly limit the temperature and time of the above fermentation. For example, fermentation can be carried out at 42 °C for 4 - 7 h.

[0058] The end point of fermentation is based on the acidity reaching 72 - 80 °T. At this time, fermentation is terminated, and the above yogurt base material can be obtained.

[0059] This yogurt base material has a high protein and fat content, is rich in nutrition, has a strong milk flavor, and a mellow taste.

[0060] The above raw material system including concentrated raw milk may further include at least one of granulated sugar, galactooligosaccharide, fructooligosaccharide, and stabilizer, which helps to increase the sweetness, nutrition, and stability of the product. It can be understood that in order to make the above components and the concentrated raw milk mix evenly, after adding the above components, the mixed system can be circulated at 65 °C - 70 °C for 20 min.

[0061] To improve the fermentation effect and make the texture of the prepared yogurt base material more uniform and the taste more delicate and smooth, before adding the second fermentation strain, the above raw material system including concentrated raw milk can be subjected to homogenization, degassing, and sterilization treatments. The present invention does not particularly limit the conditions of the above homogenization, degassing, and sterilization treatments, and conventional conditions in the art can be used.

[0062] It can be understood that in order to prevent the second fermentation strain in the above yogurt base material from continuing to ferment excessively after the fermentation is terminated, resulting in too high acidity of the yogurt base material and thus affecting the taste of the product, after the above fermentation is terminated, the obtained yogurt base material should be quickly cooled to reduce the activity of the second fermentation strain in the yogurt base material, thereby avoiding its excessive fermentation.

[0063] To make the texture of the prepared coffee yogurt more delicate and the taste more smooth, the above obtained yogurt base material can be subjected to stirring demulsification and air pressure homogenization treatments.

[0064] The present invention does not particularly limit the equipment for stirring and demulsifying and air pressure homogenization. For example, a conventional air pressure homogenizer can be used.

[0065] The raw materials of the above-mentioned coffee yogurt further include jam, which can improve the taste of the product and provide more flavor choices.

[0066] The above-mentioned jam includes at least one of caramel jam, dark chocolate jam, and coconut milk jam.

[0067] Furthermore, when the addition amount of jam in the raw materials of the above-mentioned coffee yogurt is 5 - 10 g / 100 g, the coffee flavor, yogurt flavor, and jam flavor in the product can be properly matched, achieving a better matching effect, and further optimizing the flavor and taste of the product.

[0068] The second aspect of the present invention provides a preparation method for the coffee yogurt of the first aspect, including the following steps:

[0069] Mix the coffee liquid base material and the yogurt base material, and obtain the above-mentioned coffee yogurt after homogenization;

[0070] Among them, the content of chlorogenic acid in the above-mentioned coffee liquid base material is 0.08 - 0.29 g / 100 g; the content of protein in the above-mentioned yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g; the volume ratio of the above-mentioned coffee liquid base material to the yogurt base material is (10 - 20):(80 - 90).

[0071] The content of chlorogenic acid in the above-mentioned coffee liquid base material is 0.08 - 0.29 g / 100 g. At this time, the coffee liquid base material has a weak bitter taste, a strong coffee aroma, a high content of chlorogenic acid, and a high health value; the content of protein in the above-mentioned yogurt base material is 3.8 - 4.5 g / 100 g, and the fat content is 4.5 - 6.0 g / 100 g. This yogurt base material is rich in nutrition, has a strong milk aroma, and a mellow taste.

[0072] Mix the above-mentioned coffee liquid base material and yogurt base material according to a volume ratio of (10 - 20):(80 - 90), and obtain the above-mentioned coffee yogurt after homogenization. This coffee yogurt combines the advantages of coffee and yogurt. While removing the bitter taste of coffee, it retains the coffee aroma, has a strong milk aroma and coffee flavor, a mellow taste, a moderate acidity, a moderate viscosity, good fluidity, is convenient to drink, has good water retention and stability within the shelf life, and has a high content of protein, fat, and chlorogenic acid, is rich in nutrition, and is beneficial to human health.

[0073] The pressure of the above-mentioned homogenization can be 180 bar / 30 bar.

[0074] It is understandable that after obtaining the above-mentioned coffee yogurt, filling and after-ripening treatment are required. The after-ripening treatment can be carried out according to the conventional conditions in the art. For example, the product is cooled to 2-6°C and refrigerated for 24h.

[0075] When the principle of the above-mentioned coffee yogurt includes jam, the above-mentioned preparation method further includes mixing the jam and the above-mentioned coffee yogurt.

[0076] Specifically, the above mixing is carried out in the filling process by an on-line jam addition process device to mix the jam and the above-mentioned coffee yogurt.

[0077] Hereinafter, the coffee yogurt of the present invention and its preparation method will be introduced in more detail through specific examples.

[0078] Example 1

[0079] The coffee yogurt of this example is prepared according to the following preparation method:

[0080] 1) Mix coffee beans and 0.1% glucose solution so that the above 0.1% glucose solution submerges the coffee beans to obtain a first raw material system; add Lactobacillus plantarum, Streptococcus thermophilus, and Lactobacillus acidophilus to the above first raw material system. The viable counts of Lactobacillus plantarum, Streptococcus thermophilus, and Lactobacillus acidophilus are 10 7 cfu / g, 10 5 cfu / g, 10 5 cfu / g. Among them, the total inoculation amount of Lactobacillus plantarum, Streptococcus thermophilus, and Lactobacillus acidophilus is 0.15% of the mass of the coffee beans. Fermentation is carried out at 42°C. After 24h of fermentation, stirring is carried out every 12h. When the content of chlorogenic acid in the coffee beans reaches 5.5g / 100g, fermentation is terminated. At this time, the fermentation time is 48h, and the fermented coffee beans are obtained; the fermented coffee beans are washed clean, dried and ground, and then mixed with pure water at 70°C for 20min. The mass ratio of the fermented coffee beans to water is 2:98 to obtain a first liquid material; the above first liquid material is subjected to air pressure homogenization treatment and sterilization treatment at 95°C for 300s in sequence, and then cooled to 6°C to obtain a coffee liquid base material;

[0081] 2) The raw milk is filtered and concentrated by RO membrane to obtain concentrated raw milk with a protein content of 3.8 g / 100 g and a fat content of 4.5 g / 100 g; the above-mentioned concentrated raw milk, granulated sugar, galactooligosaccharide, and sodium carboxymethylcellulose are circulated at 65 °C - 70 °C for 20 min. Among them, the mass ratio of concentrated raw milk, granulated sugar, galactooligosaccharide, and sodium carboxymethylcellulose is 926.5:70:3:0.5. After homogenization, degassing, and sterilization treatments in sequence, a second raw material system is obtained; Streptococcus thermophilus, Lactobacillus bulgaricus, and Bifidobacterium lactis are added to the second raw material system. The viable counts of Streptococcus thermophilus, Lactobacillus bulgaricus, and Bifidobacterium lactis are 10 7 cfu / g, 10 5 cfu / g, 10 5 cfu / g. Among them, the total inoculation amount of Streptococcus thermophilus, Lactobacillus bulgaricus, and Bifidobacterium lactis is 0.5 g / 100 g, and fermentation is carried out at 42 °C. When the acidity reaches 72 - 80 °T, fermentation is stopped and rapidly cooled, and stirring for demulsification and air pressure homogenization are carried out in sequence to obtain a yogurt base material.

[0082] 3) The above-mentioned coffee liquid base material and yogurt base material are mixed according to a volume ratio of 10%:90%, and homogenized at 180 bar / 30 bar to obtain a second material; 5% caramel jam is added to the second material and then filled. The filled product is cooled to 2 - 6 °C and refrigerated for 24 h to obtain coffee yogurt;

[0083] Example 2

[0084] This example is basically the same as Example 1, except that:

[0085] 1) In step 1), glucose is replaced by sucrose; Lactobacillus casei, Leuconostoc mesenteroides, and Pediococcus acidilactici are used to replace Lactobacillus plantarum, Streptococcus thermophilus, and Lactobacillus acidophilus. Among them, the viable counts of Lactobacillus casei, Leuconostoc mesenteroides, and Pediococcus acidilactici are 10 7 cfu / g, 10 5 cfu / g, 10 5 cfu / g; the inoculation amount is modified to 0.06%; the fermentation temperature is modified to 37 °C; the temperature of pure water is modified to 65 - 70 °C; the cooling temperature after sterilization is modified to 4 - 6 °C;

[0086] 2) In step 2), the protein content of the concentrated raw milk is modified to 4%;

[0087] 3) In step 3), the volume ratio of the coffee liquid base material and the yogurt base material is modified to 20%:80%; caramel jam is replaced by dark chocolate jam.

[0088] Example 3

[0089] This example is basically the same as Example 1, with the differences being:

[0090] 1) In step 1), glucose is replaced with sucrose; Streptococcus thermophilus is replaced with Pediococcus acidilactici; the fermentation temperature is modified to 37 °C; the temperature of pure water is modified to 65 - 70 °C; the cooling temperature after sterilization is modified to 4 - 6 °C;

[0091] 2) In step 3), the volume ratio of the coffee liquid base material to the yogurt base material is modified to 20% : 80%; caramel jam is replaced with coconut milk jam.

[0092] Example 4

[0093] This example is basically the same as Example 3, with the differences being:

[0094] In step 2), Lactobacillus plantarum is replaced with Bifidobacterium lactis, and the viable count is 10 6 cfu / g.

[0095] Example 5

[0096] This example is basically the same as Example 1, with the differences being:

[0097] In step 1, when the chlorogenic acid content reaches 6.5 g / 100 g, the fermentation is terminated.

[0098] Example 6

[0099] This example is basically the same as Example 1, with the differences being:

[0100] In step 1, when the chlorogenic acid content reaches 7.0 g / 100 g, the fermentation is terminated.

[0101] Example 7

[0102] This example is basically the same as Example 1, with the differences being:

[0103] In step 2, the protein content of the concentrated raw milk is modified to 4.5 g / 100 g;

[0104] Comparative Example 1

[0105] This comparative example is basically the same as Example 1, with the differences being:

[0106] 1) In step 1), the concentration of glucose is modified to 0.05%; Lactobacillus bulgaricus and Pediococcus acidilactici are used to replace Lactobacillus plantarum and Lactobacillus acidophilus, and the viable counts of Lactobacillus bulgaricus and Pediococcus acidilactici are 10 7 cfu / g and 10 5 cfu / g respectively; the inoculation amount is modified to 0.2%; the temperature of pure water is modified to 65 - 70 °C; the sterilization temperature is modified to 95 ± 2 °C; the cooling temperature after sterilization is modified to 4 - 6 °C;

[0107] 2) In step 2), the protein content of the concentrated raw milk is modified to 3.0%, and the fat content is modified to 4.0%; Lactobacillus plantarum is used to replace Bifidobacterium lactis, and the viable count is 10 8 cfu / g;

[0108] 3) In step 2), no air pressure homogenization treatment is carried out.

[0109] Comparative Example 2

[0110] This comparative example is basically the same as Example 2, the differences are as follows:

[0111] 1) Fermentation is stopped after the acidity in step 2) reaches 85°T;

[0112] 2) In step 3), the volume ratio of the coffee liquid base material to the yogurt base material is modified to 30%:70%; no homogenization treatment is carried out.

[0113] Comparative Example 3

[0114] This comparative example is basically the same as Example 3, the differences are as follows:

[0115] In step 1), glucose is used to replace sucrose; the viable counts of Bacillus subtilis, Aspergillus niger, and Lactobacillus acidophilus are 10 5 cfu / g, 10 5 cfu / g, 10 5 cfu / g respectively, which replace Lactobacillus plantarum, Pediococcus acidilactici, and Lactobacillus acidophilus; the inoculation amount is modified to 0.06%; the fermentation temperature is modified to 37°C.

[0116] Comparative Example 4

[0117] This comparative example is basically the same as Example 1, the differences are as follows:

[0118] Fermentation is terminated when the chlorogenic acid content in step 1) is 4.0.

[0119] Comparative Example 5

[0120] This comparative example is basically the same as Example 1, the differences are as follows:

[0121] The volume ratio of the coffee liquid base material to the yogurt base material is modified to 30%:70%.

[0122] Comparative Example 6

[0123] This comparative example is basically the same as Example 1, the differences are as follows:

[0124] The volume ratio of the coffee liquid base material to the yogurt base material is modified to 5%:95%.

[0125] Test Example

[0126] 1. Detect the following parameters of the products in the above examples and comparative examples:

[0127] 1) Chlorogenic acid content: Detect the chlorogenic acid content in the products and the corresponding coffee liquid bases using high performance liquid chromatography. The specific results are shown in Table 1.

[0128] 2) Protein content: Detect the protein content of the products according to the method of GB 5009.5. The specific results are shown in Table 1.

[0129] 3) Fat content: Detect the fat content of the products according to the method of GB 5009.6. The specific results are shown in Table 1.

[0130] 4) Acidity: Detect the acidity of the products within the shelf life according to the method of GB 5009.239. The specific results are shown in Table 2.

[0131] 5) Viscosity: Use a rheometer with the model Anton Paar MCR302 and a rotor model CC27 - 53603 to detect the viscosity of the products within the shelf life. After measuring 60 points, take the average value. The specific results are shown in Table 3.

[0132] 6) Product stability:

[0133] A. Stability sensory evaluation: Select 30 people for stability sensory evaluation, and score the stability of the products within the shelf life with the degree of water separation and layering as indicators. The full score is 100 points for both, and the total score is the average value. Among them, a sensory evaluation score of 65 or above is qualified. The specific results are shown in Table 4.

[0134] B. Water holding rate: Take a product with a mass of m to be measured, centrifuge it at 4000g for 15 minutes, and measure the mass m after removing the water 1 , and its water holding rate (%) = m 1 / m × 100%. The specific results are shown in Table 4.

[0135] 7) Flavor sensory evaluation: Select 30 people to conduct flavor sensory evaluation on the products, and score them with milk fragrance, bitterness, smoothness, sour - sweet ratio, and overall preference as indicators. The full score is 100 points for all, and the total score is the average value. The specific results are shown in Table 5.

[0136] 2. Test results

[0137] Table 1 Chlorogenic acid, protein and fat contents

[0138]

[0139] Table 1 results show that the content of chlorogenic acid in the coffee liquid base is related to the fermentation degree of coffee beans, the content of chlorogenic acid in the fermented coffee beans, and the ratio of coffee liquid base to water; the content of chlorogenic acid in the product is affected by the ratio of coffee liquid base to yogurt base and the content of their respective components; the concentration of the raw milk base affects the protein and fat content of the yogurt base, and thus affects the protein and fat content in the product. In addition, compared with Example 1, the carbon source content and the type of strain during the fermentation of coffee beans may affect the content of chlorogenic acid in Comparative Example 1 and Comparative Example 3.

[0140] Table 2 Acidity (°T)

[0141]

[0142]

[0143] Table 2 acidity results show that the coffee liquid base and the yogurt base act synergistically to make the acidity of each example product meet the requirements during the shelf life; generally, the larger the proportion of the yogurt base content, the more serious the post-acidification of the product during storage; the type of starter culture for the coffee base and the yogurt base also affects the acidity stability of the product during storage. In short, the acidity of the product of the present invention is affected by many factors. Only when all aspects of factors are maintained at a reasonable level and through synergistic action can the acidity of the product be appropriate and the situation of excessive post-acidification be avoided.

[0144] Table 3 Viscosity (mPa·s)

[0145]

[0146]

[0147] Table 3 viscosity results show that when the addition amount of the yogurt base is 80%-90%, the viscosity of the product is relatively refreshing and the change in the viscosity of the product during storage is small; the higher the addition amount of the yogurt base, the more viscosity is produced during storage; the type of starter culture also affects the change in the viscosity of the product during storage; in short, the viscosity of the product is related to the components of the coffee liquid base, the components of the yogurt base, as well as their ratio and preparation process, etc., and is the result of the synergistic action of various factors.

[0148] Table 4 Product stability results

[0149]

[0150]

[0151] Table 4 shows the product stability results: products with a higher proportion of yogurt base have a higher water holding rate, and products with higher raw milk indicators have a higher water holding rate. In short, the stability of the product is related to the coffee liquid base composition, yogurt base composition, the ratio between the two, and the preparation process, etc., and is the result of the synergistic effect of various factors.

[0152] Table 5 Flavor Sensory Evaluation (score)

[0153]

[0154] Table 5 Flavor Sensory Evaluation shows that: according to the product sensory evaluation scores combined with various indicators, it is determined that the fermentation is terminated when the chlorogenic acid content in the fermented coffee beans reaches 5.5 - 8.5 g / 100 g; the raw milk is concentrated to a protein content of 3.8 - 4.5 g / 100 g and a fat content of 4.5 - 6.0%, and the fermentation is terminated at 72 - 80 °T; the ratio of coffee base to yogurt base is (10 - 20):(80 - 90), and at this time, all indicators of the product are moderate and the product flavor is excellent.

[0155] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coffee yogurt, characterized in that: Its acidity is 72-95°T, viscosity is 100-400mPa·s, water holding capacity is 28-43%, chlorogenic acid content is 0.011-0.058g / 100g, protein content is 3.04-4.05g / 100g, and fat content is 3.8-5.4g / 100g.

2. The coffee yogurt according to claim 1, characterized in that Its raw materials include coffee liquid base and yogurt base; Among them, the content of chlorogenic acid in the coffee liquid base is 0.08-0.29g / 100g; the content of protein in the yogurt base is 3.8-4.5g / 100g, and the fat content is 4.5-6.0g / 100g; the volume ratio of the coffee liquid base to the yogurt base is (10-20): (80-90).

3. The coffee yogurt according to claim 2, characterized in that: The coffee liquid base is prepared according to a method comprising the following process: adding a first fermentation strain to a raw material system comprising coffee beans and sugar solution for fermentation, terminating the fermentation when the content of chlorogenic acid in the coffee beans reaches 5.5-8.5 g / 100 g, grinding the fermented coffee beans and mixing with water to obtain the coffee liquid base; Wherein, the mass ratio of the fermented coffee beans to water is (1.5-3.5): (96.5-98.5).

4. The coffee yogurt according to claim 3, characterized in that: The first fermentation bacteria are three of Lactobacillus plantarum, Lactobacillus casei, Leuconostoc mesenteroides, Streptococcus thermophilus, Lactobacillus bulgaricus, Pediococcus acidilactici and Lactobacillus acidophilus.

5. The coffee yogurt according to claim 3 or 4, characterized in that: The sugar solution is at least one of glucose, fructose or sucrose aqueous solution.

6. The coffee yogurt according to any one of claims 2 to 5, characterized in that: The yogurt base is prepared according to a method comprising the following processes: filtering and concentrating raw milk to obtain concentrated raw milk with a protein content of 3.8-4.5 g / 100 g and a fat content of 4.5-6.0 g / 100 g, then adding a second fermentation strain to the raw material system including the concentrated raw milk for fermentation, and stopping the fermentation after the acidity reaches 72-80°T to obtain the yogurt base.

7. The coffee yogurt according to any one of claims 1 to 6, characterized in that: The raw materials of the coffee yogurt also include jam.

8. The coffee yogurt according to claim 7, characterized in that: The added amount of the jam is 5-10g / 100g.

9. A method for preparing coffee yogurt according to any one of claims 1 to 8, characterized in that: The following steps are involved: The coffee liquid base and the yogurt base are mixed and homogenized to obtain the coffee yogurt; Among them, the content of chlorogenic acid in the coffee liquid base is 0.08-0.29g / 100g; the content of protein in the yogurt base is 3.8-4.5g / 100g, and the fat content is 4.5-6.0g / 100g; the volume ratio of the coffee liquid base to the yogurt base is (10-20): (80-90).

10. The preparation method according to claim 9, characterized in that: The method also includes mixing the jam and the coffee yogurt.

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