Fruit peel-containing fermented milk and preparation method thereof

Abstract

The invention provides fruit peel-containing fermented milk and a preparation method thereof, and the fermented milk meets the following conditions: after the fermented milk is canned, the fermented milk sequentially comprises a first part, a second part and a third part in the height direction, and the mass percentage content difference of the fruit peel in each part in the fermented milk is less than or equal to 10%; wherein the ratio of the height of each part to the total height is 20%-40%. Compared with the prior art, the fermented milk product provided by the invention always keeps uniform fruit peel particle distribution in the shelf life, so that a consumer can directly drink the fermented milk product, and can continuously experience a unique chewing taste in the drinking process, thereby bringing true, real and pleasant feelings to the consumer.

Description

Technical Field

[0001] The invention relates to a dairy drink, in particular to a fermented milk containing peel and a preparation method thereof, belonging to the field of food. Background Art

[0002] Fermented milk (yogurt) is an acidic curd-like product made by fermenting milk or dairy products under the action of characteristic bacteria. Fermented milk is deeply loved by consumers because of its effects of promoting intestinal digestion, preventing constipation and good characteristic flavor.

[0003] Fruit peels account for a large proportion of most fruits and are rich in nutrients. For example, citrus peel, orange peel, pineapple peel, and grapefruit peel are rich in dietary fiber; orange peel, tangerine peel, grapefruit peel, lychee peel, banana peel, apple peel, plum peel, loquat peel, and mango peel contain strong antioxidants. However, fruit peels have not been taken seriously during fruit processing and fresh consumption, and are usually discarded directly.

[0004] If the peel is combined with fermented milk, it can not only avoid the waste of the peel, but also give the fermented milk a unique chewing taste and certain health benefits. However, if the peel is simply mixed with fermented milk, the peel particles are difficult to distribute evenly and will precipitate in a short time, which will bring a bad drinking experience to consumers. Summary of the invention

[0005] The invention provides a fermented milk containing peels, which has the advantages of uniform distribution of peel particles, high product stability and the like.

[0006] The present invention also provides a method for preparing fermented milk containing peels, which can prepare the fermented milk containing peels, and the process is simple and easy to control.

[0007] On the one hand, the present invention provides a fermented milk containing peels, which satisfies the following conditions: when the fermented milk is canned, the fermented milk includes a first part, a second part and a third part in sequence in the height direction, and the difference in the mass percentage of the peels in each part in the total peels in the fermented milk is ≤10%; wherein the ratio of the height of each part to the total height is 20%-40%.

[0008] Furthermore, the number of viable bacteria in the fermented milk is ≥10 8 CFU / g.

[0009] Furthermore, the peel is the peel of citrus fruit.

[0010] Furthermore, the fermented milk is prepared by a method comprising at least the following processes:

[0011] The peel-containing jam with a viscosity of 6 cm to 10 cm and the yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s are mixed to obtain the fermented milk containing the peel, wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

[0012] On the other hand, the present invention provides a method for preparing the above-mentioned fermented milk containing peel, comprising the following steps: mixing a peel-containing jam with a viscosity of 6 cm to 10 cm and a yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s to obtain the fermented milk containing peel, wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

[0013] Furthermore, the raw materials of the fermented milk include, in terms of mass percentage, 85wt% to 92wt% of yogurt base and 8wt% to 15wt% of fruit peel jam.

[0014] Furthermore, the pH of the peel-containing jam is 3-4.

[0015] Furthermore, the raw material system including raw milk, sweetener and protein powder is degassed, homogenized and sterilized, and a starter is added to ferment to the target acidity to obtain the yogurt base with a viscosity of 1500mPa·s to 2500mPa·s.

[0016] Furthermore, the peel is mixed with the sugar solution and boiled to obtain the peel-containing jam with a viscosity of 6 cm to 10 cm.

[0017] Furthermore, before boiling, the peel is frozen at -15 to -20°C for 20 to 30 hours.

[0018] The fermented milk product provided by the present invention always keeps the peel particles evenly distributed during the shelf life, so consumers can drink it directly and can continuously experience the unique chewing taste during the drinking process, thereby giving consumers a sense of authenticity and pleasure. DETAILED DESCRIPTION

[0019] In order to make the purpose, 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 combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Combining the peel with fermented milk has many advantages, but the peel particles have a high specific gravity and are difficult to distribute evenly in the fermented milk. During the shelf life, the particles will further settle, making it inconvenient to drink and giving consumers a bad experience. In view of this, the present invention adopts the following technical solutions:

[0021] In a first aspect, the present invention provides a fermented milk containing peels, which satisfies the following conditions: when the fermented milk is canned, the fermented milk includes a first part, a second part and a third part in sequence in the height direction, and the difference in the mass percentage of the peels in each part to the total peels in the fermented milk is ≤10%; wherein the ratio of the height of each part to the total height is 20% to 40%.

[0022] It should be noted that the fermented milk of the present invention can meet the above conditions as long as it is within the shelf life. As for the state of the fermented milk, the present invention does not make any specific limitation. For example, it can be in transportation after filling, on the shelf, etc.

[0023] The present invention provides fermented milk in which peel particles are evenly distributed, and the distribution of peel particles does not change much in the early shelf life (≤7 days) and the late shelf life (8-21 days), and the above conditions are always met. Therefore, consumers can drink it at any time and can continue to experience the unique chewing taste during the drinking process, thereby giving consumers a sense of authenticity and pleasure.

[0024] In order to illustrate the calculation method of "the difference in the mass percentage of the peel in each part in the fermented milk" of the present invention, the difference N in the mass percentage of the peel in the first part and the second part in the fermented milk is taken as an example: N = (mass of peel in the first part / mass of total peel in the fermented milk-mass of peel in the second part / mass of total peel in the fermented milk) · 100%, wherein N ≤ 10%; the calculation of the difference in the mass percentage of the peel in the fermented milk between any other two parts is similar.

[0025] The present invention does not specifically limit the canning standard of fermented milk, which is generally the canning size commonly seen in the beverage shelf area of ​​a supermarket. For example, the total height may be 30 cm, 20 cm, 15 cm, 10 cm, etc.

[0026] In some embodiments, the peel is a citrus fruit peel.

[0027] Citrus fruit peel is the peel of citrus fruit, which is generally composed of three parts. The exocarp or oil cell layer is the outermost tissue layer of the fruit, containing epidermis and thin-walled cells; the mesocarp, also called the spongy layer or white skin layer, constitutes the main part of the thickness of the peel; the endocarp is part of the chamber membrane and is located on the inner side of the carpel. Citrus fruit peel is rich in nutrients such as dietary fiber, vitamins, hesperidin, various minerals and carotene, which meets the current demand for healthy diets and can be combined with fermented milk; and the present invention has also found through research that citrus fruit peel not only has a better chewing taste than other fruit peels, but also due to the unique structure of citrus fruit peel, it is easier to be evenly and stably distributed in fermented milk.

[0028] In the present invention, the citrus fruit peel includes but is not limited to: one or a combination of tangerine peel, orange peel, grapefruit peel, lemon peel, etc.

[0029] In some embodiments, the viable count of the fermented milk is ≥10 8 CFU / g. Among them, the number of viable bacteria is one of the important indicators for evaluating the quality of fermented milk drinks. During the shelf life, the number of viable bacteria of a high-quality drink should be at a high level and can remain stable. The number of viable bacteria of the drink of the present invention can be maintained at not less than 10 during the shelf life. 8 CFU / ml, high viable count and good stability.

[0030] In some embodiments, the fermented milk is prepared by a method comprising at least the following steps:

[0031] The peel-containing jam with a viscosity of 6 cm to 10 cm and the yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s are mixed to obtain the fermented milk containing the peel, wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

[0032] The above preparation method can obtain fermented milk containing peel with uniform distribution of peel particles without adding thickener and / or stabilizer by adjusting the viscosity of the raw materials, the size and proportion of the peel; the present invention has found through exploration that if the size or content of the peel is not within the scope of the present invention, it will not only affect the distribution of the peel particles, but also affect the overall taste of the fermented milk.

[0033] In the above preparation method, the size of the peel can be understood as the maximum size of the peel particles.

[0034] In another aspect, the present invention provides a method for preparing the above-mentioned fermented milk containing peel, comprising the following steps:

[0035] The peel-containing jam with a viscosity of 6 cm to 10 cm and the yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s are mixed to obtain the fermented milk containing the peel, wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

[0036] In the preparation method provided by the present invention, by limiting the viscosity of the fruit peel jam and yogurt base, the fruit peel size and the fruit peel content and other parameters, the fruit peel can be stably and evenly distributed in the fermented milk.

[0037] In some embodiments, the raw materials of the fermented milk include, by weight percentage: 85wt% to 92wt% of yogurt base and 8wt% to 15wt% of fruit peel jam.

[0038] Preferably, the raw materials of the peel jam include: fresh fruit peel, sugar and water, and do not include thickener and / or stabilizer.

[0039] In some embodiments, the pH of the peel jam is 3 to 4. The pH range can ensure the taste of the peel jam and keep its microbial content within a low range, which helps to delay the shelf life of the fermented milk product. It is understood that when preparing the peel jam with a pH of 3 to 4, an acidic food additive can be added to adjust the acidity of the jam, such as sodium citrate.

[0040] In some embodiments, the raw materials containing peel jam also include edible flavors, such as yogurt flavor, orange flavor, etc.

[0041] Preferably, the raw materials of the yogurt base include: raw milk, sweetener, protein powder and starter.

[0042] Exemplarily, the raw milk mentioned above refers to fresh milk that complies with my country's fresh milk purchase standard GB 6914, which can be whole milk, skimmed milk or partially skimmed milk, or a reconstituted product made by reducing milk powder, condensed milk or whey protein.

[0043] The above-mentioned sweet substances include but are not limited to one or a combination of white sugar, fructose, glucose, steviol glycosides, sucralose, cyclamate, acesulfame potassium, erythritol, maltitol, aspartame, neotame, xylitol, etc. The specific amount of sweetener added is determined after matching calculation based on the target sweetness of the product and the sweetness that the sweetener can provide, and the amount added should comply with the requirements of the corresponding national standards.

[0044] The above-mentioned protein powder includes but is not limited to milk protein powder, whey protein powder, casein powder, etc., or a combination of several of them.

[0045] The above-mentioned fermentation agent includes but is not limited to one or more of Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium longum, Lactobacillus helveticus, Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophilus, Lactobacillus bulgaricus, etc., or a combination of several thereof; wherein the addition amount of the fermentation agent is 0.1-0.5 U / kg 酸奶基料原料总和 .

[0046] The above raw materials may also include food adjuvants, such as at least one of stabilizers, dietary fiber, vitamins, minerals, β-glucan, edible flavors, salt, etc., so as to give the product more abundant nutrition, further improve the product flavor, and increase the variety of products. The present invention does not specifically limit the amount of the above food adjuvant added, and it can be determined according to the conventional amount in the art. Among them, if a stabilizer is added to the above raw materials, the stabilizer includes but is not limited to a combination of one or more of modified starch, agar, gelatin, pectin, gellan gum, carrageenan, etc.

[0047] In some embodiments, the peel is mixed with a sugar solution and boiled to obtain the peel-containing jam with a viscosity of 6 cm to 10 cm.

[0048] Preferably, before boiling, the peel is frozen at -15 to -20°C for 20 to 30 hours.

[0049] The present invention finds that directly boiling the peel through the traditional candied process will cause the peel in the fermented milk to have a relatively soft taste. However, the above embodiment directly prepares the peel-containing jam after a freezing process at -15 to -20°C, which can retain the original flavor of the peel to the greatest extent and ensure that the peel has a more obvious chewing taste.

[0050] In some embodiments, the preparation of the yogurt base comprises the following steps: degassing, homogenizing and sterilizing a raw material system comprising raw milk, sweetener and protein powder in sequence, adding a starter and fermenting to a target acidity to obtain a yogurt base with a viscosity of 1500mPa·s to 2500mPa·s.

[0051] The conditions for the degassing, homogenizing and sterilizing treatments are not specifically limited in the present invention, and the technicians can adjust them as needed. In order to achieve better dispersibility and stability of the fermented milk, preferably, the degassing is carried out at 60°C and 18MPa pressure; the homogenization temperature is 55-60°C, and the homogenization pressure is 30-200bar; the sterilization is pasteurization, the sterilization temperature is 90-95°C, and the sterilization time is 200-300s.

[0052] It is understandable that the above-mentioned raw material system may further include food adjuvants, for example, at least one of a stabilizer, dietary fiber, vitamins, minerals, β-glucan, edible flavors, salt, etc., wherein the stabilizer includes but is not limited to one or a combination of modified starch, agar, gelatin, pectin, gellan gum, carrageenan, etc.

[0053] In some embodiments, after the raw material system is sterilized, the sample is cooled to 43°C, a starter is added, and fermentation is performed at 43°C until the acidity reaches 70-75°T, the fermentation is stopped, and the emulsion is broken and the temperature is cooled to 10-15°C through a plate exchanger to obtain the yogurt base.

[0054] In addition, if the fermented milk of the present invention is canned, the fermented milk must be cooled to below 10°C before canning and cold-canned at below 10°C. The canned beverage must be refrigerated and stored at 0-4°C to avoid product deterioration.

[0055] Hereinafter, the lactic acid bacteria of the present invention and the preparation method thereof are introduced in more detail through specific examples.

[0056] The raw milk used in the following preparation process comes from Yili Freedom Ranch, and the edible flavors come from Shanghai Bairun Flavors & Fragrances Co., Ltd.

[0057] Example 1

[0058] This embodiment provides a fermented milk containing peels, comprising the following raw materials in percentage by weight: 92 wt% of a yogurt base and 8 wt% of a jam containing peels;

[0059] The preparation method thereof comprises the following steps:

[0060] 1. Preparation of jam containing peel:

[0061] 1.1: Fruit preparation: Select oranges, peel, wash, dice the peel into 3 mm cubes, and freeze at -18°C for 24 h.

[0062] 1.2: Boiling sugar: dissolve white sugar in water, boil until the sugar is completely melted, control the temperature at 50°C, and prepare a sugar solution (in the sugar solution, white sugar accounts for 25wt%).

[0063] 1.3: Put the peels from step 1.1 into the sugar solution from step 1.2 and boil, add sodium citrate and edible flavors, and reach the end point pH 3.8 to obtain the peel jam (containing 30wt% peels and 0.1wt% edible flavors).

[0064] 1.4: pasteurize the jam containing peel in step 1.3 at 95°C for 10 minutes.

[0065] 1.5: Cool the fruit peel jam obtained by sterilization in step 1.4 to below 60°C and fill it, and refrigerate it after filling.

[0066] 1.6: The filled fruit peel jam was used as the test sample, and the viscosity of the fruit peel jam was tested using a BOSTWICK viscometer (flow distance within 60 seconds at 25°C). The test results are shown in Table 1.

[0067] 2. Preparation of yogurt base:

[0068] 2.1: Ingredients: Taking the batching milk as 100% by mass, heat 89wt% of the raw milk to 55°C, add 10wt% of white sugar and 0.3wt% of whey protein powder, dissolve the materials at 60°C, add purified water to make the volume to 1kg, and obtain the batching milk.

[0069] 2.2: Degassing: Degas the batch milk prepared in step 2.1 at 60°C and 18 MPa pressure.

[0070] 2.3: Homogenization: The degassed batch milk enters the homogenization system for homogenization, with a homogenization temperature of 60°C and a homogenization pressure of 30 / 200 bar.

[0071] 2.4: Pasteurization: The homogenized batch milk enters the sterilization system for pasteurization, the sterilization temperature is 95℃, and the sterilization time is 300s.

[0072] 2.5: Fermentation: Cool the sterilized milk in step 2.4 to 43°C, add a starter (0.05U of thermophilic Streptococcus and 0.05U of Bulgarian Lactobacillus), and ferment at 43°C until the acidity reaches 70-75°T, then stop the fermentation to obtain a yogurt base.

[0073] 2.6: Cooling: After the yogurt base is demulsified, cool it to 10-15℃ via plate exchanger and set aside.

[0074] 2.7: The viscosity of the yogurt base was tested at room temperature using an Anton Paar rheometer (CC27 rotor) using the cooled yogurt base as the test sample. The test results are shown in Table 1.

[0075] 3. Preparation of fermented milk containing peel:

[0076] 3.1: Mixed jam: weigh the yogurt base obtained in step 2.6 and the peel-containing jam obtained in step 1.5 in a mass ratio of 92:8, mix them evenly through an online mixing system to obtain a fermented milk product (peel content 2.4wt%).

[0077] 3.2: Filling: The fermented milk product obtained in step 3.1 is filled and refrigerated at 4-6°C for 24 hours to mature.

[0078] Example 2

[0079] This embodiment provides a fermented milk containing peels, comprising the following raw materials in percentage by weight: 90wt% of a yogurt base and 10wt% of a jam containing peels;

[0080] The preparation method thereof comprises the following steps:

[0081] 1. Preparation of jam containing peel:

[0082] 1.1: Fruit preparation: Select oranges and lemons, peel, wash, cut the peel into 5mm cubes, and freeze at -18℃ for 36h.

[0083] 1.2: Boiling sugar: dissolve white sugar in water, boil until the sugar is completely melted, control the temperature at 50°C, and prepare a sugar solution (in the sugar solution, white sugar accounts for 30wt%).

[0084] 1.3: Put the peels from step 1.1 into the sugar solution from step 1.2 and boil, add sodium citrate and edible flavors, and reach the end point pH 3.8 to obtain the peel jam (containing 40wt% peels and 0.15wt% edible flavors).

[0085] 1.4: pasteurize the jam containing peel in step 1.3 at 95°C for 10 minutes.

[0086] 1.5: Cool the sterilized jam containing peel in step 1.4 to below 60°C and fill it, and refrigerate it after filling.

[0087] 1.6: The filled fruit peel jam was used as the test sample, and its viscosity was tested by the same viscosity testing method as in step 1.6 of Example 1. The results are shown in Table 1.

[0088] 2. Preparation of yogurt base:

[0089] 2.1: Batching: Taking batching milk as 100% by mass, heat 90wt% of raw milk to 55°C, add 8wt% of white sugar and 1wt% of whey protein powder, dissolve the materials at 60°C, add purified water to make the volume to 1kg, and obtain batching milk.

[0090] 2.2: Degassing: Degas the batch milk prepared in step 2.1 at 60°C and 18 MPa pressure.

[0091] 2.3: Homogenization: The degassed batch milk enters the homogenization system for homogenization, with a homogenization temperature of 60°C and a homogenization pressure of 30 / 200 bar.

[0092] 2.4: Pasteurization: The homogenized batch milk enters the sterilization system for pasteurization, the sterilization temperature is 95℃, and the sterilization time is 300s.

[0093] 2.5: Fermentation: Cool the batch milk treated in step 2.4 to 43°C, add a starter (0.05U of thermophilic Streptococcus and 0.05U of Bulgarian Lactobacillus), and ferment at 43°C until the acidity reaches 70-75°T, then stop the fermentation to obtain a yogurt base.

[0094] 2.6: Cooling: After the yogurt base is demulsified, it is cooled to 10-15°C via a plate exchanger.

[0095] 2.7: The cooled yogurt base was used as the test sample, and its viscosity was tested according to the same viscosity detection method as in step 2.7 of Example 1. The test results are shown in Table 1.

[0096] 3. Preparation of fermented milk containing peel:

[0097] 3.1: Mixed jam: weigh the yogurt base obtained in step 2.6 and the peel-containing jam obtained in step 1.5 in a mass ratio of 90:10, mix them evenly through an online mixing system to obtain a fermented milk product (peel content 8wt%).

[0098] 3.2: Filling: The fermented milk product obtained in step 3.1 is filled and refrigerated at 4-6°C for 24 hours to mature.

[0099] Example 3

[0100] This embodiment provides a fermented milk containing peels, comprising the following raw materials in percentage by weight: 85 wt% of a yogurt base and 15 wt% of a jam containing peels;

[0101] The preparation method thereof comprises the following steps:

[0102] 1. Jam preparation:

[0103] 1.1: Fruit preparation: Select oranges, lemons, and tangerines, peel, wash, cut the peel into 6 mm cubes, and freeze at -18°C for 48 h.

[0104] 1.2: Boiling sugar: dissolve white sugar in water, boil until the sugar is completely melted, control the temperature at 50°C, and prepare a sugar solution (in the sugar solution, white sugar accounts for 35wt%).

[0105] 1.3: Put the peels from step 1.1 into the sugar solution from step 1.2 and boil, add sodium citrate and edible flavors, and reach the end point pH 3.8 to obtain the peel jam (containing 50wt% peels and 0.15wt% edible flavors).

[0106] 1.4: pasteurize the jam containing peel in step 1.3 at 95°C for 10 minutes.

[0107] 1.5: Cool the sterilized jam containing peel in step 1.4 to below 60°C and fill it, and refrigerate it after filling.

[0108] 1.6: The filled fruit peel jam was used as the test sample, and its viscosity was tested according to the same viscosity detection method as in step 1.6 of Example 1. The test results are shown in Table 1.

[0109] 2. Preparation of yogurt base:

[0110] 2.1: Ingredients: Taking the batching milk as 100% by mass, heat 91wt% of the raw milk to 55°C, add 7wt% of white sugar, 0.2wt% of whey protein powder, 1wt% of hydroxypropyl distarch phosphate, and 0.04wt% of agar, dissolve the materials at 60°C, add purified water to make the volume to 1kg, and obtain the batching milk.

[0111] 2.2: Degassing: Degas the batch milk prepared in step 2.1 at 60°C and 18 MPa pressure.

[0112] 2.3: Homogenization: The degassed batch milk enters the homogenization system for homogenization, with a homogenization temperature of 60°C and a homogenization pressure of 30 / 200 bar.

[0113] 2.4: Pasteurization: The homogenized batch milk enters the sterilization system for pasteurization, the sterilization temperature is 95℃, and the sterilization time is 300s.

[0114] 2.5: Fermentation: Cool the batch milk obtained in step 2.4 to 43°C, add a starter (0.05U of thermophilic Streptococcus and 0.05U of Bulgarian Lactobacillus), and ferment at 43°C until the acidity reaches 70-75°T, then stop the fermentation to obtain a yogurt base.

[0115] 2.6: Cooling: After the yogurt base is demulsified, it is cooled to 10-15°C via a plate exchanger.

[0116] 2.7: The cooled yogurt base was used as the test sample, and its viscosity was tested according to the same viscosity detection method as in step 2.7 of Example 1. The test results are shown in Table 1.

[0117] 3. Preparation of fermented milk containing peel:

[0118] 3.1: Mixed jam: weigh the yogurt base obtained in step 2.6 and the peel-containing jam obtained in step 1.5 in a mass ratio of 85:15, mix them evenly through an online mixing system to obtain a fermented milk product (peel content 7.5wt%).

[0119] 3.2: Filling: The fermented milk product obtained in step 3.1 is filled and refrigerated at 4-6°C for 24 hours to mature.

[0120] Example 4

[0121] This embodiment provides a fermented milk containing peels. The preparation method thereof is different from that of Example 1 in that the jam prepared in this embodiment is not subjected to a freezing process at -18°C for 24 hours after peeling, but is subjected to a candied (peel: white sugar = 3:7) boiling (95°C for 10 minutes) process, and the other steps are the same.

[0122] Example 5

[0123] This embodiment provides a fermented milk containing peels. The preparation method thereof is different from that of Embodiment 1 in that the peels of the jam prepared in this embodiment are selected from tangerine peels, and the other steps are the same.

[0124] Comparative Example 1

[0125] This embodiment provides a fermented milk containing peels. The preparation method thereof is different from that of Embodiment 1 in that: when preparing the peel-containing jam in this embodiment, the size of the peel is 8 mm, and the other steps are the same.

[0126] Comparative Example 2

[0127] This example provides a fermented milk containing peel. The preparation method thereof is different from that of Example 3 in that: in this example, the amount of peel added to the peel-containing jam is increased to 60wt%, so that the peel content in the fermented milk is 9wt%, and other steps remain unchanged.

[0128] Comparative Example 3

[0129] This example provides a fermented milk containing peels. The preparation method thereof is different from that of Example 3 in that: in this example, 8 wt % hydroxypropyl distarch phosphate is additionally added during sugar boiling to increase the viscosity of the peel jam to 13 cm, and the other steps remain unchanged.

[0130] Comparative Example 4

[0131] This example provides a fermented milk containing peel. The preparation method thereof is different from that of Example 2 in that the yogurt base prepared in this example is refined by a refiner pump (30%) and then transferred to an online mixing system to increase the viscosity of the yogurt base to 506 mPa·s, and the other steps remain unchanged.

[0132] Test example

[0133] The products of the above embodiments and comparative examples were subjected to the following tests:

[0134] 1) Product peel distribution

[0135] The fermented milk of Examples 1-5 and Comparative Examples 1-4 were used as test samples. The test samples were divided into three equal parts in the height direction. The contents of the upper, middle and lower peels were tested at 0 days, 7 days, 14 days and 21 days of shelf life, respectively. The content was calculated as follows: (mass of each layer of peel / total mass of fermented milk peel) 100%. The test results are shown in Table 2.

[0136] 2) Viable bacteria count test

[0137] The viable bacteria count test was carried out in accordance with "GB 4789.35-2016 National Food Safety Standard Food Microbiology Inspection Lactic Acid Bacteria Inspection". The fermented milk of Examples 1-5 was used as the test sample. Under refrigerated conditions (4-6°C), the viable bacteria count was tested at 0 days, 7 days, 14 days, and 21 days of shelf life. Each sample was tested three times and the average value was taken. The specific results are shown in Table 3.

[0138] 3) Product sensory testing

[0139] 30 professional sensory evaluators were randomly selected, and the fermented milk of Examples 1-5 and Comparative Examples 1-4 were used as test samples for sensory evaluation of product preference and peel taste. The full score was 5 points, and the higher the score, the higher the preference of the sample and the better the peel taste. Each sample was tested three times and the average value was taken. The product sensory evaluation results are shown in Table 4.

[0140] 4) Product peel washing retention rate test

[0141] The fermented milk of Examples 1 and 4-5 was used as the test sample. Equal amounts of different groups of test samples were placed on a sieve with a hole diameter of 1 mm (circular sieve, diameter 20 cm), rinsed with tap water for 3 minutes, then placed on gauze, and dried at room temperature for 5 minutes. The peel on the surface of the sieve was collected and weighed, and the peel water washing retention rate was calculated according to the following formula: the mass of the peel on the surface of the sieve after rinsing / the mass of the test sample·100%; the results are shown in Table 5.

[0142] Table 1 Viscosity test

[0143]

[0144] It can be seen from the data in Table 1 that the viscosity of the fruit peel jams in Examples 1-5 and Comparative Examples 1-2 is between 6 and 10 cm, and the viscosity of the yogurt base is between 1500 mPa·s and 2500 mPa·s. However, the viscosity of the fruit peel jam in Comparative Example 3 is higher due to the addition of hydroxypropyl distarch phosphate, and the viscosity of the yogurt base in Comparative Example 3 is lower than that of other embodiments and comparative examples due to the refinement treatment.

[0145] Table 2 Distribution of fermented milk peel

[0146]

[0147]

[0148] It can be seen from the data in Table 2 that the fermented milk products of Examples 1-5 always maintain good distribution of peel particles during the shelf life of 0-21 days; while the fermented milk products of Comparative Examples 1-4 have poor uniformity of peel distribution due to changes in peel size, content or jam viscosity.

[0149] Table 3 Viable bacteria count test

[0150]

[0151] From the data in Table 3, it can be seen that the number of viable bacteria in the fermented milk of the present invention is ≥10 within the shelf life of 0-21 days. 8 CFU / g, meeting national standards.

[0152] Table 4 Sensory test results

[0153]

[0154] It can be seen from the data in Table 4 that the fermented milk product liking and peel taste scores of Examples 1-5 are both high; in particular, the fermented milk product liking and peel taste scores of Example 1-3 are the highest.

[0155] Table 5 Product peel washing retention rate

[0156]

[0157] From the results given in Table 5, it can be seen that the peel retention rate of the fermented milk of Example 1 after washing with water is relatively high, while the peels of Examples 4-5 are relatively soft due to changes in the preparation process or peel selection, so the peel retention rates of the fermented milk after washing with water are relatively low.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fermented milk containing peel, characterized in that: The fermented milk meets the following conditions: when the fermented milk is canned, the fermented milk includes a first part, a second part and a third part in sequence in the height direction, and the difference in the mass percentage of the peel in each part to the total peel in the fermented milk is ≤10%; wherein the ratio of the height of each part to the total height is 20% to 40%.

2. The fermented milk containing peel according to claim 1, characterized in that The number of viable bacteria in the fermented milk is ≥10 8 CFU / g.

3. The fermented milk containing peel according to claim 1, characterized in that The peel is a citrus fruit peel.

4. The fermented milk containing peel according to any one of claims 1 to 3, characterized in that: Prepared by a method comprising at least the following steps: The peel-containing jam with a viscosity of 6 cm to 10 cm and the yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s are mixed to obtain the fermented milk containing the peel; wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

5. A method for preparing fermented milk containing peel according to any one of claims 1 to 4, characterized in that: The following steps are involved: The peel-containing jam with a viscosity of 6 cm to 10 cm and the yogurt base with a viscosity of 1500 mPa·s to 2500 mPa·s are mixed to obtain the fermented milk containing the peel; wherein the size of the peel is 3 mm to 6 mm, and the mass percentage of the peel in the fermented milk is 2.4 wt% to 7.5 wt%.

6. The preparation method according to claim 5, characterized in that: The raw materials of the fermented milk include, in terms of mass percentage, 85wt% to 92wt% of yogurt base and 8wt% to 15wt% of fruit peel jam.

7. The preparation method according to claim 5 or 6, characterized in that: The pH of the peel-containing jam is 3-4.

8. The preparation method according to claim 5 or 6, characterized in that: The raw material system including raw milk, sweetener and protein powder is degassed, homogenized and sterilized, and a starter is added to ferment to the target acidity to obtain the yogurt base with a viscosity of 1500mPa·s to 2500mPa·s.

9. The preparation method according to claim 5 or 6, characterized in that: The peel is mixed with the sugar solution and boiled to obtain the peel-containing jam with a viscosity of 6 cm to 10 cm.

10. The preparation method according to claim 9, characterized in that: Before the boiling, the peel is frozen at -15 to -20°C for 20 to 30 hours.

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