Natural preservative for seasoning flour products and preparation method of natural preservative

Abstract

The invention provides a natural preservative for seasoning flour products and a preparation method of the natural preservative, and the preservative comprises the following components in percentage by weight: 2.5%-4.5% of a microencapsulated active core material, 1.8%-2.8% of trehalose grafted modified chitosan lactate, 2.8%-3.8% of composite phosphate, 0.15%-0.25% of vitamin C palmitate and 86%-92% of RS3 type resistant starch. The preservative disclosed by the invention is wide in antibacterial spectrum and covers putrefying bacteria of the whole category. Through the synergistic effect of GMC, protamine and chitosan lactate, 9 types of main putrefying bacteria in flour products can be inhibited, and the problem that an existing preservative is narrow in antibacterial spectrum is solved. GMC is a preservative allowed by national standard, protamine and chitosan lactate are natural components, and all the components are safe and non-toxic; the preservative is low in addition amount and controllable in cost, and meanwhile, the risk that the preservative exceeds the standard is avoided. All the components not only have a bacteriostatic effect, but also can synergistically improve the quality of flour products.

Description

Technical Field

[0001] This invention relates to the field of noodle product technology, and in particular to a natural preservative for flavored noodle products and its preparation method. Background Technology

[0002] Noodles and other noodle products are a traditional staple food for Chinese people. As a traditional staple food, noodles, especially their derivative products (fresh wet noodles), have seen a continuous increase in market demand in recent years due to their characteristics such as "freshness without dehydration, chewy texture, and complete retention of nutrients." However, the high moisture content of noodle products used for seasoning provides an ideal growth environment for microorganisms (including bacteria, molds, and yeasts), leading to rapid spoilage.

[0003] In existing technologies, chemical methods are commonly used for preservation, specifically by adding preservatives to inhibit microbial growth. However, chemical methods have the following problems: 1. Limited types of preservatives and narrow antibacterial spectrum: The types of preservatives allowed are limited, making it difficult to cover the complex microbial community in flour products. They cannot simultaneously inhibit multiple dominant spoilage bacteria such as bacteria (Bacillus, Staphylococcus, Enterococcus, Pantothenia), molds (Aspergillus, Penicillium), and yeasts (Saccharomyces cerevisiae, Rhodotorula rubra), resulting in unstable preservation effects.

[0004] 2. Limited antibacterial effect: Single preservatives have weak inhibitory ability against mixed contamination of multiple microorganisms. For example, GMC has a significant inhibitory effect on mold, but poor inhibitory ability on Gram-negative bacteria (such as pantothenia); propionate is the opposite, which makes it difficult to meet market demand for preservation at room temperature.

[0005] 3. Shortcomings of natural preservatives: Natural preservatives such as tea polyphenols and curcumin are highly safe, but their antibacterial activity is low when used alone, and large doses are required to be effective, which increases costs. Summary of the Invention

[0006] In view of the above problems, the present invention is proposed to provide a natural preservative for flavored noodle products that overcomes or at least partially solves the above problems, and a method for preparing the same.

[0007] One objective of this invention is to address the problems of existing preservatives having a narrow antibacterial spectrum, short shelf life at room temperature, and difficulty in balancing quality and safety.

[0008] Specifically, a natural preservative for a flavored noodle product, by weight percentage, comprises: Microencapsulated active core material 2.5%-4.5%, trehalose-grafted modified chitosan lactate 1.8%-2.8%, complex phosphate 2.8%-3.8%, vitamin C palmitate 0.15%-0.25%, RS3 type resistant starch 86%-92%; The microencapsulated active core material consists of a core material and a wall material. The core material is a compound of enzymatically hydrolyzed protamine and glyceryl monocaprylate (GMC), with a weight ratio of enzymatically hydrolyzed protamine to GMC of 1:0.9-1.1. The wall material is a compound of maltodextrin and gum arabic, with a weight ratio of maltodextrin to gum arabic of 1:1.2-1.4. The weight ratio of the core material to the wall material is 1:2.2-2.8.

[0009] Optionally, its components, by weight percentage, are: The microencapsulated active core material comprises 3.2%, trehalose-grafted modified chitosan lactate 2.2%, composite phosphate 3.2%, vitamin C palmitate 0.2%, and RS3 resistant starch 91.2%. In the microencapsulated active core material, the weight ratio of enzymatically hydrolyzed protamine to GMC is 1:1, the weight ratio of maltodextrin to gum arabic in the wall material is 1:1.3, and the weight ratio of core material to wall material is 1:2.5.

[0010] Optionally, its components, by weight percentage, are: The microencapsulated active core material comprises 4.0%, trehalose-grafted modified chitosan lactate 2.6%, composite phosphate 3.6%, vitamin C palmitate 0.22%, and RS3 resistant starch 91.8%. In the microencapsulated active core material, the weight ratio of enzymatically hydrolyzed protamine to GMC is 1:1.1, the weight ratio of maltodextrin to gum arabic in the wall material is 1:1.4, and the weight ratio of core material to wall material is 1:2.8.

[0011] Optionally, its components, by weight percentage, are: The microencapsulated active core material comprises 2.5%, trehalose-grafted modified chitosan lactate 2.0%, composite phosphate 3.0%, vitamin C palmitate 0.16%, and RS3 resistant starch 88%. In the microencapsulated active core material, the weight ratio of enzymatically hydrolyzed protamine to GMC is 1:0.9, the weight ratio of maltodextrin to gum arabic in the wall material is 1:1.2, and the weight ratio of core material to wall material is 1:2.2.

[0012] Optionally, the complex phosphate is composed of sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate in a weight ratio of 2:1:1.

[0013] Optionally, the RS3 type resistant starch has an amylose content of ≥70%.

[0014] A method for preparing a natural preservative for flavored noodle products according to any one of the above claims, comprising the following steps: Step 1: Prepare enzymatically hydrolyzed protamine, trehalose-grafted modified chitosan lactate, and composite phosphate according to the specified ratio; Step 2: Preparation of microencapsulated active core material: Enzymatically hydrolyzed protamine sulfate and GMC are mixed as core material, and maltodextrin and gum arabic are mixed as wall material. After mixing the core material and wall material, the mixture is homogenized and spray-dried to obtain microcapsule powder. Step 3: Add the microencapsulated active core material, trehalose-grafted modified chitosan lactate, compound phosphate, vitamin C palmitate, and RS3 resistant starch to a double helix mixer and mix at 300-350 rpm for 45-55 minutes. Then, pass the mixture through an 80-100 mesh sieve to obtain a natural preservative for flavored noodle products.

[0015] Optionally, the preparation of the microencapsulated active core material further includes a homogenization step: after the core material and the wall material are mixed, they are homogenized at 20,000-22,000 rpm for 2-3 minutes, and then spray-dried, with the inlet air temperature controlled at 180-190℃ and the outlet air temperature at 80-85℃, to obtain microcapsule powder.

[0016] Optionally, the preparation method of the enzymatically hydrolyzed protamine is as follows: protamine and deionized water are mixed at a weight ratio of 1:15-20, 0.35%-0.45% of papain by weight of protamine is added, the pH is adjusted to 6.6-6.8, enzymatic hydrolysis is carried out at 52-54℃ for 1.6-1.8h, the enzyme is inactivated at 80℃ for 15min after enzymatic hydrolysis, and then freeze-dried to obtain the product.

[0017] Optionally, the grafting rate of the trehalose-grafted modified chitosan lactate is 9%-11%, and its preparation method is as follows: chitosan lactate and trehalose are dissolved in 1% acetic acid solution at a weight ratio of 1:0.8-1.0, 0.5%-0.7% of ammonium persulfate by weight of chitosan lactate is added, and the reaction is carried out at 60-65℃ for 3-3.5h. After dialyzing, it is freeze-dried to obtain the product.

[0018] Glyceryl monocaprylate (GMC): A chemical preservative with three main functions: 1. Broad-spectrum antibacterial properties, inhibiting bacteria, molds, and yeasts. Its mechanism of action is to disrupt the phospholipid structure of microbial cell membranes, leading to leakage of cell contents; 2. Emulsifying function, improving the binding degree of protein and starch in flour and enhancing the toughness of flour products; 3. High safety, as it can be decomposed into caprylic acid and glycerol in the human body, leaving no residue.

[0019] Protamine: A natural alkaline protein extracted from fish testes, composed of 30-50 amino acids, with four main functions: 1. Complementary antibacterial spectrum, with significant inhibitory effect against Gram-negative bacteria, compensating for the shortcomings of GMC; 2. Good thermal stability, maintaining over 85% antibacterial activity even at the maturation temperature (30-40℃) during the dough-making process; 3. High safety, with acute toxicity tests showing low LD50. 50>5000 mg / kg, belonging to the non-toxic level; 4. Synergistic effect. When compounded with GMC and chitosan lactate, it can reduce the minimum inhibitory concentration of each component through the dual effects of "destroying cell membranes + interfering with enzyme activities".

[0020] Chitosan lactate: Solves the problem that traditional chitosan is insoluble in water. Its core functions include: 1. Targeted inhibition of Enterococcus. Enterococcus in flour products is the main bacterium causing "rancid taste". Chitosan lactate can bind to the negative charge of the Enterococcus cell membrane through positive charges, blocking its nutrient absorption. The MIC for Enterococcus is only 625 μg / mL; 2. Improve color. It can form a transparent film on the surface of noodles, reducing the contact between oxygen and flour products and delaying the yellowing caused by fat oxidation; 3. Good biocompatibility. It can be degraded by human intestinal flora without environmental residues.

[0021] Compound phosphate: Composed of sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate in a weight ratio of 2:1:1, it has three major functions: 1. Improve the gelatinization characteristics of flour. By binding with calcium ions in flour, it increases the gelatinization temperature of starch, reduces starch retrogradation during the storage of flour products, and avoids the hardening of the taste; 2. Reduce water activity. It can reduce the water activity of flour products from 0.96 to below 0.92. For every 0.01 reduction in water activity, the microbial growth rate can decrease by 10%-15%; 3. Enhance appearance, making the surface of flour products smoother and increasing the whiteness (L* value) by 2-3 units.

[0022] The method of the present invention has the following beneficial effects: 1. Wide antibacterial spectrum, covering all categories of spoilage bacteria. Through the synergistic effect of GMC, protamine, and chitosan lactate, 9 major spoilage bacteria (Bacillus, Staphylococcus, Enterococcus, Pantoea, Human epiphytic Pseudomonas, Microbacterium flavum, Phyllobacterium azaleae, Aspergillus, Saccharomyces cerevisiae) in flour products can be inhibited. Among them, the inhibitory effects on Staphylococcus saprophyticus and Enterococcus faecalis are synergistic effects (FIC ≤ 0.5), the inhibitory effects on Bacillus salivarius and Bacillus licheniformis are additive effects (0.5 < FIC ≤ 1), and only Enterococcus durans has an irrelevant effect, solving the problem of narrow antibacterial spectra of existing preservatives.

[0023] 2. Safe and non-toxic, with a small addition amount: In the preservative of the present invention, glycerol monocaprylate GMC is a preservative permitted by national standards, protamine and chitosan lactate are natural ingredients, edible corn starch and compound phosphate are all conventional food auxiliaries, and all components are safe and non-toxic; and the total addition amount of the preservative is only 0.05%-0.2% of the weight of flour, with a small addition amount, controllable cost, and at the same time avoiding the risk of excessive preservatives.

[0024] 3. Does not affect the quality of flour products: Each component not only has an antibacterial effect but can also synergistically improve the quality of flour products.

[0025] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0026] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic flowchart of a method for preparing a natural preservative for flavored noodle products according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of the preparation method of microencapsulated active core material in a method for preparing a natural preservative for flavored noodle products according to an embodiment of the present invention; Figure 3 This is a schematic flowchart of the preparation method of enzymatically hydrolyzed protamine in a method for preparing a natural preservative for flavored noodle products according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the preparation process of trehalose-grafted modified chitosan lactate in a method for preparing a natural preservative for flavored noodle products according to an embodiment of the present invention. Detailed Implementation

[0027] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0028] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0029] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may represent singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to such processes, methods, products, or apparatus.

[0030] The method of using the preservative for flour products according to this application includes the following steps: 1) Weigh out 0.12%-0.16% of the preservative by weight of the flour raw material, and mix 60%-70% of the preservative with sterile water (water temperature 25-30℃) to obtain a preservative solution.

[0031] 2) Add the raw material powder and preservative solution to the vacuum dough mixer and knead for 15-20 minutes (vacuum degree -0.085 to -0.09MPa), then let it mature for 25-35 minutes.

[0032] 3) Dilute the remaining 30%-40% of the preservative with anhydrous ethanol to a concentration of 5%-8%, and spray it evenly onto the surface of the dough during the calendering process. The amount of coating should be 0.8%-1.2% of the weight of the dough. 4) Continue rolling, shredding, or shaping to obtain the flour product.

[0033] The present application will be further described below with reference to embodiments and test examples. Example 1: Preparation and application of preservatives for flour products (Formula 1)

[0034] 1. Formula composition: The ingredients include 1% caprylic / caprylic acid glyceride (GMC), 1% protamine sulfate, 1% chitosan lactate, 2% complex phosphate, and 95% edible corn starch.

[0035] 2. Preservative preparation steps: Raw material pretreatment: GMC (solid) is melted in a constant temperature oven at 42℃, protamine sulfate and chitosan lactate are passed through an 80-mesh sieve, and compound phosphate and edible corn starch are passed through a 100-mesh sieve.

[0036] Weigh: Weigh 10g of GMC, 10g of protamine sulfate, 10g of chitosan lactate, 20g of compound phosphate, and 950g of edible corn starch, for a total weight of 1000g.

[0037] Mixing: Add to a twin-helix mixer and mix at 320 rpm for 60 minutes.

[0038] Packaging: Vacuum aluminum foil bag packaging (vacuum degree -0.09MPa) to obtain the finished preservative (denoted as "preservative A").

[0039] 3. Preparation of flour products: Weigh 500g of medium-gluten wheat flour (total bacterial count 10²CFU / g), and weigh 1g of preservative A as 0.2% of the flour weight. Add preservative A to 20 mL of sterile water (28°C) and stir for 6 minutes until dissolved to obtain a preservative solution. Add flour and preservative solution to a vacuum dough mixer and knead for 18 minutes until the dough has a moisture content of 32%. Cook at 32℃ for 30 minutes, roll 4 times, shred, and package into 100g bags. Example 2: Preparation and application of preservatives for flour products (Formula 2)

[0040] 1. Formula Composition The ingredients include 1% caprylic / caprylic acid glyceride (GMC), 3% protamine sulfate, 3% chitosan lactate, 3% complex phosphate, and 90% edible corn starch.

[0041] 2. Preservative Preparation Steps Raw material pretreatment: Same as in Example 1; Weigh: Weigh 10g GMC, 30g protamine sulfate, 30g chitosan lactate, 30g compound phosphate, and 900g edible corn starch, for a total weight of 1000g. Mixing: Twin-helix mixer, 340 rpm, mix for 60 minutes; Packaging: Vacuum packaging yields the preservative product (denoted as "Preservative B").

[0042] 3. Preparation of flour products: Add preservative B at 0.1% of the flour weight (0.5g for every 500g of flour), and follow the same steps as in Example 1. Example 3: Preparation and application of preservatives for flour products (Formula 3)

[0043] 1. Formula Composition The ingredients include 1% caprylic / caprylic acid glyceride (GMC), 5% protamine sulfate, 5% chitosan lactate, 5% complex phosphate, and 84% edible corn starch.

[0044] 2. Preservative Preparation Steps Raw material pretreatment: Same as Example 1; Weigh: Weigh 10g GMC, 50g protamine, 50g chitosan lactate, 50g compound phosphate, and 840g edible corn starch, for a total weight of 1000g. Mixing: Twin-helix mixer, 350 rpm, mix for 60 minutes; Packaging: Vacuum packaging yields the preservative product (denoted as "Preservative C").

[0045] 3. Preparation of flour products: Add preservative C at 0.05% of the flour weight (0.25g for 500g flour), and the remaining steps are the same as in Example 1. Example 4: Preparation and application of preservatives for flour products (Formula 4)

[0046] 1. Formula Composition The ingredients include 0.5% caprylic / caprylic acid glyceride (GMC), 1% protamine sulfate, 1% chitosan lactate, 2% complex phosphate, and 95.5% edible corn starch.

[0047] 2. Preservative Preparation Steps Raw material pretreatment: Same as in Example 1; Weigh: Weigh 5g of GMC, 10g of protamine sulfate, 10g of chitosan lactate, 20g of compound phosphate, and 955g of edible corn starch, for a total weight of 1000g. Mixing: Twin-helix mixer, 300 rpm, mix for 60 minutes; Packaging: Vacuum packaging yields the preservative product (denoted as "Preservative D").

[0048] 3. Preparation of flour products: Add preservative D at 0.2% of the flour weight (1g for every 500g of flour), and follow the same steps as in Example 1. Example 5: Preparation and application of preservatives for flour products (Formula 5)

[0049] 1. Formula Composition The composition includes 0.8% caprylic / caprylic acid glyceride (GMC), 2% protamine sulfate, 2% chitosan lactate, 2% complex phosphate, and 92.2% edible corn starch.

[0050] 2. Preservative Preparation Steps Raw material pretreatment: Same as in Example 1; Weighing: Weigh 8g of GMC, 20g of protamine sulfate, 20g of chitosan lactate, 20g of compound phosphate, and 922g of edible corn starch, for a total weight of 1000g; Mixing: Twin-helix mixer, 330 rpm, mix for 60 minutes; Packaging: Vacuum packaging yields the preservative product (denoted as "Preservative E").

[0051] 3. Preparation of flour products: Add preservative E at 0.15% of the flour weight (0.75g for 500g flour), and the remaining steps are the same as in Example 1.

[0052] To further verify the technical effects of the present invention, 2 groups of test examples were designed to compare the differences between the preservatives of the present invention and the prior art. Test Example 1: Inhibitory effect of the preservative of the present invention on the dominant spoilage bacteria of the flour products

[0053] 1. Test materials Test strains: 11 dominant bacteria isolated from spoiled flour products (Staphylococcus epidermidis, Bacillus salivarius, Bacillus licheniformis, Staphylococcus saprophyticus, Bacillus zhangzhouensis, Halomonas humanensis, Microbacterium flavescens, Phyllobacterium ardisiae, Pantoea agglomerans, Enterococcus faecalis, Enterococcus durans); Test samples: Preservative C (formulation 3) of the present invention, GMC monomer (0.1%), protamine monomer (0.1%), chitosan lactate monomer (0.2%).

[0054] 2. Test methods Minimum inhibitory concentration (MIC) detection: Using the two-fold dilution method, prepare sample solutions with different concentrations in a 96-well plate, add the bacterial solution (final concentration 10 5 -10 6 CFU / mL), incubate at 37 °C for 48 h, and observe the lowest concentration without bacterial growth; Combined antibacterial test: Using the checkerboard method, determine the fractional inhibitory concentration (FIC) of the combination of protamine and chitosan lactate, FIC = (combined MIC / protamine monomer MIC) + (combined MIC / chitosan lactate monomer MIC), judgment criteria: FIC ≤ 0.5 (synergistic), 0.5 < FIC ≤ 1 (additive), 1 < FIC ≤ 2 (irrelevant), FIC > 2 (antagonistic).

[0055] 3. Test results strains GMC monomer MIC (μg / mL) MIC (μg / mL) of protamine monomer MIC (μg / mL) of chitosan lactate monomer Preservative CMIC (μg / mL) Protamine + Chitosan Lactate FIC Function type Staphylococcus sebaceus 250 312.5 625 125 0.75 Add Bacillus salivarius 125 78.125 1250 62.5 0.625 Add Bacillus licheniformis 125 78.125 625 62.5 0.625 Add Staphylococcus aureus 250 312.5 625 125 0.375 Collaboration Zhangzhou Bacillus 125 156.25 625 62.5 0.5 Collaboration Human epilithomonas 500 156.25 625 250 0.5 Collaboration Microbacterium flavum 250 156.25 625 125 1 Add Purple Botrytis cinerea 500 156.25 1250 250 0.375 Collaboration Pantothenia glutinosa 500 156.25 625 250 0.625 Add Enterococcus faecalis 500 625 625 250 0.5 Collaboration Enterococcus tenuifolia 500 625 625 250 1.125 irrelevant Conclusion: The MIC of the preservative C of the present invention is significantly lower than that of each monomer, and protamine and chitosan lactate show a synergistic / additive effect on 7 strains, proving that the antibacterial effect is significantly enhanced after compounding. Test Example 2: Comparison of the freshness preservation effect of the preservative of the present invention on flour products

[0056] 1. Test materials Test samples: Preservatives A-E of the present invention, blank control (without preservative), positive control (7 preservative monomers: ε-polylysine 0.8%, GMC 0.1%, chitosan lactate 0.2%, sodium dehydroacetate 0.05%, Nisin 0.2%, calcium propionate 0.03%, protamine 0.1%; 2 commercially available preservatives: Preservative I 1%, Preservative II 1.6%); Test objects: Flour products (prepared from 500 g of flour, packaged in 10 g / bags).

[0057] 2. Test methods All samples were stored at 4°C, and the total number of colonies was regularly detected. The end of the shelf life was defined as the total number of colonies > 10 5 CFU / g (5.0 Log CFU / g).

[0058] 3. Test results Serial Number sample Total bacterial count at 25℃ (LogCFU / g) Shelf life at 25°C (days) 1 Blank control 6.24 144 2 Commercially available preservative I 5.39 140 3 Commercially available preservative II 6.54 150 4 ε-polylysine 5.44 152 5 GMC monomer 6.72 151 6 Chitosan lactate monomer 5.42 155 7 Sodium dehydroacetate 5.45 152 8 Nisin 6.75 155 9 Calcium propionate 6.13 155 10 Protamine monomer 6 160 11 Preservative A (Formula 1) 5.28 180 12 Preservative B (Formula 2) 5.39 178 13 Preservative C (Formula 3) 4.38 185 14 Preservative D (Formula 4) 5.32 182 15 Preservative E (Formula 5) 5.67 178 Conclusion: The shelf lives of all preservatives of the present invention are significantly longer than those of the blank control and the positive control.

[0059] The method of the present invention has the following beneficial effects: 1. Wide antibacterial spectrum, covering all categories of spoilage bacteria. Through the synergistic effect of GMC, protamine, and chitosan lactate, 9 main spoilage bacteria (Bacillus, Staphylococcus, Enterococcus, Pantoea, Halomonas elongata, Microbacterium flavescens, Phyllobacterium myrsinacearum, Aspergillus, Saccharomyces cerevisiae) in flour products can be inhibited. Among them, the inhibitory effects on Staphylococcus saprophyticus and Enterococcus faecalis are synergistic effects (FIC ≤ 0.5), the inhibitory effects on Bacillus salivarius and Bacillus licheniformis are additive effects (0.5 < FIC ≤ 1), and only Enterococcus durans has an irrelevant effect, solving the problem of narrow antibacterial spectra of existing preservatives.

[0060] 2. Safe and non-toxic, with a small addition amount: In the preservatives of the present invention, glyceryl monocaprylate GMC is a preservative permitted by national standards, protamine and chitosan lactate are natural ingredients, and edible corn starch and compound phosphate are all conventional food auxiliaries. All components are safe and non-toxic; and the total addition amount of the preservatives is only 0.05% - 0.2% of the weight of flour. The addition amount is small, the cost is controllable, and at the same time, the risk of exceeding the standard of preservatives is avoided.[[ID=二十一]] [[ID=二十二]]

[0061] [[ID=二十三]]3. Does not affect the quality of flour products: Each component not only has an antibacterial effect but can also synergistically improve the quality of flour products.[[ID=二十四]] [[ID=二十五]]

[0062] [[ID=二十六]]At this point, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived from the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and determined to cover all these other variations or modifications.

Claims

1. A natural preservative for a seasoned noodle product, characterized by comprising: The components thereof include, by weight percentage: Microencapsulated active core material 2.5%-4.5%, trehalose grafted modified chitosan lactate 1.8%-2.8%, composite phosphate 2.8%-3.8%, vitamin C palmitate 0.15%-0.25%, RS3 type resistant starch 86%-92%; The microencapsulated active core material is composed of a core material and a wall material, the core material is a compound of enzymatic protamine and glycerol monocaprylate (GMC), the weight ratio of enzymatic protamine to GMC in the core material is 1:0.9-1.1, the wall material is a compound of malt dextrin and gum arabic, the weight ratio of dextrin to gum arabic is 1:1.2-1.4, and the weight ratio of the core material to the wall material is 1:2.2-2.

8.

2. The natural preservative for seasoned noodles according to claim 1, characterized by, The components thereof include, by weight percentage: Microencapsulated active core material 3.2%, trehalose grafted modified chitosan lactate 2.2%, composite phosphate 3.2%, vitamin C palmitate 0.2%, RS3 type resistant starch 91.2%; in the microencapsulated active core material, the weight ratio of enzymatic protamine to GMC in the core material is 1:1, the weight ratio of malt dextrin to gum arabic in the wall material is 1:1.3, and the weight ratio of the core material to the wall material is 1:2.

5.

3. The natural preservative for seasoned noodles according to claim 1, characterized by, The components thereof include, by weight percentage: Microencapsulated active core material 4.0%, trehalose grafted modified chitosan lactate 2.6%, composite phosphate 3.6%, vitamin C palmitate 0.22%, RS3 type resistant starch 91.8%; in the microencapsulated active core material, the weight ratio of enzymatic protamine to GMC in the core material is 1:1.1, the weight ratio of malt dextrin to gum arabic in the wall material is 1:1.4, and the weight ratio of the core material to the wall material is 1:2.

8.

4. The natural preservative for seasoned noodles according to claim 1, characterized by, The components thereof include, by weight percentage: Microencapsulated active core material 2.5%, trehalose grafted modified chitosan lactate 2.0%, composite phosphate 3.0%, vitamin C palmitate 0.16%, RS3 type resistant starch 88%; in the microencapsulated active core material, the weight ratio of enzymatic protamine to GMC in the core material is 1:0.9, the weight ratio of malt dextrin to gum arabic in the wall material is 1:1.2, and the weight ratio of the core material to the wall material is 1:2.

2.

5. The natural preservative for seasoned noodles according to claim 1, characterized by, The composite phosphate is composed of sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate in a weight ratio of 2:1:

1.

6. The natural preservative for seasoned noodles according to claim 1, characterized by, The RS3 type resistant starch has an amylose content of ≥70%.

7. A preparation method of the natural preservative for the flavoring noodle product according to any one of claims 1-6, characterized in that, The method comprises the following steps: Step one: preparing enzymatic protamine, trehalose grafted modified chitosan lactate, and composite phosphate according to the proportion; Step two: preparing microencapsulated active core material: mixing enzymatic protamine and GMC as the core material, and mixing malt dextrin and gum arabic as the wall material, then homogenizing and spray drying the mixture of the core material and the wall material to obtain microcapsule powder; Step three: the microencapsulated active core material, trehalose grafted modified chitosan lactate, complex phosphate, vitamin C palmitate, RS3 type resistant starch were added into a double helix mixer, mixed at 300-350 rpm for 45-55 min, and sieved through an 80-100 mesh sieve to obtain the natural preservative for flavoring flour products.

8. A preparation method of the natural preservative for flavoring flour products according to claim 7, characterized in that, The preparation of the microencapsulated active core material further comprises a homogenization step: after the core material is mixed with the wall material, homogenization is performed at 20,000-22,000 rpm for 2-3 min, and then spray drying is performed to control the inlet air temperature at 180-190 ℃ and the outlet air temperature at 80-85 ℃ to obtain the microcapsule powder.

9. A method for preparing the natural preservative for the flavoring noodle product according to claim 7, characterized by, The preparation method of the enzymatic protamine is as follows: protamine and deionized water are mixed at a weight ratio of 1:15-20, 0.35%-0.45% of papain by weight of the protamine is added, the pH is adjusted to 6.6-6.8, and enzymatic hydrolysis is performed at 52-54 ℃ for 1.6-1.8 h, after which the enzyme is inactivated at 80 ℃ for 15 min, and then freeze-drying is performed to obtain the product.

10. A method for preparing the natural preservative for the flavoring noodle product according to claim 7, characterized by, The grafting rate of the trehalose grafted modified chitosan lactate is 9%-11%, and the preparation method is as follows: chitosan lactate and trehalose are dissolved in a 1% acetic acid solution at a weight ratio of 1:0.8-1.0, 0.5%-0.7% of ammonium persulfate by weight of the chitosan lactate is added, and reaction is performed at 60-65 ℃ for 3-3.5 h, after which dialysis is performed and freeze-drying is performed to obtain the product.

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