High-efficiency mildew-proof and bacteriostatic fresh-keeping agent for starch products and use method thereof

Abstract

This invention discloses a highly efficient antifungal and antibacterial preservative for starch products and its application method, aiming to solve the problems of short antibacterial effect, narrow process adaptability, and easy deterioration of product quality in existing starch product preservation technologies. The preservative, by weight, consists of 35-55 parts whey fermentation product, 12-28 parts corn fermentation product, 8-22 parts glucono-δ-lactone, and 12-28 parts maltodextrin. It constructs a broad-spectrum, long-lasting antifungal and antibacterial system through the synergistic antibacterial effect of natural fermentation products, slow-release acidification, and the combination of an anti-aging carrier. This invention supports two processes: dry powder mixing and slurry addition, adaptable to both solid starch premixing and wet slurry forming scenarios. The graded feeding and mother liquor dripping process ensure uniform dispersion of components, achieving synergistic internal and external antibacterial action. This solution eliminates the need for chemically synthesized preservatives, ensuring high safety, preserving the original flavor and taste of starch products, while inhibiting microbial growth, delaying starch aging, and significantly extending shelf life, making it suitable for industrial-scale production.

Description

Technical Field

[0001] This invention relates to the field of food preservation technology, and in particular to a highly efficient anti-mold and antibacterial preservative for starch products and its application method. Background Technology

[0002] Starch products are food categories made from edible starches such as corn starch, tapioca starch, and potato starch as core raw materials, through processes such as gelatinization, molding, cooling, and drying. They are widely used as staple foods, side dishes, and catering ingredients. With the rapid development of the pre-prepared food and ready-to-eat food industries, the market demand for fresh and ready-to-eat starch products continues to rise, placing higher demands on product storage stability and shelf life.

[0003] Pure starch products are mainly composed of carbohydrates, whose molecules are rich in hydrophilic hydroxyl groups. They have strong water-holding capacity, a loose structure, and lack natural antibacterial components, making them an ideal breeding ground for molds and pathogens. During storage, transportation, and sales, these products easily absorb moisture and microorganisms from the environment, leading to the growth of putrefactive molds such as Penicillium and Aspergillus niger, as well as pathogens such as Escherichia coli. This causes them to become moldy, sour, and sticky, significantly shortening their shelf life and potentially producing toxic substances such as aflatoxin, posing a food safety risk.

[0004] Existing anti-mold and antibacterial technologies have significant shortcomings: high-temperature sterilization can only achieve instantaneous sterilization, which can easily damage the starch gel structure, leading to soft and mushy products and deteriorated taste; single chemical preservatives have a narrow antibacterial spectrum and poor inhibitory effect on mold, and there are safety controversies regarding the addition of high doses; surface-sprayed biological antibacterial agents are easily water-soluble and lost, and cannot achieve long-term antibacterial effect inside and outside.

[0005] Chinese invention patent application CN121647295A discloses a tapioca preservative and its preservation method. It uses a water-based system composed of casein, rennet, food-grade calcium salt and antibacterial agent. By spraying and drying, an enzymatically cross-linked protein coating is formed on the surface of the tapioca, which extends the shelf life of the tapioca by combining physical barrier and slow-release antibacterial method, and reduces the risk of using chemical preservatives to a certain extent. However, this technology still has significant limitations in application: First, it uses a surface spraying film-forming treatment method, where the antibacterial components only adhere to the surface of the product. The film is easily detached and lost due to friction and water rinsing, failing to achieve synergistic antibacterial action inside and outside the product, resulting in insufficient long-term storage stability. Second, this preservative is a protein film-forming system, designed only for tapioca pearls, and cannot be adapted to starch products of different forms and processing techniques, such as vermicelli, cold skin noodles, and starch premix powder, resulting in poor process versatility. Third, this technology only provides a single application method of surface spraying, and cannot be integrated into mainstream processing steps such as dry powder premixing and wet slurry preparation of starch products, making it difficult to integrate into existing large-scale production lines. Fourth, it only has surface antibacterial and moisture barrier effects, without addressing the need for starch aging inhibition, and cannot improve the problems of dryness, cracking, and deterioration in taste of starch products during storage.

[0006] Therefore, there is an urgent need to develop a highly efficient anti-mold and antibacterial preservative suitable for pure starch products and its application method, which takes into account multiple needs such as long-lasting antibacterial effect, quality preservation, process compatibility and anti-aging. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings and deficiencies of the prior art by providing a highly efficient anti-mold and antibacterial preservative for starch products and its application method. This invention solves the problems of easy loss of antibacterial components, narrow process adaptability, and inability to simultaneously achieve anti-mold and antibacterial properties and starch aging inhibition in existing starch product preservation technologies, thereby achieving safe and long-lasting preservation and quality maintenance of pure starch products.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a highly efficient anti-mold and antibacterial preservative for starch products, which is composed of the following raw material components by weight: 35-55 parts whey fermentation product, 12-28 parts corn fermentation product, 8-22 parts glucono-δ-lactone, and 12-28 parts maltodextrin. This preservative uses natural fermentation products as the core antibacterial component, combined with slow-release acid-regulating components and multifunctional carrier components, forming a three-layer synergistic system of "core antibacterial - environmental regulation - quality improvement": whey fermentation products and corn fermentation products work synergistically to disrupt microbial cell membranes and protein synthesis through metabolites such as natural organic acids and antimicrobial peptides, while covering a variety of harmful microorganisms such as molds and putrefactive bacteria, thus broadening the antibacterial spectrum; gluconate-δ-lactone slowly hydrolyzes and deacidifies in the system, continuously building a stable slightly acidic antibacterial environment, compensating for the later-stage efficacy decay of natural fermentation products, and achieving long-lasting antibacterial effect; maltodextrin, as a dispersing carrier and quality-improving agent, not only ensures the uniform dispersion of the preservative in different processing systems, but also inhibits starch aging, locks in water and maintains shape, and delays the quality deterioration of products during storage.

[0009] According to the above scheme, preferably, the high-efficiency antifungal and antibacterial preservative for starch products is composed of the following raw material components by weight: 45 parts whey fermentation product, 20 parts corn fermentation product, 15 parts glucono-δ-lactone, and 20 parts maltodextrin. This ratio provides optimal synergistic effect among the components, simultaneously achieving the best antibacterial and antifungal effect while maintaining starch quality.

[0010] The present invention also provides two methods of using the above-mentioned high-efficiency anti-mold and antibacterial preservative for starch products, namely, the method of using dry powder by mixing and the method of using slurry by adding, which can be adapted to the production needs of starch products with different processing technology.

[0011] The method for mixing and applying the dry powder is applicable to the anti-mold treatment of solid raw materials such as dry starch and starch premix powder, and includes the following steps: (1) Starch raw material pretreatment: The starch raw material to be treated is sieved through an 80-120 mesh screen to remove impurities and put into a closed mixing equipment. The ambient temperature is controlled at 15-25℃ and the relative humidity is ≤60% to avoid the dry powder from absorbing moisture and clumping, thus providing a stable basic condition for subsequent mixing treatment. (2) Pretreatment of preservative: Weigh each raw material component of the high-efficiency anti-mold and antibacterial preservative according to the preset mass ratio, and crush each raw material component through a 100-120 mesh sieve to remove agglomerated particles and avoid local enrichment and uneven dispersion during subsequent mixing. (3) Graded gradient mixing: The preservative is added in stages. First, 30% to 50% of the total mass of the preservative is added and stirred at 200 to 300 r / min for 3 to 5 minutes to complete the premixing. Then, the remaining preservative is added and the stirring speed is adjusted to 350 to 450 r / min. The mixture is stirred continuously in a closed environment for 8 to 12 minutes to prevent external dust and bacteria from falling in. At the same time, the powder is turned over without dead corners so that the preservative is evenly attached to and dispersed on the surface of the starch powder particles and between the particles. (4) Static stabilization: After stirring, let stand for 5 to 10 minutes in a dry and sterile environment to complete the anti-mold and antibacterial pretreatment of the starch dry powder system.

[0012] According to the above scheme, after the mixing in step (3) is completed, the mixed powder at the top, middle and bottom of the mixing equipment is sampled to detect the content of the effective components of the preservative. When the content deviation at each point is ≤3%, it is determined that the mixing is uniform and qualified. The amount of the high-efficiency anti-mold and antibacterial preservative for starch products is 0.1% to 1.0% of the mass of the starch raw material to be treated. It can be flexibly adjusted according to the moisture content of the product and the expected shelf life. In this invention, the amount of the high-efficiency anti-mold and antibacterial preservative for starch products is preferably 0.3% of the mass of the starch raw material to be treated.

[0013] The method for adding the slurry is applicable to the processing of starch products using wet slurry preparation and wet blank forming, and includes the following steps: (1) Starch slurry pretreatment: Mix starch raw materials with purified water according to the ratio to prepare starch slurry with the target solid content. Control the slurry temperature to 20-35℃ and stir at 150-250r / min until the starch is completely dispersed and there is no dry powder clumping. Remove the floating bubbles on the surface of the slurry and the sediment of impurities at the bottom. (2) Preparation of preservative mother liquor: The high-efficiency anti-mildew and antibacterial preservative is added to purified water at a temperature of 30-40℃ and stirred until the components are completely dissolved to obtain a preservative mother liquor without precipitation or flocculent suspension. (3) Homogenization and blending treatment: Keep the starch slurry continuously stirred, and add the preservative mother liquor to the starch slurry at a uniform rate. The addition time is controlled to be 2 to 4 minutes. After the addition is completed, adjust the stirring speed to 200 to 300 r / min and continue stirring for 10 to 15 minutes to make the effective components of the preservative evenly dispersed in the gaps between the water molecules and starch molecules in the starch slurry. (4) Stabilization treatment: After stirring, let it stand at a constant temperature for 3 to 8 minutes to release the air bubbles trapped in the slurry, so that the preservative components can fully combine with the starch molecules and complete the anti-mold and antibacterial pretreatment of the starch slurry.

[0014] According to the above scheme, preferably, for high-viscosity starch slurry with a solid content ≥30%, low-speed shear stirring is used simultaneously during the stirring process in step (3) to eliminate local concentration differences in the slurry; after step (4) is completed, the pretreated starch slurry is sent to the cooking, extrusion, molding and cooling processes to prepare anti-mold starch products; the amount of high-efficiency anti-mold and antibacterial preservative added to the starch products is 0.1% to 1.0% of the mass of the starch raw materials to be treated, and can be flexibly adjusted according to the product moisture content and expected shelf life. Preferably, the amount of high-efficiency anti-mold and antibacterial preservative added to the starch products is 0.3% of the mass of the starch raw materials to be treated.

[0015] The beneficial effects of this invention are as follows: 1. Multi-component synergistic antibacterial effect, broad-spectrum and long-lasting, with significant anti-mold effect: This invention uses whey fermentation product as the core antibacterial agent, combined with corn fermentation product for synergistic effect. Through natural organic acids, antimicrobial peptides and other active substances, it destroys the cell membrane structure of microorganisms and inhibits the synthesis and reproduction of microbial proteins. It has a strong inhibitory effect on Penicillium, Aspergillus, Rhizopus and common spoilage bacteria that are common in starch products, making up for the narrow antibacterial spectrum of single fermentation products. With the addition of gluconate-δ-lactone slow-release acidity adjustment, a stable slightly acidic antibacterial environment can be continuously constructed to inhibit the reproduction of microorganisms from the perspective of microbial growth conditions. It solves the industry pain points of short antibacterial time and easy mold and sourness in the later stage of storage of traditional preservation methods, and significantly reduces the risk of starch products becoming moldy, sticky and spoiled.

[0016] 2. Adaptable to both dry and wet processing, ensuring uniform component dispersion and strong batch stability: This invention features two dedicated processes for dry powder mixing and slurry addition, suitable for both solid starch raw material premixing and wet slurry forming—two mainstream production scenarios. Maltodextrin acts as a dispersion carrier in the formula, inhibiting the agglomeration of active components in the dry powder system. Combined with a graded gradient mixing process, this ensures uniform distribution of preservative components within the starch powder. In the slurry system, it promotes rapid dissolution and homogenization of all components. Combined with a uniform dripping process for the mother liquor, this effectively avoids uneven local concentrations and precipitation of active ingredients. Through the synergistic adaptation of the formula and processes, the antibacterial components are evenly distributed throughout the product, effectively preventing localized antibacterial failure and significantly improving the consistency and stability of the preservation effect across batches.

[0017] 3. Natural food-grade ingredients, safe and residue-free, suitable for health food needs: This formula uses two types of natural fermentation products, whey fermentation and corn fermentation, as core antibacterial ingredients, combined with food-grade glucono-delta-lactone and maltodextrin. All components meet national food safety standards and do not contain benzoic acid, sorbic acid, or other chemically synthesized preservatives. Compared to traditional chemical preservatives, this system has no chemical residues, is non-irritating, does not increase the metabolic burden on the liver and kidneys, and does not react adversely with starch molecules to produce harmful substances. It can meet the safety requirements of staple foods and high-end health starch products, overcoming the application limitations and safety controversies of chemical preservatives.

[0018] 4. Combines starch retrogradation inhibition, fully preserving the original quality of the product: This preservative not only has a single antibacterial function, but also simultaneously achieves the dual effects of antibacterial and anti-mold properties and quality preservation. The mild, slightly acidic environment formed by gluconate-δ-lactone can delay starch molecule recrystallization and inhibit starch retrogradation; maltodextrin can form hydrogen bonds with starch molecules, locking in the internal moisture of the product, reducing moisture migration and loss, and alleviating problems such as dryness, cracking, and decreased softness and chewiness. At the same time, all components have a mild aroma and no acidic or astringent irritation, and will not damage the original color, fragrance, and smooth, chewy texture of starch products, avoiding flavor deterioration and taste degradation caused by traditional preservation processes, effectively improving the product's edible quality and added value.

[0019] 5. Excellent process compatibility, low overall cost, and suitable for large-scale mass production: Both application methods of this invention can be directly connected to existing starch product production lines without modifying production equipment or adding complex processes. It is adaptable to the processing flow of various products such as vermicelli, tapioca pearls, cold skin noodles, and starch premixed powder. The formulation components offer high cost-effectiveness; maltodextrin simultaneously serves as a dispersant and anti-aging agent, eliminating the need for additional quality improvers. This achieves multiple uses with a single agent, effectively reducing overall raw material and processing costs, and possesses significant industrialization potential and economic benefits. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. All raw materials used in the present invention are food-grade. In the following embodiments and comparative examples, the starch raw material to be treated is 1000 parts by weight, and the amount of compound preservative added is uniformly 0.3% of the mass of the starch raw material to be treated, corresponding to a total mass of 3 parts by weight of the compound preservative. Each embodiment selects different component ratios within the raw material ratio range defined by the present invention, and verifies the synergistic effect and optimal ratio through ratio comparison under the same process. The present invention is equipped with two application processes: dry powder mixing and slurry addition, which can be adapted to the anti-mold and antibacterial treatment of various dry powder and wet-formed starch products.

[0021] Example 1: Anti-mold and antibacterial treatment of vermicelli products (dry powder mixing process) This embodiment is applicable to the industrial production of sweet potato starch and potato starch noodles. Taking into account the process characteristics of dry powder preparation, dough mixing and extrusion molding of noodles, a process of directly mixing and adding dry preservative powder is adopted to verify the anti-mold and antibacterial effect of the low proportion of fermentation component formulation.

[0022] In this embodiment, the compound preservative is formulated with the following composition by weight: 38 parts whey ferment, 12 parts corn ferment, 22 parts glucono-δ-lactone, and 28 parts maltodextrin. The compound preservative is weighed at 0.3% of the mass of the starch raw material to be treated and added to the system, that is, 3 parts of the above compound preservative are used for every 1000 parts by weight of starch raw material.

[0023] The specific steps are as follows: (1) Starch raw material pretreatment: Take 1000 parts by weight of refined sweet potato starch, sieve it through a 100-mesh food-grade sieve to remove lumps, impurities and moldy particles, put the sieved pure starch into a closed dry powder mixer, control the ambient temperature at 18-22℃ and the relative humidity at ≤55%, keep the starch dry powder dry and clean, and set aside for later use.

[0024] (2) Pretreatment of preservative: Weigh each raw material component accurately according to the above ratio, mix them thoroughly, and then sieve them through a 110-mesh sieve to remove powder agglomerates and obtain a compound anti-mildew and fresh-keeping dry powder with excellent dispersibility.

[0025] (3) Graded gradient mixing: The step-by-step feeding and mixing method is adopted. First, 50% of the total mass of the preservative is added to the starch raw material and stirred at 300r / min for 3min to complete the premixing. Then, the remaining preservative powder is added and the speed is increased to 350r / min and stirred in a closed container for 12min to make the preservative components evenly adhered and dispersed in the starch powder, without local enrichment or mixing dead corners.

[0026] (4) Conventional molding and processing: After mixing, the starch powder is dried and left to stand for 8 minutes to eliminate static agglomeration of the powder. Then, according to the conventional vermicelli production process, water is added to make slurry, vacuum kneading, high-temperature extrusion and cooking, cooling and shaping, hanging to air dry, cutting, and aseptic sealing packaging to obtain anti-mildew vermicelli products.

[0027] The preservation effect and product quality of this embodiment were jointly verified through sensory evaluation, microbiological testing, physicochemical determination, and texture analysis: The total bacterial count and total mold count of samples were periodically tested according to GB4789.2 and GB4789.15. Sensory evaluation was combined with visual observation of mold formation, tactile evaluation of stickiness, and olfactory identification of off-odors and sourness. pH value, texture hardness, and chewiness were simultaneously measured. The shelf life was determined based on microbial indicators exceeding food safety standards or significant sensory deterioration. The prepared vermicelli was translucent, odorless, chewy, and resistant to boiling, and did not easily break. The dried vermicelli had a shelf life of over 11 months at room temperature with sealing, without mold, rancidity, or significant cracking. The wet vermicelli showed no mold growth after 6 days at room temperature and 18 days refrigerated at 0-4℃, with microbial indicators meeting food safety standards, demonstrating significantly improved product quality stability.

[0028] Example 2: Anti-mold and antibacterial treatment of vermicelli products (dry powder mixing process) This embodiment uses the exact same vermicelli production process as Embodiment 1, only adjusting the preservative component ratio to an intermediate value, to compare and verify the synergistic effect of the optimal ratio under the same process.

[0029] In this embodiment, the compound preservative is formulated with the following composition by weight: 45 parts whey ferment, 20 parts corn ferment, 15 parts glucono-δ-lactone, and 20 parts maltodextrin. The compound preservative is weighed at 0.3% of the mass of the starch raw material to be treated and added to the system, that is, 3 parts of the above compound preservative are used for every 1000 parts by weight of starch raw material.

[0030] The preparation steps are exactly the same as in Example 1.

[0031] The same testing methods as in Example 1 were used to verify that the vermicelli prepared in this example had better color transparency, chewiness, and breakage rate than that in Example 1. The dried vermicelli had a shelf life of more than 12 months at room temperature with sealing, without mold, rancidity, or cracking. The wet vermicelli showed no mold growth after 7 days at room temperature and 20 days of refrigeration at 0-4℃. The antibacterial effect and quality maintenance were significantly improved compared to the low fermentation ratio group, proving that this ratio has a better synergistic effect in the dry vermicelli process.

[0032] Example 3: Anti-mold and antibacterial treatment of tapioca pearl products (dry powder mixing process) This embodiment is applicable to the production of tapioca starch spherical products such as milk tea tapioca balls and pearl tapioca balls. In response to the pain points of tapioca balls such as high moisture content, loose colloid, easy mold and sourness, and easy softening and spoilage during refrigeration, a premixed addition process of dry powder preservative is adopted to verify the application effect of intermediate ratio in the tapioca ball system.

[0033] In this embodiment, the compound preservative is formulated with the following composition by weight: 45 parts whey ferment, 20 parts corn ferment, 15 parts glucono-δ-lactone, and 20 parts maltodextrin. The compound preservative is weighed at 0.3% of the mass of the starch raw material to be treated and added to the system, that is, 3 parts of the above compound preservative are used for every 1000 parts by weight of starch raw material.

[0034] The specific steps are as follows: (1) Pretreatment of cassava starch powder: Take 1000 parts by weight of refined cassava starch, sieve it through a 100-mesh sieve to remove impurities, remove dry powder lumps and impurities, place it in a closed and clean mixing equipment, and dry it at room temperature for later use to prevent the dry powder from absorbing moisture and becoming contaminated with bacteria.

[0035] (2) Pre-treatment of preservative: Weigh each raw material component precisely according to the above ratio, mix them evenly and pass them through a 110-mesh fine sieve to obtain a finely dispersed compound preservative dry powder, ensuring that it is fully compatible with cassava starch.

[0036] (3) Gradual mixing: The step-by-step feeding and mixing method is adopted. First, 40% of the total mass of the preservative is added and stirred at 200 r / min for 5 min to complete the premixing. Then, the remaining preservative powder is added and the speed is adjusted to 450 r / min and stirred in a closed manner for 8 min. The excellent dispersibility of maltodextrin is used to drive the fermentation and antibacterial components to be evenly dispersed in the cassava starch system, so as to achieve overall homogeneous mixing of powder without agglomeration or local concentration differences.

[0037] (4) Preparation of tapioca pearls after molding and ripening: After mixing, the starch powder is dried and left to stand for 7 minutes to eliminate static electricity agglomeration of the powder. Purified water is added to the composite starch powder to make a uniform slurry. After extrusion granulation, molding, high temperature cooking at 95-100℃ for 9 minutes, rinsing with cold water, and draining, the anti-mildew tapioca pearls are aseptically packaged to obtain anti-mildew tapioca pearl products.

[0038] The combined verification of microbial detection, sensory evaluation and texture elasticity measurement showed that the tapioca pearls prepared in this embodiment are transparent and elastic, non-sticky and odorless. They can be stably stored for more than 15 days when refrigerated at 0-4℃, without mold spots, rancidity, or soft and disintegrated phenomena. The antibacterial effect and taste quality are excellent and balanced, which greatly reduces the production loss of commercial tapioca pearls.

[0039] Example 4: Anti-mold and antibacterial treatment of tapioca pearl products (dry powder mixing process) This embodiment uses the exact same tapioca pearl production process as Embodiment 3, only increasing the proportion of fermented components and decreasing the proportion of acidifying and carrier components. It is used to compare and verify the application effect of the high fermented component ratio under the same process, and to prove the optimality of the intermediate ratio.

[0040] In this embodiment, the compound preservative is formulated with the following composition by weight: 55 parts whey ferment, 25 parts corn ferment, 8 parts glucono-δ-lactone, and 12 parts maltodextrin. The compound preservative is weighed at 0.3% of the mass of the starch raw material to be treated and added to the system, that is, 3 parts of the above compound preservative are used for every 1000 parts by weight of starch raw material.

[0041] The preparation steps are exactly the same as in Example 3.

[0042] The same testing methods as in Example 3 were used to verify that the antibacterial effect of this example was slightly improved, and the time for mold growth under refrigeration was delayed by 1 to 2 days. However, due to the decrease in the proportion of glucono-δ-lactone and maltodextrin, the slow-release acidification and anti-aging effects were weakened. The elasticity of the tapioca pearls decreased and the softening speed was slightly accelerated in the later stage of refrigeration. In addition, the slight flavor impact brought by the fermentation product was somewhat apparent. Overall, the food quality and cost performance were not as good as the intermediate ratio group. This proves that 45 parts of whey fermentation product, 20 parts of corn fermentation product, 15 parts of glucono-δ-lactone, and 20 parts of maltodextrin are the optimal synergistic ratio that balances antibacterial effect and quality.

[0043] Example 5: Anti-mold and antibacterial treatment of fresh cold skin noodles (slurry addition process) This embodiment is applicable to the industrial production of fresh starch-based cold skin noodles using a wet process. Addressing the industry pain points of fresh cold skin noodles, such as high water content, easy growth of mold and bacteria, easy souring and stickiness at room temperature, and extremely short shelf life, a process of dissolving and adding preservative slurry is adopted to verify the application effect of the optimal ratio in the wet forming system.

[0044] In this embodiment, the compound preservative is formulated with the following composition by weight: 45 parts whey ferment, 20 parts corn ferment, 15 parts glucono-δ-lactone, and 20 parts maltodextrin. The compound preservative is weighed at 0.3% of the mass of the starch raw material to be treated and added to the system, that is, 3 parts of the above compound preservative are used for every 1000 parts by weight of starch raw material.

[0045] The specific steps are as follows: (1) Pretreatment of Liangpi starch slurry: Take 1000 parts by weight of refined wheat starch, add 1800 parts by weight of purified water, control the temperature of the slurry at 25℃, stir at 200r / min for 10min, and prepare a fine Liangpi starch slurry without lumps or dry powder particles. Let it stand for 2min to remove surface bubbles and set aside.

[0046] (2) Preparation of preservative mother liquor: Weigh a total of 3 parts by weight of each raw material compound dry powder according to the above ratio, put it into 200 parts by weight of purified water at 35℃, stir thoroughly until the soluble components are completely dissolved, forming a uniform and stable preservative suspension with no obvious large precipitates or agglomerates, and fully activate the antibacterial active ingredients.

[0047] (3) Homogenization and blending treatment: Keep the starch slurry continuously stirred at 250 r / min, and add the preservative suspension to the starch slurry at a uniform rate. The addition time is controlled at 3 min to avoid excessive local concentration caused by rapid addition. After the addition is completed, stir at a constant temperature for 12 min to make the preservative components evenly penetrate and disperse in the starch slurry system.

[0048] (4) Steaming, molding and packaging of cold noodles: After stirring, let stand for 5 minutes to remove bubbles, spread the homogenized starch slurry evenly on the steaming tray, steam at 95-100℃ for 4 minutes, cool naturally and demold, and obtain fresh anti-mold cold noodles after sterile finishing and sealing packaging.

[0049] The combined verification of total bacterial count, mold count, pH value determination and sensory evaluation showed that the preservation components were evenly dispersed in the high-moisture cold skin system, with comprehensive antibacterial coverage; the prepared fresh cold skin was translucent and chewy, without obvious sour or astringent odor, and without stickiness. It could be stored at room temperature for 7 days and refrigerated at 0-4℃ for more than 18 days. The total mold count throughout the process met food safety standards, and there was no sourness or spoilage. The long-term preservation effect and the balance between food quality were excellent.

[0050] Scale settings Comparative Example 1 (Blank Control Group) Without adding any preservatives, the remaining raw material amounts and preparation processes were completely consistent with those in Examples 2, 3, and 5, respectively, to prepare vermicelli, tapioca pearls, and cold skin noodles. Using the same testing methods, it was verified that after being left at room temperature for 2-3 days, the vermicelli developed mold spots, became sour, and broke; the tapioca pearls became soft, sticky, and sprouted mold; and the cold skin noodles became severely sticky, rancid, and spoiled. The total bacterial count and mold count far exceeded food safety limits, completely rendering them unmarketable.

[0051] Comparative Example 2 (Single Preservative Control Group) A single glucono-δ-lactone was used as the preservative, with a total addition mass consistent with the previous example (3 parts by mass). The amounts of other raw materials and the preparation process were completely consistent with those of Examples 2, 3, and 5, respectively. Verification using the same testing methods showed that the product only had a short-term acid-suppressing effect. After 5 days, the tapioca pearls and cold noodles began to mold and turn sour, and mold grew on the surface of the vermicelli. The antibacterial effect was short-lived and had a narrow antibacterial spectrum, failing to achieve long-term preservation.

[0052] Based on the test results of Examples 1-5 and Comparative Examples 1-2, it can be seen that within the component ratio range defined in claim 1 of this invention, good anti-mold and antibacterial effects and quality maintenance can be achieved. Through comparison of the ratios under the same process, it can be verified that the intermediate ratio of 45 parts whey fermented product, 20 parts corn fermented product, 15 parts glucono-δ-lactone, and 20 parts maltodextrin achieves the optimal balance between antibacterial effect, taste quality, anti-aging effect and raw material cost, and is the best ratio for synergistic effect.

[0053] This invention addresses the production process characteristics of two types of starch products: dry powder forming (vermicelli, tapioca pearls) and wet forming (fresh cold noodles). Two suitable application processes—dry powder mixing and slurry addition—are tailored to each process. These methods achieve broad-spectrum and long-lasting anti-mold and antibacterial effects while fully preserving the original taste, color, and edible quality of the starch products. Compared to the blank control group and the single preservative group, this invention significantly delays the deterioration process of products, such as mold growth, souring, and hardening, effectively solving the industry pain points of easy mold growth, easy aging, and short shelf life commonly found in starch products produced by different processes. Furthermore, the overall process is highly compatible with existing starch product production lines, the components are safe and have no side effects, making it suitable for large-scale industrial application.

[0054] The above description is only a preferred embodiment of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included in the scope of this patent application.

Claims

1. A highly efficient antifungal and antibacterial preservative for starch products, characterized in that, By weight, it consists of the following raw material components: 35-55 parts whey fermentation product, 12-28 parts corn fermentation product, 8-22 parts glucono-δ-lactone, and 12-28 parts maltodextrin.

2. The high-efficiency anti-mold and antibacterial preservative for starch products according to claim 1, characterized in that, It is composed of the following raw material components: 45 parts whey fermentation product, 20 parts corn fermentation product, 15 parts glucono-δ-lactone, and 20 parts maltodextrin.

3. A method for mixing and applying a dry powder containing the high-efficiency antifungal and antibacterial preservative for starch products according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Starch raw material pretreatment: The starch raw material to be treated is sieved through an 80-120 mesh screen to remove impurities, and then put into a closed mixing equipment. The ambient temperature is controlled at 15-25℃ and the relative humidity is ≤60%. (2) Pretreatment of preservative: Weigh each raw material component of the high-efficiency anti-mildew and antibacterial preservative according to the preset mass ratio, and crush each raw material component through a 100-120 mesh sieve to remove agglomerated particles; (3) Graded gradient mixing: The preservative is added in stages. First, 30% to 50% of the total mass of the preservative is added and stirred at 200 to 300 r / min for 3 to 5 minutes to complete the premixing. Then, the remaining preservative is added and the stirring speed is adjusted to 350 to 450 r / min. The mixture is stirred continuously in a closed environment for 8 to 12 minutes. (4) Static stabilization: After stirring, let stand for 5 to 10 minutes in a dry and sterile environment to complete the anti-mold and antibacterial pretreatment of the starch dry powder system.

4. The method for mixing and using dry powder according to claim 3, characterized in that, After step (3) is completed, sample the mixed powder from the top, middle and bottom of the mixing equipment to test the content of the effective ingredients of the preservative. If the content deviation at each point is ≤3%, it is judged to be uniform and qualified.

5. The method for mixing and using dry powder according to claim 3, characterized in that, The amount of the high-efficiency anti-mold and antibacterial preservative added to the starch products is 0.3% of the mass of the starch raw material to be treated.

6. A method for adding a slurry containing the high-efficiency antifungal and antibacterial preservative for starch products according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Starch slurry pretreatment: Mix starch raw materials with purified water according to the ratio to prepare starch slurry with the target solid content. Control the slurry temperature to 20-35℃ and stir at 150-250r / min until the starch is completely dispersed and there is no dry powder clumping. Remove the floating bubbles on the surface of the slurry and the sediment of impurities at the bottom. (2) Preparation of preservative mother liquor: The high-efficiency anti-mildew and antibacterial preservative is added to purified water at a temperature of 30-40℃ and stirred until the components are completely dissolved to obtain a preservative mother liquor without precipitation or flocculent suspension. (3) Homogenization and blending treatment: Keep the starch slurry continuously stirred, and add the preservative mother liquor to the starch slurry at a uniform rate. The addition time is controlled to be 2 to 4 minutes. After the addition is completed, adjust the stirring speed to 200 to 300 r / min and continue stirring for 10 to 15 minutes to make the effective components of the preservative evenly dispersed in the gaps between the water molecules and starch molecules in the starch slurry. (4) Stabilization treatment: After stirring, let it stand at a constant temperature for 3 to 8 minutes to release the air bubbles trapped in the slurry, so that the preservative components can fully combine with the starch molecules and complete the anti-mold and antibacterial pretreatment of the starch slurry.

7. The method for adding and using slurry according to claim 6, characterized in that, In step (3), for high-viscosity starch slurry with a solid content ≥30%, low-speed shear stirring is used simultaneously during the stirring process to eliminate local concentration differences in the slurry.

8. The method for adding and using slurry according to claim 6, characterized in that, After step (4) is completed, the pretreated starch slurry is sent to the cooking, extrusion, molding and cooling processes to prepare anti-mildew starch products.

9. The method for adding and using slurry according to claim 6, characterized in that, The amount of the high-efficiency anti-mold and antibacterial preservative added to the starch products is 0.3% of the mass of the starch raw material to be treated.