Method for improving the taste of corn noodles by multi-bacterial synergistic fermentation of corn and application thereof

Abstract

The present application relates to the technical field of food fermentation, in particular to a method for improving the taste of corn noodles by multi-microbial synergistic fermentation of corn and application thereof. The method provided by the present application uses lactic acid bacteria, Bacillus amyloliquefaciens and yeast to synergistically ferment corn to prepare fermented corn flour. Multi-microbial fermentation can effectively improve the processing characteristics of corn flour and enhance the antioxidant, free radical removal and other health and probiotic functions of corn flour. Further, the fermented corn flour is mixed with puffed corn flour and corn starch at a specific ratio to prepare pure corn noodles, which have significant advantages in viscoelasticity and ductility and better comprehensive texture characteristics and sensory scores.

Description

Technical Field

[0001] This invention relates to the field of food fermentation technology, specifically to a method and application of multi-strain synergistic fermentation of corn to improve the texture of corn noodles. Background Technology

[0002] Noodles are an important staple food product, and corn noodles, with their high dietary fiber and low glycemic index, align with modern healthy eating concepts, resulting in huge market demand. However, corn itself lacks gluten protein and has a dense starch granule structure, leading to poor water absorption and extensibility, making it difficult to form a stable noodle mesh structure. To achieve the chewy, smooth, and elastic texture that consumers expect, additives or modifications are necessary; unprocessed pure corn flour cannot meet the requirements for noodle production. Traditional corn noodle production requires the addition of 10%-30% gluten protein, high-gluten wheat flour, wheat gluten, xanthan gum, and other gluten enhancers in addition to corn flour to compensate for the material deficiencies of corn flour and improve the chewiness and resistance to overcooking of the noodles.

[0003] Patent application number 202411868601.4 discloses a probiotic-infused golden corn noodle and its preparation method. This patent uses probiotics to ferment corn flour, and in addition to fermented corn flour, wheat flour and other auxiliary materials need to be added to the raw materials for making corn noodles. Patent application number 201911141026.7 discloses a corn noodle and its preparation method. This patent uses protease and lactic acid bacteria to make a modified corn paste, and then adds corn flour, high-gluten wheat flour, and gluten to obtain a mixed powder; then the mixed powder, salt, xanthan gum, baking soda, oil, and fermentation liquid are mixed and kneaded to make corn noodles. The corn paste produced by this patent technology also requires the addition of multiple auxiliary materials to make noodles containing corn raw materials, and is not pure corn noodles. The invention patent with application number 202210172097.9 discloses a process for preparing corn flour noodles using environmentally friendly green technology. This patent uses soaking and puffing technology to cook the corn flour. After processing, the corn flour is kneaded in a special vacuum dough mixer. The corn flour ground by the flour mill is discharged into the kneading bucket of the vacuum dough mixer through a feeding mechanism to make noodles. This process does not require the addition of any auxiliary materials other than corn raw materials. The noodles are made from pure corn flour. However, it requires the special professional noodle machine developed by this invention patent. Otherwise, it is impossible to make corn noodles of the same quality. This production method is limited to specific processing equipment and is difficult to promote, popularize and apply on a large scale.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method and application for multi-strain synergistic fermentation of corn to improve the texture of corn noodles.

[0006] Specifically, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for multi-strain synergistic fermentation of corn to improve the taste of corn noodles, wherein corn flour and water are mixed at a mass ratio of 1:1-2 to obtain corn slurry; the corn slurry is used for synergistic fermentation of a mixed strain of multi-strains; the mixed strain, based on the effective viable cell count, includes 50±5% Lactobacillus plantarum Lp, 25±5% Bacillus amyloliquefaciens ZXW01 and 25±5% Saccharomyces cerevisiae SC.

[0008] Preferably, the preservation number of the *Lactobacillus plantarum* Lp is CGMCC No. 10453; the preservation number of the *Bacillus amyloliquefaciens* ZXW01 is CGMCC No. 8464; and the preservation number of the *Saccharomyces cerevisiae* SC is CICC No. 30178.

[0009] Preferably, the viable count of the mixed bacterial strain is (6±2)×10⁻⁶. 8 The total inoculum amount of the mixed strain, calculated as CFU / mL, is 10%-20% of the total volume of corn steep liquor; the fermentation temperature is 30℃-37℃; and the fermentation time is 12-48h.

[0010] After corn flour undergoes synergistic fermentation with lactic acid bacteria, Bacillus amyloliquefaciens, and yeast, its composition and structure are improved, increasing protein and amylose content. The extensibility and elasticity, characteristic for pasta processing, are also effectively enhanced. The three bacteria work synergistically to enzymatically break down the protein and starch in corn into amino acids, vitamins, and phenolic active ingredients, improving the antioxidant and free radical scavenging functions of fermented corn flour. Furthermore, this synergistic fermentation can replace the addition of exogenous enzymes such as pullulanase, protease, and cellulase, eliminating the need for complex enzyme preparation processes, reducing production costs, and shortening the fermentation cycle.

[0011] Secondly, the present invention provides the application of the method for multi-strain synergistic fermentation of corn to improve the taste of corn noodles in the processing of corn noodles. The application includes: the corn slurry is fermented and then spray-dried to obtain fermented corn flour; the fermented corn flour is used in the processing of corn noodles.

[0012] Preferably, the raw materials for the corn noodles include the fermented corn flour, puffed corn flour, and corn starch, and the mass ratio of the fermented corn flour, the puffed corn flour, and the corn starch is 40-45:30-40:15-30.

[0013] More preferably, the mass ratio of the fermented corn flour, the puffed corn flour, and the corn starch is 45:30-35:20-25.

[0014] More preferably, the mass ratio of the fermented corn flour, the puffed corn flour, and the corn starch is 45:35:20.

[0015] Preferably, the raw materials for the corn noodles also include edible salt, and the amount of edible salt added is 1.0%-1.5% of the sum of the mass of the fermented corn flour, the puffed corn flour and the corn starch.

[0016] Preferably, the puffed corn flour has a moisture content of 7%-14% and a gelatinization degree of 92%-98%.

[0017] Preferably, the fermented corn flour, the puffed corn flour, and the corn starch are mixed to obtain corn noodle powder; the corn noodle powder is mixed with water at a mass ratio of 2:1.1-1.4, kneaded into dough, left to stand at 20-30℃ for 20-30 minutes, then pressed into sheets and cut to obtain the corn noodles.

[0018] In a more specific embodiment, this invention prepares fermented corn flour while simultaneously compressing and melting ordinary corn flour at 145℃-180℃ using an extruder to obtain puffed corn flour. Then, the fermented corn flour, puffed corn flour, corn starch, and salt are uniformly mixed in a specific ratio to form corn flour, which is then mixed with water and kneaded to make noodles. On one hand, this method employs a multi-strain synergistic fermentation process using lactic acid bacteria, Bacillus amyloliquefaciens, and yeast, effectively shortening the fermentation time. Multiple bacteria secrete various enzymes, avoiding the need for expensive enzyme preparations that would increase costs. During fermentation, the microbial community secretes amylase, pullulanase, protease, and amylopectin, effectively improving the viscoelasticity and extensibility of corn, enhancing processing performance, and producing polyphenols. This process also enhances the ability to remove free radicals such as ABTS, improving antioxidant and anti-aging health and probiotic functions. On the other hand, the corn noodles made from a specific ratio of corn flour raw materials produced by this method are chewy, smooth, and not easily broken, exhibiting excellent overall textural properties and sensory evaluation.

[0019] Thirdly, the present invention provides corn noodles processed by the application method described above.

[0020] Beneficial effects:

[0021] This invention provides a method and application for improving the texture of corn noodles through multi-strain synergistic fermentation of corn. The method uses a synergistic fermentation process involving lactic acid bacteria, Bacillus amyloliquefaciens, and yeast to produce fermented corn flour, effectively improving the processing characteristics of the corn flour and enhancing the product's health and probiotic functions. Further mixing this fermented corn flour with puffed corn flour and corn starch in a specific ratio yields pure corn noodles with significant advantages in viscoelasticity and extensibility, resulting in superior overall textural properties and sensory evaluation. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be described below.

[0023] Figure 1 The content of amylose in corn fermented by different combinations of microorganisms in Experimental Example 1 of this invention.

[0024] Figure 2 The protein content of corn fermented by different combinations of microorganisms in Experiment Example 1 of this invention.

[0025] Figure 3 The total starch content of corn fermented by different combinations of microorganisms in Experiment Example 1 of this invention.

[0026] Figure 4 The content of corn polyphenols in different strain combinations fermented in Experimental Example 2 of this invention.

[0027] Figure 5 The free radical removal rate of corn fermented with ABTS by different strain combinations in Experimental Example 2 of this invention is shown.

[0028] Figure 6 The soup from cooked pure corn noodles in Experiment Example 3 of this invention is clear and without any broken strands.

[0029] Figure 7 This refers to the state of the cooked pure corn noodles in Experiment Example 3 of this invention, which are smooth and chewy when placed in a dish. Detailed Implementation

[0030] This invention discloses a method for multi-strain synergistic fermentation of corn to improve the texture of corn noodles. This method uses biological enzymatic hydrolysis to modify corn, without the need to add other grains besides corn. It can produce chewy and smooth pure corn noodles using ordinary commercially available noodle machines or hand-held noodle presses, improving the extensibility and viscoelasticity of corn. It solves the problems of poor stickiness, easy breakage, and difficulty in shaping pure corn flour noodles, as well as the defects such as serious cloudiness, high breakage rate, and long cooking time during the cooking process, thus meeting the needs of corn lovers.

[0031] The method provided by this invention uses ordinary corn as raw material. The ordinary corn is crushed, pulped, inoculated, fermented, puffed, mixed, kneaded, pressed, and cut into noodles.

[0032] Specifically, the steps include:

[0033] Step 1: Select dent or semi-dent corn kernels free of impurities and mold, and grind them into corn flour of 100-140 mesh. Add twice the volume of water to the ground 100-140 mesh corn flour to make corn syrup.

[0034] Step 2: Inoculate the corn steep liquor with 10%-20% (v / v) of a mixed microbial culture, including Lactobacillus plantarum (Lp), Bacillus amyloliquefaciens (ZXW01(Z)), and Saccharomyces cerevisiae (SC). The fermentation tank temperature is 32℃-37℃, and the fermentation time is 12-48 h with a stirring speed of 100-180 rpm. When the pH value drops to 3.5-4.5, rinse with clean neutral water until the pH value reaches 6.5-7.5. Then, use a plate and frame press to separate the solid and liquid components, and dry the solid to constant weight to obtain 100-140 mesh fermented corn flour.

[0035] Step 3: Add ordinary corn flour (100-140 mesh, 15%-20% moisture content) to an extrusion puffing machine. The corn flour is heated to 80℃-100℃ in the feeding zone for pre-gelatinization for 10-20 seconds. It is then conveyed to the extrusion zone at 145℃-180℃ and screw speed of 420-480rpm for compression and melting for 20-30 seconds. After that, it is cooled to 125℃-140℃ in the die head for puffing and shaping for 5-10 seconds, resulting in puffed corn flour with a gelatinization degree of 92%-98%.

[0036] Step 4: Mix 35%-50% fermented corn flour, 20%-40% puffed corn flour, 15%-40% corn starch, and 1%-1.5% salt evenly to make corn noodle powder. Mix the corn noodle powder with water at a ratio of 2:1-1.4 and knead the dough. Cover with a damp cloth or plastic wrap and let it stand at 20℃-30℃ for 20-25 minutes to make chewy, smooth, and flavorful pure corn noodles.

[0037] In the following more specific embodiment, in step 1, the raw material pretreatment firstly involves washing the threshed corn kernels, soaking them for 40-48 hours after washing, grinding the corn kernels to 120-140 mesh, and adding water in a ratio of 1:1-2 to make corn slurry.

[0038] In the following more specific embodiments, the mixed strain in step 2 consists of Lactobacillus plantarum Lp, Bacillus amyloliquefaciens ZXW01(Z), and Saccharomyces cerevisiae SC.

[0039] The *Lactobacillus plantarum* culture medium was prepared using lactic acid bacteria culture medium, the main components of which were: 8-12 g peptone, 8-12 g beef extract, 15-25 g glucose, 4-6 g yeast extract, 1.5-2.5 g triammonium citrate, 1.0-1.5 mL Tween 80, 2.5-3.5 g anhydrous sodium acetate, 1.5-2.5 g dipotassium hydrogen phosphate, 0.48-0.68 g magnesium sulfate, 0.2-0.3 g manganese sulfate, 1 L water, pH 6.2-6.6. The medium was sterilized at 116℃ for 30 min, cooled, and then inoculated with *Lactobacillus plantarum*. The culture was then incubated at 30-37℃ for 18-24 h as the inoculum.

[0040] The amylopectin secretion medium for Bacillus amyloliquefaciens is as follows: amylopectin 15-25 g / L, peptone 5-10 g / L, yeast extract 3-8 g / L, NaCl 4-6 g / L, MgSO4·7H2O 0.1-0.5 g / L, MnSO4·H2O 5-10 mg / L, pH: 6.5-7.0. The medium is incubated at 30-37℃ with an incubator set to 180-200 r / min for 24-48 h, and viable cell counts are checked periodically.

[0041] The brewer's yeast is grown on a potato culture medium, which consists of 180-220g of potato, 15-25g of glucose, and water to a final volume of 1L per liter. The potatoes are cut into small pieces, boiled to extract the yeast, filtered, packaged, and then autoclaved at 121℃. 5%-10% of the brewer's yeast is inoculated into the sterilized culture medium and cultured at 30℃-35℃ for 72-96 hours as a starter culture before being inoculated into corn steep liquor.

[0042] This invention involves inoculating corn steep liquor with a specific ratio of *Lactobacillus plantarum* Lp, *Bacillus amyloliquefaciens* ZXW01(Z), and *Saccharomyces cerevisiae* SC, followed by fermentation to obtain fermented corn flour. *Lactobacillus plantarum* produces lactic acid, lowering the environmental pH and activating phytase from grains, promoting the gradual hydrolysis of phytic acid. This prevents excessive phytic acid from binding with minerals such as iron and zinc in the body to form insoluble complexes, reducing bioavailability and lowering the risk of iron-deficiency anemia or zinc deficiency. Simultaneously, the lactic acid produced by *Lactobacillus plantarum* rapidly lowers the pH to below 4.5, inhibiting the growth of putrefactive bacteria and pathogenic bacteria (such as *Escherichia coli* and *Staphylococcus aureus*), forming a biological barrier and ensuring the safety of fermented food. Bacillus amyloliquefaciens and brewer's yeast secrete amylase to hydrolyze α-1,4 glycosidic bonds, forming tiny pores and channels on and inside the starch. This porous starch increases the specific surface area, disrupts the starch's arrangement, leading to decreased starch crystallinity and an increased proportion of amorphous starch. This makes the starch more prone to absorbing water and swelling upon heating, accelerating the reduction of gelatinization temperature. Bacillus amyloliquefaciens also secretes pullulanase, which efficiently debranchs starch, specifically cleaving α-1,6-glycosidic bonds in amylopectin, significantly improving amylopectin conversion efficiency, altering the ratio of amylose to amylopectin and the chain length distribution, effectively improving starch retrogradation characteristics, preventing noodles from hardening or retrogradation during cooling or storage, and maintaining a smooth texture. Furthermore, the fermentation process using Bacillus amyloliquefaciens and brewer's yeast produces amino acids and small peptides from secreted proteases. The yeast converts starch into glucose, lactic acid, etc., improving flavor and promoting digestion, and synthesizing vitamins B1, B2, and B3 to support energy metabolism and nervous system health, among other beneficial effects.

[0043] The fermentation conditions for step 2 include: using *Lactobacillus plantarum* Lp, *Bacillus amyloliquefaciens* ZXW01(Z), and *Saccharomyces cerevisiae* SC, and growing the strains to the logarithmic growth phase with a viable microbial count of (6±2)×10⁻⁶. 8CFU / mL was used as the seed culture. Seven treatments with different bacterial compositions and viable cell ratios were set up to verify the effects of bacterial composition and ratio on the main nutrients in fermented corn. The seven treatments were: sterile control (CK), Z+Lp (1:1 ratio of bacterial count), SC+Lp (1:1), Z+SC+Lp (1:1:1), 2Z+SC+Lp (2:1:1), Z+2SC+Lp (1:2:1), and Z+SC+2Lp (1:1:2). The total inoculum amount was 10%-20% of the total corn steep liquor volume. The inoculum was fermented at 30℃-37℃ for 12-40 hours. Samples were taken periodically to analyze the changes in amylose, amylopectin, and protein content in the fermented corn. Suitable corn fermentation bacterial strain combinations for noodle making were screened, and their antioxidant capacity, polyphenol content, free radical scavenging ability, and ABTS scavenging rate were analyzed and measured after fermentation. The fermented corn slurry was centrifuged to separate the solids and liquids, the solids were collected, washed with water until neutral, and then spray-dried to obtain fermented corn flour.

[0044] In the following more specific embodiment, the processing method of puffed corn is as follows: ordinary corn flour with a moisture content of 15%-20% and a mesh size of 100-140 is added to an extrusion puffing machine. The corn flour is heated to 80℃-100℃ in the feeding zone for pre-gelatinization for 10-20s, and then conveyed to the extrusion zone at 145℃-180℃ and a screw speed of 420-480 rpm for compression and melting for 20-30s. After that, the temperature is reduced to 125℃-140℃ in the die head for puffing and shaping for 5-10s, resulting in puffed corn flour with a gelatinization degree of 92%-98%.

[0045] In the following more specific embodiment, the method for making noodles is as follows: Weigh out each ingredient according to the following proportions: 35%-50% fermented corn flour, 20%-40% puffed corn flour, 15%-40% corn starch, and 1%-2% NaCl. Mix these ingredients evenly for 5 minutes to produce corn noodle powder. Mix the corn noodle powder with water at a mass ratio of 2:1.1-1.4 and knead thoroughly. Let the dough rest at 20℃-30℃ for 20-30 minutes. The rested dough is then rolled into sheets using a rolling mill and cut into noodles of various widths.

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0047] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "specific implementation," or "some specific implementations," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0050] In the embodiments provided in this specification, unless specific techniques or conditions are specified, the techniques or conditions described in the literature in this field, or the product instructions, shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased from legitimate channels.

[0051] In the following examples, Bacillus amyloliquefaciens (ZXW01) was purchased from the China General Microbiological Culture Collection Center (CGMCC), accession number CGMCC.8464; Lactobacillus plantarum (Lp) was purchased from the China General Microbiological Culture Collection Center, accession number CGMCC.10453; and Saccharomyces cerevisiae (SC) was purchased from the China Industrial Microbiological Culture Collection Center (CICC), accession number CICC.30178.

[0052] Example 1

[0053] This embodiment provides a method for improving the texture of corn noodles through multi-strain synergistic fermentation of corn, the specific steps of which are as follows:

[0054] (1) Raw material pretreatment:

[0055] After washing the threshed corn kernels, soak them for 36 hours, then grind them to 130 mesh and add water in a 1:1.5 ratio to make corn syrup.

[0056] (2) Fermentation of microorganisms to obtain fermented corn flour:

[0057] Use viable bacteria count (6±2)×10 8 A mixed inoculum of CFU / mL was used to ferment the corn steep liquor obtained in step (1). The effective viable bacteria in the mixed inoculum included *Lactobacillus plantarum* Lp (50±1% cell count), *Bacillus amyloliquefaciens* ZXW01(Z) (25±1%), and *Saccharomyces cerevisiae* SC (25±1%). The total inoculum volume was 15% of the total corn steep liquor volume, and fermentation was carried out at 30°C for 36 hours. The fermented corn steep liquor was then separated into solid and liquid components using a centrifuge. The solid was collected, washed with water until neutral, and spray-dried to obtain fermented corn flour.

[0058] Example 2

[0059] This embodiment provides corn noodles and a method for preparing the same, with the specific steps as follows:

[0060] (1) Take 45 parts of fermented corn flour, 35 parts of puffed corn flour, 20 parts of corn starch, and 1.5 parts of salt (NaCl), mix them evenly for 5 minutes, and make corn noodle powder. Among them, the fermented corn flour was prepared by Example 1. The preparation method of puffed corn flour is as follows: ordinary corn flour with 120 mesh and 18% moisture content is added to an extrusion puffing machine. The corn flour is heated to 90°C in the feeding zone for pre-gelatinization for 15 seconds, and then conveyed to the extrusion zone at 160°C and screw speed of 450 rpm for compression and melting for 25 seconds. After that, it is cooled to 130°C in the die head for puffing and shaping for 8 seconds to obtain puffed corn flour with a gelatinization degree of 95%.

[0061] (2) Mix corn noodle powder and water at a mass ratio of 2:1.3 and knead thoroughly. Let the dough rest at 25℃ for 25 minutes. The rested dough is then rolled into sheets and cut into noodles by a rolling mill.

[0062] Experimental Example 1

[0063] This experimental example analyzes the effects of multimicrobial fermentation of corn on the content of major nutrients in corn.

[0064] Propagate three strains: *Lactobacillus plantarum* Lp, *Bacillus amyloliquefaciens* ZXW01(Z), and *Saccharomyces cerevisiae* SC. The strains were grown to the logarithmic growth phase and the viable microbial count reached (6±2)×10⁻⁶. 8CFU / mL was used as the seed culture. Seven treatments with different bacterial compositions and viable cell ratios were set up to verify the effects of bacterial composition and ratio on the main nutrients in fermented maize. The seven treatments were: sterile control (CK), Z+Lp (1:1 ratio of bacterial strain to live bacteria), SC+Lp (1:1), Z+SC+Lp (1:1:1), 2Z+SC+Lp (2:1:1), Z+2SC+Lp (1:2:1), and Z+SC+2Lp (1:1:2). The inoculum volume was 15% of the total maize steep liquor volume. After inoculation, fermentation was carried out at 30℃ for 30 h. The differences in amylose, protein, and total starch content in fermented maize were compared among the treatments. Amylose content was measured 24 h after inoculation. The amylose content of the seven treatments were 28.81%, 32.94%, 35.12%, 35.26%, 38.15%, 37.94%, and 39.21%, respectively. Figure 1 The results of fermentation with different microbial strains showed that the amylose content in maize after fermentation was increased to varying degrees compared with the aseptic control. Among the seven treatments, the Z+SC+2Lp strain combination showed the most significant increase in amylose content, reaching 39.21%. Meanwhile, the protein content was measured after 24 hours of fermentation, and the values ​​for the seven treatments were 8.06%, 8.55%, 8.67%, 8.92%, 9.08%, 9.14%, and 9.29%, respectively. Figure 2 Data comparison revealed that the protein content of corn generally increased after fermentation with different microbial strains. The 3-strain combination showed a more significant increase in protein compared to the 2-strain combination. The lowest protein content was found in the SC+Lp strain combination, while the highest protein content was found in the Z+SC+2Lp strain combination. After 24 hours of fermentation, the total starch content of the corn in each treatment was measured, and the values ​​for the seven treatments were 72.5%, 69.22%, 70.15%, 67.16%, 64.67%, 65.54%, and 66.38%, respectively. Figure 3 Comparison of total starch content data revealed that the total starch content of corn decreased after treatment with the inoculum compared to the uninoculated control. Among them, the total starch content was highest in the SC+Lp inoculum combination and lowest in the 2Z+SC+Lp combination.

[0065] Experiment Example 2

[0066] This experiment analyzed the content of phenolic substances and antioxidant active ingredients in corn fermented with different combinations of microbial strains.

[0067] Propagate the three strains: Lactobacillus plantarum Lp, Bacillus amyloliquefaciens ZXW01(Z), and Saccharomyces cerevisiae SC. The strains were grown to the logarithmic growth phase and the viable microbial count reached (6±2)×10⁻⁶. 8CFU / mL was used as the seed culture. Seven combinations with different bacterial strain compositions and viable cell ratios were set up to verify the effects of bacterial strain composition and ratio on the phenolic compounds and antioxidant activity of fermented corn. The seven bacterial combinations were: sterile control (CK), Z+Lp (strain ratio 1:1), SC+Lp (1:1), Z+SC+Lp (1:1:1), 2Z+SC+Lp (2:1:1), Z+2SC+Lp (1:2:1), and Z+SC+2Lp (1:1:2). The inoculum size was 15% of the total corn steep liquor volume. After inoculation at the specified ratio, samples were collected at 30℃ for 12h, 24h, and 48h. The polyphenolic compounds and ABTS scavenging rate in the fermented corn flour were measured, as well as the free radical scavenging ability of the fermented corn flour and indicators related to delaying cellular oxidative damage were determined. The phenolic compound content was measured at 30℃ for 12h, 24h, and 48h. Figure 4 It represents the changes in polyphenol content at different fermentation times for various microbial strains. Figure 4 The comparison showed that phenolic substances were significantly increased in both inoculated and uninoculated control (CK) cultures, and the phenolic substance content increased significantly with the extension of fermentation time from 12h to 48h. Comparing the two strain combinations, the Z+LP combination showed significantly higher polyphenol content than the SC+LP combination. Comparing the three-strain combinations with different viable cell ratios, the 2Z+SC+Lp combination had the highest polyphenol content, followed by the Z+SC+2Lp combination. Furthermore, the free radical scavenging ability of fermented corn ABTS was measured after 12h, 24h, and 48h of incubation at 30℃. Figure 5 This is a comparison of the changes in the amount of free radicals removed by ABTS at different fermentation times for various bacterial strains. Figure 5 Comparison of ABTS free radical scavenging values ​​of fermented corn at 12h, 24h, and 48h revealed that the Z+SC+2Lp strain combination exhibited the strongest ABTS scavenging ability, followed by the 2Z+SC+Lp strain combination. The experiment showed that post-fermentation, both the classification of substances and the ABTS free radical scavenging ability increased antioxidant capacity. Most importantly, the chewiness and elasticity of noodles are primarily determined by protein; higher protein content increases extensibility and chewiness. Fermentation results indicated that protein levels increased in all seven treatments of fermented corn, with the Z+SC+2L strain showing the highest protein content, which is beneficial for producing chewy noodles. Therefore, subsequent studies used the Z+SC+2L strain, specifically a combination of 0%±5% *Lactobacillus plantarum* Lp, 25±5% *Bacillus amyloliquefaciens* ZXW01, and 25±5% *Saccharomyces cerevisiae* SC strains, for corn fermentation. The fermented corn flour from the Z+SC+2L strain was used for subsequent experiments.

[0068] Experimental Example 3

[0069] This experiment analyzes the cooking quality of corn noodles made from different combinations of corn flour.

[0070] Pure corn noodle flour was prepared in nine combinations of fermented corn flour, puffed corn flour, corn starch, and salt in specific proportions (see Table 1). The differences in noodle quality resulting from pure corn flour with different proportions of fermented corn flour, puffed corn flour, corn starch, and salt were compared.

[0071] Table 1. Composition of pure corn noodle flour

[0072] deal with Fermented corn flour puffed corn flour corn starch Salt(%) 1 35 35 30 1.5 2 40 20 40 1.5 3 40 20 40 1.0 4 40 25 35 1.5 5 40 30 30 1.0 6 45 30 25 1.5 7 45 35 20 1.5 8 45 40 15 1.5 9 50 30 20 1.5

[0073] Nine types of flour were mixed according to the proportions of fermented corn flour, puffed corn flour, corn starch, and salt in Table 1. Water was added at a flour:water ratio of 20 / 13, and the mixture was stirred to form dough. The dough was then allowed to rest at room temperature for 25 minutes. The dough was then pressed using a pasta machine, dried, and boiled until it floated to the surface and had a firm core. The cooking quality of the noodles (including water absorption rate, breakage rate, and cooking loss rate) was measured and analyzed. Water absorption rate was determined by soaking method, cooking loss rate was determined by weighing the filtrate after boiling, and breakage rate was analyzed by counting method after boiling.

[0074] Fifteen noodles of the same length were taken from each sample and weighed, recorded as W1. The noodles were boiled in boiling water until they floated and had no hard core. Excess water was absorbed from the surface of the noodles with filter paper, and the weight was recorded as W2. The number of noodles that broke at this time was recorded as N. The noodles were placed in a drying oven and dried at 50℃ for 8 hours to remove moisture. The weight of the noodles at this time was recorded as W3. The water absorption rate of the noodles was calculated according to formula (1), the breakage rate of the noodles was calculated according to formula (2), and the cooking loss rate of the noodles was calculated according to formula (3). Each indicator was measured three times to eliminate errors.

[0075] Water absorption rate of noodles (%) = (W2-W1) / W1*100% Formula (1)

[0076] The breakage rate of noodles (%) = (10-N) / 10*100% Formula (2)

[0077] The cooking loss rate of noodles (%) = (W1-W3) / W1*100% Formula (3)

[0078] The results are shown in Table 2.

[0079] Table 2 Evaluation and Analysis of Cooking Characteristics of Pure Corn Noodles

[0080] deal with Water absorption rate % Broken strip rate % Cooking loss % 1 81 2.7 6.14 2 74 6.8 7.98 3 75 6.5 6.77 4 79 5.5 6.49 5 81 0 5.15 6 83 0 2.56 7 89 0 2.02 8 92 0 5.59 9 84 5.9 6.98

[0081] During the cooking process, the water absorption rate, breakage rate, and cooking loss rate of each treatment were measured. No cloudy soup or breakage was observed in the cooking processes of treatments 5, 6, 7, and 8. Figure 6 As can be seen, the broth after cooking corn noodles is clear, and... Figure 7The cooked pure corn noodles, when placed in a dish, are smooth and chewy. This demonstrates that optimizing the ratio of fermented corn flour to physically extruded corn flour can significantly improve the viscoelasticity and extensibility of corn noodles.

[0082] Experiment Example 4

[0083] This experimental example provides a comprehensive sensory evaluation of the corn noodles in Experiment Example 3.

[0084] Nine types of flour from Table 1 were selected, and water was added at a ratio of flour:water = 20 / 13. The corresponding amount of sodium chloride for each treatment in Table 1 was also added. After mixing well, dough was formed and allowed to stand at room temperature for 25 minutes. Noodles were obtained by pressing the dough with a hand-held pasta machine, dried to constant weight, and then boiled in boiling water until they floated and the core was no longer hard. The noodles were then removed and the differences in the main quality characteristics of corn noodles with different flour combinations were measured.

[0085] The hardness, elasticity, and chewiness of the noodles were analyzed using a texture analyzer. The main differences in characteristics were comprehensively measured and analyzed, and the results are shown in Table 3.

[0086] Table 3 Comprehensive analysis of the textural properties of corn noodles

[0087] deal with Hardness / g Chewable / g Elasticity / g 1 4028.6 2253 0.66 2 4963.2 2978.1 0.49 3 4904.7 3331.3 0.51 4 4422.3 3248.5 0.58 5 3965.2 2291.8 0.78 6 3321.5 2415.4 0.80 7 3671.8 2919.8 0.84 8 2459.4 2408.6 0.72 9 2981.3 2477.3 0.71

[0088] Fifteen healthy students and teachers were randomly selected to rate the noodles made from the nine types of noodle powder listed in Table 1 based on their color, surface condition, toughness, stickiness, smoothness, palatability, and taste (corresponding to seven consumer sensory indicators). The rating rules are shown in Table 4. 100 points: Excellent performance, ideal texture, high toughness, non-sticky, elastic, and no breaks; 90 points: Excellent performance, slightly less than perfect, good in toughness, hardness, and taste; 80 points: Excellent, slightly less than perfect, good in toughness, hardness, and taste, but slightly lacking; 70 points: Good, basically meets taste requirements, may be slightly sticky or lack elasticity; 60 points: Medium, obvious taste defects; 50 points or below: Unacceptable, with obvious sensory defects.

[0089] Table 4 Sensory rating table for corn noodles

[0090] Evaluation indicators Fraction Scoring Criteria Color 20 Bright white or bright yellow: 15-20; Medium brightness or slightly dark: 10-14; Darker color: 5-9 Surface condition 15 Smooth, fine, and transparent texture: 13-15; Relatively smooth and transparent texture: 9-12; Rough surface with severe deformation: 6-8. toughness 20 Good chewiness and elasticity: 15-20; average chewiness: 10-14; poor chewiness and low elasticity: 5-9. viscous 10 Good viscoelasticity: 7-10; average: 4-6; no viscoelasticity: 1-3. Smoothness 10 Smooth, refreshing, and not sticky: 9-10; Relatively smooth; sticky: 5-8; Not refreshing and sticky: 1-4 Palatability 15 Moderate force required to bite through noodles: 12-15 (slightly soft or firm): 7-11 (very soft or too firm): 5-6 Taste 10 Corn aroma 9-10; No fresh aroma 5-8; Off-odor 1-4 statistics 100

[0091] Table 5. Sensory evaluation results of pure corn noodles in Experiment 3

[0092] deal with Color Surface condition toughness viscous Smoothness Palatability Taste Total Score 1 16.09 12.27 15.48 8.41 8.53 10.61 7.26 78.65 2 12.38 8.11 11.79 7.19 9.91 7.81 8.47 65.46 3 12.37 8.35 12.17 7.19 9.87 8.18 7.26 65.39 4 13.77 9.48 13.75 7.78 9.08 9.27 7.92 71.05 5 15.22 14.71 17.17 8.39 8.25 12.48 8.47 85.69 6 15.81 14.94 18.16 9.09 7.70 12.17 9.13 86.50 7 18.33 14.97 19.12 9.58 7.98 13.38 9.79 93.15 8 18.55 13.39 15.65 9.91 6.33 10.67 9.75 84.25 9 16.39 9.08 16.61 9.58 6.60 11.41 9.58 79.35

[0093] Table 5 compares the sensory evaluations of nine different noodle treatments, including noodle color, surface condition, toughness, stickiness, smoothness, palatability, taste, and overall optimal treatment. The results in Table 5 show that the optimal treatments for noodle color, surface condition, toughness, stickiness, smoothness, palatability, taste, and overall optimal treatment are No. 8, No. 7, No. 7, No. 8, No. 2, No. 7, No. 7, No. 7, and No. 7, respectively. The overall evaluation results indicate that the noodles made from flour combination No. 7 have the best performance (93.15 points). This suggests that noodles made with a mixture of 45% fermented corn flour, 30% puffed corn flour, 20% corn starch, and 1.5% salt have the best performance and taste. Based on the evaluation of the cooking characteristics of the nine processed noodles in Table 2, comparing water absorption rate, breakage rate, and cooking loss rate, it was found that noodles No. 6 and No. 7 had a breakage rate of zero and cooking loss rates of 2.02% and 2.56%, respectively. This indicates that noodles No. 6 and No. 7 have good viscoelasticity and very low cooking loss rates, making them an excellent method for processing pure corn noodles. Table 3 provides a comprehensive analysis of the textural properties of corn noodles. Comparing the hardness, chewiness, and elasticity of the noodles, it was also found that noodles No. 6 and No. 7 had elasticity of 0.86g and 0.87g, respectively, and their chewiness and hardness were also appropriate and palatable. In conclusion, based on the comparison in Tables 2, 3, and 5, corn noodle powder No. 7 is the best, followed by noodle powder No. 6.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for improving the mouthfeel of corn noodles by multi-microbial synergistic fermentation of corn, characterized by, Corn flour and water are mixed in a mass ratio of 1:1-2 to obtain corn syrup; the corn syrup is fermented using a mixed microbial culture; the mixed microbial culture comprises 50%±5% Lactobacillus plantarum Lp, 25±5% Bacillus amyloliquefaciens ZXW01 and 25±5% Saccharomyces cerevisiae SC, based on the number of effective viable cells.

2. The method for improving the texture of corn noodles through multi-strain synergistic fermentation of corn according to claim 1, characterized in that, The preservation number of *Lactobacillus plantarum* Lp is CGMCC No. 10453; the preservation number of *Bacillus amyloliquefaciens* ZXW01 is CGMCC No. 8464; and the preservation number of *Saccharomyces cerevisiae* SC is CICC No. 30178.

3. The method for improving the texture of corn noodles through multi-strain synergistic fermentation of corn according to claim 1 or 2, characterized in that, Based on the viable count of the mixed strain being (6±2)×10⁸ CFU / ml, the total inoculation amount of the mixed strain is 10%-20% of the total volume of corn steep liquor; the fermentation temperature is 30℃-37℃; and the fermentation time is 12-48h.

4. The application of the method for multi-strain synergistic fermentation of corn to improve the texture of corn noodles according to any one of claims 1-3 in corn noodle processing, characterized in that, The corn syrup is fermented and then spray-dried to obtain fermented corn flour; the fermented corn flour is used in the processing of corn noodles.

5. The application according to claim 4, characterized in that, The raw materials for the corn noodles include the fermented corn flour, puffed corn flour, and corn starch, and the mass ratio of the fermented corn flour, the puffed corn flour, and the corn starch is 40-45:30-40:15-30.

6. The application according to claim 5, characterized in that, The mass ratio of the fermented corn flour, the puffed corn flour, and the corn starch is 45:30-35:20-25.

7. The application according to claim 5, characterized in that, The raw materials for the corn noodles also include edible salt, and the amount of edible salt added is 1.0%-1.5% of the sum of the mass of the fermented corn flour, the puffed corn flour and the corn starch.

8. The application according to claim 5, characterized in that, The puffed corn flour has a moisture content of 7%-14% and a gelatinization degree of 92%-98%.

9. The application according to claim 5, characterized in that, The fermented corn flour, the puffed corn flour, and the corn starch are mixed to obtain corn noodle powder; the corn noodle powder is mixed with water at a mass ratio of 2:1.1-1.4, kneaded into dough, left to stand at 20-30℃ for 20-30 minutes, then pressed into sheets and cut to obtain the corn noodles.

10. Corn noodles, characterized in that, It is prepared by the application method described in claims 4-9.

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