Blueberry yoghurt block containing dendrobium candidum extract and preparation method thereof

Abstract

The application relates to the field of food technology, and particularly relates to a blueberry yoghourt block containing dendrobium officinale extract and a preparation method thereof.A blueberry yoghourt block containing dendrobium officinale extract comprises the following preparation raw materials in mass fractions: raw cow milk, white granulated sugar, blueberry extract, dendrobium officinale extract, hyaluronate, whey protein powder, pectin, fructooligosaccharide, gamma-polyglutamic acid, freeze-dried lactic acid bacteria powder, inulin, casein phosphopeptide, wherein the mass fraction ratio of the hyaluronate, the gamma-polyglutamic acid and the dendrobium officinale extract is 1:1:10-15.The blueberry yoghourt block containing dendrobium officinale extract prepared by the application not only has good taste and rich nutrition, but also has the multiple beneficial technical effects of promoting immune regulation, antioxidant function, enhancing the digestive system, improving the survival rate and activity of lactic acid bacteria and the like, and is a high-value functional dairy product.

Description

Technical Field

[0001] This application relates to the field of food technology, and in particular to a blueberry yogurt block containing Dendrobium officinale extract and its preparation method. Background Technology

[0002] Yogurt is a nutrient-rich fermented dairy product, abundant in various amino acids, easily absorbed and digested. It helps maintain intestinal flora balance, improves the intestinal environment, strengthens the immune system, and enhances the body's resistance to pathogens and diseases. The probiotics in yogurt also help maintain the health of the intestinal mucosa and promote digestive function. However, yogurt has a relatively short shelf life and needs to be stored at low temperatures during transportation. Therefore, both transportation and sales require a cold chain, resulting in higher product costs.

[0003] In recent years, freeze-dried yogurt has gained significant attention due to its potential to extend shelf life and reduce costs. Freeze-dried yogurt is made by freeze-drying fermented milk using vacuum freeze-drying technology. It requires no low-temperature conditions during transportation and storage, has a crisp and refreshing texture, is suitable for all ages, and possesses good nutritional quality and market prospects.

[0004] However, the survival rate and activity of lactic acid bacteria in current freeze-dried yogurt products are low, the number of live bacteria is small, and the nutritional value of the product will also decrease. At the same time, freeze-dried yogurt products have problems such as poor rehydration and deteriorated taste.

[0005] Therefore, there is an urgent need to develop a freeze-dried yogurt with high lactic acid bacteria survival rate, high activity, good rehydration, rich nutrition, good taste, and easy preservation. Summary of the Invention

[0006] The purpose of this application is to address the shortcomings of current technology by providing a blueberry yogurt block containing Dendrobium officinale extract and its preparation method.

[0007] In a first aspect, this application provides a blueberry yogurt block containing Dendrobium officinale extract, using the following technical solution: A blueberry yogurt block containing Dendrobium officinale extract, by mass parts, comprises the following raw materials: 900-950 parts raw milk, 10-12 parts white sugar, 8-10 parts blueberry extract, 1-4.5 parts Dendrobium officinale extract, 0.1-0.3 parts hyaluronic acid salt, 6-8 parts whey protein powder, 1-1.5 parts pectin, 3-5 parts fructooligosaccharides, 0.1-0.3 parts γ-polyglutamic acid, 0.8-1.5 parts freeze-dried lactic acid bacteria powder, 2-4 parts inulin, and 0.3-0.5 parts casein phosphopeptide, wherein the mass ratio of the hyaluronic acid salt, the γ-polyglutamic acid, and the Dendrobium officinale extract is 1:1:10-15.

[0008] By adopting the above technical solution, this application uses specific raw materials and proportions to prepare blueberry yogurt blocks containing Dendrobium officinale extract, which have advantages such as high survival rate and activity of lactic acid bacteria, good rehydration, rich nutrition, good taste, and long shelf life. Blueberry extract enhances antioxidant capacity; anthocyanins in blueberries are potent natural antioxidants with antioxidant and anti-inflammatory effects. Adding them to yogurt can enhance its antioxidant capacity, help reduce free radical damage, and protect cells from oxidative stress. The dietary fiber in blueberries also helps promote intestinal peristalsis and digestion. Adding it to yogurt can increase the dietary fiber content, improve digestive function, and promote intestinal health. γ-Polyglutamic acid can form a protective membrane, encapsulating lactic acid bacteria cells, providing protection, reducing the adverse effects of the external environment on lactic acid bacteria, and helping to maintain their survival rate. γ-Polyglutamic acid has a buffering effect, regulating pH and maintaining the culture medium within a suitable pH range, providing a good growth environment and contributing to the survival of lactic acid bacteria. Gamma-polyglutamic acid also possesses antioxidant capabilities, reducing oxidative stress damage to lactic acid bacteria, protecting their cell structure and function, and improving their survival rate. Inulin, a soluble dietary fiber, provides excellent nutrition for lactic acid bacteria, promoting their growth and reproduction, increasing the number and activity of probiotics, and contributing to a balanced and healthy gut microbiota. Simultaneously, inulin increases the viscosity and fullness of yogurt, enhancing the overall eating experience. Casein phosphopeptides also increase the viscosity and fullness of yogurt, improving the overall eating experience. They can form a gel structure, increasing the viscosity of yogurt, making it smoother and more delicate, and enriching its flavor. Casein phosphopeptides also provide lactic acid bacteria with the necessary nutrients and growth factors, increasing their growth and reproduction opportunities and improving their survival rate. Dendrobium officinale extract contains various bioactive components, such as polysaccharides and saponins, which can regulate the body's immune function, enhance the activity of immune cells, and improve the body's resistance to pathogens. Dendrobium officinale extract also has multiple effects and functions, including enhancing immunity, anti-oxidation, promoting digestion, and regulating blood sugar. It contains various immunomodulatory factors and immune enhancers that can regulate the function of the body's immune system. It can stimulate the activity of macrophages, improve the body's antibacterial ability, and enhance the body's resistance to external pathogens. Hyaluronic acid improves the survival rate of beneficial bacteria in freeze-dried blueberry yogurt cubes while increasing the porosity of the cubes, making the outer molecular space hydrophobic, allowing moisture to be relatively fixed during freeze-drying and less prone to loss. The synergistic effect of Dendrobium officinale extract with hyaluronic acid and γ-polyglutamic acid can improve the survival rate and activity of lactic acid bacteria, enhance the taste and nutritional value of yogurt cubes, and simultaneously enhance the function of the immune system and improve the body's resistance.

[0009] Preferably, the hyaluronic acid salt is one of sodium hyaluronate, magnesium hyaluronate, and calcium hyaluronate; the molecular weight of the hyaluronic acid salt is in the range of 2000kDa-2500kDa.

[0010] Preferably, the preparation method of the Dendrobium officinale extract includes the following steps:

[0011] S31. Place Dendrobium officinale into an extrusion puffing machine and puff it for 30-40 minutes under a puffing pressure of 8-10 kgf. Then crush the puffed Dendrobium officinale and pass it through an 80-100 mesh sieve to obtain Dendrobium officinale powder.

[0012] S32. The obtained Dendrobium officinale powder was added to 15 times the volume of ethyl acetate and refluxed 3 times, each time for 1.5-2 hours. The mixture was then filtered and dried to obtain mixture A.

[0013] S33. Add mixture A to a mixed solvent of water and ethanol in a volume ratio of 6:1, and extract by vacuum distillation at a temperature of 45-50℃ and a vacuum degree of 0.1MPa to obtain a concentrated distillate.

[0014] S34. Add activated carbon to the distillation concentrate and stir for 2 hours, then filter, freeze at -40℃, and freeze-dry to obtain Dendrobium officinale extract.

[0015] By employing the above-mentioned technical solution, polysaccharides, saponins, and other active ingredients can be effectively extracted from Dendrobium officinale and prepared into a soluble Dendrobium officinale extract. This Dendrobium officinale extract can synergistically work with hyaluronic acid and γ-polyglutamic acid to enhance the survival rate and activity of lactic acid bacteria, improving the taste and shelf life of yogurt cubes. During this process, various immunomodulatory factors and immune enhancers in the Dendrobium officinale extract can regulate the function of the body's immune system, increase the activity of immune cells, and enhance the body's resistance to pathogens. The antioxidant components in the Dendrobium officinale extract can help eliminate free radicals, playing an antioxidant role. Simultaneously, the bioactive components in the Dendrobium officinale extract promote digestion, improve intestinal health, and enhance nutrient absorption. By optimizing the extraction method to obtain high-quality Dendrobium officinale extract, and combining it with other raw materials, blueberry yogurt cubes can be made more nutritious, have a better taste, a longer shelf life, and maintain high lactic acid bacteria activity and survival rate. The synergistic effect of Dendrobium officinale extract and other ingredients gives blueberry yogurt blocks more health benefits and improves the overall quality and nutritional value of the product.

[0016] Preferably, in step S33, the mass ratio of the mixture A to the mixed solvent is 1:10-15.

[0017] Preferably, in step S34, the mass ratio of activated carbon to distillate concentrate is 1:50-60.

[0018] Preferably, the molecular weight of the γ-polyglutamic acid is 300-500 kDa.

[0019] Preferably, the mass ratio of the casein phosphopeptide to the inulin is 1:8-10.

[0020] By employing the above-mentioned technical solutions, casein phosphopeptides can provide lactic acid bacteria with the necessary nutrients and growth factors, increasing their chances of growth and reproduction, thereby increasing their survival rate and activity. Casein phosphopeptides can form a gel structure, increasing the viscosity and fullness of yogurt, improving the overall eating experience, and making the taste more delicate and rich. Inulin, a soluble dietary fiber, has a nutritional effect on lactic acid bacteria, promoting their growth and reproduction, and helping to maintain the balance and health of the intestinal flora. In addition, inulin can also improve the viscosity and fullness of yogurt, improving the overall taste experience. When casein phosphopeptides and inulin are combined in an appropriate ratio, they can work synergistically to make the yogurt cubes taste richer and more delicate, and increase the number and activity of probiotics, thereby improving the overall quality and nutritional value of the product. Therefore, a reasonable combination of casein phosphopeptides and inulin can improve the taste and nutritional value of yogurt cubes and promote the growth of lactic acid bacteria, thereby achieving a synergistic effect and enhancing the overall quality of yogurt cubes.

[0021] Secondly, this application provides a method for preparing blueberry yogurt blocks containing Dendrobium officinale extract, using the following technical solution:

[0022] As a general technical concept, this application also provides a method for preparing the above-mentioned blueberry yogurt block containing Dendrobium officinale extract, including the following steps:

[0023] S81. According to the mass fractions, raw milk, white sugar, blueberry extract, Dendrobium officinale extract, hyaluronic acid, whey protein powder, pectin, fructooligosaccharides, γ-polyglutamic acid, inulin and casein phosphopeptide are mixed, heated to 80-90℃ and stirred to obtain the first mixture.

[0024] S82. The first mixture is sterilized, cooled, and then lactic acid bacteria freeze-dried powder is added. After mixing, it is allowed to stand to obtain the second mixture.

[0025] S83. Ferment the second mixture at 35-40℃ for 6-8 hours to obtain fermented yogurt;

[0026] S84. Pour the fermented yogurt into a mold, then freeze it in a freezer at -30℃ for 3-5 hours to obtain frozen yogurt;

[0027] S85. Place frozen yogurt into a vacuum freeze dryer for vacuum freeze drying to obtain blueberry yogurt blocks containing Dendrobium officinale extract.

[0028] By adopting the above technical solution, this application first mixes the raw materials, sterilizes them, mixes them with lactic acid bacteria freeze-dried powder, ferments, freezes, and finally obtains blueberry yogurt blocks containing Dendrobium officinale extract. The preparation method is simple and has low energy consumption.

[0029] Preferably, in step S82, the sterilization process is as follows: the first mixture is kept at 90-95°C for 5-10 minutes.

[0030] Preferably, in step S85, the vacuum degree of the vacuum freeze-drying is 10-20 Pa, and the freeze-drying time is 24-30 h.

[0031] In summary, the beneficial technical effects of this application are as follows:

[0032] 1. High survival rate and activity of lactic acid bacteria: The addition of a protective film formed by γ-polyglutamic acid and the nutrients provided by inulin can promote the growth and reproduction of lactic acid bacteria, increase their survival rate and activity, and help maintain the balance and health of the intestinal flora.

[0033] 2. Superior taste and nutrition: The casein phosphopeptides and inulin in the formula can increase the viscosity and fullness of the yogurt, enhance the overall eating experience, and provide the lactic acid bacteria with the necessary nutrients and growth factors.

[0034] 3. Immune regulation and antioxidant functions: Dendrobium officinale extract contains a variety of bioactive components, such as polysaccharides and saponins, which can enhance the activity of immune cells and improve the body's resistance to pathogens. It also has multiple effects such as anti-oxidation, promoting digestion and regulating blood sugar, which helps to enhance overall health.

[0035] 4. Improved rehydration and shelf life: The addition of hyaluronic acid salts improves the survival rate of beneficial bacteria during freeze-drying and increases the porosity of blueberry yogurt blocks, making the moisture relatively fixed during the freeze-drying process, which helps to extend the product's shelf life. Detailed Implementation

[0036] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments used without specified manufacturers are all commercially available products. Blueberry extract: Fufeng Snowt Biotechnology Co., Ltd., purity: 98%.

[0037] Preparation Example 1: Preparation of Dendrobium officinale extract

[0038] The preparation method of Dendrobium officinale extract includes the following steps:

[0039] S31. Place 100g of Dendrobium officinale into an extrusion puffing machine, puff it for 30 minutes at a puffing pressure of 8kgf, then crush the puffed Dendrobium officinale and pass it through an 80-mesh sieve to obtain Dendrobium officinale powder.

[0040] S32. The obtained Dendrobium officinale powder was added to 15 times the volume of ethyl acetate and refluxed 3 times, each time for 1.5 hours. The mixture was then filtered and dried to obtain mixture A.

[0041] S33. Take 20g of mixture A and add it to 200g of a mixed solvent of water and ethanol with a volume ratio of 6:1. Extract the mixture by vacuum distillation at 45℃ and 0.1MPa to obtain a concentrated distillate.

[0042] S34. Take 0.5g of activated carbon and add it to 25g of distilled concentrate. Stir for 2 hours, then filter, freeze at -40℃, and freeze-dry to obtain Dendrobium officinale extract.

[0043] Preparation Example 2: Preparation of Dendrobium officinale extract

[0044] The preparation method of Dendrobium officinale extract includes the following steps:

[0045] S31. Place 100g of Dendrobium officinale into an extrusion puffing machine, puff it for 40 minutes under a puffing pressure of 10kgf, then crush the puffed Dendrobium officinale and pass it through a 100-mesh sieve to obtain Dendrobium officinale powder.

[0046] S32. The obtained Dendrobium officinale powder was added to 15 times the volume of ethyl acetate and refluxed 3 times, each time for 2 hours. After filtration and drying, mixture A was obtained.

[0047] S33. Take 20g of mixture A and add it to 300g of a mixed solvent of water and ethanol with a volume ratio of 6:1. Extract the mixture by vacuum distillation at 50℃ and 0.1MPa to obtain a concentrated distillate.

[0048] S34. Take 0.5g of activated carbon and add it to 30g of distilled concentrate. Stir for 2 hours, then filter, freeze at -40℃, and freeze-dry to obtain Dendrobium officinale extract.

[0049] Preparation Example 3: Preparation of Dendrobium officinale extract

[0050] The preparation method of Dendrobium officinale extract includes the following steps:

[0051] S31. Place 100g of Dendrobium officinale into an extrusion puffing machine, puff it for 35 minutes at a puffing pressure of 9kgf, then crush the puffed Dendrobium officinale and pass it through a 90-mesh sieve to obtain Dendrobium officinale powder.

[0052] S32. The obtained Dendrobium officinale powder was added to 15 times the volume of ethyl acetate and refluxed 3 times, each time for 1.8 hours. The mixture was then filtered and dried to obtain mixture A.

[0053] S33. Add 20g of mixture A to 250g of a mixed solvent of water and ethanol in a volume ratio of 6:1, and extract by vacuum distillation at 48℃ and 0.1MPa to obtain a concentrated distillate.

[0054] S34. Add 0.5g of activated carbon to 28g of distilled concentrate and stir for 2 hours. Then filter, freeze at -40℃, and freeze-dry to obtain Dendrobium officinale extract.

[0055] Example 1

[0056] A blueberry yogurt block containing Dendrobium officinale extract, comprising, by weight, the following raw materials: 900g raw milk, 10g white sugar, 8g blueberry extract, 1g Dendrobium officinale extract, 0.1g hyaluronic acid salt, 6g whey protein powder, 1g pectin, 3g fructooligosaccharides, 0.1g γ-polyglutamic acid, 0.8g freeze-dried lactic acid bacteria powder, 2g inulin, and 0.3g casein phosphopeptide. The hyaluronic acid salt is sodium hyaluronate with a molecular weight of 2000kDa; the γ-polyglutamic acid has a molecular weight of 300kDa; and the Dendrobium officinale extract is prepared as in Preparation Example 1.

[0057] The above-mentioned method for preparing blueberry yogurt blocks containing Dendrobium officinale extract includes the following steps:

[0058] S81. According to the mass fractions, raw milk, white sugar, blueberry extract, Dendrobium officinale extract, hyaluronic acid, whey protein powder, pectin, fructooligosaccharides, γ-polyglutamic acid, inulin and casein phosphopeptide are mixed, heated to 80°C and stirred to obtain the first mixture.

[0059] S82. The first mixture is sterilized. The sterilization process is as follows: the first mixture is kept at 90°C for 10 minutes; cooled, lactic acid bacteria freeze-dried powder is added, mixed well and allowed to stand to obtain the second mixture.

[0060] S83. Ferment the second mixture at 35°C for 8 hours to obtain fermented yogurt;

[0061] S84. Pour the fermented yogurt into a mold, then freeze it in a freezer at -30℃ for 3 hours to obtain frozen yogurt;

[0062] S85. Place the frozen yogurt into a vacuum freeze dryer for vacuum freeze drying at a vacuum degree of 10 Pa for 24 hours to obtain blueberry yogurt blocks containing Dendrobium officinale extract.

[0063] Example 2

[0064] A blueberry yogurt block containing Dendrobium officinale extract comprises, by weight, the following raw materials: 950g raw milk, 12g white sugar, 10g blueberry extract, 4.5g Dendrobium officinale extract, 0.3g hyaluronic acid salt, 8g whey protein powder, 1.5g pectin, 5g fructooligosaccharides, 0.3g γ-polyglutamic acid, 1.5g freeze-dried lactic acid bacteria powder, 4g inulin, and 0.3g casein phosphopeptide. The hyaluronic acid salt is magnesium hyaluronic acid with a molecular weight of 2500kDa; the γ-polyglutamic acid has a molecular weight of 500kDa; and the Dendrobium officinale extract was prepared as in Preparation Example 2.

[0065] The above-mentioned method for preparing blueberry yogurt blocks containing Dendrobium officinale extract includes the following steps:

[0066] S81. According to the mass fractions, raw milk, white sugar, blueberry extract, Dendrobium officinale extract, hyaluronic acid, whey protein powder, pectin, fructooligosaccharides, γ-polyglutamic acid, inulin and casein phosphopeptide are mixed, heated to 90°C and stirred to obtain the first mixture.

[0067] S82. The first mixture is sterilized. The sterilization process is as follows: the first mixture is kept at 95°C for 5 minutes; cooled, lactic acid bacteria freeze-dried powder is added, mixed well and allowed to stand to obtain the second mixture.

[0068] S83. Ferment the second mixture at 40°C for 6 hours to obtain fermented yogurt;

[0069] S84. Pour the fermented yogurt into a mold, then freeze it in a freezer at -30℃ for 5 hours to obtain frozen yogurt;

[0070] S85. Place the frozen yogurt into a vacuum freeze dryer for vacuum freeze drying at a vacuum degree of 20 Pa for 30 hours to obtain blueberry yogurt blocks containing Dendrobium officinale extract.

[0071] Example 3

[0072] A blueberry yogurt block containing Dendrobium officinale extract comprises, by weight, the following raw materials: 930g raw milk, 11g white sugar, 9g blueberry extract, 2.6g Dendrobium officinale extract, 0.2g hyaluronic acid salt, 7g whey protein powder, 1.3g pectin, 4g fructooligosaccharides, 0.2g γ-polyglutamic acid, 1.2g freeze-dried lactic acid bacteria powder, 2.8g inulin, and 0.4g casein phosphopeptide. The hyaluronic acid salt is calcium hyaluronic acid with a molecular weight of 2300kDa; the γ-polyglutamic acid has a molecular weight of 400kDa; and the Dendrobium officinale extract was prepared as in Preparation Example 3.

[0073] The above-mentioned method for preparing blueberry yogurt blocks containing Dendrobium officinale extract includes the following steps:

[0074] S81. According to the mass fractions, raw milk, white sugar, blueberry extract, Dendrobium officinale extract, hyaluronic acid, whey protein powder, pectin, fructooligosaccharides, γ-polyglutamic acid, inulin and casein phosphopeptide are mixed, heated to 85°C and stirred to obtain the first mixture.

[0075] S82. The first mixture is sterilized. The sterilization process is as follows: the first mixture is kept at 93°C for 8 minutes; cooled, lactic acid bacteria freeze-dried powder is added, mixed well and allowed to stand to obtain the second mixture.

[0076] S83. Ferment the second mixture at 38°C for 7 hours to obtain fermented yogurt;

[0077] S84. Pour the fermented yogurt into a mold, then freeze it in a freezer at -30℃ for 4 hours to obtain frozen yogurt;

[0078] S85. Place the frozen yogurt into a vacuum freeze dryer for vacuum freeze drying at a vacuum degree of 15 Pa for 27 hours to obtain blueberry yogurt blocks containing Dendrobium officinale extract.

[0079] Example 4

[0080] Same as Example 3, except that inulin 3.2g and casein phosphopeptide 0.4g were used.

[0081] Example 5

[0082] Same as Example 3, except that 4g of inulin and 0.4g of casein phosphopeptide were used.

[0083] Example 6

[0084] Same as Example 3, except that inulin 3.6g and casein phosphopeptide 0.4g were used.

[0085] Comparative Example 1

[0086] Same as in Example 6, except that 1.6g of Dendrobium officinale extract, 0.2g of hyaluronic acid, and 0.2g of γ-polyglutamic acid were used.

[0087] Comparative Example 2

[0088] Same as in Example 6, except that 3.4g of Dendrobium officinale extract, 0.2g of hyaluronic acid, and 0.2g of γ-polyglutamic acid were used.

[0089] Comparative Example 3

[0090] Same as in Example 6, except that 0g of Dendrobium officinale extract, 0.2g of hyaluronic acid, and 0.2g of γ-polyglutamic acid were used.

[0091] Comparative Example 4

[0092] Similar to Example 6, except that Dendrobium officinale extract produced by Shaanxi Baichuan Biotechnology Co., Ltd. is used instead of Dendrobium officinale extract prepared in Preparation Example 3.

[0093] Performance testing

[0094] The blueberry yogurt blocks containing Dendrobium officinale extract prepared in Examples 1-6 and Comparative Examples 1-4 were sampled and tested. The test results are shown in Table 2.

[0095] Survival rate of beneficial bacteria in freeze-dried yogurt blocks: The total number of colonies in yogurt before and after freeze-drying was determined by plate counting method. Survival rate % = total number of colonies before freeze-drying / total number of colonies after freeze-drying and rehydration * 100%;

[0096] Rehydration of freeze-dried yogurt blocks: Place freeze-dried yogurt in water at 37°C, observe and record the time from the bottom of the sample contacting the water to the top of the sample being completely wetted. The time for complete wetting represents the rehydration of the yogurt block, and the shorter the time, the better the rehydration. Shelf life is determined according to the standard (T / CNFIA 001-2017 General Guidelines for Shelf Life of Food).

[0097] Sensory evaluation: A scoring method was used, with a sensory evaluation team of 10 professionally trained personnel. The scorers evaluated the blueberry yogurt blocks containing Dendrobium officinale extract based on four aspects: appearance (smooth and even without bloom or sand-like defects), aroma (balanced sweetness and tartness with no off-flavors), texture (presence of cavitation, breakage, or glassy consistency), and mouthfeel (crispyness, stickiness, and sweetness). The total score was 100 points, and the average value was taken as the final result. The evaluation criteria for sensory evaluation are shown in Table 1.

[0098] Table 1 Sensory Evaluation Criteria

[0099]

[0100] Table 2 Performance Test Table

[0101] project Survival rate (%) Rehydration time / s Sensory rating (points) Shelf life (months) Example 1 69.3 71 90 12 Example 2 70.2 68 92 12 Example 3 69.8 74 91 12 Example 4 73.1 59 95 12 Example 5 72.7 61 96 12 Example 6 73.5 56 98 12 Comparative Example 1 64.3 95 82 9 Comparative Example 2 63.8 98 81 9 Comparative Example 3 59.3 112 75 7 Comparative Example 4 68.2 72 88 11

[0102] Analyzing the data in Table 1, we can see that:

[0103] 1) The blueberry yogurt blocks containing Dendrobium officinale extract prepared in Examples 4-6 have the characteristics of high survival rate and high activity of lactic acid bacteria, good rehydration, rich nutrition, good taste and easy preservation.

[0104] 2) A comparative analysis of the performance of blueberry yogurt blocks containing Dendrobium officinale extract prepared in Example 6 and Examples 1-3 shows that a mass ratio of casein phosphopeptide to inulin of 1:8-10 is more conducive to improving the survival rate of lactic acid bacteria, rehydration and overall sensory effect of blueberry yogurt blocks containing Dendrobium officinale extract.

[0105] 3) The performance comparison analysis of blueberry yogurt blocks containing Dendrobium officinale extract prepared in Example 6 and Comparative Examples 1-3 shows that the mass ratio of hyaluronic acid salt, γ-polyglutamic acid and Dendrobium officinale extract is between 1:1:10-15, which can significantly improve the survival rate of lactic acid bacteria, rehydration, overall sensory effect and shelf life of blueberry yogurt blocks containing Dendrobium officinale extract.

[0106] 4) The performance comparison analysis of blueberry yogurt blocks containing Dendrobium officinale extract prepared in Example 6 and Comparative Example 4 shows that the Dendrobium officinale extract prepared in this application, through optimized extraction method, can obtain high-quality Dendrobium officinale extract. Combined with its ratio with other raw materials, it can make blueberry yogurt blocks more nutritious, have a better taste, a longer shelf life, and maintain high lactic acid bacteria activity and high survival rate.

[0107] The above embodiments are only used to explain the technical solutions of this application and are not intended to limit it. Although the above embodiments have provided specific descriptions of this application, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this invention. Any modifications and equivalent substitutions that do not depart from the spirit and scope of this application should be covered within the protection scope of this application.

Claims

1. A blueberry yogurt block containing Dendrobium officinale extract, characterized in that, The preparation ingredients, by weight, include the following: 900-950 parts raw milk, 10-12 parts white sugar, 8-10 parts blueberry extract, 1-4.5 parts Dendrobium officinale extract, 0.1-0.3 parts sodium hyaluronate, 6-8 parts whey protein powder, 1-1.5 parts pectin, 3-5 parts fructooligosaccharides, 0.1-0.3 parts γ-polyglutamic acid, 0.8-1.5 parts lyophilized lactic acid bacteria powder, 2-4 parts inulin, and 0.3-0.5 parts casein phosphopeptide, wherein the weight ratio of sodium hyaluronate, γ-polyglutamic acid, and Dendrobium officinale extract is 1:1:10-15; The molecular weight range of the sodium hyaluronate is 2000kDa-2500kDa; The molecular weight of the γ-polyglutamic acid is 300-500 kDa.

2. A method for preparing blueberry yogurt blocks containing Dendrobium officinale extract as described in claim 1, characterized in that, Includes the following steps: According to the mass fractions, raw milk, white sugar, blueberry extract, Dendrobium officinale extract, sodium hyaluronate, whey protein powder, pectin, fructooligosaccharides, γ-polyglutamic acid, inulin and casein phosphopeptide are mixed, heated to 80-90℃ and stirred to obtain the first mixture; The first mixture was sterilized, cooled, and then lactic acid bacteria lyophilized powder was added. After mixing and standing, the mixture was obtained as the second mixture. The second mixture is fermented at 35-40℃ for 6-8 hours to obtain fermented yogurt; Pour the fermented yogurt into molds and freeze at -30°C for 3-5 hours to obtain frozen yogurt; Frozen yogurt was placed in a vacuum freeze dryer for vacuum freeze drying to obtain blueberry yogurt blocks containing Dendrobium officinale extract.

3. The method for preparing blueberry yogurt blocks containing Dendrobium officinale extract according to claim 2, characterized in that, The sterilization process is as follows: the first mixture is kept at 90-95℃ for 5-10 minutes.

4. The method for preparing blueberry yogurt blocks containing Dendrobium officinale extract according to claim 2, characterized in that, The vacuum degree of the vacuum freeze-drying process is 10-20 Pa, and the freeze-drying time is 24-30 h.

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