A lotus leaf and wolfberry compound medicinal and edible noodle and its preparation process

Abstract

This invention relates to the field of food processing technology, and discloses a lotus leaf and wolfberry composite food-medicinal noodle and its preparation process. The process includes acid-base regulation of a mixture containing lotus leaf flavonoids and chlorophyll extracts, wolfberry homogenized pulp, and zinc gluconate to obtain a functional stock solution through magnesium-zinc substitution; mixing high-gluten wheat flour and L-ascorbic acid with the stock solution, and continuously kneading under positive pressure micro-oxygen conditions to promote the formation of disulfide bonds and cross-linking within the dough; after cross-linking, spraying a carrier liquid containing sodium hexametaphosphate in a micro-mist state onto the dough for complexation and passivation; and then allowing the dough to mature, roll, cut into strips, and dehydrate and dry with hot air to obtain the finished product. This invention avoids browning and fading of plant pigments during processing and storage through the magnesium-zinc substitution reaction, and compensates for the weakening of the gluten network by plant components using a micro-oxygen cross-linking mechanism, thereby improving the color stability and cooking resistance of the composite noodles.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a lotus leaf and wolfberry compound medicinal and edible noodle and its preparation process. Background Technology

[0002] With increasing health awareness, adding medicinal and edible plant ingredients to traditional noodle products has become a common development trend in the food industry. Lotus leaves and goji berries contain a variety of beneficial components and are often used in the processing of compound noodles.

[0003] However, there are significant technical bottlenecks in the existing preparation process of plant-based composite noodles. Plant raw materials contain abundant natural chlorophyll. During the drying, processing, and subsequent storage of noodles, these pigment molecules are easily affected by temperature and moisture conditions, resulting in the loss of central magnesium ions and a demagnesiation browning reaction. This causes the noodles to fade or turn yellow, making it difficult to maintain their original color for a long time.

[0004] Meanwhile, to ensure the functional properties of noodles, a high proportion of plant extracts and raw pulp is usually added. The introduction of these non-gluten substances alters the moisture distribution within the dough and spatially blocks the normal cross-linking of disulfide bonds in wheat flour gluten proteins, thereby weakening the network structure strength of the dough. This structural deterioration makes the finished noodles prone to defects such as loose texture, high breakage rate, and cloudy soup during rolling and cooking. Conventional physical additives and dough mixing processes usually cannot simultaneously solve the problems of pigment degradation and gluten network weakening. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a lotus leaf and wolfberry compound medicinal and edible noodle and its preparation process, which solves the problems of chlorophyll demagnesiation and browning fading in existing high-concentration plant compound noodles during processing and storage, as well as the loose noodle structure and poor cooking resistance caused by non-gluten plant components hindering the formation of disulfide bonds in the dough.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a lotus leaf and wolfberry compound food and medicinal noodle, which adopts the following technical solution:

[0008] A compound medicinal and edible noodle made from lotus leaf and wolfberry includes the following ingredients in parts by weight: 100 parts high-gluten wheat flour; 8 to 12 parts lotus leaf flavonoid and chlorophyll extract; 12 to 18 parts homogenized wolfberry pulp; 0.05 to 0.10 parts zinc gluconate; 0.08 to 0.15 parts L-ascorbic acid; and 0.10 to 0.20 parts sodium hexametaphosphate.

[0009] By adopting the above technical solution, and through the use of functional liquid extraction combined with micro-oxygen in-situ cross-linking processing, the following reaction mechanism occurs within the noodle system, thus achieving noodles with stable color and good cooking resistance:

[0010] To address the issue of unstable plant pigments, the natural chlorophyll in lotus leaf extract easily loses its central magnesium ion under heat and non-neutral environments, forming brownish-yellow pheophytin. This solution introduces zinc gluconate as a free metal ion donor, promoting the replacement of the central free magnesium ion in the chlorophyll with free zinc ions. Because the coordination bond energy of zinc ions is higher than that of magnesium ions, the resulting zinc-substituted chlorophyll molecules have a more stable molecular structure, helping noodles maintain their original color and reducing degradation and fading during drying, cooking, and light-protected storage.

[0011] In terms of dough remodeling, L-ascorbic acid, zinc gluconate, and trace oxygen collectively constitute a redox catalytic system during dough processing. The glutenin and prolysin side chains in high-gluten wheat flour are rich in thiol functional groups. Free zinc ions, combined with ascorbic acid, cause the spatial conformation of gluten protein molecules to unfold and fold, exposing the thiol groups that were originally hidden inside the molecule to the liquid interface. In the micro-oxygen environment of the dough, the exposed thiol groups undergo oxidative dehydrogenation reactions, with adjacent thiol groups losing hydrogen atoms and combining to form disulfide bonds and water molecules. The continuously generated disulfide bonds construct a high-density three-dimensional gluten network, compensating for the structural degradation caused by the addition of lotus leaf extract and wolfberry puree to the dough skeleton.

[0012] To control the degree of the above cross-linking reaction, sodium hexametaphosphate, after entering the reaction system, utilizes the high negative charge density of polyphosphate ions to rapidly complex excess free zinc ions in the system, terminating the thiol-catalyzed oxidation process and preventing the dough from hardening or breaking and losing water due to excessive cross-linking of the gluten network.

[0013] Preferably, the raw materials comprise the following parts by weight: 100 parts high-gluten wheat flour, 10 parts lotus leaf flavonoid and chlorophyll extract, 15 parts homogenized wolfberry pulp, 0.075 parts zinc gluconate, 0.10 parts L-ascorbic acid, and 0.15 parts sodium hexametaphosphate.

[0014] By adopting the above technical solution, the material ratio is set so that the free zinc ions provided in the system can be well matched with the molar substitution amount of chlorophyll molecules in the plant extract, so that the reaction proceeds in the direction of generating zinc chlorophyll, avoiding the astringent taste caused by metal ion residue. At the same time, the reduction potential provided by L-ascorbic acid is adapted to the amount of hydrogen atom transfer required for the appropriate cross-linking of gluten network.

[0015] Preferably, the specific preparation method of the lotus leaf flavonoid and chlorophyll extract includes: adding an ethanol aqueous solution with a volume fraction of 60% to 70% to pulverized dried lotus leaf powder at a liquid-to-solid ratio of 10:1 to 20:1 mL / g; extracting under light-protected stirring at an extraction temperature of 40 to 50°C for 1.5 to 2.5 h; filtering the obtained extract through a microporous membrane with a pore size of 0.20 to 0.45 μm to remove residue; then transferring the clear liquid to a vacuum concentration vessel; recovering ethanol under a vacuum of -0.09 to -0.08 MPa and a temperature of 40°C until the mass fraction of solids in the extract reaches 10% to 15%.

[0016] By adopting the above technical solutions, controlling the volume fraction of ethanol and the low-temperature extraction temperature, the effective dissolution of flavonoids and chlorophyll was achieved and thermal degradation was avoided; cross-flow filtration removed coarse plant fibers and insoluble impurities; vacuum decompression concentration controlled the solid content of the extract and prevented excessive water from being introduced into the dough, which would lead to excessive free water content.

[0017] Preferably, the specific preparation method of the homogenized wolfberry pulp includes: adding purified water at a temperature of 40 to 50°C to dried wolfberry fruits at a weight ratio of 1:2.5 to 1:3.5 and soaking them for 30 to 45 minutes; coarsely grinding the rehydrated wolfberries together with the soaking liquid; pumping the pulp into a colloid mill for continuous grinding and homogenization, so that the particle size D90 of the suspended solid particles in the pulp is not greater than 50 μm; and then sending the pulp into a vacuum degassing tank for degassing under conditions of -0.08 to -0.06 MPa to obtain a homogenized pulp with a solid content of 19% to 25%.

[0018] By adopting the above technical solution, the rehydrated wolfberries are subjected to multi-stage grinding and homogenization, which reduces the size of non-water-soluble polysaccharides and solid suspended particles, making them highly dispersed and suspended, thus preventing large particles from affecting the continuity of the gluten cross-linking network. Vacuum degassing eliminates air bubbles entrained during the pulping process, preventing non-enzymatic browning of the wolfberry pulp during storage and the initial stage of dough mixing.

[0019] Secondly, the present invention provides a preparation process for lotus leaf and wolfberry compound medicinal and edible noodles, which adopts the following technical solution:

[0020] A preparation process for a lotus leaf and wolfberry compound medicinal and edible noodle includes the following steps:

[0021] Weigh out 100 parts of high-gluten wheat flour, 8 to 12 parts of lotus leaf flavonoid and chlorophyll extract, 12 to 18 parts of wolfberry homogenized pulp, 0.05 to 0.10 parts of zinc gluconate, 0.08 to 0.15 parts of L-ascorbic acid, and 0.10 to 0.20 parts of sodium hexametaphosphate. Prepare purified water as the primary wetting water and quenching agent carrier, and prepare citric acid solution and sodium bicarbonate solution.

[0022] Lotus leaf flavonoids were mixed with chlorophyll extract, wolfberry homogenized pulp and zinc gluconate. Citric acid solution was added dropwise to lower the pH value of the system and the reaction was carried out under heating and stirring. Then sodium bicarbonate solution was added to steadily raise the pH value of the system. The temperature was continued to rise and the reaction was carried out under constant temperature and stirring in the dark to complete the magnesium zinc substitution reaction. After cooling, the functional stock solution was obtained.

[0023] High-gluten wheat flour is put into the dough mixing chamber, and primary wetting water pre-dissolved with L-ascorbic acid is sprayed for dry mixing. Then, the above-mentioned functional stock solution is pumped in. Under the condition of sealing the dough mixing chamber and introducing purified compressed air into the chamber to maintain a positive pressure micro-oxygen state, the dough is continuously mixed. After the cross-linking reaction is completed, the positive pressure micro-oxygen state is released. The quencher carrier liquid pre-dissolved with sodium hexametaphosphate is sprayed evenly onto the surface of the dough in a micro-mist state for passivation and quenching, and the dough is kneaded and mixed again.

[0024] After kneading, the dough is transported to a constant temperature bath for resting and maturing, and then fed into a rolling mill to be pressed into a sheet and cut into strips to obtain wet noodles;

[0025] The wet noodles are transferred to a hot air drying room for pre-drying, shaping, and dehydration to obtain the finished product of medicinal and edible noodles.

[0026] By adopting the above technical solution, the preparation process constructs a phase-separated stepwise reaction environment at both the time and operational nodes:

[0027] In the preparation of the stock solution in an independent reaction vessel, citric acid is first added dropwise to lower the pH value. Free hydrogen ions attack the porphyrin ring, causing the central magnesium ions to dissociate and form a free state. Subsequently, sodium bicarbonate is added to raise the pH value. Under constant temperature and stirring conditions, zinc ions gradually embed into the vacant porphyrin ring center. This stepwise acid-base regulation improves the zinc substitution rate and avoids the precipitation of hydroxyl groups in a purely physical mixing state of metal ions.

[0028] In the subsequent dough preparation stage, the positive pressure micro-oxygen environment increases the solubility of gaseous oxygen molecules at the interface between the liquid and solid phases of the dough, promoting the deep penetration of oxygen molecules into the dough interior. Combined with ascorbic acid that has penetrated the powder surface, this achieves relatively uniform cross-linking oxidation, improving upon the shortcomings of conventional dough kneading where oxidation only occurs on the dough surface.

[0029] Once the cross-linking reaction reaches the expected level, the sodium hexametaphosphate solution is sprayed in a micro-mist state. The atomized droplets have a large specific surface area and adhere to the surface of the dough skeleton nodes after the positive pressure is released, achieving in-situ passivation and blocking continuous cross-linking.

[0030] Preferably, the operating conditions for adjusting the pH value of the system by adding citric acid solution and the subsequent reaction are as follows: the pH value of the system is adjusted down by adding citric acid solution and maintained at 4.8 to 5.2, and the temperature is controlled at 40 to 50°C with stirring for 10 to 20 minutes; then sodium bicarbonate solution is added to raise the pH value of the system back to 6.2 to 6.8, the temperature is raised to 50 to 60°C and the reaction is carried out in the dark with stirring for 20 to 30 minutes, and after the reaction is completed, the temperature is cooled to 20 to 25°C.

[0031] By adopting the above technical solution, a pH value of 4.8 to 5.2 provides the optimal proton concentration for the demagnesiation reaction, promoting the shedding of central magnesium ions; subsequently, the pH value is raised to 6.2 to 6.8, providing the optimal slightly acidic environment for zinc ion coordination complexation, avoiding the hydrolysis of zinc ions; 50 to 60°C provides the activation energy baseline and prevents the natural substances from being carbonized and degraded by heat.

[0032] Preferably, the amount of primary wetting water is 8 to 12 parts by weight, the primary dry mixing time is 2 to 4 minutes, and the mixing speed is 30 to 50 r / min; the pressure of the positive pressure micro-oxygen state is limited to 0.03 to 0.08 MPa, and the continuous kneading and mixing time under micro-oxygen conditions is 6 to 10 minutes.

[0033] By adopting the above technical solution, the positive pressure micro-oxygen state is controlled between 0.03 and 0.08 MPa. Within this pressure range, sufficient dissolved oxygen penetration is provided, while excessive oxygen pressure will not cause the dough matrix to over-oxidize and turn white or develop air pocket defects. Combined with a time control of 6 to 10 minutes, cross-linking equilibrium is achieved.

[0034] Preferably, the specific implementation of uniformly spraying the quencher carrier liquid pre-dissolved with sodium hexametaphosphate in a micro-mist state is as follows: dissolve all the weighed proportions of sodium hexametaphosphate in 2 to 4 parts by weight of quencher carrier liquid to prepare a spray solution, and uniformly spray it through a micro-mist nozzle at a spray pressure of 0.3 to 0.5 MPa, and continue to knead for 2 to 4 minutes after spraying.

[0035] By adopting the above technical solution, the injection pressure of 0.3 to 0.5 MPa promotes droplet refinement and avoids excessively large local water droplets that cause dough to stick together; the subsequent kneading process of 2 to 4 minutes allows the passivating complexing agent to be encapsulated and stretched into the entire network system, completing the cross-linking blockage.

[0036] Preferably, the temperature for resting and maturing the dough is 20 to 30°C, the relative humidity is limited to 70% to 80%, and the maturation time is 15 to 30 minutes; the thickness of the pressed dough strip is 1.0 to 1.5 mm.

[0037] By adopting the above technical solution, the temperature and humidity of the static maturation environment are controlled, which promotes the stress relaxation of the dense macromolecular network formed in the early stage, makes the hydration inside the dough tend to be balanced, and the gluten molecules rearrange themselves, providing flexibility for subsequent rolling and reducing the probability of jagged cracks appearing on the edges of the dough.

[0038] Preferably, the pre-drying and shaping temperature in the hot air drying room is set to 30 to 40°C, the relative humidity is limited to 80% to 90%, and the pre-drying time is 1.5 to 2.5 h; the dehydration drying temperature is set to 40 to 50°C, the relative humidity is limited to 50% to 60%, and the dehydration time is 3 to 5 h, until the moisture content of the finished noodles drops below 12%.

[0039] By adopting the above technical solution and using a programmed dehydration and drying model, the initial high-humidity and low-temperature pre-drying and shaping alleviates the rapid crusting on the surface of the noodles, which causes internal pore fractures. Subsequently, in the medium-temperature and medium-humidity main dehydration stage, the internal moisture is extracted evenly to maintain the thermal stability of zinc-substituted chlorophyll and preserve the flexibility and storage stability of the final noodle product.

[0040] This invention provides a lotus leaf and wolfberry compound medicinal and edible noodle and its preparation process. It has the following beneficial effects:

[0041] 1. This invention pre-prepares a functional stock solution containing zinc gluconate, and utilizes stepwise acid-base regulation of citric acid and sodium bicarbonate to promote the replacement of free magnesium ions in lotus leaf extract with free zinc ions, generating structurally stable zinc-substituted chlorophyll; effectively improving the demagnesiation and browning phenomenon that easily occurs in natural chlorophyll during the heat processing and storage of noodles, enabling noodles to maintain their original plant color for a long time.

[0042] 2. This invention introduces a positive pressure micro-oxygen environment during the dough preparation stage. Combined with the catalytic effect of L-ascorbic acid and free zinc ions, it promotes the exposure of thiol groups on the side chains of gluten proteins and causes oxidative dehydrogenation reaction, thereby generating disulfide bonds to form a dense gluten network. This compensates for the structural weakening of the dough skeleton caused by the addition of plant pulp and extract to the dough, improves the boiling resistance of the finished noodles and reduces the breakage rate.

[0043] 3. In this invention, sodium hexametaphosphate solution is sprayed evenly in a micro-mist state at the end of the dough cross-linking process. The polyphosphate ions rapidly complex the remaining free zinc ions in the system, thereby timely terminating the catalytic oxidation process of the protein network. This avoids dough hardening and dehydration fracture caused by excessive cross-linking of the gluten network, ensuring the smooth progress of the subsequent rolling and cutting processes and the flexibility of the finished noodles. Attached Figure Description

[0044] Figure 1 The UV and Visible absorption spectra of the functional stock solutions obtained after the reaction in the embodiment group of the present invention are shown below.

[0045] Figure 2 The UV and Visible absorption spectra of the functional stock solutions obtained after the reaction in the comparative group of the present invention are shown.

[0046] Figure 3 This is a graph showing the conversion kinetics of free thiol content in the dough during the micro-oxygen catalysis stage of the present invention.

[0047] Figure 4 The diagram shows the kinetics of disulfide bond formation in the dough of this invention during the micro-oxygen catalysis stage.

[0048] Figure 5 This is a graph showing the change in ultrafiltration zinc concentration in the dough at different processing stages of the present invention;

[0049] Figure 6 This is a bar chart comparing the decrease in greenness of noodles before and after heat processing in each group according to the present invention;

[0050] Figure 7 The following is a comparison chart of the steaming quality parameters of noodles in each group according to the present invention; wherein, (a) is a bar chart comparing the steaming loss rate of noodles in each group, and (b) is a line chart comparing the water absorption rate of noodles in each group.

[0051] Figure 8 The diagram shows a comparison of the texture and tensile mechanical parameters of the cooked noodles in each group according to the present invention; wherein, (a) is a double Y-axis line graph of tensile breaking force and tensile breaking distance of each group of noodles, and (b) is a double Y-axis line graph of hardness and chewiness of each group of noodles. Detailed Implementation

[0052] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Preparation Examples 1-3:

[0054] Preparation Example 1:

[0055] This preparation example provides a method for preparing a functional raw material component, including the following steps:

[0056] (1) Preparation of lotus leaf flavonoid and chlorophyll extract:

[0057] Select dried lotus leaves and crush them through a 60-mesh sieve to obtain coarse lotus leaf powder.

[0058] Add a 60% ethanol aqueous solution to the lotus leaf powder at a liquid-to-solid ratio of 10:1 (mL / g).

[0059] Place in an extraction tank, control the extraction temperature at 40℃, and extract with stirring in the dark for 1.5 hours;

[0060] The extract was filtered through a microporous membrane with a pore size of 0.45 μm to remove residue.

[0061] The clarified liquid was transferred to a vacuum concentration vessel, and ethanol was recovered under a vacuum of -0.08 MPa and a temperature of 40°C until the mass fraction of solids in the extract reached 10%, thus obtaining the lotus leaf flavonoid and chlorophyll extract.

[0062] (2) Preparation of homogenized wolfberry pulp:

[0063] Select dried Ningxia wolfberry fruits and soak them in purified water at 40℃ for 30 minutes at a material-to-water ratio of 1:3.5 (by weight).

[0064] The rehydrated wolfberries and their soaking solution were transferred together into a pulping machine for coarse pulping.

[0065] The coarse slurry was pumped into a colloid mill for two consecutive grinding and homogenization processes to ensure that the particle size D90 of the suspended solid particles in the slurry was ≤50μm.

[0066] The homogenized slurry was fed into a vacuum degassing tank and degassed under a pressure of -0.06 MPa to obtain a homogenized wolfberry slurry with a solid content of approximately 19%.

[0067] Preparation Example 2:

[0068] This preparation example provides a method for preparing a functional raw material component, including the following steps:

[0069] (1) Preparation of lotus leaf flavonoid and chlorophyll extract:

[0070] Select dried lotus leaves and crush them through a 70-mesh sieve to obtain coarse lotus leaf powder.

[0071] Add a 65% ethanol aqueous solution to the lotus leaf powder at a liquid-to-solid ratio of 15:1 (mL / g).

[0072] Place in an extraction tank, control the extraction temperature at 45℃, and extract with stirring in the dark for 2.0 hours;

[0073] The extract was filtered through a microporous membrane with a pore size of 0.30 μm to remove residue.

[0074] The clarified liquid was transferred to a vacuum concentration vessel, and ethanol was recovered under a vacuum of -0.085 MPa and a temperature of 40°C until the mass fraction of solids in the extract reached 12.5%, thus obtaining the lotus leaf flavonoid and chlorophyll extract.

[0075] (2) Preparation of homogenized wolfberry pulp:

[0076] Select dried Ningxia wolfberry fruits and soak them in purified water at 45℃ for 38 minutes at a material-to-water ratio of 1:3.0 (by weight).

[0077] The rehydrated wolfberries and their soaking solution were transferred together into a pulping machine for coarse pulping.

[0078] The coarse slurry was pumped into a colloid mill for three consecutive grinding and homogenization processes to ensure that the particle size D90 of the suspended solid particles in the slurry was ≤50μm.

[0079] The homogenized slurry was fed into a vacuum degassing tank and degassed under a pressure of -0.07 MPa to obtain a homogenized wolfberry slurry with a solid content of approximately 21.5%.

[0080] Preparation Example 3:

[0081] This preparation example provides a method for preparing a functional raw material component, including the following steps:

[0082] (1) Preparation of lotus leaf flavonoid and chlorophyll extract:

[0083] Select dried lotus leaves and crush them through an 80-mesh sieve to obtain coarse lotus leaf powder.

[0084] Add a 70% ethanol aqueous solution to the lotus leaf powder at a liquid-to-solid ratio of 20:1 (mL / g).

[0085] Place in an extraction tank, control the extraction temperature at 50℃, and extract with stirring in the dark for 2.5 hours;

[0086] The extract was filtered through a microporous membrane with a pore size of 0.20 μm to remove residue.

[0087] The clarified liquid was transferred to a vacuum concentration vessel, and ethanol was recovered under a vacuum of -0.09 MPa and a temperature of 40°C until the mass fraction of solids in the extract reached 15%, thus obtaining the lotus leaf flavonoid and chlorophyll extract.

[0088] (2) Preparation of homogenized wolfberry pulp:

[0089] Select dried Ningxia wolfberry fruits and soak them in purified water at 50℃ for 45 minutes at a material-to-water ratio of 1:2.5 (by weight).

[0090] The rehydrated wolfberries and their soaking solution were transferred together into a pulping machine for coarse pulping.

[0091] The coarse slurry was pumped into a colloid mill for three consecutive grinding and homogenization processes to ensure that the particle size D90 of the suspended solid particles in the slurry was ≤50μm.

[0092] The homogenized slurry was fed into a vacuum degassing tank and degassed under a pressure of -0.08 MPa to obtain a homogenized wolfberry slurry with a solid content of approximately 25%.

[0093] Examples 1-4:

[0094] Example 1:

[0095] This embodiment provides a preparation process for lotus leaf and wolfberry compound medicinal and edible noodles, including the following steps:

[0096] (1) Mixing and pretreatment: Accurately weigh 100 parts of high-gluten wheat flour, 0.05 parts of zinc gluconate, 0.08 parts of L-ascorbic acid, and 0.10 parts of sodium hexametaphosphate. Measure 8 parts of the lotus leaf flavonoid and chlorophyll extract obtained in Preparation Example 1 and 12 parts of the wolfberry homogenized pulp obtained in Preparation Example 1. To control the dough hydration level within a suitable range, and considering the water introduced by the lotus leaf flavonoid and chlorophyll extract and the wolfberry homogenized pulp, the amount of externally added water was reduced. Accurately measure 12 parts of purified water (primary wetting water) and 2 parts of purified water (quencher carrier liquid). Dissolve 0.08 parts of L-ascorbic acid in the 12 parts of primary wetting water for later use.

[0097] (2) Magnesium removal and zinc substitution reaction (preparation of pre-prepared catalytic stock solution): In a light-protected reactor equipped with a temperature-controlled jacket, online pH meter, and stirring device, 8 parts of lotus leaf flavonoid and chlorophyll extract and 12 parts of homogenized wolfberry pulp were mixed. 0.05 parts of zinc gluconate were added. Food-grade citric acid solution was added dropwise to lower the pH of the system and maintain it at 5.2. The temperature inside the reactor was controlled at 40°C, and the reaction was stirred for 10 min. Subsequently, food-grade sodium bicarbonate solution was slowly added to steadily raise the pH of the system and maintain it at 6.2. The temperature inside the reactor was raised to 50°C, and the reaction was continued in the dark with constant temperature stirring for 20 min. After the reaction was completed, the jacket was cooled to 20°C with water and used as a functional stock solution for later use.

[0098] (3) Kneading dough and cross-linking with micro-oxygen:

[0099] Stage A (Skeleton Surface Activation and Vitamin C Pre-penetration): 100 parts of high-gluten wheat flour were put into the positive pressure dough mixer chamber, and 12 parts of primary wetting water containing dissolved Vitamin C were sprayed on. The mixture was then dry-mixed at 30 r / min for 2 minutes under normal pressure and temperature.

[0100] Stage B (Micro-oxygen Catalysis): Maintain stirring and pump in all the cooled functional stock solutions mentioned above. Seal the chamber and introduce purified compressed air into the chamber at constant pressure to maintain a positive pressure micro-oxygen state of 0.03 MPa inside the chamber. Continuously knead and stir for 6 minutes.

[0101] Stage C (Reaction Quenching): Relieve micro-oxygen positive pressure. Dissolve 0.10 parts of sodium hexametaphosphate in 2 parts of quenching agent carrier liquid to prepare a solution. Spray the solution evenly onto the surface of the dough particles through the top micro-mist nozzle at a spray pressure of 0.3 MPa. Continue stirring and kneading for 2 minutes until the dough kneading process is completed.

[0102] (4) Maturation and rolling: The dough is transported to a constant temperature and humidity maturation tank and allowed to stand for 15 minutes under the conditions of 20℃ and 70% relative humidity. It is then fed into a continuous rolling mill to be rolled into a dough strip with a thickness of 1.0mm, and cut into strips to obtain wet noodles.

[0103] (5) Programmed drying: Transfer to a hot air drying room and pre-dry and shape for 1.5 hours at 30°C and 80% relative humidity; raise to 40°C and 50% relative humidity and dehydrate for 3 hours until the moisture content drops below 12% to obtain the finished product.

[0104] Example 2:

[0105] This embodiment provides a preparation process for lotus leaf and wolfberry compound medicinal and edible noodles, including the following steps:

[0106] (1) Mixing and pretreatment: Accurately weigh 100 parts of high-gluten wheat flour, 0.075 parts of zinc gluconate, 0.10 parts of L-ascorbic acid, and 0.15 parts of sodium hexametaphosphate. Measure 10 parts of the lotus leaf flavonoid and chlorophyll extract obtained in Preparation Example 2 and 15 parts of the wolfberry homogenized pulp obtained in Preparation Example 2. Measure 10 parts of purified water (primary wetting water) and 3 parts of purified water (quencher carrier solution). Dissolve 0.10 parts of L-ascorbic acid in the 10 parts of primary wetting water for later use.

[0107] (2) Magnesium removal and zinc substitution reaction (preparation of pre-prepared catalytic stock solution): In a light-protected reactor, 10 parts of lotus leaf extract and 15 parts of homogenized wolfberry pulp were mixed. 0.075 parts of zinc gluconate were added. Food-grade citric acid solution was added dropwise to lower the pH of the system and maintain it at 5.0. The temperature was controlled at 45℃, and the reaction was stirred for 15 min. Subsequently, food-grade sodium bicarbonate solution was added dropwise to raise the pH of the system back to 6.5 and maintain it at 6.5. The temperature inside the reactor was raised to 55℃, and the reaction was stirred at a constant temperature in the dark for 25 min. After the reaction was completed, the mixture was cooled to 25℃ and set aside for later use.

[0108] (3) Kneading dough and cross-linking with micro-oxygen:

[0109] Stage A (Skeleton Surface Activation and Vitamin C Pre-penetration): 100 parts of high-gluten wheat flour are put into the positive pressure dough mixer chamber, and 10 parts of primary wetting water containing dissolved Vitamin C are sprayed on. The mixture is then dry-mixed at 40 r / min for 3 min.

[0110] Phase B (Micro-oxygen Catalysis): Maintain stirring and pump in all the above-mentioned functional stock solutions. Seal the chamber, introduce purified compressed air at constant pressure to maintain a positive pressure micro-oxygen state of 0.05MPa inside the chamber, and continuously knead and stir for 8 minutes.

[0111] Stage C (Reaction Quenching): Relieve micro-oxygen positive pressure. Dissolve 0.15 parts sodium hexametaphosphate in 3 parts quencher carrier liquid beforehand, and spray it evenly onto the surface of the dough particles through a micro-mist nozzle at 0.4 MPa. Continue kneading for 3 minutes until the program ends.

[0112] (4) Maturation and rolling: The dough is left to mature for 20 minutes at a temperature of 25℃ and a relative humidity of 75%. It is then pressed into a 1.2mm thick sheet and cut into strips to obtain wet noodles.

[0113] (5) Programmatic drying: Pre-dry and shape at 35℃ and 85% relative humidity for 2.0h; then raise to 45℃ and 55% relative humidity, dehydrate and dry for 4h, and the moisture content drops to below 12% to obtain the finished product.

[0114] Example 3:

[0115] This embodiment provides a preparation process for lotus leaf and wolfberry compound medicinal and edible noodles, including the following steps:

[0116] (1) Mixing and pretreatment: Accurately weigh 100 parts of high-gluten wheat flour, 0.10 parts of zinc gluconate, 0.15 parts of L-ascorbic acid, and 0.20 parts of sodium hexametaphosphate. Measure 12 parts of the lotus leaf flavonoid and chlorophyll extract obtained in Preparation Example 3 and 18 parts of the wolfberry homogenized pulp obtained in Preparation Example 3. Since the total amount of lotus leaf flavonoid and chlorophyll extract and wolfberry homogenized pulp added is relatively high, the water introduced into the system is correspondingly increased. Therefore, the amount of external water added is reduced, and 8 parts of purified water (primary wetting water) and 4 parts of purified water (quencher carrier liquid) are measured. Dissolve 0.15 parts of L-ascorbic acid in the 8 parts of primary wetting water for later use.

[0117] (2) Demagnesiation and zinc substitution reaction (preparation of pre-prepared catalytic stock solution): In a light-protected reactor, mix 12 parts of lotus leaf extract with 18 parts of homogenized wolfberry pulp. Add 0.10 parts of zinc gluconate. Adjust the pH to 4.8 by adding citric acid solution dropwise, control the temperature at 50℃, and stir for 20 min. Subsequently, add sodium bicarbonate solution to raise the pH back to 6.8, raise the temperature to 60℃, and react in the dark for 30 min. Cool to 25℃ and set aside.

[0118] (3) Kneading dough and cross-linking with micro-oxygen:

[0119] Stage A (Skeleton Surface Activation and Vitamin C Pre-penetration): 100 parts of high-gluten wheat flour were put into the positive pressure dough mixer chamber, and 8 parts of primary wetting water containing Vitamin C were sprayed on. The mixture was then dry-mixed at 50 r / min for 4 min.

[0120] Stage B (Micro-oxygen Catalysis): Pump in the cooled functional stock solution, seal the chamber, and introduce compressed air to maintain a positive pressure micro-oxygen state of 0.08MPa. Continuously knead and stir for 10 minutes.

[0121] Stage C (Reaction Quenching): Release the positive pressure. Dissolve 0.20 parts of sodium hexametaphosphate in 4 parts of quenching agent carrier liquid, spray evenly through a micro-mist nozzle at 0.5 MPa, and continue kneading for 4 minutes until the program ends.

[0122] (4) Maturation and rolling: The dough is matured at 30℃ and 80% relative humidity for 30 minutes. It is then pressed into a 1.5mm thick sheet and cut into strips to obtain wet noodles.

[0123] (5) Programmatic drying: Pre-dry at 40℃ and 90% relative humidity for 2.5h; then dehydrate at 50℃ and 60% relative humidity for 5h until the moisture content drops below 12% to obtain the finished product.

[0124] Example 4:

[0125] This embodiment provides a preparation process for lotus leaf and wolfberry compound medicinal and edible noodles, including the following steps:

[0126] (1) Mixing and pretreatment: Accurately weigh 100 parts of high-gluten wheat flour, 0.05 parts of zinc gluconate, 0.08 parts of L-ascorbic acid, and 0.10 parts of sodium hexametaphosphate. Measure 12 parts of the extract and 18 parts of the pulp obtained in Preparation Example 3. Measure 8 parts of purified water (primary wetting water) and 2 parts of purified water (quencher carrier solution). Dissolve 0.08 parts of L-ascorbic acid in 8 parts of primary wetting water for later use.

[0127] (2) Demagnesium and zinc substitution reaction: Add 12 parts of the above extract and 18 parts of the original pulp. Add 0.05 parts of zinc gluconate. Adjust the pH to 5.2 with citric acid and react at 40℃ for 10 min. Add sodium bicarbonate to raise the pH to 6.2 and react at 50℃ for 20 min. Cool to 20℃ for later use.

[0128] (3) Kneading dough and cross-linking with micro-oxygen:

[0129] Phase A: Spray 8 parts of moistening water containing vitamin C into 100 parts of high-gluten wheat flour and dry mix for 2 minutes.

[0130] Phase B: Pump in the above-mentioned stock solution. Seal the chamber, maintain a low micro-oxygen environment of 0.03 MPa, and continuously knead and stir for 6 minutes.

[0131] Phase C: Release the positive pressure. Dissolve 0.10 parts of sodium hexametaphosphate in 2 parts of quenching carrier liquid, atomize and spray at 0.3 MPa, and knead for 2 minutes to finish.

[0132] (4) Curing and rolling: Curing at 20℃ for 15 minutes, then rolling and cutting into strips.

[0133] (5) Drying: Pre-dry at 30℃ for 1.5h, then dehydrate at 40℃ for 3h to obtain the finished product.

[0134] Comparative Examples 1-6:

[0135] Comparative Example 1:

[0136] Compared with Example 2, the differences are: no zinc gluconate, L-ascorbic acid and sodium hexametaphosphate are added; the magnesium removal and zinc substitution reaction in step (2) is not performed, and the lotus leaf extract, wolfberry puree and primary wetting water are directly added to the dough mixer; step (3) is a one-time conventional kneading for 14 minutes under normal pressure, without staged operation. All other aspects are the same.

[0137] Comparative Example 2:

[0138] Compared with Example 2, the difference is that zinc gluconate is not added in steps (1) and (2). Everything else is the same.

[0139] Comparative Example 3:

[0140] Compared with Example 2, the difference is that in step (3) stage B, the chamber is not sealed and purified compressed air is not introduced into the chamber. Instead, the dough is continuously kneaded and stirred for 8 minutes under normal pressure (0.00MPa). All other aspects are the same.

[0141] Comparative Example 4:

[0142] Compared with Example 2, the difference is that 0.15 parts of sodium hexametaphosphate were directly dry-mixed with high-gluten wheat flour in step (3) stage A in dry powder form; and in step (3) stage C, only 3 parts of purified water (without sodium hexametaphosphate) were sprayed by micro-mist. All other aspects are the same.

[0143] Comparative Example 5:

[0144] Compared with Example 2, the difference is that in step (2), citric acid solution is not added dropwise to lower the pH, nor is sodium bicarbonate solution added dropwise to raise the pH. Instead, the system is heated directly to 55°C under natural mixed pH conditions and stirred for 40 minutes in the dark. All other steps are the same.

[0145] Comparative Example 6:

[0146] Compared with Example 2, the difference is that L-ascorbic acid is not added in step (1) and stage A of step (3). Everything else is the same.

[0147] Test Examples 1-6:

[0148] Test Example 1: Determination of Zinc-substituted Chlorophyll Conversion Rate

[0149] 1. The functional stock solutions or mixed stock solutions obtained at the corresponding process nodes in Examples 1 to 4 and Comparative Examples 1, 2, and 5 were used as test samples. Sampling was carried out in an ice bath environment under light-protected conditions to reduce the interference of photothermal factors on the state of the metalloporphyrin complex in the system.

[0150] 2. Accurately transfer 1.0 mL of the test sample solution into a centrifuge tube, add 9.0 mL of 80% acetone aqueous solution, and vortex extract for 15 min in a dark, room temperature environment. Then, centrifuge at 8000 rpm for 10 min. Filter the supernatant through a 0.22 μm organic phase microporous membrane and collect the filtrate as the pigment extract to be injected for testing.

[0151] 3. Quantitative analysis was performed using a high-performance liquid chromatograph equipped with a diode array detector. A conventional C18 reversed-phase column (250 mm × 4.6 mm, 5 μm) was used. Mobile phase A was methanol, mobile phase B was 0.1 mol / L aqueous acetic acid solution, and mobile phase C was acetone. The elution gradient was set according to the preset parameters, with a flow rate of 1.0 mL / min, a column temperature maintained at 30 °C, and an injection volume of 20 μL.

[0152] 4. During the liquid chromatography process, the characteristic absorption peaks of zinc-substituted chlorophyll at 652 nm and pheophytin at 667 nm were extracted. Using pre-established retention times and external standard curves, the mass concentration of each component in the original solution was calculated. Based on the ratio of the zinc-substituted chlorophyll mass concentration to the total pigment mass concentration (the sum of the concentrations of natural chlorophyll, pheophytin, and zinc-substituted chlorophyll), the conversion rate of each sample was calculated.

[0153] Table 1. Test data on zinc-substituted chlorophyll conversion rate in functional stock solutions of each embodiment and comparative example.

[0154] Group Zinc-substituted chlorophyll conversion rate (%) Example 1 84.7 Example 2 92.1 Example 3 96.3 Example 4 88.5 Comparative Example 1 Not detected Comparative Example 2 Not detected Comparative Example 5 17.4

[0155] Figure 1 These are the UV and Visible absorption spectra of the functional stock solutions obtained after the reaction in the embodiments of the present invention. The curves in the figure reflect the spectral response characteristics of the systems in Examples 1, 2, 3, and 4, and show the characteristic absorption peak of the zinc-modified chlorophyll generated in the system at a wavelength of around 652 nm under the set process parameters.

[0156] Figure 2This is the UV and Visible absorption spectrum of the functional stock solution obtained after the reaction in the comparative group. The curves in the figure reflect the spectral response characteristics of the systems in Comparative Example 1, Comparative Example 2, and Comparative Example 5, and show the characteristic absorption performance of the demagnesiation products and residues in the system at a wavelength of around 667 nm.

[0157] Based on the data and absorption spectrum analysis in Table 1, the zinc conversion rate in the functional stock solution system of the example group was relatively high after the set process procedure. During the processing of plant extracts, magnesium ions at the center of the porphyrin ring in natural chlorophyll are easily desorbed under acidic or heated conditions, generating pheophytin. Figure 2 The characteristic absorption peak is located near 667 nm in the spectrum. Figure 1 In the spectral data of the examples, the characteristic absorption peak blue-shifted to around 652 nm, indicating that the zinc substitution reaction had occurred. The conversion rates of Examples 1 to 4 ranged from 84.7% to 96.3%, indicating that the pH and temperature oscillation control applied during the process promoted the isomorphic substitution reaction.

[0158] In food macromolecular systems, simply adding a metal ion often fails to achieve high-conversion coordination substitution. In the test system, the addition of citric acid created a slightly acidic environment, acting as a proton donor to promote the desorption of magnesium ions from the porphyrin ring center, generating a relatively open demagnesiation intermediate. Subsequent addition of sodium bicarbonate caused a stable pH rise, altering the acid-base balance. Free zinc ions, under heating conditions of 50°C to 60°C, overcame the reaction barrier and embedded themselves into the porphyrin ring cavity, forming a stable coordination structure. Comparative Example 5, without staged pH control, remained at its natural pH after mixing; the kinetic conditions were insufficient to complete the aforementioned distribution steps, resulting in a conversion rate of only 17.4%.

[0159] Neither Comparative Example 1 nor Comparative Example 2 detected the target zinc-substituted chlorophyll, indicating that simple physical mixing and heating cannot complete the structural modification of chlorophyll. The functional stock solution prepared in the examples has a high zinc-substituted chlorophyll conversion rate, improves the structural stability of the pigment complex, and can reduce interference from macromolecular polysaccharides and changes in spectral characteristics caused by thermal processing in subsequent processing steps.

[0160] Test Example 2: Titration of Free Thiol Groups and Disulfide Bonds in Dough

[0161] 1. The dough samples from Examples 1 to 4, and Comparative Examples 2, 3, and 6 were used as test subjects. Samples were taken at the end of stage A (dry mixing) and the end of the micro-oxygen catalysis process in each group of processes. The obtained wet dough samples were quick-frozen in liquid nitrogen, processed to constant weight in a freeze dryer, pulverized, sieved, and defatted with n-hexane to obtain defatted dough freeze-dried powder.

[0162] 2. Weigh 50.0 mg of defatted dough lyophilized powder and place it in a centrifuge tube. Add 5.0 mL of Tris-glycine buffer containing sodium dodecyl sulfate and ethylenediaminetetraacetic acid. Stir magnetically at room temperature for 60 min, then centrifuge at 10000 r / min for 15 min. Collect the supernatant as the protein extraction solution to be tested.

[0163] 3. Take 1.0 mL of the supernatant, add 0.1 mL of 4 mg / mL dithiobisnitrobenzic acid colorimetric reagent, and let stand at room temperature for 20 min in the dark. Measure the absorbance of the mixture at 412 nm using a UV-Vis spectrophotometer, using a blank buffer solution without the sample as a control, and calculate the free thiol content by substituting the molar extinction coefficient.

[0164] 4. Take another 50.0 mg of defatted dough lyophilized powder, add Tris-glycine buffer containing urea and mercaptoethanol, and reduce the disulfide bonds in gluten protein in a sealed reaction. Add trichloroacetic acid to precipitate the protein to remove excess reducing agent. After centrifugation and washing, dissolve the protein precipitate in an extract containing sodium dodecyl sulfate. Add a colorimetric reagent, allow to stand, and measure the absorbance at 412 nm to calculate the total thiol content. Calculate the disulfide bond content of the corresponding sample based on half the difference between the total thiol content and the free thiol content.

[0165] Table 2. Test data on free thiol and disulfide bond content of dough at different processing stages in each group.

[0166] Group Stage A dry mixing completion: free thiol groups (μmol / g) Stage A dry mixing ends disulfide bond formation (μmol / g) Micro-oxygen catalysis terminates free thiol groups (μmol / g) Micro-oxygen catalysis terminates disulfide bonds (μmol / g) Example 1 11.83 9.27 3.65 13.08 Example 2 12.01 9.04 2.14 14.13 Example 3 11.75 9.12 2.58 13.81 Example 4 12.24 8.86 3.12 13.56 Comparative Example 2 11.96 9.15 8.74 10.62 Comparative Example 3 12.08 9.02 9.31 10.27 Comparative Example 6 12.11 9.09 10.05 10.03

[0167] Figure 3 This is a graph showing the conversion kinetics of free thiol content in dough during the micro-oxygen catalysis stage. The graph reflects the decay trend of free thiol concentration in the gluten protein system during the corresponding micro-oxygen catalysis cycles of Examples 1 to 4 and Comparative Examples 2, 3, and 6.

[0168] Figure 4 This is a kinetic curve of disulfide bond formation in dough during the micro-oxygen catalysis stage. The figure reflects the increasing trend of free thiol group oxidation and closure into disulfide bonds in Examples 1 to 4 and Comparative Examples 2, 3, and 6 within their respective micro-oxygen catalysis operation cycles.

[0169] In this figure, Examples 1 and 4 correspond to a 6-minute micro-oxygen catalytic cycle, Examples 2 and Comparative Examples 2, 3, and 6 correspond to an 8-minute micro-oxygen catalytic cycle, and Example 3 corresponds to a 10-minute micro-oxygen catalytic cycle; the curves in the figure are plotted based on the actual process time of each group.

[0170] Based on the data in Table 2 and the analysis of the kinetic curves, after the micro-oxygen catalysis process, the free thiol content in the example group was lower than the initial level at the end of high-pressure dry mixing, while the disulfide bond content increased accordingly. In the dough system, the establishment of the spatial network strength of glutenin and gliadin depends on the oxidative cross-linking of free thiol groups between peptide chains. The natural oxidation process in conventional noodle processing is limited by the dissolved oxygen diffusion rate within the system, resulting in relatively slow gluten network formation. The example introduced ascorbic acid and zinc ions under closed positive pressure conditions, increasing the dissolved oxygen partial pressure in the dough liquid phase environment and altering the protein oxidation pathway through the catalytic properties of transition metals. Ascorbic acid is converted into a dehydroascorbic acid intermediate in the microenvironment. This intermediate acquires hydrogen protons from free thiol groups, promoting covalent closure of adjacent free thiol groups to form disulfide bonds.

[0171] The test data from the comparative examples reflect the dependence of the crosslinking reaction on specific catalytic conditions. Comparative Example 2, without the addition of a zinc source, lacked transition metal catalytic centers, and the free thiol content decreased slowly during the stirring phase, showing no obvious catalytic acceleration characteristics. Comparative Example 3, kneaded under normal pressure, failed to establish a pressurized micro-oxygen environment; the dissolved oxygen reserve in the liquid phase was insufficient to sustain the oxidation reaction, thus hindering the ascorbic acid-mediated catalytic cycle. Figure 3 and Figure 4 The conversion curves in this group showed a flattening slope in the later stages. Comparative Example 6 lacked ascorbic acid, and the dough system lost the proton transfer medium for oxygen-to-oxidant conversion, resulting in a lower disulfide bond synthesis rate. The treatment system, composed of free metal ions, reducing agents, and a positive pressure micro-oxygen environment, affected the bonding rate of the gluten network's internal structure. In composite doughs containing exogenous high-molecular-weight polysaccharides, in-situ catalytic mechanisms could promote the formation and fixation of the protein spatial framework under water distribution competition conditions.

[0172] Test Example 3: Tracking of Ultrafiltration-Produced Zinc Concentration in Dough

[0173] 1. The dough samples from Examples 1 to 4 and Comparative Example 4 were used as test subjects. Samples were taken after the micro-oxygen catalysis process, the processing process, and after the dough was rolled and formed, simulating a 2-hour resting time. The obtained wet dough samples were quick-frozen in liquid nitrogen, processed to constant weight in a freeze dryer, pulverized, sieved, and defatted to obtain defatted dough freeze-dried powder.

[0174] 2. Weigh 2.00g of defatted dough freeze-dried powder and place it in a homogenizer. Add 20.0mL of ultrapure water and homogenize at 12000r / min for 5min under ice bath conditions to dissolve the aqueous phase and free ions of the dough. Transfer the homogenate to a centrifuge tube and centrifuge at 8000r / min for 10min. Collect the supernatant containing soluble components.

[0175] 3. Transfer the supernatant to an ultrafiltration centrifuge tube with a molecular weight cutoff of 3 kDa and centrifuge at 5000 rpm for 30 min. The ultrafiltration membrane is used to retain zinc complexed with gluten and the large molecular polymer formed by sodium hexametaphosphate and zinc, separating the small molecular zinc ions in the free state into the ultrafiltrate.

[0176] 4. Measure 1.0 mL of the ultrafiltrate and place it in a microwave digestion vessel. Add 65% nitric acid solution (by volume) for microwave digestion. After digestion, remove the acid and bring the volume to a final level. Use inductively coupled plasma mass spectrometry (ICP-MS) to determine the mass concentration of ultrafilterable zinc in the sample solution. Calculate the dry basis content of the dough based on the sample mass.

[0177] Table 3. Test data of ultrafiltration zinc concentration in dough at different processing stages for each group.

[0178] Group Micro-oxygen catalysis completed, ultrafiltration zinc concentration (mg / kg) The final concentration of ultrafiltration zinc (mg / kg) after the treatment process is complete. The concentration of ultrafiltration zinc (mg / kg) after calendering and simulating 2 hours of storage can be determined. Example 1 16.24 1.83 1.62 Example 2 15.89 1.35 1.18 Example 3 16.71 2.12 1.84 Example 4 15.48 1.57 1.45 Comparative Example 4 9.34 8.12 6.55

[0179] Figure 5 This is a graph showing the changes in ultrafiltration-capable zinc concentration in the dough at different processing stages. The graph reflects the changing trends of small-molecule mobile zinc content in the aqueous phase of the dough during three process nodes: micro-oxygen catalysis, quenching treatment, and simulated placement after calendering in Examples 1 to 4 and Comparative Example 4.

[0180] Based on the data in Table 3 and Figure 5 The trend shows that after sodium hexametaphosphate atomization treatment in the example group, the concentration of ultrafilterable zinc in the dough decreased from the high concentration at the end of micro-oxygen catalysis and remained at a low level during the simulated placement stage after calendering. In the early stage of gluten network construction, free zinc ions act as a catalytic medium, promoting the conversion of thiol groups between protein peptide chains to disulfide bonds. After the gluten network is initially formed, if active metal ions are not removed in time, the residual migratory zinc can easily cause continuous cross-linking during noodle cooking and storage, resulting in brittle noodles. Sodium hexametaphosphate is a polyphosphate compound with multiple coordinating oxygen atoms in its molecular structure. In the liquid phase, it undergoes multidentate chelation with zinc ions, causing some zinc to transform from a small, ultrafilterable molecule migratory state to a bound or aggregated state that is difficult to permeate the ultrafiltration membrane. The significant decrease in the concentration of ultrafilterable zinc in the ultrafiltrate indicates that the zinc catalytic activity has been effectively passivated.

[0181] The test data of Comparative Example 4 reflects the influence of treatment timing and mass transfer method on coordination equilibrium. In Comparative Example 4, sodium hexametaphosphate was added in dry powder form during the initial dry mixing stage. The concentration of ultrafilterable zinc at the end of micro-oxygen catalysis was lower than that in the Example group. The multidentate chelating agent chelated some free zinc ions in the early stage of the reaction, reducing the concentration of free metal ions required to maintain the catalytic cycle and limiting the crosslinking kinetics in the early stage. In subsequent processing stages, due to the mass transfer and diffusion limitations of the low-moisture dough system, the dry powder sodium hexametaphosphate was difficult to achieve uniform dissolution and diffusion. After the treatment process and calendering, and after simulated placement, the concentration of ultrafilterable zinc in Comparative Example 4 was higher than that in the Example group, and showed a slow decreasing trend, indicating that there were still migratory zinc states in the dough that were not fully complexed or passivated and continued to participate in the reaction. In the Example, an atomized spray method was used to spread the sodium hexametaphosphate aqueous solution as micron-sized droplets on the dough surface, increasing the contact surface area. This method reduces the diffusion resistance of solid particles, promotes rapid chelation reaction, completes the coordination and catalytic passivation of mobile zinc, terminates the catalytic reaction, and helps maintain the stability of the rheological quality of noodles.

[0182] Test Example 4: Evaluation of Optical Color and Thermal Fading Rate

[0183] 1. Noodles prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were used as test subjects. Raw noodles were laid flat in a standard light source colorimetric box, and optical parameters were measured at six randomly selected locations on the surface using a colorimeter. The L and a values ​​under the CIE standard were recorded at each measurement point, and the arithmetic mean was calculated as the initial color parameter of the raw noodles. A negative a value characterizes the greenness of the sample; the absolute value of a was used to quantitatively evaluate the greenness of the sample.

[0184] 2. Heat deionized water in a constant temperature water bath until boiling. Place each group of raw noodles into the boiling water and cook at a gentle simmer for 3 minutes. Remove the noodles and immerse them in 20°C cold water for 30 seconds. Drain the surface water.

[0185] 3. Under the same light source and measurement environment, use a colorimeter to measure the color parameters of cooked and cooled noodles, and record the average data of the absolute values ​​of L and a of the cooked noodles.

[0186] 4. Calculate the heat processing fading rate by dividing the difference between the absolute value of 'a' in raw noodles and the absolute value of 'a' in cooked noodles by the initial absolute value of 'a' in raw noodles. The heat processing fading rate is used to evaluate the structural stability of plant pigments under high-temperature water bath conditions and their retention in noodles.

[0187] Table 4. Test data on color parameters and fading rate of noodles before and after heat processing for each group.

[0188] Group raw noodle L value Absolute value of raw noodle a L-value of cooked noodles Absolute value of cooked dough a Fading rate (%) Example 1 71.2 6.85 65.4 6.12 10.7 Example 2 70.8 7.32 66.1 6.65 9.2 Example 3 72.5 7.14 67.3 6.58 7.8 Example 4 69.9 6.91 64.8 6.22 10 Comparative Example 1 68.4 4.25 60.1 1.14 73.2 Comparative Example 2 68.1 4.31 59.5 1.28 70.3 Comparative Example 3 71.1 7.02 63.2 5.35 23.8 Comparative Example 4 70.5 6.98 64.1 5.61 19.6 Comparative Example 5 69.1 5.18 61.5 2.73 47.3 Comparative Example 6 71.4 6.88 64 5.41 21.4

[0189] Note: The fading rate is calculated based on the original, unrounded absolute value of 'a'. The absolute values ​​of 'a' in the table are the rounded values.

[0190] Figure 6 This is a bar chart comparing the decrease in greenness of noodles before and after heat processing. Figure 6 The changes in the absolute value of a before and after boiling in water are shown in Examples 1 to 4 and Comparative Examples 1 to 6, reflecting the preservation of the green characteristics of noodles by different processing techniques.

[0191] Based on the data in Table 4 and Figure 6 The trend shows that the noodles in the example have a high initial greenness, and the greenness decays only slightly after boiling, with the fading rate remaining below 11%. In the processing of plant extract noodles, the appearance color depends on natural chlorophyll. During the boiling stage, raw noodles undergo starch gelatinization and high-temperature boiling water penetration, and the humid and hot environment promotes the desorption of magnesium ions in the center of the porphyrin ring. The desorption process causes chlorophyll to transform into pheophytin, resulting in yellowing and browning of the noodle surface. Comparative Examples 1 and 2 have fading rates higher than 70%, demonstrating the heat-sensitive nature of natural pigments. In the absence of a zinc source, the pigment molecular skeleton degrades in boiling water. Comparative Example 5 omits the acid-base adjustment step in the process, resulting in insufficient zinc substitution conversion of the plant extract, residual free natural chlorophyll in the noodle matrix, and significant pheophytin degradation at high temperatures, with a fading rate approaching 50%. The example uses isomorphic substitution treatment with metal ions, utilizing zinc ions to form coordination bonds in the porphyrin ring, which improves the pigment molecules' resistance to thermal stress and maintains the structural integrity of the pigment molecules under boiling water bath conditions.

[0192] Besides differences in the thermal stability of molecular structures, the density of the noodle matrix's physical structure also affects pigment retention. Comparative Examples 3, 4, and 6 underwent isomorphic substitution treatment in the early stages, resulting in raw noodles with a certain degree of greenness, but the fading rate after cooking was approximately 20%, higher than in the Example. The lack of a micro-oxygen environment, premature quenching, or absence of a reducing agent affected the construction of the disulfide bond cross-linking network within the dough. The loosely structured noodle matrix is ​​prone to excessive water absorption and swelling in a boiling water bath, increasing the probability of dissolution of soluble components and weakly bound pigment molecules. This causes some of the formed zinc-substituted chlorophyll or its bound pigments to migrate and be lost with the broth, resulting in a decrease in the greenness of the cooked noodles. In the Example, a protein physical network was constructed using micro-oxygen catalysis technology. The dense cross-linked backbone limited the excessive swelling of starch granules in a hydration thermodynamic environment. The physical embedding and barrier protection of the gluten network, combined with the improved heat resistance at the chemical substitution level, reduced pigment leaching and deterioration of the noodle's appearance during heat processing.

[0193] Test Example 5: Macroscopic Evaluation of Noodle Cooking Quality

[0194] 1. The noodles prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were used as test subjects. Noodle samples of the same length were cut from the noodle strips of each group, weighed 20.00g, and the initial mass was recorded.

[0195] 2. Measure 500mL of deionized water and place it in a beaker. Heat the water to a boil. Add the raw noodles to the boiling water and cook for 5 minutes at a gentle simmer until the center of the noodles is no longer white.

[0196] 3. After cooking, remove the noodles and immerse them in 20℃ deionized water to cool for 30 seconds. Remove the noodles and lay them flat on filter paper to drain surface moisture for 5 minutes. Weigh the cooked noodles. Calculate the mass of water absorbed by the noodles based on the difference between the cooked and raw noodles. The percentage of this absorbed water to the initial mass of the raw noodles is taken as the water absorption rate.

[0197] 4. Collect the noodle soup from the cooking and cooling stages, and transfer it to an evaporating dish of known mass. After evaporating most of the moisture in a constant-temperature water bath, transfer it to a 105℃ forced-air drying oven and dry until the mass is constant. Weigh the remaining dry matter and calculate the percentage of dry matter mass to the initial mass of raw noodles as the cooking loss rate.

[0198] Table 5. Test data on the steaming and cooking quality of noodles in each group.

[0199] Group Initial mass of raw dough (g) Weigh the cooked flour (g). Water absorption rate (%) Cooking loss rate (%) Example 1 20.02 48.51 142.3 4.12 Example 2 20.05 49.14 145.1 3.86 Example 3 20.01 48.18 140.8 4.35 Example 4 20.04 49.82 148.6 4.09 Comparative Example 1 20.03 53.16 165.4 7.82 Comparative Example 2 20.06 52.7 162.7 7.45 Comparative Example 3 20.02 54.29 171.2 8.63 Comparative Example 4 20.05 51.91 158.9 6.54 Comparative Example 5 20.01 52.09 160.3 7.11 Comparative Example 6 20.04 53.81 168.5 8.19

[0200] Figure 7 This is a comparison chart of the steaming and cooking quality parameters of noodles in different groups. Figure 7 (a) is a bar chart comparing the noodle cooking loss rates of each group. Figure 7 (b) is a line graph comparing the water absorption rates of noodles in each group. Figure 7 (a) shows the dry matter dissolution of each group of noodles during the heat processing; Figure 7 (b) shows the changes in the degree of water absorption and expansion of the noodles. The two sets of subplots together reflect the impact of the processing technology on the gluten network structure and the quality of steaming and cooking.

[0201] According to Table 5 and Figure 7Based on the data characteristics, the cooking loss rate of the noodles in the examples was controlled below 4.5%, and the water absorption rate was relatively stable. In the noodle processing system with added plant pulp, the insoluble dietary fiber and polysaccharides brought in by the exogenous plant raw materials are dispersed in the dough matrix, forming steric hindrance near the cross-linking sites of glutenin and gliadin. Conventional plant noodles have low structural strength due to insufficient internal cross-linking. During cooking, the noodles absorb too much water and swell, and the internal starch granules detach from the protein network and enter the aqueous phase, causing the soup to become cloudy and dry matter to be lost. The cooking loss rates of Comparative Examples 3 and 6 both exceeded 8%, indicating that under conditions of lack of microaerobic pressurization or proton transfer medium, the gluten network development is limited and the structure is loose, and the rate of water penetration into the deep layers of the noodles is accelerated in the boiling water bath environment.

[0202] The test data from the examples verified the improvement effect of the micro-oxygen catalysis process on the gluten network structure. In dough systems with low moisture content, positive pressure micro-oxygen treatment increased the dissolved oxygen concentration in the liquid phase of the system. Combined with the redox reaction of transition metal ions and ascorbic acid, this promoted the conversion of free thiol groups into disulfide bonds. Through in-situ catalytic reaction, the gluten protein peptide chains reduced the steric hindrance caused by plant polysaccharides, forming a dense three-dimensional network framework. This network structure limited the excessive penetration of high-temperature moisture into the noodle interior, reduced the dissolution of free starch particles and soluble solids from the noodle interior into the broth, and maintained the macroscopic cooking quality of the noodles.

[0203] Test Example 6: Texture and Mechanical Tensile Evaluation of Cooked Noodles

[0204] 1. The noodles prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were used as test subjects. Raw noodles of uniform length and with a flat surface were selected from each group of noodles for mechanical property determination.

[0205] 2. Cook the selected raw noodles in boiling water for 5 minutes. Remove the noodles and cool them in 20℃ deionized water for 30 seconds. Take them out and spread them flat on filter paper to drain the surface moisture, so that the surface moisture of the noodles is consistent with the cooking state before the test.

[0206] 3. Use a texture analyzer with a cylindrical probe to perform a full texture compression test on a single cooked noodle. Set the compression deformation to 70%, record the force changes on the probe, and calculate the noodle's hardness, elasticity, and chewiness. Test six noodles in each group in parallel and calculate the arithmetic mean.

[0207] 4. Replace the tensile clamp probe of the texture analyzer. Fix both ends of a single cooked noodle in the upper and lower clamps, maintaining a consistent initial clamping distance. Stretch the noodle upwards at a constant rate until it breaks. Record the maximum tensile force the noodle withstands at break and the upward displacement of the probe; this displacement distance is recorded as the tensile fracture distance. Perform six parallel tests on each group of noodles and calculate the arithmetic mean.

[0208] Table 6. Texture and tensile mechanical properties of cooked noodles for each group.

[0209] Group Hardness (g) elasticity chewing Tensile breaking force (g) Tensile fracture distance (mm) Example 1 1215.3 0.881 956.4 41.2 25.4 Example 2 1243.6 0.895 981.2 42.8 26.1 Example 3 1198.5 0.876 935.8 39.5 24.8 Example 4 1261.2 0.889 972.1 40.6 25.7 Comparative Example 1 845.2 0.723 521.6 19.3 13.5 Comparative Example 2 862.8 0.731 534.2 20.1 14.2 Comparative Example 3 1015.4 0.795 712.5 28.5 18.6 Comparative Example 4 985.6 0.781 695.3 26.4 17.5 Comparative Example 5 924.1 0.756 618.9 23.8 15.9 Comparative Example 6 1042.7 0.802 745.8 30.2 19.4

[0210] Figure 8 This is a comparison chart of the texture and tensile mechanical parameters of cooked noodles in each group. Figure 8 (a) is a double Y-axis line graph of tensile breaking force and tensile breaking distance for each group of noodles. The left Y-axis corresponds to the tensile breaking force, and the right Y-axis corresponds to the tensile breaking distance. Figure 8 (b) is a double Y-axis line graph of noodle hardness and chewiness for each group. The left Y-axis corresponds to hardness, and the right Y-axis corresponds to chewiness. Figure 8 This demonstrates the effects of different processing techniques on the physical toughness and chewing properties of noodles.

[0211] According to Table 6 and Figure 8 The data distribution shows that the compressibility and tensile mechanical properties of the noodles in the examples are higher than those in the comparative examples. In the processing of plant-based composite noodle products, insoluble dietary fiber and polysaccharides introduced from plant raw materials enter the liquid phase of the dough. These macromolecular components hinder the approach of glutenin and gliadin peptide chains through steric hindrance, affecting the binding of protein network cross-linking sites and leading to a decrease in the continuity of the gluten skeleton. Test results show that the noodles in Comparative Examples 1 and 2 have lower hardness and tensile breaking strength, and the cooked noodles are softer and more prone to breakage. Comparative Examples 3 to 6 added plant pulp replaced with metal ions, but due to the lack of a positive pressure micro-oxygen environment, appropriate quenching sequence, or ascorbic acid, the development of the gluten network was insufficient to fully counteract the steric interference of macromolecular polysaccharides, resulting in lower tensile mechanical properties than the noodles in the examples.

[0212] The test data from the examples reflect the impact of micro-oxygen catalysis on the mechanical properties of noodles. In a low-moisture dough system, closed-loop positive pressure micro-oxygen operation increased the dissolved oxygen concentration in the liquid environment. Combined with the redox reaction mediated by transition metal ions and ascorbic acid, the higher dissolved oxygen concentration accelerated the conversion rate of free thiol groups in proteins to disulfide bonds. This in-situ catalytic process reduced structural defects caused by plant macromolecules, allowing gluten proteins to form a dense three-dimensional framework within the noodles. The increased cross-linking density improved the elastic recovery and tensile resistance of cooked noodles under deformation, manifested as an increase in tensile breaking force and fracture distance. The strengthening of the physical network enhanced the chewiness and firmness of the noodles, reducing the breakage rate of noodle products during industrial transfer and boiling.

Claims

1. A lotus leaf and medlar composite food-medicine homologous noodle, characterized in that, Including the following parts by weight of raw materials: 100 portions of high-gluten wheat flour; 8 to 12 parts of lotus leaf flavonoid and chlorophyll extract; 12 to 18 parts of homogenized wolfberry pulp; Zinc gluconate 0.05 to 0.10 parts; L-ascorbic acid 0.08 to 0.15 parts; Sodium hexametaphosphate, 0.10 to 0.20 parts.

2. The lotus leaf and Chinese wolfberry compound pharmico-edible noodle according to claim 1, characterized in that, It contains the following ingredients by weight: 100 parts high-gluten wheat flour, 10 parts lotus leaf flavonoid and chlorophyll extract, 15 parts homogenized wolfberry pulp, 0.075 parts zinc gluconate, 0.10 parts L-ascorbic acid, and 0.15 parts sodium hexametaphosphate. 3.The lotus leaf and Chinese wolfberry compound functional food of claim 1, characterized in that, The preparation method of the lotus leaf flavonoid and chlorophyll extract includes: Add a 60% to 70% (v / v) ethanol aqueous solution to the pulverized dried lotus leaf powder at a liquid-to-solid ratio of 10:1 to 20:1 mL / g. Extract under light-protected conditions at an extraction temperature of 40 to 50°C for 1.5 to 2.5 h. Remove the residue by cross-flow filtration through a microporous membrane with a pore size of 0.20 to 0.45 μm. Then, transfer the supernatant to a vacuum concentration vessel and recover the ethanol under a vacuum of -0.09 to -0.08 MPa and a temperature of 40°C until the solid content in the extract reaches 10% to 15%.

4. The lotus leaf and Chinese wolfberry compound functional food noodles according to claim 1, characterized in that, The method for preparing the homogenized wolfberry pulp includes: Add purified water at 40 to 50°C to dried wolfberry fruits at a weight ratio of 1:2.5 to 1:3.5 and soak for 30 to 45 minutes. After coarsely grinding the rehydrated wolfberries and soaking liquid together, pump them into a colloid mill for continuous grinding and homogenization, so that the particle size D90 of the suspended solid particles in the slurry is no greater than 50 μm. Then, send the slurry into a vacuum degassing tank and degas it under conditions of -0.08 to -0.06 MPa to obtain a homogeneous pulp with a solid content of 19% to 25%.

5. A preparation process of a lotus leaf and medlar composite food-medicine homologous noodle, characterized in that, The preparation of the lotus leaf and wolfberry compound medicinal and edible noodles according to any one of claims 1-4 includes the following steps: Weigh out 100 parts of high-gluten wheat flour, 8 to 12 parts of lotus leaf flavonoid and chlorophyll extract, 12 to 18 parts of wolfberry homogenized pulp, 0.05 to 0.10 parts of zinc gluconate, 0.08 to 0.15 parts of L-ascorbic acid, and 0.10 to 0.20 parts of sodium hexametaphosphate. Prepare purified water as the primary wetting water and quenching agent carrier, and prepare citric acid solution and sodium bicarbonate solution. Lotus leaf flavonoids were mixed with chlorophyll extract, wolfberry homogenized pulp and zinc gluconate. Citric acid solution was added dropwise to lower the pH value of the system and the reaction was carried out under heating and stirring. Then sodium bicarbonate solution was added to steadily raise the pH value of the system. The temperature was continued to rise and the reaction was carried out under constant temperature and stirring in the dark to complete the magnesium zinc substitution reaction. After cooling, the functional stock solution was obtained. High-gluten wheat flour is added to the dough mixing chamber, and primary wetting water pre-dissolved with L-ascorbic acid is sprayed for dry mixing. Then, the above-mentioned functional stock solution is pumped in. Under the condition of sealing the dough mixing chamber and introducing purified compressed air into the chamber to maintain a positive pressure micro-oxygen state, the dough is continuously mixed. After the cross-linking reaction is completed, the positive pressure micro-oxygen state is released. The quencher carrier liquid pre-dissolved with sodium hexametaphosphate is sprayed evenly onto the surface of the dough in a micro-mist state for passivation and quenching, and the dough is kneaded and mixed again. After kneading, the dough is transported to a constant temperature bath for resting and maturing, and then fed into a rolling mill to be pressed into a sheet and cut into strips to obtain wet noodles; The wet noodles are transferred to a hot air drying room for pre-drying, shaping, and dehydration to obtain the finished product of medicinal and edible noodles.

6. The manufacturing process of claim 5, wherein, The operating conditions for adjusting the pH of the system by adding citric acid solution and subsequent reactions are as follows: The pH of the system was adjusted by adding citric acid solution and maintained at 4.8 to 5.

2. The temperature was controlled at 40 to 50°C and the reaction was stirred for 10 to 20 minutes. Subsequently, sodium bicarbonate solution was added to raise the pH of the system and maintain it at 6.2 to 6.

8. The temperature was then raised to 50 to 60°C and stirred in the dark for 20 to 30 minutes. After the reaction was completed, the temperature was cooled to 20 to 25°C.

7. The manufacturing process of claim 5, wherein, The amount of primary wetting water is 8 to 12 parts by weight, the primary dry mixing time is 2 to 4 minutes, and the mixing speed is 30 to 50 r / min; The pressure under positive pressure micro-oxygen conditions is limited to 0.03 to 0.08 MPa, and the continuous kneading and mixing time under micro-oxygen conditions is 6 to 10 minutes.

8. The manufacturing process of claim 5, wherein, The implementation conditions for uniformly spraying the quencher carrier liquid pre-dissolved in sodium hexametaphosphate in a micro-mist state are as follows: Dissolve all weighed sodium hexametaphosphate in 2 to 4 parts by weight of quenching agent carrier liquid to prepare a spray solution. Spray the solution evenly through a micro-mist nozzle at a spray pressure of 0.3 to 0.5 MPa. Continue kneading for 2 to 4 minutes after spraying.

9. The manufacturing process of claim 5, wherein, The temperature for resting and maturing the dough is 20 to 30°C, the relative humidity is limited to 70% to 80%, and the maturation time is 15 to 30 minutes. The thickness of the pressed strip is 1.0 to 1.5 mm.

10. The manufacturing process of claim 5, wherein, The pre-drying and shaping temperature in the hot air drying oven is set at 30 to 40°C, the relative humidity is limited to 80% to 90%, and the pre-drying time is 1.5 to 2.5 hours. The dehydration drying temperature is set at 40 to 50°C, the relative humidity is limited to 50% to 60%, and the dehydration time is 3 to 5 hours until the moisture content of the finished noodles drops below 12%.

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