Digestible fermented dough for infants and toddlers and method for preparing the same

Abstract

The application provides a digestible fermented dough suitable for infants and children and a preparation method thereof, which comprises the following steps: atomizing and pre-hydrating flour to a water content of 20-24%, adding 0.10-0.25% of CDLB-YE05 strain powder of Saccharomyces Kazakhstan by mass of the flour, and fermenting at 30-40 DEG C for 1.5-2.5 hours, then secondly kneading to a final water content of 32-38%, vacuum kneading, aging and calendering to obtain the fermented dough. The application utilizes the characteristics of the strain, i.e. no gas production and no ethanol production, to avoid the destruction of the gluten network, and the extracellular polysaccharide and organic acid produced by the metabolism of the strain endow the noodles with a honeycomb structure, realizing the digestible property; the flower and fruit flavor substances produced by the fermentation make the noodles have a strong wheat flavor and no irritating odor; the organic acid accumulated by the fermentation forms a natural antibacterial environment, effectively prolonging the shelf life. The fermented dough prepared by the application can be sold as fresh noodles in cold storage, and can also be dried to produce dried noodles, having a good industrialization popularization prospect.

Description

Technical Field

[0001] This invention belongs to the field of infant food and noodle processing technology, specifically relating to a method for preparing easily digestible, flavorful fermented noodles suitable for infants using Kazakhstan yeast (Kazachstania servazzii) CDLB-YE05. Background Technology

[0002] Noodles, a staple food with a long history, are beloved by consumers for their diversity in form, processing, and flavor. Children's noodles, especially those targeting infants and toddlers (referring to children in early growth and development whose digestive systems are not yet fully mature, particularly those from the introduction of complementary foods to preschool age), are mostly in the form of dried noodles. These noodles typically have a moisture content of less than 14%, offering advantages such as long shelf life, ease of storage and transportation, and convenience of consumption, making them the mainstream product form in the current infant and toddler complementary food market. However, traditional dried noodles undergo high-temperature drying during production, resulting in the loss of some natural flavor compounds in the wheat, leading to a less intense wheat aroma. Simultaneously, the gluten protein undergoes a certain degree of denaturation and polymerization during drying, forming a relatively dense and rigid network structure. This makes the dried noodles hard and difficult to chew after rehydration. Since infants' digestive systems are not yet fully developed, consuming these noodles can easily cause indigestion and bloating. Furthermore, ordinary dried noodles only have a single wheat aroma, offering a limited flavor profile that is unlikely to stimulate the appetite of infants and toddlers.

[0003] While fresh noodles (moisture content > 30%) can better retain the natural flavor and nutrients of wheat and have a soft and smooth texture, their shelf life is extremely short, typically less than 24 hours at room temperature (25℃), severely limiting their industrial production and market circulation. Drying fresh noodles into dried noodles presents new problems such as loss of wheat aroma, hardening of the texture, and difficulty in digestion.

[0004] Fermentation technology, as an important biomodification method, has significant application value in improving the texture and flavor of noodles. The organic acids, alcohols, esters, and extracellular polysaccharides produced by microbial metabolism can impart unique fermented flavors to noodles and extend their shelf life to some extent. However, the microbial resources currently used in fermented noodle research and production are relatively concentrated, mainly relying on *Saccharomyces cerevisiae* and a few lactic acid bacteria (such as *Lactobacillus plantarum*), which still has significant limitations in achieving synergistic optimization of "flavor enhancement, texture strengthening, and shelf-life extension." More importantly, existing fermented noodles are not designed for infants and children, and their flavor and texture characteristics often do not match the digestive abilities and flavor preferences of infants and children.

[0005] Traditional brewing yeast produces large amounts of CO2 and ethanol during fermentation. The accumulation of CO2 easily forms irregular porous structures within the dough, damaging the noodles' density and structural integrity. Ethanol partially dissolves gluten proteins, interfering with the hydrophobic interactions and disulfide bond cross-linking between glutenin and gliadin, inhibiting the construction of a continuous, dense gluten network. Furthermore, reducing substances produced during brewing yeast metabolism (such as glutathione) can also damage the disulfide bonds and polymeric structures of gluten proteins, further weakening the gluten network. The ethanol and reducing substances produced by yeast metabolism ultimately lead to decreased noodle hardness and tensile properties, and increased cooking losses. When using a single lactic acid bacteria for fermentation, excessive acid production can easily lead to an excessively low pH, causing excessive denaturation of gluten proteins or damage to starch granules, resulting in a sour taste and softened texture. This overly sour taste is particularly unacceptable to infants and children. In addition, the alcoholic and pungent taste produced by brewing yeast fermentation masks the natural wheat aroma, failing to meet infants' preference for mild, natural flavors.

[0006] Therefore, exploring non-traditional functional microorganisms with differentiated metabolic characteristics and developing fermentation processes that can balance texture preservation, flavor enhancement, and bio-preservation, while being particularly suitable for infants and young children (easily digestible, rich wheat aroma, and non-irritating flavor), has become an important direction for overcoming current technological bottlenecks. This fermented noodle can be sold directly as fresh noodles (short shelf life under refrigeration) or processed into dried noodles using conventional drying processes (long shelf life at room temperature) to meet the actual product demands of the children's noodle market.

[0007] Kazachstania servazzii CDLB-YE05 is a novel functional yeast strain isolated from traditional fermented foods. According to genome sequencing and metabolic characteristics analysis, this strain has the following significant characteristics: (1) It does not produce gas or ethanol, which can avoid the destruction of gluten network caused by gas expansion and ethanol dissolution, and also avoid the harm of ethanol to infants and children; (2) It has a complete glycolysis pathway, and the carbon flow is mainly inclined to the synthesis of organic acids and flavor substances. Lactic acid continues to accumulate during the fermentation process, and acetic acid increases significantly in the middle and late stages. At the same time, it can synthesize a variety of volatile flavor substances with floral and fruity aromas, such as phenylethanol, ethyl acetate, and ethyl propionate. These mild sweet and fruity aromas work synergistically with the wheat aroma itself to form a rich and natural overall aroma, which greatly improves the acceptance of infants and children; (3) It has the ability to synthesize extracellular polysaccharides. The content of extracellular polysaccharides can reach 160.72 mg / L after 72 hours of fermentation. This extracellular polysaccharide helps to form a dense and moderately soft gluten network, making the protein structure easier for infants and children to digest and decompose, thus achieving the physiological effect of "easy digestion". The non-gas-producing properties and unique metabolic characteristics of this strain make it possible to improve flavor, digestibility, and biopreservation while maintaining the density of the dough structure.

[0008] However, there are currently no systematic studies or reports on the effective application of this strain in infant noodle systems, and the achievement of synergistic effects such as "easy digestibility, rich wheat aroma, optimized texture, and extended shelf life" through precise process control. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides an easily digestible fermented noodle suitable for infants and children, and its preparation method. It utilizes *Saccharomyces cerevisiae* CDLB-YE05 to prepare an easily digestible fermented noodle with a rich wheat aroma suitable for infants and children. This solves the technical problems of existing infant noodle products, such as insufficient wheat aroma, hard texture, and difficulty in digestion, as well as reliance on chemical additives and short shelf life. The invention achieves a synergistic effect of "easy digestibility, enhanced wheat aroma, optimized texture, and extended shelf life."

[0010] The fermented noodles prepared by this invention can be used directly as fresh noodles (short shelf life under refrigeration) or processed into dried noodles using conventional drying processes (long shelf life at room temperature), fully adapting to the actual product form of the infant noodle market.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A method for preparing easily digestible fermented dough suitable for infants and young children using Kazakhstan yeast CDLB-YE05 includes the following steps:

[0013] Step (1), Pre-hydration of raw materials: Place flour in a constant temperature fermentation mixer and stir at a constant speed. Add the first amount of water in an atomizing manner for 8-12 minutes, so that the flour gradually absorbs water under stirring and forms a semi-moist and fluffy powder. After the first water addition, the moisture content of the material should reach 20-24%.

[0014] Step (2), Yeast addition and fermentation: Sprinkle the CDLB-YE05 yeast powder evenly into the material obtained in step S (1), and ferment at a constant temperature of 30-40℃ for 1.5-2.5 hours; the amount of CDLB-YE05 yeast powder added is 0.10-0.25% of the flour mass;

[0015] Step (3), Secondary Kneading: Transfer the fermented dough from step (2) to a vacuum dough mixer, add water a second time to bring the final dough moisture content to 32-38%, and dissolve salt and edible alkali in the added water; the amount of salt added is 0-2.00% of the flour mass, and the amount of edible alkali added is 0-0.30% of the flour mass; knead under vacuum conditions for 8-12 minutes, with a vacuum degree of -0.06 to -0.09 MPa;

[0016] Step (4), maturation: Take out the kneaded dough flakes, cover them with a damp towel to prevent the surface from drying out, and mature them for 12-20 minutes at a temperature of 33-37℃ and a relative humidity of 75-85%.

[0017] Step (5), Rolling and Shaping: The matured dough flakes are rolled on a noodle-making machine. After the dough strip is folded and rolled, it is rolled in sequence at each of the decreasing roller gaps. Finally, it is cut into strips to obtain fermented fresh noodles. These fresh noodles can be directly packaged and refrigerated for sale, or further dried to make fermented dried noodles.

[0018] Furthermore, the preferred atomization water addition time in step (1) is 10 minutes. Atomization water addition allows water to uniformly cover the surface of flour particles in the form of micron-sized droplets, extending the water molecule penetration time and promoting the gradual hydration and cross-linking of gluten proteins. Simultaneously, continuous mechanical stirring breaks down nascent aggregates through shearing action, effectively optimizing the particle size distribution of flour flakes and increasing the proportion of small-to-medium diameter flour flakes (d < 2 mm) to over 58%, providing a uniform fermentation substrate for yeast metabolism.

[0019] Furthermore, in step (2), the preferred amount of CDLB-YE05 yeast powder added is 0.18% of the flour mass; the preferred fermentation temperature is 34℃; and the preferred fermentation time is 2.0-2.2 hours. Within this preferred range, the yeast metabolic activity and gluten protein reconstruction reach an optimal balance. The synthesis and accumulation of extracellular polysaccharides can significantly promote the tight binding of the gluten network, and the moderate accumulation of organic acids can promote the beneficial adjustment of hydrogen bonds and electrostatic interactions between protein molecules, making the final product easier for infants to digest.

[0020] Furthermore, in step (1), the dough moisture content reaches 22.61% after the first addition of water; in step (2), the fermentation time is 2.15 hours; in step (3), the final dough moisture content is 36%, the salt addition is 0.5g / 500g flour (0.1%), and the edible alkali addition is 0.25g / 500g flour (0.05%); in step S (4), the preferred maturation temperature is 35℃, the preferred relative humidity is 80%, and the preferred maturation time is 15 minutes. This optimal combination of process parameters was obtained through response surface methodology optimization. In the verification experiment, the chewy texture of the cooked noodles reached 138.53g, while maintaining good softness and digestibility.

[0021] The specific operation of the calendering in step (5) can be as follows: First, perform initial calendering at a roller spacing of 2.4-2.8 mm on the dough rolling machine to initially extend the dough. Then, fold and calender the dough strip 3-4 times. After turning the dough strip over, calender it once. Next, calender the dough strip once at 2.0-2.4 mm, 1.6-2.0 mm, and 1.2-1.6 mm in sequence. Finally, cut the dough strip into shreds at 0.8-1.2 mm. Preferably, the roller spacing is 2.6 mm, 2.2 mm, 1.8 mm, 1.4 mm, and 1.0 mm in sequence.

[0022] The final dough moisture content is 32-38%, wherein in step S (1), water is added for the first time to make the dough moisture content reach 20-24%, and in step (3), water is added a second time to make up to the final moisture content.

[0023] The Kazakhstan yeast CDLB-YE05 described is a known strain, deposited on July 17, 2023, at the Institute of Microbiology, Chinese Academy of Sciences (accession number CGMCC NO. 27948). It is available to the public through this depository or via commercial channels (such as Shenzhen Peptide Biotechnology Co., Ltd.). The basic fermentation characteristics of this strain are: no gas production, no ethanol production; sugar source utilization capacity in the order of glucose > sucrose > maltose > lactose; continuous accumulation of lactic acid up to 20.66 g / L (72 h) during fermentation; rapid accumulation of acetic acid in the middle and late stages; low and relatively stable levels of citric acid and succinic acid; total volatile flavor compounds reaching 2837.37 μg / L at 72 h, with alcohols and esters as the main components, and phenylethanol, ethyl acetate, and ethyl propionate contributing typical floral and fruity aromas; and extracellular polysaccharide content reaching 160.72 mg / L at 72 h. Genomic KEGG pathway analysis showed that this strain possesses a complete glycolysis pathway, with carbon flow mainly focused on the synthesis of organic acids and flavor compounds, while also exhibiting metabolic pathways related to polysaccharide synthesis.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This invention achieves easily digestible properties for infant and toddler flour products. Utilizing the unique metabolic characteristics of the CDLB-YE05 strain—which does not produce gas or ethanol—this invention fundamentally avoids the physical damage to the gluten network structure caused by CO2 gas expansion during traditional brewing yeast fermentation, as well as the interference of ethanol on the hydrophobic interaction between glutenin and gliadin, and the inhibition of disulfide bond cross-linking. Simultaneously, the extracellular polysaccharides produced during fermentation bind with gluten proteins through hydrogen bonds and ions, filling the gluten network pores and promoting a tighter bond. The moderate accumulation of organic acids facilitates a favorable adjustment of hydrogen bonds and electrostatic interactions between protein molecules, resulting in a more compact protein arrangement and forming a continuous, relatively uniformly distributed "honeycomb" protein-starch complex network structure. This structure makes gluten proteins easier for infants' still-developing digestive enzymes to break down, making it more suitable for their immature digestive systems and improving the product's digestibility. The dense network structure achieved good chewability, with a chewiness value of 136.35g (32.8% higher than the unfermented group); the cooking loss rate was reduced to 4.89% (24.8% lower than the unfermented group), thus reducing nutrient loss.

[0026] 2. Achieving a rich and natural wheat aroma without any pungent odor. The fermentation process of the Kazakhstani yeast CDLB-YE05 in this invention promotes the production of alcohols and esters, with isoamyl alcohol achieving an odor activity value (OAV) of 14.444, phenylethanol reaching 30.385, and methyl palmitate reaching 17.452. These substances impart a lasting, mellow sweetness to the noodles, along with a harmonious blend of floral, fruity, and lipid aromas. This, combined with the natural wheat aroma, creates a rich and natural overall flavor, effectively avoiding the alcoholic and acrid tastes often associated with traditional brewing yeast fermentation. For infants and young children with sensitive palates, this mild and non-irritating flavor experience helps increase their acceptance.

[0027] 3. This invention achieves significant extension of biological preservation and shelf life without the need for additional chemical preservatives. During the fermentation process of CDLB-YE05, lactic acid and acetic acid continuously accumulate. Under storage conditions at 25℃, the contents of lactic acid and acetic acid reach peak levels of 8157.64 μg / g and 4897.76 μg / g, respectively, after 60 hours. These two organic acids constitute the core factors of the antibacterial acidic environment, effectively inhibiting the growth of spoilage bacteria. Based on this, the method of this invention extends the shelf life of fresh noodles from 13.44 hours to 21.00 hours at room temperature (25℃), an extension rate of 56.25%; and from 4.20 days to 6.29 days under refrigerated conditions at 4℃, an extension rate of 49.76%. The inhibitory effect on mold is particularly outstanding; after 48 hours of storage at room temperature and 8 days of refrigerated storage, mold levels drop to undetectable levels. If the fermented dough obtained by this invention is further dried to make dried noodles, it can be stored for more than 6 months at room temperature while maintaining good digestibility and rich wheat aroma, fully meeting the commercial needs of the infant noodle market.

[0028] 4. The process is highly operable, produces uniform products, and is easy to industrialize. This invention employs a core process design of "multi-stage atomized water addition + constant-temperature stirring fermentation," effectively solving the problems of rapid flour particle agglomeration, large clumps of flour, and uneven fermentation substrate caused by the instantaneous localized wetting of water in traditional single-stage direct water addition. Atomized water addition significantly increases the proportion of small-to-medium diameter flour particles (d<2mm) from 45.62% in single-stage direct water addition to 58.43%, providing a larger specific surface area for yeast metabolism. Simultaneously, a four-factor, three-level model (R²=0.9518) established using response surface methodology quantifies the interaction effects between yeast addition amount, fermentation temperature, fermentation time, and the first water addition amount, providing a scientific basis for precise control of process parameters and standardization for production at different scales. This process is suitable for fresh noodle production and can also be seamlessly integrated into existing dried noodle production lines without major equipment modifications. Attached Figure Description

[0029] Figure 1 The diagram shows the effect of different water addition methods on the particle size distribution of flocs (affecting the uniformity of the fermentation substrate and the digestibility of the subsequent infant noodles). A represents the group with one-time direct water addition; B represents the group with multiple-time direct water addition; C1-C3 represent the groups with multiple-time atomization water addition for different atomization times, with C1 atomization time of 5 min; C2 atomization time of 8 min; and C3 atomization time of 10 min.

[0030] Figure 2 Contour plots and surface plots showing the interaction between yeast addition and fermentation temperature (response value is the rib value).

[0031] Figure 3 Contour plots and surface plots showing the interaction between yeast addition and fermentation time (response value is the rib value).

[0032] Figure 4 Contour plot and surface plot of the interaction between yeast addition and initial water addition (response value is the rib value).

[0033] Figure 5 Contour plot and surface plot of the interaction between fermentation temperature and fermentation time (response value is the rib value).

[0034] Figure 6 Contour plot and surface plot of the interaction between fermentation temperature and the first water addition (response value is the gluten value).

[0035] Figure 7 Contour plot and surface plot of the interaction between fermentation time and the amount of water added in the first time (response value is the gluten value).

[0036] Figure 8 Comparison of SEM microstructures of cooked noodles after different fermentation treatments (showing the protein-starch complex network structure, which is closely related to digestibility), among which... Figure 8 a1-a3: Comparative Example 1 (unfermented blank group); Figure 8 b1-b3: Comparative Examples 2 (commercial brewing yeast fermentation group); Figure 8 c1-c3: Example 1 (CDLB-YE05 fermentation group); 1: ×40 (low magnification, to observe the overall morphology); 2: ×200 (medium magnification, to observe the binding state of gluten protein and starch granules); 3: ×500 (high magnification, to observe the fine structure of the gluten network).

[0037] Figure 9 PCA analysis chromatograms of flavor compounds from different fermentation treatments (distinguishing between a rich wheat flavor infant fermented noodle and a control), in which... Figure 9 A: Principal component score plot, used to distinguish the differences in flavor profiles of samples with different fermentation treatments (CK: Comparative Example 1 unfermented blank group; SC: Comparative Example 2 brewer's yeast fermentation group; YE05: Example 1 CDLB-YE05 fermentation group). Figure 9 B: Principal component loading plot, used to identify key flavor compounds that contribute significantly to the flavor differences among samples.

[0038] Figure 10 The graph shows a comparison of the total bacterial count changes under storage conditions of 25℃ and 4℃ (YE05: Example 1; CK: Comparative Example 1, unfermented blank group; reflecting the preservation effect of infant fermented noodles in fresh condition). Figure 10 A: Curves showing the change in total bacterial count of each sample over time under storage conditions at 25℃; Figure 10 B: Curves showing the change in total bacterial count of each sample over time under 4℃ refrigeration conditions. Detailed Implementation

[0039] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the reagents, materials, etc., used in the following embodiments are commercially available unless otherwise specified.

[0040] To facilitate understanding of the technical means, creative features, objectives, and effects of this invention, the following detailed description is provided in conjunction with specific embodiments. The Kazakhstan yeast CDLB-YE05 used in the following embodiments was purchased from Shenzhen Peptide Biotechnology Co., Ltd.; the commercial brewing yeast used was Angel high-activity dry yeast (Saccharomyces cerevisiae); and the flour used was commercially available medium-gluten flour (13.5% moisture content). The fermented noodles prepared in each embodiment can be directly packaged and refrigerated for sale as fresh noodles, or processed into dried noodles using conventional noodle drying processes (such as hot air drying or sun drying) to adapt to the mainstream product form of the infant noodle market.

[0041] Example 1 (Optimal Process Example)

[0042] A method for preparing easily digestible fermented dough suitable for infants and young children includes the following steps:

[0043] (1) Pre-hydration of raw materials: Weigh 500g of flour and mix it at a constant temperature fermentation mixer. Add the first amount of water in an atomizing manner to make the dough moisture content reach 22.61%. The atomization water addition time is 10 minutes. During the mixing process, scrape off the flour flakes adhering to the machine wall after 5 minutes. The flour gradually absorbs water under mixing and forms a semi-moist and fluffy homogeneous powder.

[0044] (2) Yeast addition and fermentation: Accurately weigh 0.9g (0.18% of the flour mass) of Kazakhstan yeast CDLB-YE05, sprinkle it evenly on the material obtained in step (1), and stir and ferment for 2.15 hours under constant temperature of 34℃.

[0045] (3) Second kneading: Transfer the fermented dough from step (2) to a vacuum dough mixer, and add the remaining water to bring the final dough moisture content to 36%. This embodiment sets up two parallel preparation schemes:

[0046] Option 1 (for fresh noodle quality testing): Dissolve 0.5g of salt and 0.25g of baking soda in water added twice, then add the flour mixture and knead under vacuum for 10 minutes. Stop the machine after 5 minutes of kneading, quickly scrape off the flour adhering to the machine walls and mixing shaft, and continue kneading for another 10 minutes. The resulting dough is used to prepare fresh noodles, and the cooking quality, texture, flavor, and shelf life are measured.

[0047] Option 2 (for determining the digestibility of dried noodles): Water is added twice without adding salt or baking soda; the rest of the dough kneading process is the same as in Option 1. The resulting dough is then dried to produce dried noodles, which are used for determining the in vitro digestibility of starch and protein.

[0048] (4) Maturation: Take out the kneaded dough and place it in a maturation basin. Cover the basin with a damp towel to prevent the surface from drying out. Place it in a constant temperature and humidity chamber and mature for 15 minutes at a temperature of 35℃ and a relative humidity of 80%.

[0049] (5) Rolling and shaping: Take out the matured dough flakes and place them on the noodle-making machine. First, roll the dough at a distance of 2.6 mm between the rollers to initially stretch it. Then, fold and roll the dough strip three times to shape it. Roll it once in reverse. Next, roll the dough strip at 2.2 mm, 1.8 mm, and 1.4 mm in sequence. Finally, cut it into strips at 0.8 mm or 1.0 mm to obtain fermented fresh noodles. These fresh noodles can be used directly for infants and children or further dried to make dried noodles.

[0050] Testing revealed that the fermented fresh noodles prepared according to Scheme 1 of this embodiment had a small to medium particle size ratio of 58.43%, a gluten content of 136.35g, a cooking loss rate of 4.89%, a shelf life of 21.00h at 25℃, and a shelf life of 6.29d at 4℃. High-performance liquid chromatography (HPLC) was used to dynamically monitor the organic acid content during storage at 25℃. Lactic acid and acetic acid reached their peak values ​​at 60h, with contents of 8157.64μg / g and 4897.76μg / g, respectively. Sensory evaluation showed a mellow floral and fruity aroma, a prominent sweetness, a rich wheat aroma, and no pungent odors, making it suitable for infants and children. Quantitative analysis of volatile flavor compounds was performed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The odor activity values ​​(OAV) of isoamyl alcohol reached 14.444, phenylethanol reached 30.385, and methyl palmitate reached 17.452, imparting a lasting and mellow complex aroma of floral, fruity, and lipid notes to the product. The microstructure exhibits a continuous and uniform "honeycomb" protein-starch complex network, which is beneficial for infant digestion. The dried noodles prepared according to Scheme 2 in this embodiment retain good softness and easy digestibility after rehydration, with in vitro digestibility of starch and protein reaching 67.3% and 69.5%, respectively. The coefficient of determination (R²) of the response surface model used to determine the above optimal process parameters was 0.9518, indicating a good model fit and reliable optimization results. Figure 1 The diagram illustrates the effect of different water addition methods on floc particle size distribution: A: direct water addition in one go; B: direct water addition in multiple stages; C1: water addition via atomization in multiple stages, atomization time 5 min; C2: water addition via atomization in multiple stages, atomization time 8 min; C3: water addition via atomization in multiple stages, atomization time 10 min. (Combined with...) Figure 1 As shown, this embodiment uses an atomization time of 10 minutes (i.e., Figure 1 The pre-hydration process (C3 method) resulted in a significantly higher proportion of small-to-medium diameter flocs (d < 2 mm) compared to direct water addition in a single step. Figure 1 (A) and adding water directly in several batches ( Figure 1 (B). This uniform fermentation substrate provides a larger specific surface area for the CDLB-YE05 strain, which is conducive to the uniform attachment of metabolites and the homogenization and reconstruction of the gluten network. This lays the microscopic foundation for the subsequent densification of product structure and improvement of digestibility.

[0051] Example 2 (Low bacterial count, low temperature, long-term fermentation example)

[0052] The difference between this embodiment and embodiment 1 is as follows: in step (1), the dough moisture content reaches 24% after the first addition of water, and the atomization water addition time is 8 minutes; in step (2), the amount of yeast powder added is 0.5g (accounting for 0.10% of the flour mass), the fermentation temperature is 30℃, and the fermentation time is 2.5 hours; in step (3), water is added a second time to make up to the final dough moisture content of 36%. The remaining steps and parameters are the same as in embodiment 1.

[0053] The process parameters in this embodiment are all within the protection scope defined by this invention: the dough moisture content of 24% after the first addition of water falls into the upper limit of the "20-24%" range; the yeast powder addition of 0.10% falls into the endpoint value of the "0.10-0.25%" range; the fermentation temperature of 30℃ falls into the endpoint value of the "30-40℃" range; and the fermentation time of 2.5 hours falls into the endpoint value of the "1.5-2.5 hours" range.

[0054] Testing revealed that due to the low yeast addition and low fermentation temperature, the yeast metabolic activity in this embodiment was relatively mild, resulting in slower aroma and acid production rates. However, because the fermentation time was extended to 2.5 hours, the overall fermentation was still fully completed. The proportion of small-to-medium diameter flour particles was 53.15%, the gluten content was 128.62 g, the cooking loss rate was 5.21%, the shelf life at 25°C was 19.2 h, and the shelf life at 4°C was 5.83 d. Compared to the unfermented control group (Comparative Example 1), the gluten content increased by 25.3%, the cooking loss rate decreased by 19.8%, and the shelf life at 25°C was extended by 42.9%. The product exhibits a moderately strong fermented aroma, a mild acidity, and a natural wheat flavor, making it suitable for infants and young children.

[0055] Example 3 (High bacterial count, high temperature, short fermentation time example)

[0056] The difference between this embodiment and embodiment 1 is as follows: In step (1), after the first addition of water, the dough moisture content reaches 20%, and the atomization water addition time is 12 minutes; in step (2), the amount of yeast powder added is 1.25g (accounting for 0.25% of the flour mass), the fermentation temperature is 40℃, and the fermentation time is 1.5 hours; in step (3), water is added a second time to make up to the final dough moisture content of 36%. The remaining steps and parameters are the same as in embodiment 1.

[0057] The process parameters in this embodiment are all within the protection scope defined by this invention: the dough moisture content of 20% after the first water addition falls within the lower limit of the "20-24%" range; the yeast powder addition of 0.25% falls within the endpoint of the "0.10-0.25%" range; the fermentation temperature of 40℃ falls within the endpoint of the "30-40℃" range; and the fermentation time of 1.5 hours falls within the endpoint of the "1.5-2.5 hours" range.

[0058] Testing revealed that due to the higher yeast content and fermentation temperature, yeast metabolic activity was vigorous, resulting in faster acid and aroma production. However, the shortened fermentation time to 1.5 hours prevented excessive acidity and gluten network relaxation caused by over-fermentation. The proportion of small-to-medium diameter flour particles was 55.02%, with a gluten content of 131.45g, a cooking loss rate of 5.05%, a shelf life of 18.5 hours at 25°C, and a shelf life of 5.61 days at 4°C. Compared to the unfermented control group (Comparative Example 1), the gluten content increased by 28.1%, the cooking loss rate decreased by 22.3%, and the shelf life at 25°C was extended by 37.6%. The product exhibited a prominent fermented aroma, with a slightly stronger acidity than Example 1, but still within the acceptable range for infants and children, and a harmonious blend of wheat and fruit aromas.

[0059] Comparative Example 1 (Unfermented Blank Control Group)

[0060] The difference between this comparative example and Example 1 is that no yeast is added in step (2), and no fermentation is performed. In step (1), all 176g of water is added to the flour at once and stirred. The remaining steps are the same as in Example 1.

[0061] Testing revealed that the noodles prepared in this comparative example contained only 45.62% small-particle-size noodles, indicating poor uniformity. The cooked noodles had a chewy texture of 102.65g, a cooking loss rate of 6.50%, a shelf life of 13.44 hours at 25°C, and a shelf life of 4.20 days at 4°C. The product had only a wheat aroma, lacking any fermented fragrance, and had a hard texture and poor chewiness, making it unsuitable for infant digestion. The in vitro digestibility of starch and protein in the noodles was 57.9% and 62.9%, respectively, significantly lower than that of Example 1.

[0062] Comparative Example 2 (Commercial brewing yeast fermentation group)

[0063] The difference between this comparative example and Example 1 is that in step (2), an equal amount (0.9g) of Angel high-activity dry yeast (Saccharomyces cerevisiae) was used instead of CDLB-YE05 for fermentation. The remaining steps are the same as in Example 1.

[0064] Testing revealed that the noodles prepared in this comparative example had irregular air pockets due to gas production by the brewer's yeast, resulting in a chewy texture of 120.42g after cooking, significantly lower than that of Example 1. The cooking loss rate was 3.99%, which, although low, resulted in a slightly sour taste and overall lower flavor harmony.

[0065] Summary of quality test results for each embodiment and comparative example

[0066] The fresh noodle samples prepared in the above embodiments and comparative examples were tested for cooking quality, textural properties, flavor evaluation, and preservation effect. The dried noodle samples prepared in Example 1 and Comparative Example 1 were tested for digestibility. The test methods are as follows:

[0067] (1) Cooking quality test: The optimal cooking time, cooking loss rate and water absorption rate were determined according to AACC 66-50 method.

[0068] (2) Texture property test: The elasticity value was determined by TA-XT plus material property tester (wedge probe A / WEG, test speed 0.50mm / s, compression ratio 95%, and the elasticity was expressed by the force at which the cooked noodle thickness was sheared to 95%).

[0069] (3) Sensory evaluation: Ten trained sensory evaluators (including professional infant food evaluators) will conduct the evaluation using a 1-9 point system, focusing on assessing infant suitability indicators such as wheat aroma, no off-flavor, and soft and easy-to-chew texture.

[0070] (4) Shelf life test: Stored at 25℃ and 4℃ respectively, and the total number of colonies was determined according to GB 4789.2-2022. The shelf life endpoint was defined as the time when the total number of colonies exceeded 5 Log CFU / g.

[0071] (5) Digestibility test: The in vitro digestibility of starch and protein in noodles was determined using the INFOGEST standardized model.

[0072] The test results are summarized in Table 1:

[0073] Table 1 Test Results

[0074]

[0075] The table above clearly shows that:

[0076] (1) All three embodiments of the present invention fall within the scope of protection defined by the independent claims, and all achieve significantly better technical effects than Comparative Example 1 (unfermented blank group). In terms of gluten content, Examples 1-3 are 32.8%, 25.3%, and 28.1% higher than the blank group, respectively; in terms of shelf life, the shelf life at 25°C is extended by 56.25%, 42.9%, and 37.6%, respectively; in terms of in vitro digestibility, the starch and protein digestibility of Example 1 are 16.4% and 10.5% higher than the blank group, respectively. More importantly, all the products of the embodiments have no alcoholic or sour taste, a rich wheat aroma, and a soft and easy-to-chew texture, which is particularly suitable for the digestive capacity and flavor preferences of infants and children. This fully demonstrates that the parameter range defined by the present invention (yeast addition amount 0.10-0.25%, fermentation temperature 30-40°C, fermentation time 1.5-2.5 hours, first water addition amount 20-25%) has universality and reproducibility.

[0077] (2) Example 1 uses the optimal combination of process parameters obtained through response surface methodology (0.18% yeast addition, 34°C fermentation temperature, 2.15 hours fermentation time, and 22.61% initial water addition), achieving the best results in terms of texture, shelf life, and flavor, making it the most suitable formula for infants. Examples 2 and 3 respectively verified the feasibility of the present invention at the parameter range boundaries: Example 2 still showed significant effects under conditions of low bacterial count (0.10%), low temperature (30°C), long fermentation time (2.5 hours), and high water addition (24%); Example 3 was also effective under conditions of high bacterial count (0.25%), high temperature (40°C), short fermentation time (1.5 hours), and low water addition (20%). This indicates that the technical solution of the present invention has strong process adaptability and operational flexibility, and can adapt to the needs of different production conditions and equipment configurations.

[0078] (3) Compared with Comparative Example 2 (commercial brewing yeast fermentation group), the three embodiments of the present invention have significant advantages in terms of gluten content (Examples 1-3 are 136.35g, 128.62g and 131.45g respectively, all higher than the brewing yeast group's 120.42g), and effectively avoid the alcoholic and sour taste problems caused by brewing yeast fermentation, achieving the unique advantage of a rich wheat aroma and no irritating odor required by infants and children. This indicates that the beneficial effects of the present invention come from the synergistic effect of the unique metabolic characteristics of the CDLB-YE05 strain (no gas production, no ethanol production) and the fractional atomization water addition fermentation process, rather than a simple adjustment of the fermentation process.

[0079] (4) The fermented noodles prepared by this invention can be used as fresh noodles for short-term storage under refrigeration and directly supplied to infants and children, or they can be further dried to make dried noodles and stored at room temperature for a long time. After rehydration, the dried noodles can still maintain a dense and moderately soft gluten network structure, have a rich wheat aroma, and are easy to digest. They fully meet the current requirements of the infant noodle market, which is dominated by dried noodles, and have extremely strong commercial promotion value.

[0080] Combination Figure 2-7 The contour lines and surface plots shown indicate that the coefficient of determination (R²) of the response surface model used to determine the above optimal process parameters is 0.9518, indicating a good fit. The combination of fermentation temperature (34℃) and time (2.15 h) was optimized using the response surface methodology. Figure 2-7 The data shows that the optimal region is located at the intersection of the valley bottom and the center of the contour line. Under this condition, the yeast metabolic activity (extracellular polysaccharide yield) and the degree of cross-linking of gluten protein reach the optimal balance. Deviating from this region (such as temperatures below 32℃ or above 38℃) will lead to a significant deterioration in the gluten value or cooking loss rate.

[0081] Figure 8Comparison of SEM microstructures of strips after cooking under different fermentation treatments: a1-a3: Comparative Example 1; b1-b3: Comparative Example 2; c1-c3: Example 1; 1: ×40; 2: ×200; 3: ×500; See also Figure 8 The electron microscopy results. Specifically, Figure 8 c1-c3 (Example 1) exhibited a continuous, relatively uniform, and dense honeycomb network structure at magnifications of ×40, ×200, and ×500, with the gluten protein membrane continuously encapsulating the starch granules; while Figure 8 The network structure of a1-a3 (unfermented comparative example 1) is relatively loose, and the pores are unevenly distributed. Figure 8 Examples b1-b3 (comparative example 2 of brewer's yeast) showed obvious gluten skeleton breakage and local collapse due to gas production. The comparison indicates that the fermentation process of this invention can effectively promote the tight integration of gluten protein and starch granules. This structural feature is direct microscopic physical evidence that the product possesses both a suitable chewy texture and easy digestibility for infants and young children. This dense yet moderately porous composite network not only matches the chewy texture of the cooked noodles (chewiness value 136.35g) but also provides a favorable microscopic structural basis for the penetration and decomposition of digestive enzymes, consistent with the digestibility trend reflected in the in vitro digestibility rates of starch and protein in this embodiment (67.3% and 69.5%, respectively).

[0082] Figure 9 PCA analysis chromatograms of flavor compounds from different fermentation treatments are shown. Figure 9 A is the score graph. Figure 9 B is the load diagram. Note: "-" indicates before heating; "+" indicates after heating; CK represents Comparative Example 1, SC represents Comparative Example 2, and YE05 represents Example 1. See also... Figure 9 Principal component analysis (PCA) score plots show that Example 1 (YE05 sample) is clearly separated from the unfermented control group (CK) and the brewer's yeast group (SC) in the principal component space, indicating significant differences in their flavor profiles. Combined with loading plots, it can be seen that phenylethanol, isoamyl alcohol, and other floral aroma compounds are key differentiating markers for the product of this invention, while the brewer's yeast group shifts towards organic acids / ethanol, verifying the technical advantages of this invention in avoiding pungent odors and highlighting the synergistic effect of malty and fruity aromas.

[0083] like Figure 10 As shown, at 25℃ ( Figure 10 A) and 4℃ ( Figure 10 B) Under storage conditions, the total bacterial count growth curve (YE05) of Example 1 was significantly lower than that of the unfermented control group (CK) at all time points, and the mold count returned to zero after 48 hours of storage at room temperature and 8 days of refrigeration. This confirms that the lactic acid and acetic acid that continuously accumulate during fermentation constitute a long-lasting antibacterial environment, resulting in a substantial improvement in shelf-life indicators.

[0084] comprehensive Figures 1 to 10 Analysis shows that the present invention improves upon the microscopic powder distribution ( Figure 1 ), process window ( Figure 2-7 ), micro-network structure ( Figure 8 Flavor fingerprint spectrum ( Figure 9 ) and dynamic changes in shelf life ( Figure 10 The five dimensions of the study systematically demonstrate the synergistic superiority of Examples 1-3 in terms of infant digestibility and sensory acceptance, overcoming the single performance deficiency of the prior art.

[0085] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0086] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing easily digestible fermented dough suitable for infants and young children, characterized in that, Includes the following steps: Step (1), Pre-hydration of raw materials: Place flour in a constant temperature fermentation mixer and stir at a constant speed. Add the first amount of water in an atomizing manner for 8-12 minutes, allowing the flour to gradually absorb the water and form a semi-moist and fluffy powder. After the first water addition, the moisture content of the material should reach 20-24%. Step (2) Yeast addition and fermentation: Sprinkle the CDLB-YE05 yeast powder evenly into the material obtained in step S (1), and ferment at a constant temperature of 30-40℃ for 1.5-2.5 hours; the amount of CDLB-YE05 yeast powder added is 0.10-0.25% of the flour mass; Step (3) Second kneading: Transfer the fermented dough from step (2) to a vacuum dough mixer, add water a second time to bring the final dough moisture content to 32-38%, and dissolve salt and edible alkali in the added water; the amount of salt added is 0-2.00% of the flour mass, and the amount of edible alkali added is 0-0.3% of the flour mass; knead under vacuum conditions for 8-12 minutes; Step (4) Maturation: Take out the kneaded dough and mature it for 12-20 minutes at a temperature of 33-37℃ and a relative humidity of 75-85%. Step (5) Rolling and shaping: Roll the cooked dough flakes on a dough rolling machine. After the dough strip is folded and rolled, it is rolled at each of the decreasing roller gaps in turn. Finally, it is cut into strips to obtain fermented dough.

2. The preparation method according to claim 1, characterized in that, The atomization and water addition time in step (1) is 10 minutes.

3. The preparation method according to claim 1, characterized in that, In step (2), the amount of CDLB-YE05 yeast powder added is 0.18% of the flour mass, the fermentation temperature is 34℃, and the fermentation time is 2.0-2.2 hours.

4. The preparation method according to claim 1, characterized in that, The final dough moisture content described in step (3) is 36%.

5. The preparation method according to claim 1, characterized in that, The amount of salt added in step (3) is 0.1% of the mass of flour, and the amount of edible alkali added is 0.05% of the mass of flour.

6. The preparation method according to claim 1, characterized in that, The vacuum and surface vacuum degree mentioned in step (3) is -0.06 to -0.09 MPa.

7. The preparation method according to claim 1, characterized in that, The curing temperature in step (4) is 35°C, the relative humidity is 80%, and the curing time is 15 minutes.

8. The preparation method according to claim 1, characterized in that, The specific operation of calendering in step (5) is as follows: First, perform initial calendering at a roller gap of 2.4-2.8mm, then fold and calender the strip 3-4 times, turn the strip over and calender once, then calender the strip at 2.0-2.4mm, 1.6-2.0mm and 1.2-1.6mm in sequence, and finally cut the strip into filaments at 0.8-1.2mm.

9. The preparation method according to claim 8, characterized in that, The roller spacing in step (5) is 2.6mm, 2.2mm, 1.8mm, 1.4mm and 1.0mm respectively.

10. An easily digestible fermented dough suitable for infants and young children, characterized in that, It is prepared by any one of claims 1-9.

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