A ginseng color-protecting agent, its preparation method and application

Abstract

This invention relates to a ginseng color-protecting agent, its preparation method, and its application, belonging to the technical field of ginseng color-protecting agent preparation. The ginseng color-protecting agent, by mass percentage, comprises the following components: malic acid 0.60%~0.70%, L-ascorbic acid 0.05%~0.15%, chitosan 0.65%~0.75%, and the balance being water. This invention, through a scientifically optimized composite formula, achieves highly efficient browning inhibition, color preservation, and safe sulfur-free processing, effectively solving the problem of browning control in the processing of fresh-cut ginseng slices.

Description

Technical Field

[0001] This invention relates to a ginseng color-protecting agent, its preparation method, and its application, belonging to the technical field of ginseng color-protecting agent preparation. Background Technology

[0002] Ginseng, a high-value medicinal and edible material, is prone to browning after fresh cutting, affecting its appearance and commercial value. Belonging to the genus *Panax* in the family Araliaceae, ginseng has received widespread attention due to its unique medicinal value and numerous health benefits. As early as the ancient Chinese medical classic *Shennong Bencao Jing*, ginseng was recorded in detail, and it was listed as an important prescription drug in *Shanghan Zabing Lun*, demonstrating its widespread application in traditional Chinese medicine. Modern medical research has shown that ginseng has exhibited significant pharmacological effects in multiple areas, including anti-tumor activity, obesity control, immune enhancement, and metabolic regulation. The rich active ingredients in ginseng form the basis for its numerous pharmacological effects, including ginsenosides, ginseng polysaccharides, ginseng oligosaccharides, ginseng volatile oils, and amino acids. The chemical composition of ginseng is complex and diverse, with saponins and polysaccharides being the main active components. Traditionally, ginseng is preserved using methods such as natural storage, refrigeration, sand storage, and plastic film preservation. With the advancement of food processing technology, ginseng storage methods have now evolved into a variety of modern technologies, including freezing, chemical color-protecting agent treatment, irradiation preservation, modified atmosphere storage, and low-temperature storage.

[0003] Although scholars both domestically and internationally have made some progress in the storage, preservation, and shelf-life extension of fresh ginseng, existing research mainly focuses on whole ginseng roots, with limited exploration of the storage of fresh ginseng slices. Currently used color-protecting methods include the use of sulfites, organic acids, or single antioxidants, which have drawbacks such as sulfur residue risk, unstable color-protecting effects, and limited applicability. While there are reports of color protection using malic acid, ascorbic acid, and chitosan, these are mostly single-component or simple combinations, lacking systematic research and optimized formulations specifically targeting the browning characteristics of ginseng slices, thus requiring improvement in color-protecting efficiency.

[0004] Therefore, developing a highly efficient, safe, and specialized color-protecting agent suitable for fresh-cut ginseng slices is of significant industrial importance. Summary of the Invention

[0005] To address the aforementioned technical problems in existing technologies, this invention provides a ginseng color-protecting agent, its preparation method, and its application. Specifically, it provides a color-protecting agent for fresh-cut ginseng slices, and by optimizing the proportions of each component in the color-protecting agent, it achieves the technical effects of effectively inhibiting browning, maintaining color, and ensuring safety with no sulfur residue, thus effectively solving the problem of browning control in the processing of fresh-cut ginseng slices.

[0006] A ginseng color-protecting agent, by mass percentage, comprises the following components: malic acid 0.60%~0.70%, L-ascorbic acid 0.05%~0.15%, chitosan 0.65%~0.75%, and the balance being water.

[0007] Preferably, the ginseng color-protecting agent comprises, by mass percentage, the following components: 0.64% malic acid, 0.09% L-ascorbic acid, 0.70% chitosan, and the balance being water.

[0008] This color-protecting agent is formulated with three core components in a specific ratio, designed to specifically address the browning inhibition mechanism. Malic acid (the main active ingredient): As a metal ion chelating agent, it effectively complexes copper ions at the PPO active site, thereby directly inhibiting enzyme activity. Simultaneously, its acidic environment lowers the pH, further weakening enzyme activity. L - Ascorbic acid (antioxidant): As a strong reducing agent, it can reduce oxidized quinones to phenols, interrupting the browning chain reaction and consuming oxygen in the environment. Chitosan (physical barrier): It can form an edible semi-permeable membrane on the surface of the ginseng slices, effectively blocking oxygen from contacting the substrate and reducing moisture evaporation, maintaining the plumpness of the slices. These three components work synergistically at three levels: enzyme activity inhibition, chemical reduction blocking, and physical barrier isolation, constituting a triple browning inhibition mechanism.

[0009] The specific proportions of the components in this invention are not simply superimposed, but determined through rigorous experimental design and mathematical model optimization. First, single-factor concentration screening was conducted on malic acid, L-ascorbic acid, citric acid, and chitosan. Based on the single-factor results, three key factors—malic acid (A), L-ascorbic acid (B), and chitosan (C)—were selected, and a three-factor, three-level response surface methodology was performed using a Box-Behnken design. A quadratic regression model was established with total color as the response value. The response surface analysis revealed key interactions. The optimal theoretical proportions were obtained through model solving.

[0010] Another objective of this invention is to provide a method for preparing the above-mentioned ginseng color-protecting agent, wherein malic acid, L-ascorbic acid and chitosan are dissolved in water in sequence and stirred evenly to obtain the agent.

[0011] Another object of the present invention is to provide the application of the above-mentioned ginseng color-protecting agent or the ginseng color-protecting agent prepared by the above method in the color protection of fresh-cut ginseng slices.

[0012] Further, the fresh ginseng is sliced, then soaked in ginseng color-protecting agent for 25-35 minutes, and then drained.

[0013] Furthermore, the mass-to-volume ratio of the fresh ginseng to the ginseng color-protecting agent is 1 g : 80~120 mL.

[0014] Preferably, the mass-to-volume ratio of the fresh ginseng to the ginseng color-protecting agent is 1 g : 100 mL.

[0015] Further, select fresh ginseng that is basically the same size and maturity, fresh and plump, and free from diseases, pests and mechanical damage. Wash it with running tap water for 30 minutes, dry it, and let it ripen naturally at room temperature. Remove the mud and roots, and then slice it.

[0016] Preferably, the slice thickness is 3-4 mm.

[0017] Preferably, the soaking time is 30 minutes.

[0018] The soaking conditions provided by this invention have been verified by experiments to be sufficient to allow the active ingredients to fully penetrate and exert their effects.

[0019] The beneficial effects of this invention are:

[0020] (1) The average total color of fresh-cut ginseng slices treated with the color-protecting agent obtained in this invention is highly similar to the color characteristics of fresh, uncut ginseng, indicating that this invention can almost perfectly maintain the original appearance of the ginseng slices, with a color retention rate exceeding 96%. Compared with the traditionally widely used 0.1% sodium sulfite color-protecting process, the formula of this invention achieves the same or even better color level while increasing the color protection efficiency (calculated by the rate of color decay per unit time) by approximately 25%, indicating that the product can maintain better appearance quality within the same storage or shelf life. Using a browning index of level 3 (complete browning) as the standard, the browning process of ginseng slices treated with the color-protecting agent obtained in this invention is significantly slowed down in air at room temperature (25°C).

[0021] (2) The color-protecting agent obtained in this invention has a clear synergistic effect among malic acid (enzyme inhibition), L-ascorbic acid (chemical reduction) and chitosan (physical barrier), rather than a simple additive effect. Malic acid chelates metal ions to inhibit PPO enzyme activity, L-ascorbic acid reduces quinones to block oxidation, and chitosan forms a film to block oxygen. The multi-target effect makes the color-protecting effect more comprehensive and stable.

[0022] (3) This invention avoids the use of sulfite-based color-protecting agents, which pose a risk of sulfur residue and may cause discomfort to sensitive individuals. All components (malic acid, L-ascorbic acid, chitosan) are food additives or natural extracts permitted for use in China, which are safe and reliable and meet consumers' demand for "clean labels" and natural and healthy products.

[0023] (4) The color-protecting agent obtained by the present invention is only a dissolution process and the application process is only soaking and draining. It does not require complex or expensive equipment and is easy to integrate into existing production lines. The main active ingredient, malic acid, is inexpensive, and the amount of L-ascorbic acid and chitosan used is very small. The overall formula has a competitive advantage in raw material cost and has good prospects for industrial application.

[0024] In summary, this invention, through a scientifically optimized compound formula, achieves efficient, safe, and stable color protection and preservation of fresh-cut ginseng slices. Its technical effects demonstrate significant advantages in color retention, browning inhibition efficiency, safety, and industrialization feasibility, providing a reliable technical solution for the intensive processing of this type of high-value agricultural product. Attached Figure Description

[0025] Figure 1 This is a technical roadmap for optimizing the formulation of the color-protecting agent in this invention.

[0026] Figure 2 The graph shows the effect of different organic acid treatments on the total color of fresh ginseng slices.

[0027] Figure 3 The interaction diagram shows the effect of malic acid addition and L-ascorbic acid addition on total color.

[0028] Figure 4 The interaction diagram shows the effect of chitosan addition and L-ascorbic acid addition on total color.

[0029] Figure 5 This is a graph showing the interaction between the amount of chitosan and the amount of malic acid added on the total color.

[0030] Figure 6 This is a schematic diagram of the optimized mixing ratio. Detailed Implementation

[0031] The following non-limiting embodiments are intended to enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way.

[0032] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0033] The ginseng was purchased from Jilin Ginseng Planting Base Co., Ltd., and L-ascorbic acid, malic acid, and chitosan were purchased from Maclean's Reagent.

[0034] Example 1 The test material used in this study was fresh ginseng slices. Ginseng slices of similar size and maturity were selected, which were fresh, plump, and free from pests, diseases, and mechanical damage. They were washed with running tap water for 30 minutes, dried, and then allowed to ripen naturally at room temperature. After removing mud and fibrous roots, they were ready for use.

[0035] After completing the pretreatment steps, ginseng slices with a thickness of 3-4 mm were cut. 1.0 g of each ginseng slice was immersed in 100 mL of different concentrations of color-protecting agents for 30 min, then drained. A browning index of 3 was used as the indicator of complete browning. The slices were then left to stand in air at room temperature (25℃) until complete browning, and the browning time was observed and recorded. The formulations of different concentrations of color-protecting agents are shown in Table 1. The preparation method includes the following steps: malic acid, citric acid, L-ascorbic acid, and chitosan are dissolved in water sequentially and stirred evenly. Each treatment was repeated three times, with pure water immersion as a control. The color-protecting effects of different color-protecting agents and their concentrations on ginseng slices were recorded and compared. Based on the experimental data, the optimal type and effective concentration range of color-protecting agent were determined, providing a theoretical basis for subsequent processing and storage.

[0036] Table 1 Single-factor design table for color-protecting agent formulation

[0037] (1) Determination of color Lo of fresh ginseng slices before and after organic acid treatment was determined using a colorimeter. a and b The value is calculated using the following formula: ΔE value:

[0038] In Equation 1: L L represents brightness. =0 represents black, L =100 represents white; a >0 represents redness, a <0 represents greenness; b >0 represents yellowness, b <0 represents blueness.

[0039] (2) Response surface analysis of the formulation of color-protecting agent for fresh ginseng slices Based on previous single-factor experiments, this study investigated the color-protecting effects of two selected mixed organic acid treatments on fresh-cut ginseng slices, using malic acid and... L Using ascorbic acid concentration as the variable and the total color of ginseng slices for each treatment combination as the response value, with 0.5% as the effective lower limit concentration and 2.25% as the effective upper limit concentration, a three-factor, three-level Box-Behnken design was used in Design-Expert 8.0.6 software to deduce the optimal combination of retinoic acid and benzoic acid concentrations for effectively delaying the color change of fresh ginseng slices. Based on this software design, suitable composite organic acid treatment combinations will be selected. The ginseng slice treatment methods and browning time observation methods for each treatment combination will be consistent with those described above.

[0040] Table 2. Experimental Design for Factor-Level Response Surface Analysis

[0041] Results of the single-factor experiment: Figure 2 The effects of different organic acid soaking treatments on the overall color of fresh ginseng slices were investigated. It was found that when the organic acid concentration was between 0.25% and 0.75%, the overall color of the malic acid, L-ascorbic acid, and citric acid treatment groups all showed an upward trend. This upward trend resulted in color values ​​reaching the range of 80-87, a range closely resembling the color characteristics of fresh ginseng. In summary, malic acid performed better than L-ascorbic acid and citric acid in maintaining the color of fresh ginseng.

[0042] Response surface methodology results: Data were processed and experimental results were analyzed using GraphPad Prism 10 and Design-Expert 8.0.6. Based on the results selected from the single-factor experiments, three factors were chosen as influencing factors on the extraction rate. The total color test value of ginseng slices was used as the response value for a Box-Behnken experiment with three factors and three levels. Table 3 summarizes the experimental design and the results of 17 runs using the Box-Behnken design, and Table 4 presents the ANOVA analysis of the binomial model.

[0043] Table 3 Results of response surface methodology experiments

[0044] Table 4. ANOVA analysis of the binomial model.

[0045] Using Design Expert 8.0.6 software, a multivariate analysis was conducted with malic acid, L-ascorbic acid, and chitosan additions as variables and total color as the response value. The resulting quadratic regression equation was: Total color of ginseng slices = +84.61A - 1.2B + 1.12C - 1.18AB - 4.2AC + 2.500E - 003BC - 3.71A 2 -0.54B 2 +0.27C 2 ANOVA analysis using a binomial model was performed, and the results are shown in Table 4. The data indicates that a P-value < 0.01 is considered significant, while a P-value of 0.1546 for the lack-of-fit term is considered highly insignificant. In conclusion, this model is effective and can be used as an optimized process for preparing color-protecting agents for ginseng slices. Furthermore, the model's coefficient of determination R0... 2= 0.8994, this data indicates a good fit, confirming a high degree of correlation between the predicted and actual values. Furthermore, according to the regression analysis of variance in the table, different factors have varying effects on the overall color, with the order of influence of the three factors being: malic acid > chitosan > L-ascorbic acid.

[0046] Response surface optimization analysis: The RSM regression equation was solved using the response surface design method to obtain the interaction term relationship diagram. Figure 3-5 In the figure, response surface and contour plots show the effects of apple, L-ascorbic acid and chitosan additions on the total color of ginseng slices after treatment with the composite color protectant.

[0047] The effect of malic acid and L-ascorbic acid addition on total color: From Figure 3 The contour lines and 3D surface plots drawn in the paper reveal the effects of malic acid and L-ascorbic acid addition on the total color, as well as the interaction between the two.

[0048] The effects of chitosan and L-ascorbic acid addition on sensory scores: From Figure 4 The contour lines and 3D surface plots drawn in the paper reveal the effects of malic acid and L-ascorbic acid addition on the total color, as well as the interaction between the two.

[0049] Effects of chitosan and L-ascorbic acid addition on total color: by Figure 4 The contour lines and 3D surface plots drawn in the diagram reveal the effects of chitosan and malic acid additions on the total color, as well as the interaction between the two. The effect on the response value was significant (P<0.01).

[0050] The response data was analyzed using the statistical software Design-Expert. The optimal conditions for the three factors examined, determined through regression model analysis, were: malic acid addition = 0.64%, L-ascorbic acid addition = 0.09%, and chitosan addition = 0.71%. Figure 6 As shown. After actual adjustments, the malic acid addition was 0.64%, L-ascorbic acid addition was 0.09%, and chitosan addition was 0.70%. The experiment was repeated three times under these conditions. Under these conditions, the total color was 86.50, which is close to the 86.51 predicted by the regression model. This shows that the model and method have good feasibility.

[0051] This study systematically analyzed the anti-browning effects of different color-protecting agents on fresh-cut ginseng slices, and clarified the mechanism of action of key factors by combining single-factor experiments and response surface methodology. Single-factor experiments showed that ( Figure 2When the concentration of organic acids is in the range of 0.25% to 0.75%, the overall color value (ΔE) of the malic acid, L-ascorbic acid and citric acid treatment groups is as follows: The color intensity was significantly improved to 80-87, approaching the level of fresh ginseng. Malic acid exhibited the best color-protecting effect (P<0.05), which is closely related to its strong metal ion chelating ability. A quantitative relationship model between the addition amount of malic acid, L-ascorbic acid, chitosan, and total color was established based on Box-Behnken response surface methodology: Total color = +84.61+1.2A+1.12B-1.18AB-4.2AC+0.0025BC-3.71A 2 -0.54B 2 +0.27C 2 The model was highly significant (P<0.01) and the lack-of-fit term was not significant (P =0.1546), with a coefficient of determination R0. 2 = 0.8994, confirming a good agreement between the predicted and measured values ​​(Table 4). The influence of factors was ranked as follows: malic acid > chitosan > L-ascorbic acid (P<0.05), further verifying the dominant role of malic acid. Response surface methodology revealed key interactions: malic acid and L-ascorbic acid synergistically improved color in low-to-medium-high concentration combinations (~0.5% A>0.5% B) (P<0.01); the interaction effect between chitosan and malic acid was extremely significant (P<0.01), and the combination of chitosan above 0.7% and malic acid between 0.5% and 0.8% enhanced the antioxidant effect through a physical oxygen barrier mechanism. The optimal formulation was obtained through model optimization: malic acid 0.64%, L-ascorbic acid 0.09%, chitosan 0.71% (… Figure 6 The verification experiment (chitosan fine-tuned to 0.70%) measured a total color of 86.50 ± 0.32, with a relative error of <0.01% compared to the predicted value of 86.51. Compared to the traditional sulfite color-protecting process (Lee, Y., Demes-Causse, E., Yoo, J. et al. Structural basis for malate-driven, porelipid-regulated activation of the Arabidopsis vacuolar anion channel ALMT9[J]. Nat Commun 2025, 16, 1817), the color-protecting agent obtained in this invention has significant advantages: First, it uses natural components to avoid the risk of sulfur residue, meeting food safety requirements; second, it obtains the optimal color-protecting agent formulation process conditions through precise response surface optimization; third, the raw material cost is controllable (low price of malic acid and low dosage of chitosan), possessing industrialization potential.

[0052] In summary, this study successfully constructed a highly efficient color-protecting system for fresh-cut ginseng slices, determining the optimal compound formula to be 0.64% malic acid, 0.09% L-ascorbic acid, and 0.70% chitosan. This formula significantly delayed the browning process (total color 86.50) through a triple mechanism of enzyme activity inhibition, physical oxygen barrier, and synergistic antioxidant action, providing a theoretical basis and technical support for the industrial processing of fresh ginseng slices.

Claims

1. A ginseng color-protecting agent, characterized in that: The ginseng color-protecting agent comprises, by weight percentage: 0.60%~0.70% malic acid, 0.05%~0.15% L-ascorbic acid, 0.65%~0.75% chitosan, and the balance being water.

2. The ginseng color-protecting agent according to claim 1, characterized in that: The ginseng color-protecting agent comprises, by weight percentage, the following components: 0.64% malic acid, 0.09% L-ascorbic acid, 0.70% chitosan, and the balance being water.

3. The method for preparing the ginseng color-protecting agent according to claim 1 or 2, characterized in that: Malic acid, L-ascorbic acid and chitosan are dissolved in water sequentially and stirred until homogeneous to obtain the final product.

4. The application of the ginseng color-protecting agent according to claim 1 or 2 or the ginseng color-protecting agent prepared by the method according to claim 3 in the color protection of fresh-cut ginseng slices.

5. The application according to claim 4, characterized in that: Slice the fresh ginseng, then soak it in ginseng color-protecting agent for 25-35 minutes, then remove and drain.

6. The application according to claim 5, characterized in that: The mass-to-volume ratio of fresh ginseng to ginseng color-protecting agent is 1 g : 80~120 mL.

7. The application according to claim 5, characterized in that: The slice thickness is 3~4 mm.

8. The application according to claim 5, characterized in that: Soaking time is 30 minutes.

9. The application according to claim 5, characterized in that: Select fresh ginseng that is of similar size and maturity, is fresh and plump, and free from pests, diseases, and mechanical damage. Wash it with running tap water for 30 minutes, dry it, and let it ripen naturally at room temperature. Remove the dirt and rootlets, and then slice it.

Images