Preparation and application of compound preservative for leisure food

Abstract

The application belongs to the field of food preservation technology, and particularly relates to preparation and application of a compound preservative for leisure food, which is composed of the following components in percentage by weight: cinnamon extract 40-68%, malic acid 25-50%, and fumaric acid 5-10%, with the sum of the three being 100%. The cinnamon extract is a powder extract obtained by extracting the bark of a cinnamon tree with 60-80% ethanol water solution, and the content of cinnamyl aldehyde is not less than 75%. The preparation method comprises the following steps: weighing the components according to the proportion, placing them in a V-shaped mixer or a screw belt mixer, mixing at a speed of 20-40 rpm for 30 minutes at room temperature until uniform, and sieving through a 60-mesh sieve to obtain the finished product. The three components have a significant synergistic effect after compounding, can simultaneously inhibit the growth of microorganisms and oxidation and deterioration, are safe and non-toxic, and can be applied to the preservation and corrosion prevention of spicy leisure food, marinated products, meat products and starch products.

Description

Technical Field

[0001] This invention belongs to the field of food preservation technology, specifically relating to the preparation and application of a compound preservative for snack foods. Background Technology

[0002] Preservation of snack foods is a core technological aspect for ensuring the development of the food industry, extending shelf life, and maintaining food quality and safety. The four main categories of snack foods—braised products, meat products, starch-based products, and spicy snack foods—are rich in nutrients such as protein, starch, and oil. Because their processing often involves multiple steps including heating, seasoning, and shaping, they are susceptible to microbial contamination, oxidative rancidity, and starch aging. This can lead to quality deterioration, such as off-flavors, mold, and reduced texture, severely restricting their distribution and shelf life.

[0003] Currently, preservation technologies for the aforementioned foods mainly fall into two categories: physical preservation and chemical preservation. Physical preservation technologies, such as low-temperature refrigeration, vacuum packaging, and irradiation, can inhibit microbial growth and oxidation reactions to a certain extent, but they have limitations such as high cost, high energy consumption, large equipment investment, and potential impact on product flavor and texture, making them particularly unsuitable for small and medium-sized production enterprises and ambient temperature distribution scenarios. Chemical preservation technologies, due to their advantages of low cost, simple operation, and direct preservation effects, have become the most widely used preservation method in the food industry. Among them, single chemical preservatives such as sodium benzoate, potassium sorbate, and sodium dehydroacetate have achieved large-scale application in specific food categories.

[0004] However, with the diversified development of the food industry and the increasing demands of consumers for food safety and quality, the shortcomings of using single chemical preservatives are becoming increasingly apparent: First, they lack specificity, as the matrix characteristics of different foods vary significantly, making it difficult for a single preservative to meet the complex preservation needs of multiple food categories; second, there are safety controversies, as excessive use or long-term intake of some synthetic preservatives may have potential impacts on human health, leading to a surge in consumer demand for natural, green, and additive-free foods; third, there is a lack of synergistic effects, as a single preservative often only works on a specific degradation pathway and cannot simultaneously address quality degradation caused by multiple factors, while the arbitrary combination of multiple preservatives may have antagonistic effects or even produce harmful substances.

[0005] Natural plant extracts have become a hot research area in preservative development in recent years due to their safe origin and multiple activities such as antibacterial and antioxidant properties. Among existing technologies, CN102885379B discloses a microencapsulated preservative with cinnamaldehyde as the core active ingredient. Microencapsulation technology improves the stability of cinnamaldehyde to some extent, achieving a minimum inhibitory concentration (MIC) of 0.10% against Escherichia coli and 0.15% against Staphylococcus aureus. However, it remains a single active ingredient with a narrow antibacterial spectrum, and the problem of significant interference of the characteristic cinnamon odor with food flavor when used at high concentrations in complex food matrices remains unresolved. CN106577989A discloses a compound natural preservative for meat products, composed of cinnamon oil, chitosan, sodium diacetate, nisin, and lysozyme. While the multi-component compounding broadens the antibacterial spectrum to some extent, the large number of components (five) increases the complexity and cost of the formulation. Furthermore, nisin is only effective against Gram-positive bacteria, with limited inhibitory effects on Gram-negative bacteria and molds. It also does not address synergistic effects with organic acids such as malic acid and fumaric acid. CN101513222B discloses a feed acidifier with citric acid, fumaric acid, malic acid, and lactic acid as main components. It utilizes the synergistic acidification effect of organic acids to adjust feed pH. However, this is a feed product and does not involve food preservation; it also does not investigate synergistic effects with plant-derived antibacterial components such as cinnamon extract.

[0006] In addition, although there have been attempts to combine plant extracts with organic acids for food preservation in existing technologies, these solutions generally have the following shortcomings: (1) The compounding ratio has not been systematically optimized, and there may be antagonism rather than synergy between the components. There is a lack of quantitative verification of the synergistic effect mechanism (such as FIC index determination), and it cannot be proven that the compounding effect is better than the simple addition of single components; (2) The compatibility study has not been carried out for the special matrix characteristics of spicy snack foods with high oil, high salt content and strong irritation, and the preservation effect is unstable in actual application; (3) There is a lack of safety evaluation data to support it, and it is difficult to meet the compliance requirements of food-grade application; (4) There is a lack of stability test data of the preservative product itself, and the active ingredients may degrade and become ineffective during storage and transportation; (5) The usage method is complicated and requires additional procedures or special equipment, which is not conducive to industrial promotion.

[0007] Therefore, developing a specialized compound preservative that is targeted, safe, and highly effective, by systematically optimizing the compound ratio of cinnamon extract, malic acid, and fumaric acid to address the complex matrix characteristics of spicy snack foods and leveraging their synergistic effects, along with establishing a simple and easy-to-implement preservation application method, has become a key need to solve the current pain points in snack food preservation and promote the upgrading of preservation technology in the industry. This invention is developed based on this technological background. Summary of the Invention

[0008] The technical problem to be solved by this invention is to provide a natural, safe, and efficient compound preservative that can simultaneously inhibit microbial growth and oxidative deterioration and is suitable for complex matrices such as spicy snack foods, in order to address the problems of insufficient targeting, safety controversies, and lack of synergistic effects in existing snack food preservation technologies. The invention also provides a simple and easy preparation method and preservation application method.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A compound preservative for snack foods is composed of the following components by weight percentage: 40%–68% cinnamon extract, 25%–50% malic acid, and 5%–10% fumaric acid, with the sum of the weight percentages of the three components being 100%.

[0010] The cinnamon extract is a powdered extract obtained by extracting, concentrating, and drying cinnamon bark using a 60%–80% (v / v) ethanol aqueous solution, with a cinnamaldehyde content of not less than 75% (on a dry basis). The malic acid is food-grade DL-malic acid with a purity of not less than 99.0%. The fumaric acid is food-grade fumaric acid with a purity of not less than 99.0%.

[0011] The preferred compound preservative formula is: 68% cinnamon extract, 25% malic acid, and 7% fumaric acid.

[0012] The preferred compound preservative formula is: 63% cinnamon extract, 32% malic acid, and 5% fumaric acid.

[0013] The preferred compound preservative formula is: 50% cinnamon extract, 40% malic acid, and 10% fumaric acid.

[0014] The preferred compound preservative formula is: 55% cinnamon extract, 36% malic acid, and 9% fumaric acid.

[0015] The preferred compound preservative formula is: 45% cinnamon extract, 50% malic acid, and 5% fumaric acid.

[0016] The preferred compound preservative formula is: 40% cinnamon extract, 50% malic acid, and 10% fumaric acid.

[0017] The preparation method of the compound preservative is as follows: weigh cinnamon extract, malic acid and fumaric acid according to the above weight percentages, place them in a V-type mixer or a ribbon mixer, mix them at 20-40 rpm for 30 minutes at room temperature until uniform, and pass them through a 60-mesh sieve to obtain the finished product.

[0018] The compound preservative is used for the preservation and anti-corrosion of spicy snack foods, braised products, meat products, and starch products.

[0019] The above-mentioned compound preservative is used as follows: Weigh out 0.05% to 0.2% of the compound preservative by weight of the semi-finished product, add it to the spicy snack food seasoning and mix well, then add it directly to the semi-finished product for seasoning, vacuum package it, and store it at room temperature. The addition amount can be further preferably 0.05%, 0.1%, 0.15%, or 0.2% of the semi-finished product weight.

[0020] The beneficial effects are: (1) Natural, safe, compliant and reliable: Cinnamon extract is a natural plant extract, and malic acid and fumaric acid are both food-grade raw materials with natural sources or high biocompatibility. All three components are listed in the list of permitted food additives in GB2760 "National Food Safety Standard for the Use of Food Additives", and their use is safe and compliant. According to toxicological safety evaluation, the oral LD50 of cinnamon extract in rats is greater than 5000 mg / kg (practically non-toxic), the LD50 of malic acid is 1600 mg / kg, and the LD50 of fumaric acid is 10700 mg / kg. The oral LD50 of the three combined is greater than 5000 mg / kg (practically non-toxic), with no risk of chemically synthesized preservative residues, which is in line with the trend of clean label development and consumers' demand for natural foods.

[0021] (2) Synergistic Effect and Multi-Pathway Preservation: In vitro antibacterial tests verified that the combined cinnamon extract, malic acid, and fumaric acid exhibited a fractional inhibitory concentration index (FICindex) of 0.375 against Escherichia coli and Staphylococcus aureus, which is less than 0.5, indicating a significant synergistic effect among the three components, rather than a simple additive effect. Cinnamon extract contains active ingredients such as cinnamaldehyde, which significantly inhibit pathogenic bacteria such as Escherichia coli and Staphylococcus aureus, as well as spoilage microorganisms such as molds and yeasts (MIC of 0.5–2.5 mg / mL), and also possesses antioxidant capabilities. Malic acid and fumaric acid disrupt the microbial environment by lowering the pH of the food system to below 4.5, and also possess the ability to chelate metal ions (Fe3+, Cu2+), thus delaying oil oxidation. The synergistic effect of the three components provides a broad antibacterial spectrum and simultaneously addresses the two major quality deterioration problems of microbial contamination and oxidative spoilage.

[0022] (3) Product stability and long shelf life: Accelerated stability testing verified that after 6 months of storage at 25°C, the cinnamaldehyde content of the compound preservative of this invention decreased from 78.3% to 78.1%, a decrease of only 0.2%, with no significant change in the minimum inhibitory concentration (MIC); after 6 months of storage at 40°C, the cinnamaldehyde content decreased to 77.5%, with no significant change in the MIC; after 6 months of storage under accelerated high-temperature conditions at 60°C, the cinnamaldehyde content decreased to 76.2%, still higher than the lower limit of the quality standard of 75%, and the MIC increased slightly but remained within the effective inhibitory concentration range. This indicates that the compound preservative of this invention has good stability under normal temperature storage conditions and can meet the shelf life requirements of industrial production and distribution.

[0023] (4) Strong adaptability: Targeting the characteristics of spicy snack foods—high oil content, high salt content, and strong stimulating flavor—the compound preservative of this invention can effectively inhibit microbial growth and oil oxidation without interfering with the original spicy flavor, while imparting a mild natural aroma and refreshing sourness to the food, thus enhancing its flavor profile and eating experience. Sensory evaluation verified that the spicy snack meat products with 0.1% compound preservative added showed no significant difference in color, aroma, and taste compared to the blank control group (p>0.05), and maintained superior flavor quality in the later stages of storage due to delayed oxidation.

[0024] (5) Simple process and low cost: The preparation process is only simple mixing, without the need for complex equipment and harsh conditions. The production cost is only RMB 0.15 to RMB 0.20 per kilogram of product. The method of use is to add the seasonings simultaneously with the external seasonings. No additional procedures are required. The operation is simple and easy to promote and apply industrially. Under normal temperature (25°C±2°C) circulation conditions, the shelf life of spicy snack foods can be extended from 30 days to 90 to 120 days. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of the preparation method of the compound preservative of the present invention. Detailed Implementation

[0026] The technical solutions will now be clearly and completely described in conjunction with embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. The technical solutions of the present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0027] The raw materials and reagents used in the following examples are as follows: Malic acid: Food-grade DL-malic acid, 99.5% purity, commercially available.

[0028] Fumaric acid: food-grade fumaric acid, 99.3% purity, commercially available.

[0029] Sodium benzoate: food grade, 99.0% purity, commercially available.

[0030] Potassium sorbate: food grade, 99.0% purity, commercially available.

[0031] Sodium dehydroacetate: food grade, 98.5% purity, commercially available.

[0032] The detection methods used in the following examples are performed in accordance with the following national standards: Total bacterial count determination: GB4789.2 National Food Safety Standard for Microbiological Examination of Food - Determination of Total Bacterial Count.

[0033] Coliform count: GB4789.3 National Food Safety Standard - Microbiological Examination of Food - Coliform count.

[0034] Mold and yeast count: GB4789.15 National Food Safety Standard for Microbiological Examination of Food: Mold and yeast count.

[0035] Peroxide value determination: GB5009.227 "National Food Safety Standard - Determination of Peroxide Value in Food".

[0036] Acid value determination: GB5009.229 National Food Safety Standard - Determination of acid value in food.

[0037] Cinnamaldehyde content determination: High performance liquid chromatography as specified in GB1886.62 "National Food Safety Standard for Food Additives - Cinnamaldehyde".

[0038] Sensory evaluation: Referring to GB / T29605 "Guidelines for Sensory Evaluation of Food", the 9-point preference scale (1 = extremely dislike, 9 = extremely like) was used, and the evaluation was conducted by an evaluation group composed of 10 trained sensory evaluators.

[0039] (I) Synergistic effect verification test To verify whether the combination of cinnamon extract, malic acid and fumaric acid has a synergistic effect, the minimum inhibitory concentration (MIC) of each component against Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC6538) was determined by micro-broth dilution method, and the fractionated inhibitory concentration index (FICindex) was calculated.

[0040] Calculation formula of FIC index: FIC index = MIC of (A) in combination / MIC of (A) used alone + MIC of (B) in combination / MIC of (B) used alone + MIC of (C) in combination / MIC of (C) used alone. Judgment criteria: FIC index ≤ 0.5 indicates synergistic effect; 0.5 < FIC index ≤ 1.0 indicates additive effect; 1.0 < FIC index ≤ 4.0 indicates irrelevant effect; FIC index > 4.0 indicates antagonistic effect.

[0041] The compounding ratio is the formula of Example 1 (68% of cinnamon extract, 25% of malic acid, 7% of fumaric acid), and the MIC in combination is calculated based on the actual concentration of each component in the compound system.

[0042] Table 1 Determination results of MIC and FIC index of each component used alone and in combination

[0043] The results show that after the compounding of cinnamon extract, malic acid and fumaric acid, the FIC index against Escherichia coli and Staphylococcus aureus is both 0.375, which is less than 0.5, and is determined as synergistic effect. This indicates that after the three components are compounded, the effective antibacterial concentration of each component is reduced to 1 / 8 of that when used alone, which is significantly better than the antibacterial effect of simple addition of single components, confirming that the compound system of the present invention has a clear synergistic mechanism.

[0044] (II) Time-kill curve test To further verify the synergistic bactericidal effect of the compound system, time-kill curve measurement was carried out. With Escherichia coli (ATCC25922) used as the test bacterium, the initial inoculation concentration was 1.0×10^6CFU / mL, and the following groups were set respectively: (1) Blank control group (without any preservative); (2) Single cinnamon extract group (with a concentration of 2.5mg / mL, i.e., MIC when used alone); (3) Compound preservative group (formula of Example 1, with concentrations of each component being 0.3125mg / mL, 1.25mg / mL and 1.0mg / mL respectively, i.e., MIC in combination). Samples were taken at 0, 2, 4, 8, 12 and 24 hours, and the number of viable bacteria was determined by plate counting method.

[0045] Table 2 Determination results of time-kill curves of compound preservative and single cinnamon extract against Escherichia coli

[0046] The time-sterilization curve results showed that, under the same total amount of active substances, the compound preservative group reduced the viable E. coli count from 1.0 × 10^6 CFU / mL to 1.0 × 10^3 CFU / mL within 8 hours, achieving a sterilization rate of 99.9%, representing a three-logarithmic-order sterilization effect. In contrast, the single cinnamon extract group only reduced the count from 1.0 × 10^6 to 2.0 × 10^5 CFU / mL within the same time period, a reduction of only about one logarithmic order. The compound system achieved complete sterilization (viable bacteria count < 100 CFU / mL) within 24 hours, while the single cinnamon extract group still had 5.0 × 10^4 CFU / mL surviving after 24 hours. This result far exceeded the expectations of simply adding the components together, representing an unexpected technical effect and further confirming the synergistic effect of the three compounds.

[0047] Synergistic effect analysis: Cinnamaldehyde in cinnamon extract exerts its antibacterial effect by disrupting the integrity of microbial cell membranes and inhibiting ATPase activity. Malic acid and fumaric acid lower the pH of the system, acidifying the microbial cells and disrupting the cell membrane proton gradient, providing more favorable osmotic conditions for cinnamaldehyde to enter the cells, thus significantly enhancing the antibacterial effect of cinnamon extract. Furthermore, the metal ion chelating ability of malic acid and fumaric acid can remove trace metal ions required for microbial growth, further inhibiting microbial metabolism. These three mechanisms work synergistically, achieving a synergistic effect greater than the sum of its parts (1+1+1>3).

[0048] (III) Accelerated stability test of preservatives To verify the stability of the compound preservative product during storage, accelerated stability testing was conducted in accordance with the "Guidelines for Stability Testing of Raw Materials and Preparations". The compound preservative prepared in Example 1 was stored in the dark at 25°C±2°C, 40°C±2°C, and 60°C±2°C, respectively. Samples were taken at 0, 1, 3, and 6 months to detect changes in appearance, cinnamaldehyde content (HPLC method), and minimum inhibitory concentration (MIC, against Escherichia coli).

[0049] Table 3 Results of accelerated stability test of compound preservatives

[0050] Stability test results show that the compound preservative of this invention, after 6 months of storage at 25°C, exhibits a decrease of only 0.2% in cinnamaldehyde content and no change in the MIC, indicating stable product performance. After 6 months of accelerated storage at 40°C, the cinnamaldehyde content decreases to 77.5%, with a slight increase in MIC, but still within the effective antibacterial concentration range. After 6 months of accelerated storage at 60°C, the cinnamaldehyde content decreases to 76.2%, still exceeding the lower limit of the 75% quality standard, with an MIC of 0.375 mg / mL, significantly lower than the MIC of single cinnamon extract (2.5 mg / mL), ensuring effective preservation. Based on the Arrhenius equation, the estimated shelf life of this product at 25°C is no less than 24 months, meeting the shelf-life requirements for industrial production and distribution.

[0051] (iv) Safety evaluation To verify the food safety of the compound preservative, toxicological safety evaluations were conducted on each component and the compound product, and compliance was confirmed in accordance with FDA GRAS (Generally Recognized As Safe) status and relevant food safety standards.

[0052] Table 4. Toxicological safety evaluation data of each component and compound preservative.

[0053] Safety evaluation results show that all three components of the compound preservative of this invention are FDA-recognized GRAS substances, listed in the GB2760 list of permitted food additives, and their oral LD50 in rats is at the low toxicity or practically non-toxic level. The oral LD50 of the compound preservative product is greater than 5000 mg / kg (practically non-toxic level), with no mutagenic, teratogenic, or other safety risks. Under the recommended usage (0.05%–0.2% of the semi-finished product weight), the actual intake of each component is far lower than the safety assessment reference value, indicating safe and reliable use.

[0054] (V) Preparation Examples Example 1 A compound preservative for snack foods comprises the following components by weight percentage: 68% cinnamon extract, 25% malic acid, and 7% fumaric acid. Each component is weighed according to the above weight percentages, placed in a V-type mixer, and mixed at 30 rpm for 30 minutes at room temperature until homogeneous. The mixture is then passed through a 60-mesh sieve to obtain the finished product.

[0055] Example 2 A compound preservative for snack foods comprises the following components by weight percentage: 63% cinnamon extract, 32% malic acid, and 5% fumaric acid. The preparation method is the same as in Example 1.

[0056] Example 3 A compound preservative for snack foods comprises the following components by weight percentage: 50% cinnamon extract, 40% malic acid, and 10% fumaric acid. The preparation method is the same as in Example 1.

[0057] Example 4 A compound preservative for snack foods comprises the following components by weight percentage: 55% cinnamon extract, 36% malic acid, and 9% fumaric acid. The preparation method is the same as in Example 1.

[0058] Example 5 A compound preservative for snack foods comprises the following components by weight percentage: 45% cinnamon extract, 50% malic acid, and 5% fumaric acid. The preparation method is the same as in Example 1.

[0059] Example 6 A compound preservative for snack foods comprises the following components by weight percentage: 40% cinnamon extract, 50% malic acid, and 10% fumaric acid. The preparation method is the same as in Example 1.

[0060] (vi) Application Example 1 - Spicy Snack Meat Products Weigh the compound preservative prepared in Example 1, and weigh it at 0.05% of the weight of the spicy snack meat product semi-finished product (spicy beef jerky). Add it to the external seasoning (chili powder, Sichuan pepper, sesame, etc.) and mix evenly. Then add it directly to the semi-finished product for seasoning. After vacuum packaging, store it at room temperature (25°C±2°C).

[0061] Meanwhile, the following control groups were set up: (1) Blank control group: no preservatives were added; (2) Sodium benzoate control group: an equal amount (0.05%) of sodium benzoate was added; (3) Potassium sorbate control group: an equal amount (0.05%) of potassium sorbate was added; (4) Single cinnamon extract control group: an equal amount (0.05%) of single cinnamon extract was added. Except for the type of preservative, the other process conditions of each group were completely the same.

[0062] Samples were taken on days 0, 30, 60, and 90 of storage. The total bacterial count was determined according to GB 4789.2, and sensory evaluation was conducted according to GB / T 29605. The limit standard for total bacterial count was in accordance with GB 2726 "National Food Safety Standard for Cooked Meat Products" (n=5, c=2, m=10^4, M=10^5 CFU / g).

[0063] Table 5. Changes in total bacterial count during room temperature storage for each group in Application Example 1.

[0064] The total bacterial count results showed that the blank control group exceeded the limit standard (>10^5 CFU / g) on ​​day 30; the sodium benzoate group and potassium sorbate group both exceeded the limit standard on day 90; the single cinnamon extract group was close to the upper limit on day 60 and exceeded the limit on day 90; while the compound preservative group of this invention had a total bacterial count of only 1.8×10^4 CFU / g on day 90, which still met the limit standard of GB2726, and the preservation effect was significantly better than that of the control groups.

[0065] Table 6. Sensory evaluation results (out of 9 points) of each group after 90 days of storage at room temperature in Application Example 1.

[0066] Sensory evaluation results showed that by day 90, the sensory evaluation of the blank control group was completely unacceptable (score <3.5); the sensory evaluation scores of the chemical preservative control groups and the single cinnamon group were between 5.0 and 6.5, which were acceptable but the quality had obviously declined; while the sensory evaluation scores of the compound preservative group of this invention were all above 7.8, with an overall acceptance of 8.0 points, which was significantly higher than that of the control groups (p<0.01), and the product color, flavor and texture were well maintained.

[0067] (vii) Application Example 2 - Spicy Snack Noodle Products Weigh the compound preservative prepared in Example 3, and weigh it at 0.1% of the weight of the spicy snack noodle product semi-finished product (spicy gluten). Add it to the external seasoning and mix evenly. Then add it directly to the semi-finished product for seasoning. After vacuum packaging, store it at room temperature (25°C±2°C).

[0068] A blank control group and a single preservative control group (0.1% cinnamon extract and 0.1% malic acid) were also set up. Samples were taken on days 0, 30, 60, 90, and 120 of storage. Peroxide value was determined according to GB5009.227, and mold count was determined according to GB4789.15. The peroxide value limit standard was set according to GB17400 "National Food Safety Standard for Instant Noodles" (≤0.25g / 100g).

[0069] Table 7. Changes in peroxide value during room temperature storage for each group in Application Example 2.

[0070] Table 8. Changes in mold counts during room temperature storage for each group in Application Example 2.

[0071] The results showed that the peroxide value of the blank control group exceeded the standard limit (0.25g / 100g) on ​​day 60, and the mold count exceeded the standard on day 45. All indicators of the single preservative control group were worse than those of the compound preservative group, with the single malic acid group exceeding the mold count on day 120. In contrast, the peroxide value of the compound preservative group was only 0.18g / 100g on day 120, which was far below the limit standard, and the mold count was 3.0×10^3 CFU / g, which was far below the limit standard, demonstrating excellent antioxidant and antibacterial preservation performance.

[0072] (viii) Application Example 3 - Spicy Snack Braised Products Weigh the compound preservative prepared in Example 5, and weigh it at 0.2% of the weight of the spicy casual braised product semi-finished product (braised duck neck). Add it to the external seasoning and mix evenly. Then add it directly to the semi-finished product for seasoning. After vacuum packaging, store it at room temperature (25°C±2°C).

[0073] A blank control group and a single cinnamon extract control group (0.2%) were also set up. Samples were taken on days 0, 25, 50, 75, and 100 of storage, and the total bacterial count was determined according to GB4789.2, followed by sensory evaluation.

[0074] Table 9. Changes in total bacterial count during room temperature storage for each group in Application Example 3.

[0075] The results showed that the product of this compound preservative group had better appearance, aroma, and taste than the control group during a 100-day storage period. The total bacterial count on day 100 was 8.0 × 10^4 CFU / g, significantly lower than the blank control group and the single cinnamon extract control group. This indicates that the addition of malic acid and fumaric acid significantly enhanced the antibacterial effect of cinnamon extract, and the three components showed a significant synergistic effect, consistent with the results of in vitro FICindex determination.

[0076] (ix) Application Example 4 – Spicy Snack Starch Products Weigh the compound preservative prepared in Example 4, and weigh it at 0.15% of the weight of the spicy snack starch product semi-finished product (spicy potato chips). Add it to the external seasoning and mix evenly. Then add it directly to the semi-finished product for seasoning. After vacuum packaging, store it at room temperature (25°C±2°C).

[0077] A blank control group and a single cinnamon extract control group (0.15%) were also set up. Samples were taken on days 0, 30, 60, and 90 of storage. The total bacterial count was determined according to GB4789.2, and the mold count was determined according to GB4789.15. The limit standard for total bacterial count was in accordance with GB7099 "National Food Safety Standard for Pastries and Bread" (less than or equal to 10^4 CFU / g).

[0078] Table 10. Changes in microbial indicators during room temperature storage for each group in Application Example 4 (Starch Products)

[0079] The results showed that starch-based products, due to their high starch content, are highly susceptible to mold contamination. The blank control group exceeded the total bacterial count limit on day 30 and the mold count limit on day 60; the single cinnamon extract group exceeded the total bacterial count limit on day 60 and the mold count limit on day 90; while the compound preservative group of this invention had a total bacterial count of 9.0 × 10^3 CFU / g and a mold count of 4.0 × 10^2 CFU / g on day 90, both meeting the limits of GB7099. This indicates that the compound preservative of this invention also has excellent preservation effects on starch-based products. The addition of malic acid and fumaric acid significantly enhanced the system's inhibitory ability against mold, compensating for the insufficient inhibitory effect of single cinnamon extract on mold.

[0080] (X) Comparative Examples – Comparison of the Effects of Compound Preservatives and Commonly Used Chemical Preservatives To verify the preservation advantages of the compound preservative of this invention compared to commonly used chemical preservatives, spicy snack meat products (spicy beef jerky) were used as the research object, and the following groups were set up: Group A (blank control, no preservative), Group B (0.1% sodium benzoate), Group C (0.1% potassium sorbate), Group D (0.1% sodium dehydroacetate), and Group E (0.1% of the compound preservative of Example 1 of this invention). After storage at room temperature (25°C±2°C) for 60 days, the total bacterial count, peroxide value, and acid value of each group were measured, and the results are shown in the table below.

[0081] Table 11 Comparison of quality indicators of each group after 60 days of storage at room temperature in the comparative examples

[0082] Comparative examples show that, under the same addition amount (0.1%), the total bacterial count of the compound preservative of this invention is about 70 times lower than that of sodium benzoate and about 40 times lower than that of potassium sorbate; the peroxide value is only about half that of the chemical preservative group; and the acid value is also significantly lower than that of each chemical preservative group. This fully demonstrates that the compound preservative of this invention is significantly superior to commonly used single chemical preservatives in both antibacterial and antioxidant aspects, and the raw materials are natural and safe, with no risk of residual chemically synthesized preservatives.

[0083] The above embodiments and application examples demonstrate that the compound preservative of the present invention organically combines the natural antibacterial and antioxidant activity of cinnamon extract with the pH-regulating and synergistic effects of malic acid and fumaric acid. This effectively inhibits microbial growth and oil oxidation in spicy snack foods during room temperature storage, significantly extending shelf life while maintaining the product's excellent flavor and edibility. The preparation process of this invention is simple, convenient, low-cost, highly safe, and the product exhibits good stability, showing promising prospects for industrial application.

[0084] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural or methodological transformations made based on the content of this specification, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A compound preservative for snack foods, characterized in that: It is composed of the following components by weight percentage: 40%–68% cinnamon extract, 25%–50% malic acid, and 5%–10% fumaric acid, with the sum of the weight percentages of the three being 100%; wherein, the cinnamon extract is a powdered extract obtained by extracting, concentrating, and drying cinnamon bark with an aqueous ethanol solution of 60%–80% by volume, and the cinnamaldehyde content is not less than 75%.

2. The compound preservative for snack foods according to claim 1, characterized in that: The preparation method of the cinnamon extract is as follows: Cinnamon bark is extracted with 60% to 80% ethanol aqueous solution at a material-to-liquid ratio of 1:8 to 1:12 at 50 to 70°C for 1.5 to 3 hours. The extract is concentrated under reduced pressure to a relative density of 1.10 to 1.20 and then spray-dried to obtain the extract.

3. The compound preservative for snack foods according to claim 1, characterized in that: The malic acid is food-grade DL-malic acid with a purity of not less than 99.0%; the fumaric acid is food-grade fumaric acid with a purity of not less than 99.0%.

4. The compound preservative for snack foods according to claim 1, characterized in that: It consists of one of the following components by weight percentage: 68% cinnamon extract, 25% malic acid, and 7% fumaric acid; or 63% cinnamon extract, 32% malic acid, and 5% fumaric acid; or 50% cinnamon extract, 40% malic acid, and 10% fumaric acid.

5. A compound preservative for snack foods according to claim 1, characterized in that: It consists of one of the following components by weight percentage: 55% cinnamon extract, 36% malic acid, and 9% fumaric acid; or 45% cinnamon extract, 50% malic acid, and 5% fumaric acid; or 40% cinnamon extract, 50% malic acid, and 10% fumaric acid.

6. A method for preparing a compound preservative for snack foods according to any one of claims 1 to 5, characterized in that: Includes the following steps: Weigh out the cinnamon extract, malic acid, and fumaric acid by weight percentage, place them in a V-type mixer or ribbon mixer, mix at 20-40 rpm for 30 minutes at room temperature until homogeneous, and pass through a 60-mesh sieve to obtain the final product.

7. A compound preservative for snack foods according to any one of claims 1 to 5, characterized in that: This preservative is used in the preservation and anti-corrosion of spicy snack foods, braised products, meat products, or starchy products.

8. A compound preservative for snack foods, characterized in that: Includes the following steps: Weigh out 0.05% to 0.2% of the compound preservative described in any one of claims 1 to 5 by weight of the semi-finished product, add it to the external seasoning and mix evenly, then add it to the semi-finished product for seasoning and vacuum packaging.

9. A compound preservative for snack foods according to claim 8, characterized in that: The amount of the compound preservative added is 0.05% to 0.2% of the weight of the semi-finished product; the snack food is a spicy snack food, selected from one of spicy snack meat products, spicy snack noodle products, spicy snack braised products, or spicy snack starch products.

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