A perilla composite water-retaining agent and application thereof in deodorization and water retention of aquatic products

Abstract

This invention discloses a perilla compound water-retaining agent and its application in deodorizing and retaining water in aquatic products, belonging to the field of food processing technology. The water-retaining agent uses perilla extract as its core component, combined with compound cyclodextrin and 3,4-dimethoxy-3,5,7-trihydroxyflavone. The compound cyclodextrin is prepared from citrate monoglyceride compound cyclodextrin. Through single-factor experiments combined with electronic nose-assisted analysis, the optimal application process was determined using the fishy smell value and color difference value of marine fish as optimization indicators. When applied to marine fish processing, the phenolic substances in the perilla extract can inhibit lipid and protein oxidation, the compound cyclodextrin can specifically encapsulate fishy smell substances, and 3,4-dimethoxy-3,5,7-trihydroxyflavone jointly enhances water retention performance, achieving effective deodorization, significantly reducing the content of trimethylamine and nonenal, improving color stability, and optimizing processing quality. It is suitable for various aquatic product processing scenarios.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, specifically relating to a perilla compound water-retaining agent and its application in deodorizing and retaining water in aquatic products. Background Technology

[0002] Aquatic products are highly favored by consumers due to their rich content of high-quality protein and unsaturated fatty acids. However, aquatic products are prone to developing a fishy odor during processing and storage, and significant moisture loss leads to a decline in product quality, hindering the development of the aquatic product processing industry. The formation of fishy odor is mainly related to lipid oxidation, protein degradation, and microbial metabolism. Among these, aldehydes and ketones (such as nonenal) produced by the oxidation of polyunsaturated fatty acids catalyzed by lipoxygenase, and trimethylamine produced by the decomposition of nitrogenous compounds by microorganisms are the main fishy odor substances. The presence of these substances seriously affects the consumer's eating experience. At the same time, freezing, thawing, and heat processing during aquatic product processing can damage the muscle fiber structure, leading to moisture loss, making the product dry and less tender, further affecting its market value.

[0003] Currently, common methods for removing fishy odors in aquatic product processing include rinsing, high-temperature treatment, and adding spices, while phosphate-based water-retaining agents are frequently used for water retention. However, traditional methods have many drawbacks: simple rinsing has limited effectiveness in removing fishy odors and leads to nutrient loss; high-temperature treatment easily damages the tenderness and nutrients of aquatic products; single spices have poor lasting effect in removing fishy odors; and the amount of phosphate-based water-retaining agents used is strictly limited, with excessive use affecting product flavor. Therefore, developing natural, safe, and compound additives that combine fishy odor removal and water retention functions has become a research hotspot in the industry.

[0004] Perilla, as a food and medicinal ingredient, has phenolic compounds in its extracts that possess excellent antioxidant properties, inhibiting lipid oxidation. Simultaneously, its volatile components can mask some fishy odors, and it has been used in research on deodorizing aquatic products. Cyclodextrin, due to its unique cavity structure, can encapsulate odor-causing substances; however, unmodified cyclodextrin exhibits poor encapsulation selectivity and insufficient water solubility. Current technology lacks a perilla-based composite water-retaining agent with a reasonable formulation, combined functions, and stable effects, failing to simultaneously meet the multiple requirements of deodorization, water retention, and color stabilization in aquatic product processing.

[0005] Therefore, developing a perilla-based composite water-retaining agent with perilla extract as its core, through component optimization and synergistic effects, to solve problems such as strong fishy smell and moisture loss in aquatic product processing, has significant practical significance and application value. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing deodorizing and water-retaining technologies in aquatic product processing, and to provide a perilla compound water-retaining agent and its application in deodorizing and water-retaining aquatic products. This perilla compound water-retaining agent has a scientific formula and multiple functions, which can effectively remove the fishy smell of aquatic products, improve water retention performance, and improve processing quality.

[0007] The technical solution adopted by the present invention to achieve the above objectives is as follows: A perilla compound water-retaining agent comprising perilla extract and 3,4-dimethoxy-3,5,7-trihydroxyflavone.

[0008] Preferably, the mass ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone to perilla extract is 1:2~5.

[0009] 3,4-Dimethoxy-3,5,7-Trihydroxyflavone can work with phenolic substances in perilla extract to enhance the antioxidant properties of the system, effectively inhibit lipid oxidation in aquatic products, reduce the formation of oxidized fishy odor substances such as nonenal, and also help reduce trimethylamine content. In addition, this component has excellent water-retention properties, can bind to aquatic muscle protein, protect muscle fiber structure, reduce water loss during processing and storage, and significantly improve the freeze-thaw water retention rate of aquatic products. When combined with other components, it can further optimize the processing quality and color stability of aquatic products.

[0010] Preferably, the perilla composite water-retaining agent includes composite cyclodextrin.

[0011] Preferably, the complex cyclodextrin includes glyceryl monocitrate.

[0012] Preferably, the mass ratio of the compound cyclodextrin to the perilla extract is 2:1~5.

[0013] Preferably, the mass ratio of glyceryl monocitrate to β-cyclodextrin is 1~3:20.

[0014] Combining glyceryl citrate with β-cyclodextrin optimizes the molecular structure of cyclodextrin, improving the poor inclusion selectivity and insufficient water solubility of uncombined cyclodextrin. This enhances the specific inclusion ability and efficiency of the compounded cyclodextrin for trimethylamine, nonenal, and other characteristic odor-causing substances in aquatic products. Simultaneously, the modified cyclodextrin exhibits improved water solubility, allowing for better binding with aquatic protein and reducing water loss. This enhances both deodorizing and water-retention properties. Furthermore, the addition ratio is controllable; appropriate formulation can achieve dual optimization of cyclodextrin's inclusion and water-retention functions, avoiding performance degradation due to over-modification.

[0015] Preferably, the perilla composite water-retaining agent includes deionized water.

[0016] Preferably, the mass-to-volume ratio of perilla extract to deionized water is 1g:10~50mL.

[0017] A method for preparing a perilla composite water-retaining agent, comprising: The dried perilla leaves were pulverized and sieved, then ethanol solution was added and refluxed for extraction. The extracts were combined, concentrated under reduced pressure, and then freeze-dried to obtain perilla extract. β-Cyclodextrin was dissolved in anhydrous ethanol, and then glyceryl monocitrate was added. The mixture was stirred and compounded, and then dried under vacuum after vacuum distillation to obtain the compound cyclodextrin. Perilla extract and compound cyclodextrin were dispersed in deionized water, and 3,4-dimethoxy-3,5,7-trihydroxyflavone was added. After stirring and dispersing, the mixture was ultrasonically treated and mixed evenly to obtain perilla compound water-retaining agent.

[0018] Preferably, the reflux extraction conditions include reflux extraction at 73~76℃ for 1~3 times, each time for 1~3 hours.

[0019] Preferably, the mixing and compounding conditions include mixing and compounding at 50~60℃ for 3~5 hours.

[0020] The application of perilla compound water-retaining agent in deodorizing and retaining water in aquatic products includes: The perilla compound water-retaining agent was diluted with deionized water to obtain a diluted water-retaining agent; Wash and cut the aquatic products, mix them with a diluted water-retaining agent, and soak them at a low temperature of 4-10℃ for 40-50 minutes.

[0021] Preferably, the mass-to-volume ratio of the perilla composite water-retaining agent to deionized water is 1g:1~10mL.

[0022] Preferably, the mass-to-volume ratio of aquatic products to diluted water-retaining agent is 2g:1~10mL.

[0023] Preferably, the aquatic products include marine fish.

[0024] Preferably, the marine fish includes ribbonfish.

[0025] More preferably, the perilla compound water-retaining agent includes carboxyethyl-γ-aminobutyric acid, and the mass ratio of carboxyethyl-γ-aminobutyric acid to perilla extract is 1:5~10.

[0026] Carboxyethyl-γ-aminobutyric acid (CABA) is a functional enhancing component of the perilla compound water-retaining agent. It can work together with other components to further inhibit microbial metabolism and lipid oxidation reactions during the processing and storage of aquatic products, reducing the generation of fishy-smelling substances from the source and making the deodorizing effect more lasting and stable. At the same time, this component can bind with the muscle protein of aquatic products to form a more stable hydrophilic system, enhancing the structural stability of the water-retaining hydrophilic system, further reducing water loss, and significantly improving the freezing and thawing water retention rate of aquatic products. Toxicity tests have verified that it has no toxic side effects and can further optimize the overall processing quality and storage stability of aquatic products.

[0027] This invention also provides a method for preparing and applying a perilla composite water-retaining agent. The preparation steps mainly include the preparation steps of perilla extract, the preparation steps of compound cyclodextrin, the preparation steps of the perilla composite water-retaining agent, and the preparation steps of processing marine fish, as detailed below: Step 1, the preparation of perilla extract, includes: Pulverize dried perilla leaves and pass them through a 30-50 mesh sieve to obtain perilla leaf powder. Add the perilla leaf powder to a 60-80% (v / v) ethanol solution and reflux extract at 73-76℃ for 1-3 times, 1-3 hours each time. Combine the extracts, concentrate under reduced pressure, and freeze-dry at -45 to -35℃ for 20-25 hours to obtain perilla extract.

[0028] Preferably, the mass-to-volume ratio of perilla leaf powder to 60-80% (v / v) ethanol solution is 1g:10-20mL.

[0029] Step two, the preparation of the complex cyclodextrin includes, β-Cyclodextrin was dissolved in anhydrous ethanol, and then citrate monoglyceride was added. The mixture was stirred at 50-60℃ for 3-5 hours to form a compound. After vacuum distillation, the compound was dried under vacuum at 55-65℃ for 7-9 hours to obtain the compound cyclodextrin.

[0030] Preferably, the mass ratio of β-cyclodextrin to anhydrous ethanol is 1 g: 2~10 mL.

[0031] Preferably, the mass ratio of glyceryl monocitrate to β-cyclodextrin is 1~3:20.

[0032] Step 3, the preparation of the perilla composite water-retaining agent includes, Perilla extract and compound cyclodextrin were dispersed in deionized water, and 3,4-dimethoxy-3,5,7-trihydroxyflavone was added. The mixture was stirred and dispersed for 20-40 minutes, and then sonicated for 10-20 minutes to obtain perilla compound water-retaining agent.

[0033] Preferably, the mass-to-volume ratio of perilla extract to deionized water is 1g:10~50mL.

[0034] Preferably, the mass ratio of the compound cyclodextrin to the perilla extract is 2:1~5.

[0035] Preferably, the mass ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone to perilla extract is 1:2~5.

[0036] Furthermore, the perilla compound water-retaining agent should be selected, which includes carboxyethyl-γ-aminobutyric acid.

[0037] More preferably, the mass ratio of carboxyethyl-γ-aminobutyric acid to perilla extract is 1:5~10.

[0038] Step four, the preparation of processed marine fish includes, Add perilla compound water-retaining agent to deionized water to obtain diluted water-retaining agent; clean fresh ribbonfish by removing the head and internal organs, cut into 3-10cm long fish segments, add diluted water-retaining agent, soak at 4-10℃ for 40-50 minutes, remove and drain the surface water, and refrigerate to obtain processed marine fish.

[0039] Preferably, the mass-to-volume ratio of the perilla composite water-retaining agent to deionized water is 1g:1~10mL.

[0040] Preferably, the mass-to-volume ratio of fish segments to diluted water-retaining agent is 2g:1~10mL.

[0041] The components of the perilla composite water-retaining agent of this invention work synergistically. The phenolic substances in the perilla extract can inhibit lipid and protein oxidation; the compound cyclodextrin can specifically encapsulate trimethylamine, nonenal, and other fishy-smelling substances; 3,4-dimethoxy-3,5,7-trihydroxyflavone can jointly enhance antioxidant and water-retaining properties; and carboxyethyl-γ-aminobutyric acid further inhibits microbial metabolism and lipid oxidation, while enhancing the stability of the water-retaining hydrophilic system. Aquatic products treated with the optimized process show a significant reduction in trimethylamine and nonenal content, a substantial increase in freeze-thaw water retention rate, and good color stability, resulting in optimized processing quality. Furthermore, the components used in the perilla composite water-retaining agent of this invention are natural or food-grade modified raw materials, verified as practically non-toxic through acute and subchronic toxicity tests. They have no adverse effects on liver and kidney function or blood lipid levels, exhibiting excellent biocompatibility. This invention solves the problems of poor effectiveness in deodorizing and water-retaining traditional aquatic product methods, limitations on the use of additives, and easy nutrient loss, and has significant practical significance and wide application value in the field of aquatic product processing. Attached Figure Description

[0042] Figure 1 This is a schematic diagram showing the results of trimethylamine content determination in processed marine fish.

[0043] Figure 2 This is a schematic diagram showing the results of nonenal content determination in processed marine fish.

[0044] Figure 3 This is a schematic diagram showing the water retention rate test results of the perilla composite water-retaining agent.

[0045] Figure 4 This is a schematic diagram showing the biosafety test results of the perilla composite water-retaining agent. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Example 1: This embodiment provides a method for preparing and applying a perilla composite water-retaining agent. The preparation steps mainly include the preparation steps of perilla extract, the preparation steps of compound cyclodextrin, the preparation steps of perilla composite water-retaining agent, and the preparation steps of processing marine fish, as detailed below.

[0049] Step 1: Preparation of Perilla Extract: Dried perilla leaves were pulverized and passed through a 40-mesh sieve to obtain perilla leaf powder. The perilla leaf powder was added to a 70% (v / v) ethanol solution and extracted twice by reflux at 75℃ for 2 hours each time. The extracts were combined, concentrated under reduced pressure, and then freeze-dried at -40℃ for 24 hours to obtain the perilla extract. The mass-to-volume ratio of perilla leaf powder to 70% (v / v) ethanol solution was 1 g: 12 mL.

[0050] Step 2: Preparation of the complex cyclodextrin: β-cyclodextrin was dissolved in anhydrous ethanol, and glyceryl citrate was added. The mixture was stirred and compounded at 55°C for 4 hours. After vacuum distillation, it was dried under vacuum at 60°C for 8 hours to obtain the complex cyclodextrin. The mass ratio of β-cyclodextrin to anhydrous ethanol was 1 g: 5 mL; the CAS number of glyceryl citrate was 36291-32-4, and the mass ratio of glyceryl citrate to β-cyclodextrin was 1:10.

[0051] Step 3: Preparation of Perilla Composite Water-Retaining Agent: Perilla extract and compound cyclodextrin were dispersed in deionized water, and 3,4-dimethoxy-3,5,7-trihydroxyflavone was added. The mixture was stirred and dispersed for 25 min, and then sonicated for 12 min to obtain the perilla composite water-retaining agent. The mass-to-volume ratio of perilla extract to deionized water was 1 g:25 mL, and the mass ratio of compound cyclodextrin to perilla extract was 2:3. The CAS number of 3,4-dimethoxy-3,5,7-trihydroxyflavone was 33429-83-3, and the mass ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone to perilla extract was 1:4.

[0052] Step 4: Preparation of processed marine fish: Add perilla compound water-retaining agent to deionized water to obtain a diluted water-retaining agent; clean fresh ribbonfish by removing the head and internal organs, cut into 5cm long segments, add the diluted water-retaining agent, soak at 8℃ for 45 minutes, remove and drain the surface water, and refrigerate to obtain processed marine fish. The mass-volume ratio of perilla compound water-retaining agent to deionized water is 1g:5mL, and the mass-volume ratio of fish segments to diluted water-retaining agent is 2g:5mL.

[0053] Example 2: This embodiment provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 1 is in the preparation of the composite cyclodextrin. In Example 2, the mass ratio of glyceryl citrate to β-cyclodextrin is adjusted from 1:10 in Example 1 to 3:20.

[0054] Example 3: This embodiment provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 2 is that in the preparation of the perilla composite water-retaining agent, the mass ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone to perilla extract in Example 3 is adjusted from 1:4 in Example 2 to 1.5:4.

[0055] Example 4: This embodiment provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 3 is that in the preparation of the perilla composite water-retaining agent, carboxyethyl-γ-aminobutyric acid (CAE) is added in Example 4. The CAS number of CAE is 4386-03-2, and the mass ratio of CAE to perilla extract is 1:8.

[0056] Comparative Example 1: This comparative example provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 1 is in the preparation of the composite cyclodextrin. In Example 2, the mass ratio of glyceryl citrate to β-cyclodextrin was adjusted from 1:10 in Example 1 to 1:5.

[0057] Comparative Example 2: This comparative example provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 1 is that in the preparation of the perilla composite water-retaining agent, the composite cyclodextrin in Example 2 is adjusted to cyclodextrin, and the mass ratio of cyclodextrin to perilla extract is 2:3.

[0058] Comparative Example 3: This comparative example provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 2 is that in the preparation of the perilla composite water-retaining agent, the 3,4-dimethoxy-3,5,7-trihydroxyflavone in Example 2 is replaced with quercetin, and the mass ratio of quercetin to perilla extract is 1:4.

[0059] Comparative Example 4: This comparative example provides a method for preparing and applying a perilla composite water-retaining agent. The only difference from Example 4 is that in the preparation of the perilla composite water-retaining agent, the carboxyethyl-γ-aminobutyric acid in Example 4 is adjusted to L-alanine, and the mass ratio of L-alanine to perilla extract is 1:8.

[0060] Experimental Example 1: Determination of trimethylamine and nonenal content in processed marine fish.

[0061] Test samples: Processed marine fish prepared in each embodiment and comparative example.

[0062] Test methods: Processed marine fish prepared in each example and comparative example, as well as untreated marine fish, were used as blank control group samples. The contents of trimethylamine and nonenal were determined by gas chromatography-mass spectrometry (GC-MS). Sample pretreatment: 5g of fish sample was taken, 10mL of anhydrous ethanol was added, homogenized and extracted for 15min, the supernatant was collected by centrifugation, filtered through a 0.45μm organic phase filter membrane, and then analyzed by GC-MS. GC conditions: HP-5MS column (30m×0.25mm×0.25μm), column temperature program: initial temperature 40℃, hold for 2 min, increase to 150℃ at 5℃ / min, then increase to 250℃ at 10℃ / min, hold for 5 min; injection port temperature 230℃, split ratio 10:1, carrier gas helium, flow rate 1 mL / min; MS conditions: ion source temperature 200℃, transfer line temperature 250℃, full scan mode, scan range 30~500 amu; the contents of trimethylamine and nonenal in the sample were calculated by external standard method.

[0063] The results of the trimethylamine content determination of processed marine fish are as follows: Figure 1 As shown, the results of the nonenal content determination in processed marine fish are as follows: Figure 2As shown; the perilla composite water-retaining agent prepared in Example 1 significantly reduced the content of trimethylamine and nonenal through the antioxidant effect of perilla extract and the encapsulation of fishy substances by composite cyclodextrin, with a reduction of more than 60% and 70% respectively compared with the blank control group; Example 2 adjusted the mass ratio of citrate monoglyceride to β-cyclodextrin to 3:20, optimized the structure of composite cyclodextrin, improved the encapsulation efficiency of fishy substances, and further reduced the content of fishy substances compared with Example 1; Example 3 increased the addition ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone, which, together with perilla extract, enhanced antioxidant properties, reduced nonenal produced by lipid oxidation, and also helped reduce trimethylamine, with its content continuing to decrease compared with Example 2; Example 4 added carboxyethyl-γ-aminobutyric acid, which, together with other components, further inhibited microbial metabolism and lipid oxidation, becoming the group with the lowest content of fishy substances among all samples. In Comparative Example 1, the mass ratio of glyceryl monocitrate to β-cyclodextrin was adjusted to 1:5. Excessive β-cyclodextrin resulted in a decrease in the inclusion capacity of the cyclodextrin, leading to a significantly higher content of fishy-smelling substances compared to other examples. Comparative Example 2 used non-complexed cyclodextrin, which had poor inclusion selectivity and insufficient water solubility, failing to effectively encapsulate fishy-smelling substances and significantly reducing its deodorizing effect. In Comparative Example 3, 3,4-dimethoxy-3,5,7-trihydroxyflavone was replaced with quercetin. The combined antioxidant effect of quercetin and perilla extract was weaker than the original components, resulting in a decreased lipid oxidation inhibition effect and increased nonenal and trimethylamine content. In Comparative Example 4, carboxyethyl-γ-aminobutyric acid was replaced with L-alanine. The combined inhibitory effect of L-alanine was weaker than the original components, and the fishy-smelling substance content was slightly higher than in Example 4.

[0064] Experimental Example 2: Water retention rate test of perilla composite water-retaining agent.

[0065] Test samples: Processed marine fish prepared in each embodiment and comparative example.

[0066] Test method: Processed marine fish prepared in each example and comparative example, as well as untreated marine fish, were used as blank control group samples. The initial mass m1 was weighed and then stored frozen at -18℃ for 72h. After thawing, the surface moisture was absorbed with filter paper and the thawed mass m2 was weighed. The freezing and thawing water retention rate (%) = (m2 / m1) × 100%.

[0067] The water retention rate test results of the perilla composite water-retaining agent are as follows: Figure 3As shown, Example 1 effectively protected the muscle fiber structure of aquatic products through the combined action of its components, significantly improving the water retention rate compared to the blank control group, demonstrating a remarkable water retention effect. Example 2 optimized the preparation ratio of the compound cyclodextrin, and its improved structure allowed it to better bind with aquatic product proteins, reducing water loss and slightly improving the water retention rate compared to Example 1. Example 3 increased the amount of 3,4-dimethoxy-3,5,7-trihydroxyflavone, which enhanced the combined water-retention effect of this component, further improving the water retention rate. Example 4 added carboxyethyl-γ-aminobutyric acid, which formed a more stable hydrophilic system after binding with proteins, achieving the highest water retention rate among all samples. In Comparative Example 1, excessive addition of glyceryl monocitrate led to over-modification of the cyclodextrin, resulting in decreased binding ability with proteins and a water retention rate significantly lower than in the examples. In Comparative Example 2, non-complexed cyclodextrin was used, which had poor water solubility and could not effectively bind with proteins, resulting in poor water retention and a water retention rate only slightly higher than the blank control group. In Comparative Example 3, quercetin was replaced with 3,4-dimethoxy-3,5,7-trihydroxyflavone, but the combined water retention effect of quercetin was insufficient, and the water retention rate was significantly lower than in Example 2. In Comparative Example 4, L-alanine was replaced with carboxyethyl-γ-aminobutyric acid, but the hydrophilic binding ability of L-alanine with proteins was weaker than that of the original component, and the water retention rate was slightly lower than in Example 4.

[0068] Experimental Example 3: Biosafety Test of Perilla Composite Water Retention Agent.

[0069] Test samples: Perilla composite water-retaining agents prepared in each example and comparative example.

[0070] Test method: Sixty healthy SPF-grade Kunming mice (half male and half female, weighing 18-22g) were randomly divided into 6 groups of 10 mice each, namely the Example 1-5 groups and the blank control group. The mice in the blank control group were administered physiological saline by gavage, while the mice in the Example 1-5 groups were administered the corresponding prepared perilla compound water-retaining agent diluted solution by gavage. The dosage for mice was converted to 100 times the maximum daily intake dose for humans. The water-retaining agent diluted solution was prepared with physiological saline. The mice were administered the solution by gavage once a day for 30 consecutive days. During the experiment, the general condition of the mice was observed, including their mental state, diet, water intake, activity, and mortality. After the experiment, the mice were weighed, and blood was collected by enucleation. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr), total cholesterol (TC), and triglycerides (TG) were measured using a fully automated biochemical analyzer to assess liver and kidney function and blood lipid levels. At the same time, an acute oral toxicity test was performed. Twenty healthy Kunming mice (half male and half female, weighing 18-22g) were selected and administered the maximum concentration diluted solution of the perilla compound water-retaining agent from Example 4 by gavage at a volume of 0.4mL / 10g body weight. The mice were observed for 7 consecutive days, and the poisoning and mortality were recorded.

[0071] The biosafety test results of the perilla compound water-retaining agent are as follows: Figure 4 As shown, no poisoning symptoms or deaths were observed in mice within 7 days after gavage. Their mental state, diet, and activity were all normal, indicating that the perilla compound water-retaining agent is practically non-toxic. Compared with the blank control group, the mice in groups 1-5 were in good general condition, with no abnormal symptoms or deaths. Their body weight gain trend was consistent, and there was no significant difference between groups. Serum ALT, AST, BUN, Cr, TC, and TG levels were all within the normal physiological range, and there were no significant differences between groups. Example 1, as the basic formulation of the perilla compound water-retaining agent, consists of natural or modified food-grade raw materials. Acute and subchronic toxicity tests verified that it had no toxic effects, no adverse effects on liver and kidney function or blood lipid levels in mice, and normal morphology of all organs and tissues, demonstrating good biocompatibility. Example 2 only adjusted the proportion of citric acid monoglyceride in the preparation of the compound cyclodextrin, without adding any new components. Its raw material safety was consistent with Example 1, and the test results showed no toxic reactions, meeting biocompatibility standards. Example 3 increased the addition ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone. This component is a natural flavonoid with no food safety risks. It did not produce toxicity when combined with other components, and all indicators in mice were normal. Example 4 added carboxyethyl-γ-aminobutyric acid (GABA), an amino acid derivative permitted for use in food. It was non-toxic when combined with the original components, becoming the most optimized formulation among all examples. Its biocompatibility still met the requirements for food processing additives, with no toxic side effects. Overall, the perilla composite water-retaining agents prepared in each embodiment of the present invention all possess excellent biocompatibility and can be safely applied in the field of aquatic product processing.

[0072] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0073] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A perilla composite water-retaining agent, characterized in that: The perilla composite water-retaining agent comprises perilla extract and 3,4-dimethoxy-3,5,7-trihydroxyflavone, wherein the mass ratio of 3,4-dimethoxy-3,5,7-trihydroxyflavone to perilla extract is 1:2~5.

2. The perilla composite water-retaining agent according to claim 1, characterized in that: The perilla complex water-retaining agent includes a complex cyclodextrin, which includes monoglyceride citrate, and the mass ratio of the complex cyclodextrin to the perilla extract is 2:1~5.

3. The perilla composite water-retaining agent according to claim 2, characterized in that: The mass ratio of the citrate monoglyceride to β-cyclodextrin is 1~3:

20.

4. The perilla composite water-retaining agent according to claim 1, characterized in that: The perilla composite water-retaining agent includes deionized water, and the mass-to-volume ratio of the perilla extract to the deionized water is 1g:10~50mL.

5. The preparation method of the perilla composite water-retaining agent according to claim 2 or 3, characterized in that: include, The dried perilla leaves were pulverized and sieved, then ethanol solution was added and refluxed for extraction. The extracts were combined, concentrated under reduced pressure, and then freeze-dried to obtain perilla extract. β-Cyclodextrin was dissolved in anhydrous ethanol, and then glyceryl monocitrate was added. The mixture was stirred and compounded, and then dried under vacuum after vacuum distillation to obtain the compound cyclodextrin. Perilla extract and compound cyclodextrin were dispersed in deionized water, and 3,4-dimethoxy-3,5,7-trihydroxyflavone was added. After stirring and dispersing, the mixture was ultrasonically treated and mixed evenly to obtain perilla compound water-retaining agent.

6. The preparation method according to claim 5, characterized in that: The reflux extraction conditions include reflux extraction at 73~76℃ for 1~3 times, each time for 1~3 hours.

7. The preparation method according to claim 6, characterized in that: The mixing and compounding conditions include mixing and compounding at 50~60℃ for 3~5 hours.

8. The application of the perilla compound water-retaining agent according to any one of claims 1-5 in deodorizing and retaining water in aquatic products, characterized in that: include, The perilla compound water-retaining agent was diluted with deionized water to obtain a diluted water-retaining agent; Wash and cut the aquatic products, mix them with a diluted water-retaining agent, and soak them at a low temperature of 4-10℃ for 40-50 minutes.

9. The application according to claim 8, characterized in that: The mass-to-volume ratio of the perilla composite water-retaining agent to deionized water is 1g:1~10mL, and the mass-to-volume ratio of the aquatic product to the diluted water-retaining agent is 2g:1~10mL.

10. The application according to claim 8, characterized in that: The aquatic products include marine fish, and the marine fish include ribbonfish.

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