Fermented lotus seed yogurt and preparation method thereof

Abstract

The application belongs to the technical field of food science and technology, and particularly relates to a fermented lotus seed yogurt with improved flavor and a preparation method thereof. The fermented lotus seed yogurt comprises the following components in parts by weight: lotus seed milk 14-20 parts; milk 72-92 parts; sugar 6-8 parts; citrus fiber 0.1-0.2 parts; high-fat pectin 0.05-0.1 parts; and fermentation bacteria powder 0.1-0.2 parts. The fermented lotus seed yogurt has the advantages of uniform texture, difficulty in stratification and smooth taste.

Description

Technical Field

[0001] This invention belongs to the field of food science and technology, specifically relating to a fermented beverage made from a mixture of plant milk and animal milk, and more particularly to a fermented lotus seed yogurt with stable texture and excellent taste, and its preparation method. Background Technology

[0002] With the increasing demand from consumers for healthy, low-calorie, and lactose-intolerant alternatives, the market for plant-based fermented beverages (such as fermented soy milk, almond milk, and coconut milk) is rapidly expanding. Lotus seeds, rich in starch, protein, and various trace elements, are a typical food and medicine homology ingredient, thus the development of lotus seed fermented beverages has broad prospects. However, existing plant-based fermented beverages generally suffer from textural instability. During fermentation, the decrease in pH causes denaturation and aggregation of plant and milk proteins. Combined with heat treatment, this easily leads to dehydration and shrinkage, resulting in whey separation, particle precipitation, and stratification, severely affecting the product's shelf-life stability and consumer sensory experience. Commonly used stabilizers in existing technologies include carrageenan and CMC, but in acidic, high-temperature, and plant-milk protein complex systems, high addition amounts are often required to achieve a certain level of stability, easily leading to unpleasant sensations such as stickiness and a greasy mouthfeel. Therefore, it is necessary to provide a novel stable system and its formula and process suitable for fermented lotus seed yogurt, which can improve the textural stability of the system under high temperature sterilization and acidic fermentation conditions while maintaining the good flavor, taste and nutritional characteristics of the product, and reduce whey precipitation and sedimentation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a fermented lotus seed yogurt with uniform texture, non-layering, and smooth taste, and a method for preparing the same.

[0004] To solve the above-mentioned technical problems, the present invention provides a fermented lotus seed yogurt with stable texture, comprising the following components by weight: 14-20 parts lotus seed milk; 72-92 parts milk; 6-8 parts sugar; 0.1-0.2 parts citrus fiber; 0.05-0.1 parts high-fat pectin; and 0.1-0.2 parts fermentation starter.

[0005] As an improvement to the fermented lotus seed yogurt of the present invention: the lotus seed milk is prepared by boiling, crushing and filtering lotus seeds and water in a weight ratio of 1:(5±0.5).

[0006] As a further improvement to the fermented lotus seed yogurt of the present invention: the weight ratio of citrus fiber to high-fat pectin is 1~4:1.

[0007] As a further improvement to the fermented lotus seed yogurt of the present invention: the degree of esterification of the high-fat pectin is 72%.

[0008] As a further improvement to the fermented lotus seed yogurt of the present invention: more than 90% of the citrus fiber particles are required to be less than 125 micrometers.

[0009] As a further improvement to the fermented lotus seed yogurt of the present invention: the lotus seeds are white lotus seeds from Chuzhou.

[0010] This invention also provides a method for preparing the above-mentioned fermented lotus seed yogurt, comprising the following steps: S1. Preparation of lotus seed milk: Lotus seeds were boiled in boiling water for 20±2 minutes according to a weight ratio of lotus seeds to water of 1: (5±0.5). The mixture was then ground into a paste, and the resulting paste was filtered to obtain lotus seed milk (a fine lotus seed milk used as a base material). S2. Mixing and Dissolving: The lotus seed milk obtained in step S1 is mixed with milk, sugar, high-fat pectin, and citrus fiber. The mixture is stirred under heating conditions until the citrus fiber and high-fat pectin (as a stabilizer) are completely dissolved to obtain a mixed liquid. S3. Filling and sterilization: The mixture obtained in step S2 is filled into a sealed container and subjected to high-temperature water bath sterilization. S4. Fermentation: Cool the sterilized liquid obtained in step S3 to the fermentation temperature, inoculate with fermentation starter culture, and ferment at a constant temperature for 6±0.5 hours. The fermentation temperature was 42±0.5℃; S5. Post-ripening: The product obtained from fermentation in step S4 is subjected to post-ripening at 3-5°C for at least 12 hours (generally 12-18 hours) to obtain fermented lotus seed yogurt.

[0011] As an improvement to the method of the present invention: the heating in step S2 is carried out in a boiling water bath.

[0012] As a further improvement to the method of the present invention: the high-temperature water bath sterilization in step S3 is: boiling in boiling water for 40±5 minutes.

[0013] As a further improvement to the method of the present invention: the slurry in step S3 is filtered in two stages by passing it through 150-mesh and 200-mesh filters in sequence.

[0014] In summary, the preparation method of this invention includes: fine preparation of lotus seed milk (two-stage filtration), complete dissolution of the stabilizer under heat, thorough sterilization after filling, controlled fermentation, and necessary cold-cooling ripening. This entire process ensures that the final product meets both microbial safety and textural stability standards.

[0015] The key innovation of this invention lies in the selection of the stabilizer system: a combination of high-fat pectin and trace amounts of citrus fiber is used.

[0016] High-fat pectin (pectin with an esterification degree higher than 50%) can form a stable gel network in acidic environments, providing excellent protection for protein particles. However, its effectiveness is insufficient when used alone under high-intensity heat processing. Adding trace amounts of citrus fiber allows its fiber network to synergistically enhance the high-fat pectin, significantly improving the water retention and heat resistance of the entire system. This ensures that the beverage remains homogeneous and stable even under the dual challenges of boiling water sterilization and acidic fermentation.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention creatively employs a stabilizer system composed of high-fat pectin and trace amounts of citrus fiber. High-fat pectin can form a stable three-dimensional gel network in an acidic fermentation environment, effectively encapsulating and protecting protein particles, preventing protein aggregation and precipitation due to heat and acidification. Simultaneously, the citrus fiber network and high-fat pectin produce a significant synergistic effect, greatly enhancing the system's water-holding capacity and structural strength. This composite stabilizer system can withstand the dual challenges of high-intensity heat processing such as subsequent boiling water sterilization and fermentation acid production, ensuring that the product maintains a uniform and stable suspension state throughout its shelf life, without stratification or water separation. In other words, this invention overcomes the defects of existing fermented plant-based milk beverages, such as unstable texture and easy water separation and stratification.

[0018] 2. Through meticulous pretreatment of lotus seed milk (two-stage filtration) and the optimization effect of compound stabilizers, the final product has a delicate texture, no grainy feel, and a smooth mouthfeel. The stable system avoids the formation of protein particles or sediment. At the same time, through controlled fermentation and sufficient cold refrigeration and ripening, the product develops a unique fermented flavor, with a balanced sweet and sour taste, and a perfect blend of lotus seed fragrance and milky aroma, resulting in a rich and layered taste.

[0019] 3. The complete preparation process provided by this invention, from the precise preparation of lotus seed milk and the full dissolution of stabilizers under heat, to thorough sterilization after filling, controlled fermentation, and necessary cold-chain ripening, has clearly defined parameter controls at each step. This process not only ensures the controllability and consistency of the fermentation process, producing products with stable quality, but also guarantees the microbiological safety of the product and extends its shelf life through thorough heat sterilization and cold-chain ripening.

[0020] 4. The selected stabilizers, high-fat pectin and citrus fiber, are both derived from natural plants, meeting current consumer demands for clean labels and healthy beverages. By precisely limiting the optimal ratio of citrus fiber to high-fat pectin within the range of (1:1) to (4:1) and controlling the fineness of the citrus fiber, the best stabilizing effect is achieved with minimal addition, avoiding unpleasant tastes such as a sticky or overly viscous texture caused by excessive use of colloids.

[0021] In summary, this invention, through the synergistic effect of high-fat pectin and citrus fiber, effectively inhibits whey precipitation and sedimentation while preserving the fermented flavor and characteristic aroma of lotus seeds, significantly improving the textural stability and sensory quality of fermented lotus seed yogurt, and providing a new technical solution for the stabilization of plant-based fermented beverages. Attached Figure Description

[0022] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] Figure 1 A comparison of the types and total content of substances in fermented lotus seed yogurt and fermented milk yogurt; Figure 2 A comparison of the aroma compound distribution between fermented lotus seed yogurt and fermented milk yogurt; Figure 3 It is the main aroma component of fermented lotus seed yogurt; Figure 4 It is the main aroma substance in fermented lotus seed yogurt. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto: Except for lotus seed milk, all other ingredients in this invention can be obtained through conventional commercial means.

[0025] For example: Citrus fiber can be purchased from Liyang Biotechnology Co., Ltd.; high-fat pectin can be purchased from Jiahe Food Industry Co., Ltd.; fermentation starter can be purchased from Angel Yeast Co., Ltd. (Baizuan Old Yogurt Type Yogurt Starter, 4-strain Yogurt Starter).

[0026] Example 1: A fermented lotus seed yogurt with a stable texture, which is composed of the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, 0.1 parts high-fat pectin, 0.1 parts citrus fiber, and 0.1 parts fermentation starter.

[0027] Follow these steps in sequence: S1. Pretreatment of lotus seed milk: Following the weight ratio of cored lotus seeds to water of 1:5, boil the cored lotus seeds in boiling water for 20 minutes, then grind them into a paste. The resulting paste is then filtered through 150-mesh and 200-mesh filters in two stages to obtain a fine lotus seed milk. S2. Mixing and dissolving: Mix the lotus seed milk (20 parts), milk (72 parts), sugar (8 parts), high-fat pectin (0.1 parts), and citrus fiber (0.1 parts) obtained in step (1), and stir in a boiling water bath until the stabilizer (i.e., citrus fiber and high-fat pectin) is completely dissolved to obtain a mixed liquid; S3. Filling and sterilization: The mixture is filled into a sealed container and boiled in boiling water for 40 minutes to achieve high-temperature water bath sterilization. S4. Fermentation: Cool the sterilized liquid to a fermentation temperature of 42℃, add 0.1 parts of fermentation starter, and ferment at a constant temperature of 42℃ for 6 hours; S5. Post-ripening: After fermentation, the product obtained from step S4 was subjected to post-fermentation at 4°C for 12 hours to obtain fermented lotus seed yogurt.

[0028] Example 2: A fermented lotus seed yogurt with a stable texture, comprising the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, 0.05 parts high-fat pectin, 0.2 parts citrus fiber, and 0.1 parts fermentation starter.

[0029] The preparation method is the same as in Example 1.

[0030] Example 3: A fermented lotus seed yogurt with a stable texture, comprising the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, 0.05 parts high-fat pectin, 0.1 parts citrus fiber, and 0.1 parts fermentation starter.

[0031] The preparation method is the same as in Example 1.

[0032] Example 4: A fermented lotus seed yogurt with a stable texture, comprising the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, 0.1 parts high-fat pectin, 0.2 parts citrus fiber, and 0.1 parts fermentation starter.

[0033] The preparation method is the same as in Example 1.

[0034] Yogurt Comparison: A fermented yogurt, specifically a lotus seed yogurt, is composed of the following components in parts by weight: Milk 92 parts, sugar 8 parts, high-fat pectin 0.05 parts, citrus fiber 0.2 parts, fermentation starter 0.1 parts.

[0035] The preparation method is as follows: compared with Example 1, step S1 is omitted, and the use of "lotus seed milk" in step S2 is omitted accordingly. The rest of the preparation method is the same as that in Example 1.

[0036] Comparative Example 1: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 14 parts lotus seed milk; 78 parts milk; 8 parts sugar; and 0.1 parts fermentation starter.

[0037] The preparation method is as follows: compared with Example 1, the use of high-fat pectin and citrus fiber is omitted in step S2; the rest is the same as the preparation method of Example 1.

[0038] Comparative Example 2: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 14 parts lotus seed milk; 80 parts milk; 6 parts sugar; and 0.2 parts fermentation starter.

[0039] The preparation method is the same as that of Comparative Example 1.

[0040] Comparative Example 3: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, and 0.1 parts fermentation starter.

[0041] The preparation method is the same as that of Comparative Example 1.

[0042] Comparative Example 4: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 20 parts lotus seed milk, 74 parts milk, 6 parts sugar, and 0.2 parts fermentation starter.

[0043] The preparation method is the same as that of Comparative Example 1.

[0044] Comparative Example 5: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 16 parts lotus seed milk, 76 parts milk, 8 parts sugar, and 0.1 parts fermentation starter.

[0045] The preparation method is the same as that of Comparative Example 1.

[0046] Comparative Example 6: A fermented lotus seed yogurt, which is composed of the following components in parts by weight: 16 parts lotus seed milk, 78 parts milk, 6 parts sugar, and 0.2 parts fermentation starter.

[0047] The preparation method is the same as that of Comparative Example 1.

[0048] Comparative Example 7: A fermented lotus seed yogurt with stable texture, comprising the following components in parts by weight: 20 parts lotus seed milk, 72 parts milk, 8 parts sugar, 0.2 parts high-fat pectin, 0.1 parts citrus fiber, and 0.1 parts fermentation starter.

[0049] The preparation method is the same as in Example 1.

[0050] The components of the above cases are compared in Table 1 below.

[0051] Table 1 Example 1 20 72 8 0.1 0.1 0.1 Example 2 20 72 8 0.05 0.2 0.1 Example 3 20 72 8 0.05 0.1 0.1 Example 4 20 72 8 0.1 0.2 0.1 Yogurt Comparison / 92 8 0.05 0.2 0.1 Comparative Example 1 14 78 8 / / 0.1 Comparative Example 2 14 80 6 / / 0.2 Comparative Example 3 20 72 8 / / 0.1 Comparative Example 4 20 74 6 / / 0.2 Comparative Example 5 16 76 8 / / 0.1 Comparative Example 6 16 78 6 / / 0.2 Example 7 20 72 8 0.2 0.1 0.1 .

[0052] The following experiments were conducted on all the above embodiments and comparative examples. Experiment 1, Sensory Evaluation

[0053] Table 2 Sensory Evaluation Criteria

[0054] Table 3 Sensory evaluation scores for each embodiment and comparative example

[0055] In the sensory evaluation system in Table 2, Example 2, with a total score of 88.2, is the best performing group among all comparative examples, and its advantage is significantly different from other comparative examples. From a specific perspective, Example 2 achieved a lotus seed aroma score of 9.6 and a milk and fermentation aroma score of 9.5, ranking first among all comparative examples. These two scores far exceeded the 8.3 scores of Example 1 for milk and fermentation aroma, and also made up for the lack of lotus seed aroma score in Example 5. Its natural lotus seed fragrance is pure and without any pungent smell, and the integration of milk and fermentation aroma is excellent, without any off-flavors or disjointed aromas. At the same time, Example 2 achieved a lotus seed flavor score of 9.2, which is better than the 8.4 scores of Examples 1 and 3. The lotus seed flavor is highly recognizable in the mouth and has a moderate retention time after swallowing, with outstanding flavor layers. In terms of texture, Example 2 achieved a fineness score of 8.6, which is better than the 8.2 score of Example 3, and has no gritty or rough feel. Its viscosity score of 8.4 is also suitable for drinking needs, and the overall taste is balanced and harmonious.

[0056] The excellent sensory performance is closely related to the formulation design of Example 2. Example 2 uses a compound formulation of 0.05 parts high-fat pectin and 0.2 parts citrus fiber. This ratio avoids the sticky taste caused by excessive stabilizer addition, and also prevents system instability caused by insufficient stabilizer. At the same time, the combination of fiber network and gel network can effectively fix the aroma components in lotus seed milk, reduce the volatilization and loss of aroma during fermentation, and thus ensure the purity and integration of aroma. The raw material ratio also provides a good foundation for flavor release. 20 parts lotus seed milk can provide sufficient lotus seed flavor substances, and the combination of 72 parts milk and 8 parts sugar balances the ratio of lotus seed fragrance and milky aroma, without masking the core flavor due to excessive sweetness.

[0057] Comparative Examples 1-6, by omitting the use of high-fat pectin and citrus fiber, confirm that high-fat pectin and citrus fiber are indispensable key components for achieving the excellent stability, ideal texture, and good sensory quality of the product of this invention. Without these two components, relying solely on lotus seed milk, milk, sugar, and fermentation starter cannot achieve the technical effects presented in the examples. Furthermore, it demonstrates that the technical effect of this invention is not the result of a single component, but rather the synergistic effect of high-fat pectin and citrus fiber in the lotus seed milk-milk composite system. This synergistic effect is key to achieving comprehensive product quality improvement and is also an important innovation that distinguishes this invention from existing technologies. In addition, the comparative examples clearly show that only a formula containing lotus seed milk, milk, sugar, high-fat pectin, citrus fiber, and fermentation starter can obtain the expected excellent quality.

[0058] Experiment 4, GC-MS Analysis The specific GC-MS analysis method is as follows: refer to GB / T 30431—2020.

[0059] A comparative analysis of the GC data of fermented lotus seed yogurt in Example 2 and a yogurt comparison example (fermented milk yogurt) shows that, as Figure 1 As shown, the two types of yogurt differed significantly in the types and amounts of aroma compounds: In terms of types, fermented milk yogurt detected 23 aroma compounds, slightly more than the 21 detected in fermented lotus seed yogurt. Figure 2 As shown, the two share only 7.32% of their substances; fermented lotus seed yogurt contains 43.9% of its unique substances, while fermented milk yogurt contains 48.78% of its unique substances; Figure 3 As shown in Figure 4, in terms of content, fermented milk yogurt accounted for 90.14% of the total content, slightly higher than the 88.22% of fermented lotus seed yogurt. Among the common substances, acetoin showed the most significant difference, and the core characteristic substances of the two types of yogurt differed: fermented lotus seed yogurt was dominated by hexanoic acid (12.14%) and 2,3-butanedione (9.46%), with organic acids making a significant contribution and a fresher flavor; fermented milk yogurt was dominated by acetoin (19.90%) and valeric acid (15.30%), with organic acids and other substances working synergistically, resulting in a richer, sweeter milk aroma. Overall, the addition of lotus seeds significantly altered the composition of yogurt aroma substances, giving the two types of yogurt distinctly different flavor characteristics.

[0060] Specifically, fermented lotus seed yogurt is characterized by its "refreshing and light" flavor. The high proportion of hexanoic acid complements the natural flavor of lotus seeds, and the dominant role of organic acids makes its texture lighter. Fermented milk yogurt, on the other hand, is characterized by its "rich and full-bodied" flavor. The absolute dominance of acetoin gives it a strong, sweet milky aroma, and the presence of more unique substances makes its flavor more complex. The difference between the two types of fermented yogurt essentially lies in the alteration of the metabolic pathways of aroma compounds caused by the addition of lotus seeds, ultimately resulting in distinct flavor systems that can satisfy the different flavor preferences of consumers.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the technical solutions of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A fermented lotus seed yogurt with stable texture, characterized in that: By weight, it includes the following components: 14-20 parts lotus seed milk; 72-92 parts milk; 6-8 parts sugar; 0.1-0.2 parts citrus fiber; High-fat pectin 0.05~0.1 parts; 0.1 to 0.2 parts of fermentation starter.

2. The fermented lotus seed yogurt according to claim 1, characterized in that: The lotus seed milk is made by boiling, crushing, and filtering lotus seeds and water in a weight ratio of 1:(5±0.5).

3. The fermented lotus seed yogurt according to claim 2, characterized in that: The weight ratio of citrus fiber to high-fat pectin is 1~4:

1.

4. The fermented lotus seed yogurt according to claim 3, characterized in that: The degree of esterification of the high-fat pectin is 72%.

5. The fermented lotus seed yogurt according to claim 4, characterized in that: More than 90% of citrus fiber particles are required to be smaller than 125 microns.

6. The fermented lotus seed yogurt according to any one of claims 1 to 5, characterized in that: The lotus seeds mentioned are white lotus seeds from Chuzhou.

7. The method for preparing fermented lotus seed yogurt according to any one of claims 1 to 6, characterized in that... Includes the following steps: S1. Preparation of lotus seed milk: Lotus seeds were boiled in boiling water for 20±2 minutes according to a weight ratio of lotus seeds to water of 1: (5±0.5); then ground into a paste, and the resulting paste was filtered to obtain lotus seed milk. S2. Mixing and Dissolving: The lotus seed milk obtained in step S1 is mixed with milk, sugar, high-fat pectin and citrus fiber, and stirred under heating conditions until the citrus fiber and high-fat pectin are completely dissolved to obtain a mixed liquid. S3. Filling and sterilization: The mixture obtained in step S2 is filled into a sealed container and subjected to high-temperature water bath sterilization. S4. Fermentation: Cool the sterilized liquid obtained in step S3 to the fermentation temperature, inoculate with fermentation starter culture, and ferment at a constant temperature for 6±0.5 hours. The fermentation temperature was 42±0.5℃; S5. Post-ripening: The product obtained from fermentation in step S4 is subjected to post-ripening at 3-5°C for at least 12 hours (generally 12-18 hours) to obtain fermented lotus seed yogurt.

8. The method according to claim 7, characterized in that: The heating in step S2 is carried out in a boiling water bath.

9. The method according to claim 8, characterized in that: The high-temperature water bath sterilization in step S3 is: boiling in boiling water for 40±5 minutes.

10. The method according to claim 9, characterized in that: In step S3, the slurry is filtered through 150-mesh and 200-mesh filters in two stages.

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