A method for improving the quality and flavor of fish meat of leiocassis longirostris, a composition and application thereof

Abstract

The present application relates to a method for improving the quality and flavor of fish meat, composition and application thereof, in particular, L-carnitine and glycyrrhizic acid are compounded as functional additives, artificial compound feed is fed, and micro-flow water culture is adopted, and the feeding is carried out once every other day. Compared with the existing methods for improving fish meat quality such as 'hanging water' and'slimming', the present application has obvious fat reduction effect, significantly improves the muscle texture characteristics of longsnout catfish, adjusts the proportion of nutritional components such as coarse fat, crude protein, crude ash, moisture, total amino acid and free amino acid in the back muscle of longsnout catfish, improves the sugar and lipid metabolism level of longsnout catfish, significantly reduces the body weight consumption, improves the disease resistance of longsnout catfish, and improves the economic benefit.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture technology, specifically relating to a method, composition, and application for improving the meat quality and flavor of longsnout catfish. Background Technology

[0002] The long-snout catfish (Leiocassis longer ostris), belonging to the Bagridae family and the Leiocarigenus, is a bottom-dwelling fish, commonly known as "Jiangtuan." It is primarily farmed in ponds and cages. The long-snout catfish has tender, delicious flesh, is rich in nutrients, and has thick swim bladders. After being "slimmed down," the long-snout catfish has an excellent flavor, showing no significant difference from wild individuals, greatly expanding its consumer market. However, the "slimming down" process, due to prolonged fasting, leads to a significant decrease in body weight and reduced disease resistance, making it more susceptible to disease and increasing the risk of antibiotic residues.

[0003] Recent studies have shown that intermittent fasting can promote fat loss and health improvement. Its mechanisms of action include altering energy metabolism patterns, inducing autophagy, regulating gut microbiota, and changing circadian rhythms. For example, a strict four-week intermittent fast can reduce the body weight of healthy middle-aged individuals by 4.5% while reducing body fat, improving the fat-to-muscle ratio, lowering cardiovascular disease biomarker levels, and increasing serum β-hydroxybutyrate levels. L-carnitine and glycyrrhizic acid are healthy, environmentally friendly immune and metabolic enhancers that help improve fat metabolism, promote the entry of fatty acids into mitochondria for oxidation and decomposition, and enhance the body's immunity. Therefore, screening healthy drugs based on the "slimming" mechanism of fish and combining this with high-quality aquaculture models to develop "slimming" fish farming, improving fish meat quality and flavor, and addressing the needs of "slimming," "health," and "efficiency" will be an important future direction. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a method, composition, and application for improving the quality and flavor of longsnout catfish meat. It can simultaneously meet the needs of "weight loss", "health" and "efficiency", significantly improve the texture and flavor of longsnout catfish meat, improve the glucose and lipid metabolism level of longsnout catfish, achieve excellent fat reduction effect, improve economic benefits, and enhance the immunity of longsnout catfish.

[0005] This invention provides the application of L-carnitine and / or glycyrrhizic acid in aquaculture.

[0006] Furthermore, the application aims to improve the meat quality of the long-snout catfish.

[0007] Furthermore, the ratio of L-carnitine to glycyrrhizic acid is 0.9-1.1:1, preferably 0.95-1.05:1, and more preferably 0.97-1.03:1.

[0008] The present invention also provides a product that can improve the quality of longsnout catfish meat, the product comprising L-carnitine and / or glycyrrhizic acid, wherein the ratio of the two is 0.9-1.1:1, preferably 0.95-1.05:1, and more preferably 0.97-1.03:1.

[0009] Furthermore, the product is feed or feed additive.

[0010] Furthermore, the dosage of L-carnitine is 331mg-340mg / kg feed, and the dosage of glycyrrhizic acid is 330mg-340mg / kg feed.

[0011] This invention also provides the application of any of the above products in aquaculture.

[0012] The present invention also provides the application of any of the above products in improving the quality of longsnout catfish meat.

[0013] This invention also provides a method for improving the quality of longsnout catfish meat.

[0014] S1. Weigh L-carnitine, glycyrrhizic acid, and long-snout catfish feed accurately according to the proportions, mix and stir, and then dry.

[0015] S2. Feed once every other day for more than 30 days.

[0016] Further, the proportions mentioned in step S1 are: L-carnitine: 331mg-340mg / kg feed, glycyrrhizic acid: 330mg-340mg / kg feed, and the feeding amount in step S2 is calculated as 1.5-3% of the fish's body weight, preferably 2.1%.

[0017] The present invention has at least the following beneficial effects:

[0018] The composition and method described in this invention significantly improve the textural properties (chewability, crispness) and flavor (fishy substances) of longsnout catfish; regulate the ratio of nutrients such as crude fat, crude protein, crude ash, moisture, and free amino acids in longsnout catfish meat; improve the glucose and lipid metabolism level of longsnout catfish, minimize the impact of fasting on weight, achieve excellent fat reduction effect, and improve economic benefits; enhance the liver and intestinal health of longsnout catfish, maintain intestinal homeostasis, and improve immunity. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The changes in morphological indicators such as body weight, condition factor, and abdominal fat of long-snout catfish were measured after 30 days of rearing using the method of this invention. Here, weight refers to the change in body weight, and RF refers to condition factor (body weight / body length). 3 Fat weight refers to abdominal fat.

[0021] Figure 2 The changes in the nutritional composition (moisture, crude protein, crude fat, ash, total amino acids, and free amino acids) of long-snout catfish muscle were studied after 30 days of culture using the method of this invention.

[0022] Figure 3 The changes in glucose and lipid metabolism in the muscle of long-snout catfish were investigated after 30 days of culture using the method of this invention.

[0023] Figure 4 Pathological sections of the intestinal tissue of long-snout catfish cultured for 30 days using the method of this invention. Detailed Implementation

[0024] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are therefore merely examples and should not be used to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art. Unless specifically stated, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in this technical field. Unless specifically stated, the reagents and materials used in the following embodiments are commercially available.

[0025] Example 1

[0026] In this embodiment, L-carnitine was purchased from Anhui Cool Biotechnology Co., Ltd. L-carnitine, also known as carnitine, is a biologically active amino acid with a low molecular weight (162 g / mol). Carnitine exists in three isomers: L-, D-, and racemic (D-, L-, and racemic). Only L-carnitine can exert biological functions in the body, so the term "carnitine" generally refers to L-carnitine. L-carnitine is derived from the essential amino acids lysine and methionine. Lysine serves as both a carbon and nitrogen source donor, while methionine is a methyl donor. It also requires the participation of niacin, folic acid, vitamin B6, vitamin C, and related enzymes.

[0027] Glycyrrhizic acid was purchased from Norton Laboratory Supplies Mall. It is also known as glycyrrhizin or glycyrrhizin. The finished product is a white powder that is difficult to dissolve in cold water. Its solubility increases with increasing temperature. After dissolving, its aqueous solution is a pale white, slightly viscous, foamy substance with an aromatic odor.

[0028] The commercial feed for long-snout catfish was purchased from Yueyang Zhanxiang Biotechnology Co., Ltd. The raw materials are rich in high-quality fish meal, yeast powder, soybean meal, refined fish meat, multivitamins, starch, minerals, and various amino acids.

[0029] The micro-flow aquaculture base was selected from Xiaodongyan Ecological Aquaculture Base in Changyang Tujia Autonomous County, Yichang City, Hubei Province.

[0030] 1. A method for preparing a functional additive to improve the meat quality and flavor of catfish.

[0031] Step 1: Purchase commercially available standard L-carnitine and glycyrrhizic acid; purchase commercially available standard long-snout catfish feed.

[0032] Step 2: Weigh L-carnitine, glycyrrhizic acid, and long-snout catfish feed according to the following ratio: L-carnitine: 331mg-340mg / kg feed, glycyrrhizic acid: 330mg-340mg / kg feed. After dissolving the drugs, spray them evenly onto the feed, mix and stir, and then dry them to make functional feed.

[0033] 2. Feeding longsnout catfish with functional feed to improve meat quality and flavor

[0034] Step 1: Select Xiaodongyan Ecological Aquaculture Base in Changyang Tujia Autonomous County, Yichang City, Hubei Province. The micro-flowing water is clear, pure, and highly mobile, rich in minerals and dissolved oxygen.

[0035] Step Two: 330 healthy, muddy-smelling, and thick-swimmed long-snout catfish were raised in a spring-water breeding base and divided into three groups of 110 fish each. The groups were: a fasting group (no feeding for 30 days, F), a group fed with ordinary commercial feed every other evening (one feeding and one fasting for 30 days, ADF), and a group fed with functional feed every other evening (ADF+M). The fish were also stimulated daily with a slight flow of water.

[0036] Step 3: For the ADF group and ADF+M group, feed at 2.1% of the fish's body weight, control the breeding cycle at 30 days, observe the fish's feeding behavior regularly, and record the survival rate.

[0037] 3. Observation of growth, survival rate, body color, and abdominal fat of the long-snout catfish; determination of muscle texture and volatile substances.

[0038] After the breeding experiment, three long-snout catfish were randomly selected from each group. Their body color and morphology were observed, and their weight was measured and recorded. The weight loss rate for each group was calculated, and the survival rate of each group was recorded throughout the breeding process. Results are as follows: Figure 1 As shown in Table 1. Three fish were randomly collected from each group, and dorsal muscle was harvested. The textural properties of the muscle in each group were determined using a texture analyzer. A 2×2×2cm fish piece was placed on the sample stage, with the fish bones parallel to the stage. Fish meat TPA mode: A 36R cylindrical probe was used to test the samples. Test mode: Two compression tests were performed. The initial velocity was 5 mm / sec, the test velocity was 1 mm / sec, and the subsequent velocity was 5 mm / sec. The compression ratio was 50%, the residence time was 5 s, and the trigger force was 5 g. The results are shown in Table 1.

[0039] Table 1. Muscle texture characteristics of *Cetacea longsnout*

[0040]

[0041] Note: In the table, *, **, and *** represent p<0.05, p<0.01, and p<0.001 respectively compared to 0d.

[0042] 4. Nutritional composition of long-snout catfish muscle (moisture, crude protein, crude fat, crude ash, total amino acids, free amino acids)

[0043] After the aquaculture experiment, three longsnout catfish were randomly selected from each group, and their back muscles were harvested for analysis of moisture (MC), crude protein (CPP), crude fat (CF), ash (AC), total amino acids (TAA), and free amino acids (FAA). All measurements were performed strictly according to national standard methods. Results are as follows: Figure 2 As shown.

[0044] 5. Measurement of glucose and lipid metabolism and liver and intestinal function in *Syngonium longsnoutii* (long-snout catfish)

[0045] After the aquaculture experiment, three long-snout catfish were randomly selected from each group, and corresponding samples were collected. The activities of plasma triglycerides (TG), total cholesterol (T-CHO), blood glucose, low-density lipoprotein (LDL), high-density lipoprotein (HDL), total protein (TP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were measured using a kit (Nanjing Jiancheng Bioengineering Institute). The results are as follows: Figure 3 As shown in the figure. Histopathological sections were prepared from the intestines of each group of long-snout catfish, and the results are as follows. Figure 4 As shown.

[0046] The results show that:

[0047] Compared to day 0, the fatness of all groups decreased significantly, with the ADF+M group showing the lowest relative weight loss rate, effectively alleviating excessive weight loss during the slimming process and improving economic efficiency. Regarding muscle texture, the elasticity, cohesion, and chewiness of the ADF+M, ADF, and F groups showed an upward trend after 28 days, indicating that slimming improved the texture and flavor of the long-snout catfish. The ADF+M group showed the best effect in increasing muscle cohesion and resilience. Nutritional analysis results showed that the 28-day slimming process reduced crude fat in the long-snout catfish muscle and increased total amino acids overall, indicating improved nutritional composition. The ADF+M group showed a significant reduction in crude fat, increased umami flavor, and decreased bitter amino acids, indicating a more delicious muscle texture. Glycolipid metabolism data showed that the 28-day slimming process reduced the glycolipid metabolism level of the long-snout catfish, indirectly reflecting that the fish had lost weight and achieved a fat reduction effect. The ADF+M group showed a significant decrease in blood glucose, triglycerides, and total cholesterol levels, demonstrating a significant improvement in the body's glycolipid metabolism, which is beneficial to the fish's health. In addition, compared with day 0, the ALT and LDH activity levels of ADF+M, ADF, and F decreased, with ADF+M showing a significant decrease. Pathological examination of the foregut tissue revealed that the intestinal villus structure remained intact. This indicates that the functional additives provided by this invention can significantly improve the hepatointestinal health of the long-snout catfish and enhance its immunity.

[0048] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for improving the meat quality of longsnout catfish, improving its glucose and lipid metabolism, and improving its liver and intestinal health, characterized in that, S1. Accurately weigh L-carnitine, glycyrrhizic acid and long-snout catfish feed according to the following ratio, mix and stir, and then dry. The ratio is: L-carnitine: 331mg-340mg / kg feed, glycyrrhizic acid: 330mg-340mg / kg feed. S2. Feed once every other day, with the amount of feed calculated as 1.5-3% of the fish's body weight, and raise for more than 30 days; The fish meat quality includes: fish meat texture characteristics and nutritional components; the improvement of fish meat texture characteristics is manifested in: improved fish meat firmness, elasticity, cohesion and chewiness; the improvement of nutritional components is manifested in: decreased muscle crude fat, increased total amino acid content and decreased bitter amino acid content; The improvement in glucose and lipid metabolism in long-snout catfish includes: a decrease in blood glucose, triglyceride, and total cholesterol levels, and a decrease in body weight, body fat percentage, and abdominal fat content; The improvement in the hepatointestinal health of the long-snout catfish is manifested in the following ways: reduced activity of alanine aminotransferase and lactate dehydrogenase, intact intestinal villi structure, and improved immunity.

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