Application of ginseng leaf polysaccharide in relieving fish quality decline caused by hypoxia in water body

Abstract

The invention discloses application of ginseng leaf polysaccharide in relieving fish quality decline caused by water hypoxia, and belongs to the technical field of aquatic product culture. The ginseng leaf polysaccharide is applied to relieving fish quality decline caused by water hypoxia for the first time, and by adding the ginseng leaf polysaccharide, the problems of fish muscle oxidative damage, poor texture property, low nutritional value and the like caused by hypoxia stress can be effectively improved; the invention provides a new relieving technology for improving fish quality decline caused by hypoxia in culture, provides technical support for improving fish quality of cultured fishes under intensive culture conditions, improves freshwater fish culture benefits, and solves the problem of lack of a safe and reliable method for relieving fish quality decline caused by hypoxia in a water body at present.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, specifically to the application of ginseng leaf polysaccharide in alleviating the decline in fish meat quality caused by low oxygen levels in water. Background Technology

[0002] With the development of intensive aquaculture, low dissolved oxygen in water is a common environmental stress faced by farmed fish. Studies have found that low dissolved oxygen levels reduce the water content, crude protein, crude fat content, and muscle crude protein content of Nile tilapia, leading to a decrease in nutritional value. Simultaneously, hypoxia stress increases the content of reactive oxygen species in the fish, which causes oxidative damage to the muscle, increasing cooking losses, lowering pH and flavor, and reducing the economic value of the fish product. Therefore, how to alleviate the decline in fish meat quality caused by hypoxia stress has attracted much attention. Currently, under normal aquaculture conditions, the meat quality of farmed fish can be improved by adding antioxidants to the feed, and environmental stress can be alleviated by adding antioxidants, sodium chloride, anesthetics, and fasting to the water. However, there is almost no research on how to alleviate the decline in fish meat quality caused by hypoxia stress, and related technologies are lacking.

[0003] Ginseng leaf polysaccharides are a type of polysaccharide extracted from ginseng stems and leaves, mainly composed of pectin and heteropolysaccharides. The pectin in ginseng leaf polysaccharides has a similar composition to that in ginseng root polysaccharides, being rich in type I rhamnaldehyde and homogalacturonic acid. Therefore, ginseng leaf polysaccharides may have similar functions to ginseng root polysaccharides, such as antioxidant activity and promotion of energy metabolism. However, ginseng root polysaccharides have high extraction costs and a long harvesting period (4-6 years), while ginseng leaf polysaccharides have lower extraction costs and a shorter harvesting period (harvesting can be done annually). Therefore, although ginseng leaf polysaccharides have a slightly lower polysaccharide content, they may be more suitable for application in aquaculture.

[0004] Currently, applications of other polysaccharides have shown that adding Astragalus polysaccharides to feed can increase the crude protein and crude fat content of crucian carp, as well as improve the textural properties such as muscle hardness, adhesion, cohesion, and elasticity. Adding Glycyrrhiza polysaccharides to feed can increase the brightness of broiler breast and leg muscles and improve their water-holding capacity. Adding Morinda officinalis polysaccharides to feed can enhance the antioxidant capacity of broiler breast muscles under oxidative stress, thereby improving the water-holding capacity and hardness of the breast muscles and improving muscle quality under oxidative stress. Based on the antioxidant function of ginseng leaf polysaccharide components, adding ginseng leaf polysaccharides to feed holds promise for improving oxidative damage to fish muscles and decreased meat quality caused by hypoxia stress, but this has not yet been applied. Developing related technologies could provide a safe and reliable method to alleviate the decline in fish meat quality caused by hypoxia in water. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide the application of ginseng leaf polysaccharide in alleviating the decline in fish meat quality caused by low oxygen in water, so as to solve the problem of the lack of safe and reliable methods for alleviating the decline in fish meat quality caused by low oxygen in water.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides the application of ginseng leaf polysaccharide in alleviating the decline in fish meat quality caused by low oxygen levels in water.

[0007] The beneficial effects of this invention are as follows: This invention is the first to apply ginseng leaf polysaccharide to alleviate the decline in fish meat quality caused by low oxygen in water. By adding ginseng leaf polysaccharide, it can effectively improve the problems of oxidative damage to fish muscle, deterioration of texture properties and low nutritional value caused by low oxygen stress. It provides a new technology to alleviate the decline in fish meat quality caused by low oxygen in aquaculture, provides technical support for improving the meat quality of farmed fish under intensive aquaculture conditions, and improves the efficiency of freshwater fish farming.

[0008] Furthermore, the decline in fish quality caused by low oxygen levels in the water includes oxidative damage to fish muscle, deterioration of texture properties, and reduction in nutritional value.

[0009] Furthermore, the reduced nutritional value includes a decrease in the crude protein content of fish muscle.

[0010] In a second aspect, the present invention provides the application of the above-mentioned ginseng leaf polysaccharide in the preparation of functional feeds or drugs that alleviate the decline in fish meat quality caused by low oxygen levels in water.

[0011] The beneficial effects of this invention are as follows: the ginseng leaf polysaccharide used in this invention can be directly added to commercially available fish feed, which is simple and convenient to use and has no toxic side effects.

[0012] A third aspect of the present invention provides a functional feed for alleviating the decline in fish meat quality caused by low oxygen levels in water, comprising the aforementioned ginseng leaf polysaccharide.

[0013] Furthermore, functional feeds are prepared by mixing ginseng leaf polysaccharides into fish feed. Furthermore, the amount of ginseng leaf polysaccharide added to functional feed is 100-500 mg / kg.

[0014] Furthermore, the amount of ginseng leaf polysaccharide added to functional feed is 200-400 mg / kg.

[0015] Furthermore, the amount of ginseng leaf polysaccharide added to the functional feed is 300 mg / kg.

[0016] The beneficial effects of adopting the above-mentioned further technical solution are as follows: By applying ginseng leaf polysaccharide to fish feed and optimizing the application dosage of ginseng leaf polysaccharide, the present invention obtains a safe and reliable functional feed that alleviates the decline in fish meat quality caused by low oxygen in water.

[0017] The present invention has the following beneficial effects: 1. This invention applies ginseng leaf polysaccharide to alleviate the decline in fish meat quality caused by hypoxia in aquatic environments. Experiments have shown that, on the one hand, ginseng leaf polysaccharide alleviates the decrease in crude protein content in grass carp muscle caused by hypoxia stress, thus improving the nutritional quality of fish meat under hypoxia stress. On the other hand, ginseng leaf polysaccharide enhances the antioxidant capacity of grass carp muscle under hypoxia stress, reduces oxidative damage to muscle caused by hypoxia stress, alleviates the increase in calcium ions in muscle caused by hypoxia stress, reduces the hydrolysis of grass carp myofibrils caused by hypoxia stress, slows the rate of pH decrease and water-holding capacity decline in grass carp muscle caused by hypoxia stress, increases muscle hardness, elasticity, cohesion, and chewiness, and improves the textural properties of fish meat under hypoxia stress.

[0018] 2. The application of ginseng leaf polysaccharide in this invention is simple and convenient, with no side effects. It can effectively improve the oxidative damage to fish muscle caused by hypoxia stress, as well as the deterioration of texture and reduced nutritional value. It provides a new mitigation technology for improving the decline in fish meat quality caused by hypoxia in aquaculture. Attached Figure Description

[0019] Figure 1 The effect of ginseng leaf polysaccharide on the gene expression levels of glycoprotein M6Bb and proteoglycan 4-like protein in grass carp muscle after hypoxia stress; Figure 2 The effect of ginseng leaf polysaccharide on the expression levels of myosin, fibronectin and integrin genes in grass carp muscle after hypoxia stress; Figure 3 The effect of ginseng leaf polysaccharide on the expression levels of desmin, troponin T and focal adhesion protein in grass carp muscle after hypoxia stress; Figure 4 The effects of ginseng leaf polysaccharide on the activity or gene expression level of enzymes related to protein hydrolysis in grass carp muscle after hypoxia stress were investigated. Among them, A represents calpain activity, and B represents the mRNA levels of cathepsin B, L and calpain. Figure 5 The effect of ginseng leaf polysaccharide on calcium in grass carp muscle after hypoxia stress 2+ The effect of content; Figure 6 Ginseng leaf polysaccharide on the effect of calcium in grass carp muscle after hypoxia stress 2+ -The effect of ATPase activity and RyR1 gene expression level, where A is Ca 2+ -ATPase activity, B is the RyR1 gene; Figure 7 The study investigated the effects of ginseng leaf polysaccharide on oxidative damage and antioxidant capacity in grass carp muscle under hypoxic stress. The components included: A (reactive oxygen species), B (malondialdehyde), C (protein carbonyl group), D (catalase), E (copper-zinc superoxide dismutase), and F (glutathione peroxidase). Detailed Implementation

[0020] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0021] Example 1: Effects of ginseng leaf polysaccharides on the nutritional composition of grass carp muscle under hypoxia stress I. Experimental Methods Five hundred and forty healthy grass carp weighing 679 ± 1.29 g were randomly divided into six treatment groups, with three replicates per group and thirty fish per replicate. Each group was fed a diet containing different levels of ginseng leaf polysaccharide (0, 100, 200, 300, 400, and 500 mg / kg). The experiment lasted for 60 days. Feeding was conducted at 7:00, 11:00, 15:00, and 19:00 daily until full. Feed intake was observed 20 minutes later, and uneaten feed was accurately recorded. Water was regularly changed and disinfected, and water temperature, pH, and dissolved oxygen were maintained at 27 ± 2℃, 7.5 ± 0.5, and ≥ 6.0 mg / L, respectively.

[0022] After 60 days of feeding, 24 fish were randomly selected from each treatment to undergo a 96-hour hypoxia stress experiment. Each treatment was divided into two groups of 12 fish each: a normoxic control group (dissolved oxygen ≥ 6 mg / L) and a hypoxia stress group (1 ± 0.5 mg / L). During the hypoxia stress experiment, dissolved oxygen levels were controlled by intermittent oxygen supply using an air compressor, and dissolved oxygen levels were measured using a YSI electronic dissolved oxygen meter. No water was changed and no fish were fed during the experiment.

[0023] After the hypoxia stress test, the patient was anesthetized and euthanized. The muscle tissue was then rapidly dissected and separated to quantify the nutritional composition of the muscle.

[0024] II. Test Results The experimental results of the effects of ginseng leaf polysaccharide on the nutritional composition of grass carp muscle under hypoxia stress are shown in Table 1.

[0025] Table 1. Effects of ginseng leaf polysaccharides on the nutritional composition of grass carp muscle under hypoxia stress.

[0026] In the table, C: normoxic control group, H: hypoxia stress group; different lowercase letters in the table indicate significant differences within the same row. P <0.05), * indicates a significant difference between the normoxic control group and the hypoxic stress group at the same dietary ginseng leaf polysaccharide level. P <0.05, t-test).

[0027] Table 1 shows that hypoxia stress increased the moisture content of grass carp muscle and decreased the crude protein and crude fat content, with reductions of 6.1% and 18.6%, respectively. Specifically, when the addition amount of ginseng leaf polysaccharide was 100 mg / kg, it increased the crude protein content of grass carp muscle after hypoxia stress by 1.9%. The results indicate that adding ginseng leaf polysaccharide to the feed can alleviate the decrease in crude protein content of muscle caused by hypoxia stress and improve the reduction in muscle nutritional value caused by hypoxia stress.

[0028] Example 2: Effects of ginseng leaf polysaccharide on the textural properties and cooking loss of grass carp muscle under hypoxia stress I. Experimental Methods The textural properties and cooking loss of the isolated muscle tissues from each experimental group in Example 1 were characterized.

[0029] II. Test Results The experimental results of the effects of ginseng leaf polysaccharide on the textural properties and cooking loss of grass carp muscle after hypoxia stress are shown in Table 2.

[0030] Table 2. Effects of ginseng leaf polysaccharides on the textural properties and cooking loss of grass carp muscle under hypoxia stress.

[0031] In the table, C: normoxic control group, H: hypoxia stress group; different lowercase letters in the table indicate significant differences within the same row. P <0.05), * indicates a significant difference between the normoxic control group and the hypoxic stress group at the same dietary ginseng leaf polysaccharide level. P <0.05, t-test).

[0032] Table 2 shows that hypoxia stress increased the cooking loss of grass carp muscle by 4.7%–25.8% and decreased muscle firmness and chewiness (reductions of 2.6%–15.2% and 2.8%–17.7%, respectively). Adding ginseng leaf polysaccharide to the feed reduced the cooking loss of grass carp muscle under hypoxia stress (maximum reduction of 33.6%) and improved muscle firmness and chewiness (maximum increases of 54.5% and 120.1%, respectively). The results indicate that adding ginseng leaf polysaccharide to the feed can improve the textural properties of muscle after hypoxia stress, with an optimal addition level of 300 mg / kg.

[0033] Example 3: Effects of ginseng leaf polysaccharide on gene and protein expression of myofibrillar and structural proteins in grass carp muscle after hypoxia stress I. Experimental Methods The gene expression levels of muscle glycoprotein M6Bb, proteoglycan 4-like protein, myosin, fibronectin, and integrin, as well as the protein expression levels of desmin, cardiactroponin T, and focal adhesion (FAK) in grass carp treated in each experimental group of Example 1 were characterized.

[0034] II. Test Results The test results are as follows Figures 1-3 As shown.

[0035] from Figure 1 It was found that hypoxia stress reduced the expression of glycoprotein M6Bb and proteoglycan 4-like protein genes in grass carp muscle. Adding 200-400 mg / kg of ginseng leaf polysaccharide to the feed significantly increased the expression of glycoprotein M6Bb and proteoglycan 4-like protein genes in grass carp muscle after hypoxia stress.

[0036] from Figure 2 It was found that hypoxia stress reduced the expression of myosin, fibronectin, and integrin genes in grass carp muscle. Adding 200-400 mg / kg of ginseng leaf polysaccharide to the feed significantly increased the expression of myosin, fibronectin, and integrin genes in grass carp muscle after hypoxia stress.

[0037] from Figure 3 It is known that hypoxia stress reduces the expression of desmin protein in grass carp muscle. Adding 200-400 mg / kg of ginseng leaf polysaccharide to the feed can significantly increase the expression of desmin and adhesion plaque protein in grass carp muscle after hypoxia stress.

[0038] The above results indicate that adding ginseng leaf polysaccharide to the feed can increase the expression of myofibril proteins and structural proteins in muscles after hypoxia stress, which is beneficial to maintaining the integrity of muscle structure and function.

[0039] Example 4: Effects of ginseng leaf polysaccharide on the activity or gene expression of enzymes related to protein hydrolysis and calcium homeostasis in grass carp muscle after hypoxia stress I. Experimental Methods The activity of calpain in the muscle of grass carp treated in each experimental group of Example 1, the gene expression of cathepsins B and L, the calcium ion content in the muscle, and the Ca2+ content were investigated. 2+ -ATPase activity and RyR1 gene expression were characterized.

[0040] II. Test Results The test results are as follows Figures 4-6 As shown.

[0041] from Figure 4 It was found that hypoxia stress increased the activity of calpain and the gene expression of cathepsins B and L in grass carp muscle, while decreasing the expression of the calpain D gene. Adding 200-400 mg / kg of ginseng leaf polysaccharide to the feed could reduce the activity of calpain and the gene expression of cathepsins B and L in grass carp muscle after hypoxia stress, and increase the expression of the calpain D gene.

[0042] from Figure 5 It is known that hypoxia stress increases the calcium ion content in grass carp muscle. Adding 200-500 mg / kg of ginseng leaf polysaccharide to the feed can reduce the calcium ion content in grass carp muscle after hypoxia stress.

[0043] from Figure 6 It was found that hypoxia stress reduced the activity of Ca2+-ATPase in grass carp muscle and increased the expression of the ryneline receptor type 1 (RyR1) gene. Adding 200-300 mg / kg of ginseng leaf polysaccharide to the feed could increase the activity of Ca2+-ATPase in grass carp muscle and decrease the expression of the RyR1 gene after hypoxia stress.

[0044] The above results indicate that adding ginseng leaf polysaccharide to the feed can improve muscle calcium ion homeostasis and inhibit muscle protein hydrolysis after hypoxia stress.

[0045] Example 5: Effects of ginseng leaf polysaccharide on oxidative damage and antioxidant capacity of grass carp muscle after hypoxia stress I. Experimental Methods The activities of reactive oxygen species (ROS), malondialdehyde (MDA), protein carbonyl group (PC), catalase (CAT), copper zinc superoxide dismutase (CuZnSOD) and glutathione peroxidase (GPx) in grass carp muscle treated in each experimental group of Example 1 were characterized.

[0046] II. Test Results The test results are as follows Figure 7 As shown.

[0047] from Figure 7 It was found that hypoxia stress increased the content of ROS, MDA, and PC in grass carp muscle, while decreasing the activities of CAT, CuZnSOD, and GPx. However, adding 200-400 mg / kg of ginseng leaf polysaccharide to the feed reduced the content of ROS, MDA, and PC in grass carp muscle after hypoxia stress, and increased the activities of CAT, CuZnSOD, and GPx. These results indicate that adding ginseng leaf polysaccharide to the feed can improve the antioxidant capacity of grass carp muscle after hypoxia stress and reduce oxidative damage.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Application of ginseng leaf polysaccharide in alleviating the decline in fish meat quality caused by low oxygen levels in water.

2. The application of ginseng leaf polysaccharide according to claim 1 in alleviating the decline in fish meat quality caused by low oxygen levels in water, characterized in that, The decline in fish quality caused by low oxygen levels in the water includes oxidative damage to fish muscle, deterioration of texture properties, and reduction in nutritional value.

3. The application of ginseng leaf polysaccharide according to claim 2 in alleviating the decline in fish meat quality caused by low oxygen levels in water, characterized in that, The reduction in nutritional value includes a decrease in the crude protein content of fish muscle.

4. The use of ginseng leaf polysaccharide according to any one of claims 1-3 in the preparation of functional feeds or drugs that alleviate the decline in fish meat quality caused by low oxygen in water.

5. A functional feed for alleviating the decline in fish meat quality caused by low oxygen levels in water, characterized in that, Includes the ginseng leaf polysaccharide as described in any one of claims 1-3.

6. The functional feed for alleviating fish meat quality decline caused by low oxygen levels in water, as described in claim 5, is characterized in that... The functional feed is prepared by mixing ginseng leaf polysaccharide into fish feed.

7. The functional feed for alleviating fish meat quality decline caused by low oxygen levels in water, as described in claim 5, is characterized in that... The amount of ginseng leaf polysaccharide added to the functional feed is 100-500 mg / kg.

8. The functional feed for alleviating fish meat quality decline caused by low oxygen levels in water, as described in claim 7, is characterized in that... The amount of ginseng leaf polysaccharide added to the functional feed is 300 mg / kg.

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