A method for preparing room temperature yogurt oats by fermenting oats with yeast probiotics

Abstract

The present invention provides a method for preparing room temperature yogurt oats by fermenting oats with yeast probiotics, comprising three steps of preparing oats fermented with yeast probiotics, preparing room temperature yogurt, and mixing and preparing products. Through separate fermentation processes, the present invention overcomes the defects of traditional mixed fermentation processes, and the prepared room temperature boulardii yeast fermented oat yogurt has the characteristics of room temperature stability, rich nutrition, unique flavor, etc., which meets the needs of middle-aged and elderly people and people with sensitive gastrointestinal tract for fermented foods at room temperature, high quality, and beneficial to intestinal health, and has broad application prospects in the field of food processing.

Description

Technical Field

[0001] The invention relates to the technical field of food fermentation, and in particular to a method for preparing room temperature yogurt oats by fermenting oats with yeast probiotics. Background Art

[0002] As people's health awareness increases, the demand for foods with health functions is growing. Yogurt is widely loved by consumers because it is rich in probiotics and easy to digest and absorb. At the same time, oats, as a nutritious grain, are rich in dietary fiber, β-glucan, multiple vitamins and minerals, etc., which have a positive effect on regulating blood sugar and blood lipids and improving intestinal function. Combining oats with yogurt can further enhance the nutritional value of the product.

[0003] However, traditional oatmeal yogurt is mostly prepared by a mixed fermentation method, which is to mix oats with raw materials such as milk and directly inoculate bacteria for fermentation. This method has many disadvantages, such as uneven fermentation, unstable product quality, and the need for low-temperature storage to maintain the activity of probiotics, which limits the convenience of consumption for some people.

[0004] As a probiotic, Saccharomyces boulardii has excellent properties such as regulating intestinal flora, enhancing intestinal barrier function, and relieving intestinal inflammation. Applying it to oat fermentation is expected to give the product additional intestinal health benefits. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing room temperature yogurt oats by fermenting oats with yeast probiotics, so as to meet the needs of middle-aged and elderly people and people with sensitive gastrointestinal tract for fermented foods at room temperature, high quality and beneficial to intestinal health, while overcoming the defects of traditional mixed fermentation processes.

[0006] The method of the present invention comprises the following steps:

[0007] Step 1: Fermented oats preparation

[0008] S11 Selection and pretreatment of oat raw materials: Select whole oats with full grains, bright color, and no pests or mildew, and remove impurities and broken grains; rinse the oats with clean water to remove dust and impurities on the surface; soak them in water;

[0009] S12 Steaming: Take out the soaked oats, drain them, spread them on the steamer, with each layer about 2cm thick, and steam them over high heat for 20-30 minutes;

[0010] S13 Saccharomyces boulardii activation: The probiotic Saccharomyces boulardii strain was inoculated into a sterile malt extract medium for activation. The inoculation amount of the activated strain was 10% of the volume of the medium. The culture temperature was 20°C. The culture time was 36 hours. The activated strain was transferred and expanded twice to obtain an activated Saccharomyces boulardii liquid, in which the concentration of the activated bacteria was 1.39×10 8 CFU / mL;

[0011] S14: Transfer the pretreated oats to a fermentation container, inoculate the activated Saccharomyces boulardii liquid into the pretreated oats at a volume ratio of 8%, add an appropriate amount of sterile water, and stir evenly. Use a breathable sealed lid to seal the container to prevent contamination by bacteria while ensuring gas exchange. Place the fermentation container in a constant temperature incubator at 32-36°C and ferment for 20-28 hours, turning it every 4 hours during the fermentation to ensure uniform fermentation. Sterilize the fermented oats: temperature 145°C, time 3s, and set aside.

[0012] Step 2: Preparation of room temperature yogurt

[0013] S21 Raw material preparation: Select high-quality fresh milk, filter and standardize it to make the protein content reach 3.0%-3.5% and the fat content reach 3.0%-4.0%;

[0014] S22 sterilization: sterilize the treated milk at 85-95℃ for 5-10 minutes, then quickly cool it to 40-45℃;

[0015] S23 Yogurt bacteria activation: Select conventional yogurt fermentation bacteria (such as thermophilic Streptococcus, Bulgarian Lactobacillus, etc.) and activate them according to the instructions of the bacteria;

[0016] S24 inoculation and fermentation: inoculate the activated yogurt bacteria into the sterilized milk at an inoculation rate of 0.5%-1.5% (v / v), ferment at 40-45°C for 3-6 hours until the acidity of the yogurt reaches 70-90°F, stop fermentation, and obtain a yogurt base.

[0017] Step 3: Product mixing

[0018] The fermented oats prepared in step one and the yogurt base prepared in step two are mixed in a volume ratio of 1:9-1:4, stirred evenly, and then 0.5%-1.5% of a sweetener and 0.1%-0.3% of a stabilizer are added according to market demand. After homogenization (pressure 15-20MPa) and filling, secondary sterilization is performed to obtain room temperature boulardii yeast fermented oatmeal yogurt.

[0019] Furthermore, the sweetener is xylitol or erythritol, etc., and the sweetener must have health properties.

[0020] Furthermore, the stabilizer is sodium carboxymethyl cellulose or pectin.

[0021] The room temperature boulardii yeast fermented oatmeal yogurt of the present invention has the following characteristics:

[0022] 1. Stability at room temperature: The product does not need to be refrigerated and can be stored at room temperature (25°C) for 60 days while still maintaining good taste, flavor and probiotic activity, greatly facilitating consumption by the middle-aged and elderly and people with sensitive stomachs.

[0023] 2. Rich in nutrition: It combines the dual nutrition of oats and yogurt, and is rich in dietary fiber, protein, probiotics and their metabolites, etc. It helps to regulate intestinal function, lower blood lipids, enhance immunity, etc.

[0024] 3. Unique flavor: Oat fermentation gives the product a unique fermentation aroma and a light cereal aroma, which complements the sweet and sour flavor of yogurt, giving it a mellow taste with rich layers.

[0025] The advantages of the separate fermentation process of the present invention compared with the traditional mixed fermentation process are:

[0026] 1. The fermentation process is highly controllable: Separate fermentation can optimize the fermentation conditions according to the fermentation characteristics of oats and milk, accurately control the fermentation time, temperature, humidity and other parameters, ensure that oats and yogurt can achieve the best fermentation effect, and avoid the problem of uneven fermentation caused by mixed fermentation due to the difficulty in taking into account the conditions.

[0027] 2. High product quality stability: Since each raw material is fermented independently, the quality of the final product is less affected by the difference in raw materials. The taste, flavor, nutritional content, etc. of products from different batches are more stable and consistent, which is conducive to industrial large-scale production.

[0028] 3. Functional enhancement: By first using Boulardii Saccharomyces cerevisiae to ferment oats in a targeted manner, its role in regulating intestinal flora and improving intestinal barrier function is fully exerted, and then mixed with yogurt to achieve the superposition of intestinal health effects. Compared with simple mixed fermentation, it can provide consumers with more significant health benefits. DETAILED DESCRIPTION

[0029] In order to more clearly understand the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now further described in detail. It should be understood that the following specific embodiments are only exemplary, and the technical solution of the present invention is not limited to the specific embodiments listed below.

[0030] Embodiment 1:

[0031] S1: Preparation of fermented oats

[0032] 10 kg of high-quality oats (whole oats with full grains, bright color, and no pests or mildew) are selected and manually sorted to remove impurities such as stones, grass clippings and broken grains.

[0033] Put the selected oats into the washing basket and rinse with running water for 3 minutes until the dust and impurities on the surface are completely removed. Soak the washed oats in the soaking liquid for 6 hours, stirring occasionally during the soaking process. After soaking, take out the oats and drain them with a strainer for 15 minutes. Spread the drained oats on the steamer, about 2 cm per layer, and steam them over high heat for 20-30 minutes.

[0034] Subsequently, the activation step of the probiotics is carried out. The specific operation is as follows: the Saccharomyces boulardii strain is introduced into 200 ml of malt extract medium that has been strictly aseptically treated, and the activation inoculation amount is accurately controlled to 10% of the total volume of the medium, and cultured for 36 hours at a constant 20°C environment. During this period, two transfer and expansion operations are carried out to obtain a highly active probiotic solution. After that, 800 ml of this activated bacterial solution is evenly inoculated into the pretreated oats, and the bacterial solution and oats are ensured to be evenly mixed by sufficient stirring. At a suitable temperature of 32 to 36°C, a fermentation process of 28 hours is carried out, during which a turning operation is performed every 4 hours to promote fermentation uniformity. After the fermentation is completed, the resulting fermented oats are sterilized and properly stored for subsequent use.

[0035] S2: Precision preparation of ambient temperature yogurt

[0036] 50 liters of high-quality fresh milk are selected as raw materials. First, they are filtered through a precise process to remove impurities, and the protein content is adjusted to 3.2% and the fat content is adjusted to 3.5% through standardization to meet the high standards for yogurt production. Then, the milk is heated to 90°C and kept for 8 minutes for sterilization, and then quickly cooled to 43°C to prepare for the inoculation of probiotics. Thermophilic Streptococcus and Bulgarian Lactobacillus are selected as fermentation strains, and activation treatment is carried out according to the instructions provided by the manufacturer. The activated strains are added to the sterilized milk at an inoculation rate of 1% (volume ratio), and fermented at a constant temperature of 43°C for 4 hours until the acidity of the yogurt reaches the 80°T standard, and then the fermentation is stopped to obtain the yogurt base.

[0037] S3: Fine mixing and blending of products

[0038] The fermented oats prepared above are precisely mixed with the yogurt base in a volume ratio of 1:9, and efficient stirring is used to ensure that the two are fully integrated. Subsequently, 1% of xylitol as a sweetener and 0.2% of sodium carboxymethyl cellulose as a stabilizer are added to the total mass of the mixture to enhance the taste and stability of the product. The mixture is homogenized under a pressure of 18MPa to refine the particles and enhance uniformity, and then the filling operation is carried out. After filling, the product needs to undergo a secondary sterilization treatment to ensure its microbial safety, and finally obtain room temperature boulardii yeast fermented oat yogurt.

[0039] The product prepared according to Example 1 was subjected to strict testing and analysis. The results showed that after being stored at room temperature (25°C) for 60 days, the probiotic content in the product remained at 1×10 7 CFU / mL and above fully verify the probiotic activity and long-term storage stability of the product, meeting the functional requirements as a health product.

[0040] Embodiment 2:

[0041] S1: Preparation of fermented oats

[0042] 10 kg of high-quality oats (whole oats with full grains, bright color, and no pests or mildew) are selected and manually sorted to remove impurities such as stones, grass clippings and broken grains.

[0043] Put the selected oats into the washing basket and rinse with running water for 3 minutes until the dust and impurities on the surface are completely removed. Soak the washed oats in the soaking liquid for 6 hours, stirring occasionally during the soaking process. After soaking, take out the oats and drain them with a strainer for 15 minutes. Spread the drained oats on the steamer, about 2 cm per layer, and steam them over high heat for 20-30 minutes.

[0044] Subsequently, the activation step of the probiotics is carried out, and the specific operation is as follows: the Saccharomyces boulardii strain is introduced into 200 ml of malt extract medium that has been strictly aseptically treated, and the activation inoculation amount is accurately controlled to 10% of the total volume of the medium, and the culture is carried out for 36 hours at a constant 20°C environment. During this period, two transfer and expansion operations are carried out to obtain a highly active probiotic solution. After that, 800 ml of this activated bacterial solution is evenly inoculated into the pretreated oats, and the bacterial solution and oats are ensured to be evenly mixed by sufficient stirring. At a suitable temperature of 32 to 36°C, a fermentation process of 26 hours is carried out, during which a turning operation is performed every 4 hours to promote fermentation uniformity. After the fermentation is completed, the resulting fermented oats are sterilized and properly stored for subsequent use.

[0045] S2: Precision preparation of ambient temperature yogurt

[0046] 50 liters of high-quality fresh milk are selected as raw materials. First, they are filtered through a precise process to remove impurities, and the protein content is adjusted to 3.2% and the fat content is adjusted to 3.5% through standardization to meet the high standards for yogurt production. Then, the milk is heated to 90°C and kept for 8 minutes for sterilization, and then quickly cooled to 43°C to prepare for the inoculation of probiotics. Thermophilic Streptococcus and Bulgarian Lactobacillus are selected as fermentation strains, and activation treatment is carried out according to the instructions provided by the manufacturer. The activated strains are added to the sterilized milk at an inoculation rate of 1% (volume ratio), and fermented at a constant temperature of 43°C for 4 hours until the acidity of the yogurt reaches the 80°T standard, and then the fermentation is stopped to obtain the yogurt base.

[0047] S3: Fine mixing and blending of products

[0048] The fermented oats prepared above are precisely mixed with the yogurt base in a volume ratio of 1:9, and efficient stirring is used to ensure that the two are fully integrated. Subsequently, 1% of xylitol as a sweetener and 0.2% of sodium carboxymethyl cellulose as a stabilizer are added to the total mass of the mixture to enhance the taste and stability of the product. The mixture is homogenized under a pressure of 18MPa to refine the particles and enhance uniformity, and then the filling operation is carried out. After filling, the product needs to undergo a secondary sterilization treatment to ensure its microbial safety, and finally obtain room temperature boulardii yeast fermented oat yogurt.

[0049] The product prepared according to Example 2 was subjected to strict testing and analysis. The results showed that after being stored at room temperature (25°C) for 60 days, the probiotic content in the product remained at 1×10 7 CFU / mL and above fully verify the probiotic activity and long-term storage stability of the product, meeting the functional requirements as a health product.

[0050] In order to further evaluate the quality of the product of the present invention, the present invention conducted a systematic sensory evaluation test on the above-mentioned Examples 1-2 and the comparative example (ordinary oatmeal yogurt). The test results are shown in Table 1.

[0051] Table 1 Sensory rating table

[0052]

[0053] The evaluation panel is composed of 30 professional tasters, including 10 food professionals, 10 ordinary consumer representatives and 10 middle-aged and elderly consumer representatives, to ensure the comprehensiveness and representativeness of the evaluation results. The evaluation criteria mainly cover appearance, aroma, taste and flavor, as follows:

[0054] 1. Appearance: Observe whether the color of the product is uniform and whether there is any stratification or precipitation. Products with uniform color and no obvious stratification or precipitation will be scored 5 points; products with basically uniform color and slight stratification or precipitation will be scored 3-4 points; products with uneven color and obvious stratification or precipitation will be scored 1-2 points.

[0055] 2. Aroma: Smell the product to determine whether it has a strong yogurt aroma, oat fermentation aroma, or a unique aroma created by the combination of the two. Products with a strong and harmonious aroma will score 5 points; products with a more obvious aroma but less harmonious aroma will score 3-4 points; products with a weak aroma or a strange smell will score 1-2 points.

[0056] 3. Taste: Taste the texture of the product, including thickness, fineness, smoothness, etc. Products with a thick, fine and smooth taste will score 5 points; products with a thicker taste, a certain degree of fineness, but a slightly less smooth taste will score 3-4 points; products with a thin, rough or grainy taste will score 1-2 points.

[0057] 4. Flavor: Taste the product, evaluate whether the sweetness and sourness of the yogurt is moderate, whether the flavor of the oatmeal fermentation is unique, and whether the overall flavor of the combination of the two is satisfactory. Products with unique flavor, moderate sweetness and sourness, and overall harmony are scored 5 points; products with relatively unique flavor, slightly different sweetness and sourness, but overall acceptable are scored 3-4 points; products with bland flavor or too sour or too sweet, and overall uncoordinated flavors are scored 1-2 points.

[0058] It can be seen from Table 1 that the product prepared in the embodiment of the present invention has excellent appearance, aroma, taste and flavor, and has high quality and market competitiveness.

[0059] The room-temperature boulardii yeast fermented oatmeal yogurt prepared by the separate fermentation process of the present invention not only meets the needs of the middle-aged and elderly people and people with sensitive gastrointestinal tracts for room-temperature, nutritious, and intestinal health-friendly food, but also overcomes many shortcomings of the traditional mixed fermentation process and has broad application prospects in the field of food processing.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that, without departing from the spirit and essence of the present invention, those skilled in the art may make various modifications, combinations, changes or substitutions to the details and features of the present invention. These modifications, combinations, changes or substitutions should also be understood to be included in the scope of protection claimed by the present invention.

Claims

1. A method for preparing room temperature yogurt oats by fermenting oats with yeast probiotics, characterized in that: The following steps are involved: Step 1: preparation of fermented oats, including selection and pretreatment of oat raw materials, cooking, activation of Saccharomyces boulardii, and inoculation and fermentation; Step 2: Preparation of room temperature yogurt, including raw material preparation, sterilization, yogurt bacteria activation, inoculation and fermentation; Step 3: Mix and prepare the product, mix the fermented oats and the yogurt base in a volume ratio of 1:9-1:4, add or not add a sweetener, add a stabilizer, homogenize and fill, and then perform secondary sterilization to obtain room temperature boulardii yeast fermented oat yogurt.

2. The method according to claim 1, characterized in that In the step of activating Saccharomyces boulardii, the inoculation amount of the activated strain is 10% of the volume of the culture medium, the culture temperature is 20°C, the culture time is 36 hours, and the activated strain is transferred and expanded twice to obtain an activated Saccharomyces boulardii bacterial liquid, wherein the concentration of the activated bacteria is 1.39×10 8 CFU / mL.

3. The method according to claim 1, characterized in that In the step of preparing the fermented oats, the pretreated oats are transferred to a fermentation container, the activated Saccharomyces boulardii liquid is inoculated into the pretreated oats at a volume ratio of 8%, an appropriate amount of sterile water is added, the mixture is stirred evenly, the container is sealed with a breathable sealing cover to prevent contamination by miscellaneous bacteria while ensuring gas exchange, the fermentation container is placed in a constant temperature incubator at 32-36° C., fermented for 20-28 hours, during which the fermentation is turned over every 4 hours to ensure uniform fermentation, and the fermented oats are sterilized instantaneously at ultra-high temperature for standby use.

4. The method according to claim 3, characterized in that The fermented oats are sterilized at a temperature of 145° C. for 3 seconds.

5. The method according to claim 1, characterized in that In the step of preparing the room temperature yogurt, high-quality fresh milk is selected, filtered and standardized to make the protein content reach 3.0%-3.5%, and the fat content reach 3.0%-4.0%, the treated milk is sterilized at 85-95°C for 5-10 minutes, then quickly cooled to 40-45°C, conventional yogurt fermentation strains: thermophilic streptococcus and bulgaricus lactobacillus are selected, activated according to the strain instructions, the activated yogurt strains are inoculated into the sterilized milk at an inoculation amount of 0.5%-1.5% (v / v), fermented at 40-45°C for 3-6 hours until the acidity of the yogurt reaches 70-90°T, and the fermentation is stopped to obtain a yogurt base.

6. The method according to claim 1, characterized in that In the step of mixing and preparing the product, the fermented oats prepared in step one and the yogurt base prepared in step two are mixed in a volume ratio of 1:9-1:4, stirred evenly, and then 0.5%-1.5% of a sweetener is added or not added according to market demand, and 0.1%-0.3% of a stabilizer is added. After homogenization and filling, secondary sterilization is performed to obtain room temperature boulardii yeast fermented oatmeal yogurt.

7. The method according to claim 6, characterized in that The sweetener is xylitol or erythritol.

8. The method according to claim 6, characterized in that The stabilizer is sodium carboxymethyl cellulose or pectin.

9. The method according to any one of claims 1 to 8, characterized in that The homogenization pressure is 15-20 MPa.

10. The method according to claim 1, characterized in that The room-temperature boulardii yeast fermented oatmeal yogurt can be stored at room temperature of 15-25° C. for 30-60 days and still maintain good taste, flavor and probiotic activity.

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