Application of procyanidine in improving muscle quality of tilapia mossambica

Abstract

The invention relates to an application of procyanidine in improving the muscle quality of tilapia, belongs to the technical field of aquaculture, solves the technical problem that the muscle quality of tilapia is reduced, especially the muscle hardness is reduced, and also can correspondingly improve the health level of brittle tilapia in the culture process. Particularly, the oxidative stress of the tilapia under a high-density culture condition is relieved. According to the application of the procyanidine in improving the muscle quality of the tilapia mossambica, the procyanidine serves as an effective component of a feed additive, and the content of the procyanidine in the feed additive is 98% or above according to the mass percentage. The raw materials used in the feed additive widely exist in plants, artificial synthesis is not needed, and the feed additive is safe, free of toxic and side effects, free of pollution to the environment, stable in source supply and simple in production process.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and particularly relates to application of proanthocyanidins in improving tilapia muscle quality. Background Art

[0002] As an important freshwater aquaculture species and export aquatic product in my country, tilapia occupies a key position in the fishery economy due to its advantages such as rapid growth, high yield, strong adaptability, delicate meat and rich nutrition. However, with the development of intensive aquaculture scale, the high-density aquaculture environment has led to a significant decline in tilapia muscle quality, especially the problem of reduced muscle hardness, which has become increasingly prominent. Muscle quality and taste not only directly affect commercial value and consumer satisfaction, but also muscle hardness is a core indicator affecting fish processing molding rate, product texture and export competitiveness. Its deterioration not only reduces the taste of food, but also restricts the market value of deep-processed products such as fish fillets and fish steaks. Therefore, improving tilapia muscle quality has become a key breakthrough in improving the economic benefits of aquaculture and the sustainable development capacity of the industry.

[0003] The most widely used method for improving tilapia muscle quality is to feed them a brittle feed supplemented with broad beans, commonly known as brittle tilapia. However, broad beans contain varying proportions of anti-nutritional factors, such as phenolics, tannins, trypsin inhibitors, and phytic acid, which can negatively impact fish health. Furthermore, to circumvent the negative effects of broad beans, researchers have explored various approaches, such as adjusting the pH and salinity of the breeding environment, and adding small amounts of vitamins, lactic acid bacteria, mannan oligosaccharides, yeast polysaccharides, spirulina, citric acid, and others to the feed. However, these substances have various deficiencies, such as poor anti-stress effects, slow onset of action, and high costs.

[0004] Patent CN118216626A proposes a feed for reducing brittle damage in tilapia and improving muscle quality. Specifically, it is a compound feed of β-glucan and broad bean powder, which can improve the growth performance of tilapia, increase the hardness and elasticity of muscle tissue, reduce the lipid content in the liver and muscle, reduce the drip loss of muscle tissue, and improve the immune function of the fish. Patents CN101548728A and CN108371231A provide various herbal additives in tilapia feed for improving the disease resistance and muscle quality of tilapia. Patent CN118160829A proposes a feed additive and application for improving the hardness and health of brittle tilapia muscle. Specifically, it is a compound feed additive for tilapia made by mixing rutin, sodium butyrate and yeast powder as raw materials, which is used to alleviate oxidative stress in tilapia, increase the hardness of brittle tilapia muscle, and improve the health of brittle tilapia.

[0005] However, some of the relevant patents, such as patent CN118216626A, are for compound feeds containing multiple ingredients. These must be fed according to the formula to achieve the desired technical effect. This presents a significant challenge for farmers who employ different base feeds and feeding methods for different breeding environments and breeds, as well as for cost considerations. While some patents are feed additives, such as patents CN108371231A, CN101548728A, and CN118160829A, which can be used with different feeds, require several, or even dozens, of raw materials, leading to complex preparation processes.

[0006] Therefore, based on the requirement of improving the muscle quality of tilapia without affecting the healthy growth of tilapia, finding one or more simple, effective, low-cost feed additives that are convenient for farmers to feed on-site has become a technical problem that needs to be solved by technicians in this field. Summary of the Invention

[0007] In response to the above technical problems, the present invention provides an application of proanthocyanidins in improving the muscle quality of tilapia, which can at least solve the technical problem of decreased muscle quality of tilapia, especially decreased muscle hardness, and can also correspondingly improve the health level of brittle tilapia during the breeding process, especially alleviate the oxidative stress of tilapia under high-density breeding conditions.

[0008] The purpose of the present invention is mainly achieved through the following technical solutions: The present invention provides an application of proanthocyanidins in improving tilapia muscle quality. The proanthocyanidins are used as an effective ingredient in a feed additive. The proanthocyanidins content in the feed additive is above 98% based on mass percentage.

[0009] Furthermore, muscle quality parameters include hardness, chewiness and gelatinization.

[0010] Furthermore, the hardness is 1167 g or more, the chewiness is 189 g or more, and the adhesiveness is 378 g or more.

[0011] Furthermore, after the proanthocyanidins are passed through an 80-mesh sieve, the sieve-undersized material is directly used as an effective ingredient of a feed additive.

[0012] Furthermore, the feed additive and the bran are uniformly mixed to obtain a mixture, and the mixture is added to a basic feed for tilapia to feed the tilapia.

[0013] Furthermore, the content of proanthocyanidins in the mixture is 2-32% by mass, and the rest is bran.

[0014] Furthermore, the mixture is added to the basic feed of tilapia so that the proanthocyanidin content is 20-320 mg / kg of the basic feed.

[0015] Furthermore, the proanthocyanidin content is 80-160 mg / kg of basic feed.

[0016] Furthermore, the production and use of basic feed meet the requirements of the national standard "Aquatic Formula Feed Part 10: Tilapia Formula Feed" (GB / T 22919.10-2024).

[0017] Furthermore, the feeding amount is 2-3% of the fish body weight per day, and the fish are fed 2-3 times a day.

[0018] Compared with the prior art, the present invention can achieve at least one of the following technical effects: (1) The most common method for improving the muscle quality of tilapia is to feed it with a brittle feed containing broad beans, commonly known as brittle tilapia. Existing brittle tilapia is fed with brittle feed, which usually requires more than 60% broad beans to be added as the core raw material. Broad beans contain different proportions of anti-nutritional factors, such as phenolic substances, tannins, trypsin inhibitors and phytic acid, which leads to a serious compression of the ratio of protein source, fat source and other functional ingredients in the formula. There are inherent defects such as limited raw material selectivity and difficulty in adjusting nutritional balance, which will have a negative impact on the health of the fish. Different from the existing technology, the present invention can significantly improve the key quality indicators of tilapia muscle hardness, chewiness, and adhesiveness without relying on a high proportion of broad beans by adding proanthocyanidins to conventional basic feed, achieving a muscle texture effect equivalent to that of brittle feed.

[0019] (2) The feed additive of the present invention makes the muscle hardness of tilapia above 1167g, with a maximum of 1521g, the chewiness above 189g, with a maximum of 267g, and the adhesiveness above 378g, with a maximum of 600g, which can achieve an effect similar to that of brittle feed.

[0020] (3) When tilapia were fed with the feed additive of the present invention, their alanine aminotransferase and aspartate aminotransferase levels were the same as those of tilapia fed with conventional basal feed. The livers of tilapia were healthy, unlike brittle feed which significantly worsened liver stress damage.

[0021] (4) The proanthocyanidin content of the present invention is controlled to 20-320 mg / kg of basic feed to avoid affecting the survival rate of tilapia and the effect of improving muscle quality. When the proanthocyanidin content exceeds 320 mg / kg of basic feed, the survival rate of tilapia and the effect of improving muscle quality will decrease.

[0022] (5) The present invention can convert 2-32% of the raw materials into CyanineAfter being evenly mixed with bran, it is added to the basic feed of tilapia, which works synergistically to improve the muscle quality of tilapia. At the same time, bran can evenly disperse the proanthocyanidins into the feed, which is conducive to the uniform feeding of the tilapia group.

[0023] (6) The raw materials used in the feed additive of the present invention are widely present in plants, do not need to be artificially synthesized, are safe, have no toxic side effects, do not pollute the environment, and have a stable source of supply and a simple production process.

[0024] (7) When the feed additive of the present invention is added to ordinary feed, the cost increases by about RMB 100 / ton. However, the price of feed using broad beans is about RMB 1,500 / ton higher than that of ordinary feed. Therefore, the feed additive of the present invention is about RMB 1,400 / ton cheaper than the brittle feed using broad beans. This technology has significantly opened up new space for formula design. Farmers can flexibly adjust the proportion of raw materials such as soybean meal, fish meal, and grains according to cost fluctuations, or add auxiliary ingredients such as immune enhancers and attractants in a targeted manner. This can achieve the synergistic goals of optimizing nutritional ratios, regulating production costs, and expanding functionality while ensuring meat quality. DETAILED DESCRIPTION

[0025] The following is a further detailed description of the application of a proanthocyanidin in improving the muscle quality of tilapia in conjunction with specific examples. These examples are only for comparison and explanation purposes, and the present invention is not limited to these examples.

[0026] Proanthocyanidins are a general term for a large class of polyphenolic compounds found widely in plants. They are widely distributed and found in the skins, shells, seeds, cores, flowers, and leaves of many plants, such as grape seeds and pine bark. As a core regulatory tool in aquaculture, feed additives can optimize ingredients and improve fish quality without changing the basic feed formula. Therefore, feed additives can be flexibly combined with different basic feed formulas according to actual needs.

[0027] In view of the above technical status, after many experiments, an application of proanthocyanidins in improving the muscle quality of tilapia was proposed. Proanthocyanidins were used as the active ingredient of tilapia feed additives. According to the percentage by mass, the proanthocyanidin content in the feed additive was above 98%, and the rest were impurities.

[0028] The muscle quality parameters of tilapia include hardness, chewiness and adhesiveness. The feed additive of the present invention can make the muscle hardness of tilapia above 1167g, chewiness above 189g and adhesiveness above 378g.

[0029] The feed additive of the present invention contains only one proanthocyanidin effective ingredient, and the proanthocyanidin not only improves the muscle quality of tilapia, but also has the effects of enhancing liver function and promoting nutrient absorption. Therefore, the feed additive of the present invention is a simple, low-cost, and convenient feed additive for on-site feeding operation. It can not only improve the muscle hardness, chewiness, and adhesiveness of tilapia, but also improve the health level of existing brittle tilapia during breeding.

[0030] It should be noted that the health level of tilapia includes an evaluation of the fish's growth performance, antioxidant status, and immune function, i.e., the fish's physical health during the farming process; while the quality of the fish meat primarily refers to its edible texture, including hardness, chewiness, and stickiness. Existing brittle tilapia farming techniques improve muscle quality at the expense of the fish's health. The proanthocyanidins of this invention have the dual effects of maintaining tilapia health and improving muscle quality.

[0031] In the application of proanthocyanidins in improving tilapia muscle quality, the proanthocyanidins are passed through an 80-mesh sieve, and the undersize fraction is directly used as an active ingredient in a feed additive. The proanthocyanidin content in the feed additive is greater than 98% by mass.

[0032] Proanthocyanidins are monomers or oligomers with a degree of polymerization of 2-4, such as catechin, epicatechin, and dimers, trimers, and tetramers of catechin and / or epicatechin. Proanthocyanidins can be the most common proanthocyanidins found in various foods, or they can be relatively rare proanthocyanidins found in certain special plants.

[0033] Specifically, proanthocyanidins can be obtained from Shanghai Yuanye Biotechnology Co., Ltd., with product number S30598, BR grade, and purity of 95%.

[0034] It should be noted that in order to match the particle size of proanthocyanidins with that of feed, the proanthocyanidins need to be passed through an 80-mesh sieve and the sieve material used as a feed additive. At the same time, in order to ensure the actual effectiveness of the feed additive, the proanthocyanidin content in the feed additive is limited to above 98%.

[0035] The present invention mixes the feed additive and bran and adds the mixture to a basic feed for tilapia, thereby feeding the tilapia. The synergistic effect of the proanthocyanidins and the bran further enhances and improves the muscle quality of the tilapia.

[0036] The muscle quality referred to in the present invention refers to muscle hardness, chewiness, and adhesiveness. Muscle hardness, chewiness, and adhesiveness are important indicators for evaluating tilapia muscle quality. These qualities are closely related to crude protein, crude fat, hydroxyproline, moisture content, and other factors. Unlike the prior art, which focuses on the antioxidant, anti-inflammatory, and immune effects of proanthocyanidins, the present invention regulates the crude protein, crude fat, hydroxyproline (the main component of collagen), and moisture content in muscle by controlling the proanthocyanidin content in the bran mixture to 2-32%, thereby improving muscle quality.

[0037] During use, the mixture can be added to the tilapia base feed to achieve a proanthocyanidin content of 20-320 mg / kg of base feed. The proanthocyanidin content in the base feed should not be too high. When the proanthocyanidin content is high, such as reaching 400 mg / kg of base feed, its effect begins to decline. Preferably, the proanthocyanidin content is 80-160 mg / kg of base feed. Within this range, the hardness is greater than 1255.75 g, the chewiness is greater than 209 g, and the adhesiveness is greater than 421 g.

[0038] Specifically, the feed additive and bran are mixed and added to the basic feed of tilapia, comprising the following steps: Step S1, uniformly mixing proanthocyanidins and bran, wherein the proanthocyanidins content is 2-32% by mass and the rest is bran, such as 16% proanthocyanidins and 84% bran; Step S2, adding the mixture of step S1 to the tilapia basic feed so that the proanthocyanidin content is 20-320 mg / kg basic feed, such as the proanthocyanidin content is 40 mg / kg basic feed, 60 mg / kg basic feed, 80 mg / kg basic feed, 100 mg / kg basic feed, 120 mg / kg basic feed, 140 mg / kg basic feed, 160 mg / kg basic feed, 180 mg / kg basic feed, 200 mg / kg basic feed, 240 mg / kg basic feed, 260 mg / kg basic feed, 280 mg / kg basic feed, 300 mg / kg basic feed, preferably 80-160 mg / kg basic feed, and mixing and feeding the mixture to tilapia.

[0039] It should be noted that in step S1, by adjusting the content of bran, it is convenient to adjust the amount of proanthocyanidins added and control the ratio of the two. In addition, the bran can evenly disperse the proanthocyanidins into the feed, which is beneficial for the uniform feeding of the tilapia group.

[0040] In step S2, the production and use of the basic feed only need to meet the requirements of the national standard "Aquatic Formula Feed Part 10: Tilapia Formula Feed" (GB / T 22919.10-2024). Specifically, the raw materials of the basic feed include, by weight percentage, 20% soybean meal, 30% cassava starch, 30% rapeseed meal, 3.65% cottonseed meal, 5% fish meal, 4.5% soybean oil, 1% bentonite, 2% monocalcium phosphate, 1.6% methionine, 0.25% choline chloride, 1% vitamin premix, and 1% mineral premix. The vitamin premix provides 5000 IU of VA, 2000 IU of VD3, 60 mg of VE, 5 mg of VB1, 20 mg of VB2, 10 mg of VB6, 120 mg of VC, 5 mg of VK3, and 40 mg of niacin per kilogram of feed. 0mg of inositol, 120mg of niacin, 10mg of calcium pantothenate, 1mg of folic acid, and 0.1mg of biotin; the mineral premix provides 26000mg of Ca(H2PO4)2, 6540mg of Ca(CH3CHOHCOO)2, 42.5mg of FeSO4, 1340mg of MgSO4, 1744mg of NaH2PO4, 870mg of NaCl, 3mg of AlCl3, 2.5mg of KIO3, 1500mgKCl, 2mg of CuCl2, 16mg of MnSO4, 20mg of CoCl2, and 60mg of ZnSO4 per kilogram of feed.

[0041] Adjust the feed daily based on fish intake, aiming for 2-3% of their body weight, two to three times daily. Each feeding session lasts 30 minutes. Uneaten feed is recovered, dried at 65°C, and weighed. Continue feeding for 10 weeks, weighing the fish and adjusting the feed every two weeks.

[0042] It should be noted that adding 20-320mg of proanthocyanidins to 1kg of basal feed can effectively improve tilapia muscle hardness, chewiness, and adhesiveness, significantly enhancing the muscle texture characteristics of tilapia. This can achieve similar effects to brittle feed, without degrading tilapia health compared to regular feed. Compared to brittle feed, it can significantly improve tilapia health, especially liver stress damage. When the proanthocyanidin content exceeds 320mg / kg of basal feed, the survival rate of tilapia and the effect of improving muscle quality decrease.

[0043] The present invention adds feed additives to ordinary feed, which increases the cost by about 100 yuan / ton, while the feed using broad beans is about 1,500 yuan / ton more expensive than ordinary feed, so the present invention is about 1,400 yuan / ton cheaper than the feed using broad beans.

[0044] Example 1

[0045] The breeding experiment was carried out in pond cages with a size of 2m×1m×1m. The cultured species was Gift Tilapia with an initial average body weight of 763.33±10.41g. There were 10 fish in each cage, and a total of 30 fish in 3 cages.

[0046] 20 mg of proanthocyanidins was added to 1 kg of basic feed for feeding.

[0047] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0048] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1: 20 mg of proanthocyanidins and 980 mg of bran were uniformly mixed according to the mass percentage; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed so that the proanthocyanidin content is 20 mg / kg basic feed, mixing well and feeding the mixture to tilapia.

[0049] Specifically, feed 2-3 times a day, and the daily feeding amount is 2%-3% of the fish body weight. The raw materials of the basic feed are calculated according to the percentage by mass, including: 20% soybean meal, 30% cassava starch, 30% rapeseed meal, 3.65% cottonseed meal, 5% fish meal, 4.5% soybean oil, 1% bentonite, 2% monocalcium phosphate, 1.6% methionine, 0.25% choline chloride, 1% vitamin premix, and 1% mineral premix. The vitamin premix provides 5000IU of VA, 2000IU of VD3, 60mg of VE, 5mg of VB1, 20mg of VB2, 10mg of VB6, 120mg of VC, 5mg of VK3, 400mg of inositol, and 120mg of mineral premix per kilogram of feed. niacin, 10mg calcium pantothenate, 1mg folic acid, 0.1mg biotin; mineral premix provides 26000mg Ca(H2PO4)2, 6540mg Ca(CH3CHOHCOO)2, 42.5mg FeSO4, 1340mg MgSO4, 1744mg NaH2PO4, 870mg NaCl, 3mg AlCl3, 2.5mg KIO3, 1500mgKCl, 2mg CuCl2, 16mg MnSO4, 20mg CoCl2, and 60mg ZnSO4 per kilogram of feed.

[0050] During the breeding experiment, the water temperature was 26℃-33℃, dissolved oxygen >5.0mg / L, pH was 7.4-7.6, total ammonia nitrogen <0.2mg / L, natural light was used, and the breeding cycle was 70 days.

[0051] After the breeding experiment, relevant performance tests were carried out. The performance tests included growth performance, serum biochemical indicators, basic nutritional components, and muscle texture. The test parameters were first collected from each cage sample and the average was taken. Then the performance test parameters of the three cages were averaged. All data results were expressed as mean ± standard deviation, i.e. (Mean ± SD, n = 3).

[0052] Among them, growth performance includes weight gain rate (WGR), specific growth rate (SGR), feed conversion rate (FCR), survival rate (SR), fatness (CF), liver-to-somatous ratio (HSI) and visceral-to-somatous ratio (VSI). The test results are shown in Table 1: Weight gain rate (WGR,%) = (W t -W0)×100 / W0; Specific growth rate (SGR,% / d) = (lnW t -lnW0)×100 / t Feed coefficient (FCR) = F / (W t -W0) Survival rate (SR,%) = N t ×100 / N0 Fullness (CF, g / cm 3 ) = W × 100 / L 3 Liver-to-body ratio (HSI,%) = W h ×100 / W Visceral-to-body ratio (VSI,%) = W v ×100 / W Among them, N t is the final digit, N0 is the initial digit; W t is the final body weight, in g / g; W0 is the initial body weight, in g / g; W is the body weight of the fish, in g / g; t is the culture time, in day / d; F is the total feed intake, in g / g; W h is the liver mass, in grams / g; W v is the visceral mass, in grams / g; L is the body length, in centimeters / cm.

[0053] Serum biochemical indicators including serum glucose (GLU), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and total cholesterol (T-CHO) were measured using an automatic biochemical analyzer. The test results are shown in Table 2.

[0054] Basic nutritional components include moisture, crude protein, crude fat, ash, and hydroxyproline. Moisture was determined using the direct drying method (GB 5009.3-2016); crude protein was determined using the Kjeldahl method (GB 5009.5-2016); crude fat was determined using the Soxhlet extraction method (GB 5009.6-2016); and ash was determined using the 550°C muffle furnace ignition method (GB 5009.4-2016). Muscle hydroxyproline content was determined using a hydroxyproline (Hyp) assay kit produced by the Nanjing Jiancheng Bioengineering Research Institute. The test results are shown in Table 3.

[0055] Muscle texture, including hardness, elasticity, viscosity, chewiness, cohesion, adhesiveness, adhesion, and resilience, was measured using a TVT300XP texture analyzer. Muscles from the upper back of the fish, near the dorsal fin, were cut into 1.0 cm × 1.0 cm × 1.0 cm pieces. TPA testing was performed at room temperature using five replicate muscle samples from each fish. The test results are shown in Table 4.

[0056] Example 2

[0057] The difference between this embodiment and Example 1 is that 40 mg of proanthocyanidins were added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0058] 40 mg of proanthocyanidins was added to 1 kg of basic feed for feeding.

[0059] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0060] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1: Calculate the percentage by mass by uniformly mixing 40 mg of proanthocyanidins and 960 mg of bran; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 40 mg / kg basic feed, mixing well and feeding the mixture to tilapia.

[0061] Example 3

[0062] The difference between this embodiment and Example 1 is that 80 mg of proanthocyanidins were added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0063] 80 mg of proanthocyanidins were added to 1 kg of basic feed for feeding.

[0064] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0065] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1, based on the mass percentage, 80 mg of proanthocyanidins and 920 mg of bran were uniformly mixed; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 80 mg / kg basic feed, mixing well and feeding the mixture to tilapia.

[0066] Example 4

[0067] The difference between this embodiment and Example 1 is that 160 mg of proanthocyanidins was added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0068] 160 mg of proanthocyanidins was added to 1 kg of basic feed for feeding.

[0069] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0070] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1: Calculate the percentage by mass by uniformly mixing 160 mg of proanthocyanidins and 840 mg of bran; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 160 mg / kg basic feed, mixing well and feeding the mixture to tilapia.

[0071] Example 5

[0072] The difference between this embodiment and Example 1 is that 240 mg of proanthocyanidins were added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0073] A tilapia feed additive, wherein the active ingredient of the feed additive is proanthocyanidins. Calculated by weight percentage, the proanthocyanidins content in the feed additive is 98%, and the remainder is impurities.

[0074] A method for preparing the feed additive includes passing proanthocyanidins through an 80-mesh sieve and using the undersize directly as a feed additive. The proanthocyanidins are from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0075] 240 mg of proanthocyanidins were added to 1 kg of basic feed for feeding.

[0076] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0077] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1: 240 mg of proanthocyanidins and 760 mg of bran were uniformly mixed according to the mass percentage; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 240 mg / kg basic feed, and then mixing and feeding the mixture to tilapia.

[0078] Example 6

[0079] The difference between this embodiment and Example 1 is that 320 mg of proanthocyanidins were added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0080] 320 mg of proanthocyanidins were added to 1 kg of basic feed for feeding.

[0081] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0082] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1: 320 mg of proanthocyanidins and 680 mg of bran were uniformly mixed according to the mass percentage; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 320 mg / kg basic feed, mixing and feeding the mixture to tilapia.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that only the basic feed was used for feeding. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutrient composition test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0085] Comparative Example 2

[0086] This comparative example differs from Example 1 in that a brittle feed was used for feeding; the remaining initial average body weight, breeding, feeding, and performance testing were identical to those in Example 1. The brittle feed, calculated by mass percentage, included: 20% soybean meal, 60% broad beans, 2.05% cottonseed meal, 5% fish meal, 4.5% soybean oil, 1% bentonite, 2% monocalcium phosphate, 3.2% methionine, 0.25% choline chloride, 1% vitamin premix, and 1% mineral premix, wherein the vitamin premix and mineral premix were the same as in Example 1. Growth performance test results are shown in Table 1, serum biochemical index test results are shown in Table 2, basic nutrient composition test results are shown in Table 3, and muscle texture test results are shown in Table 4.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 1 is that 400 mg of proanthocyanidins was added to 1 kg of basic feed. The rest of the initial average body weight, basic feed, breeding, feeding, and performance tests were exactly the same as in Example 1. The growth performance test results are shown in Table 1, the serum biochemical index test results are shown in Table 2, the basic nutritional component test results are shown in Table 3, and the muscle texture test results are shown in Table 4.

[0089] 400 mg of proanthocyanidins were added to 1 kg of basic feed for feeding.

[0090] First, the proanthocyanidins are passed through an 80-mesh sieve, and the remaining material is used directly as the active ingredient in the feed additive. Calculated by weight, the proanthocyanidin content in the feed additive is over 98%. The proanthocyanidins are sourced from Shanghai Yuanye Biotechnology Co., Ltd., product number S30598, BR grade, and 95% purity.

[0091] Secondly, the feed additive and bran are mixed and added to the basic feed of tilapia for feeding tilapia. The specific steps include: Step S1, based on the mass percentage, 400 mg of proanthocyanidins and 600 mg of bran were uniformly mixed; Step S2: adding the mixture of step S1 to each kilogram of tilapia basic feed to make the proanthocyanidin content 400 mg / kg basic feed, mixing well and feeding the mixture to tilapia.

[0092] Table 1 Growth performance test results of comparative examples and examples ; Table 2 Comparative Examples and Examples Serum Biochemical Index Test Results ; Table 3 Test results of basic nutritional components of muscle in comparative examples and examples ; Table 4 Comparative Examples and Examples Muscle Texture Test Results ; As can be seen from Table 1, in general, the survival rate of Comparative Example 1 using only the basic feed was higher; the specific growth rate and weight gain rate of Comparative Example 2 using the brittle feed were higher, but its survival rate was lower; the survival rates of Examples 1-6 using the basic feed supplemented with 20-320 mg / kg were between those of Comparative Example 1 and Comparative Example 2, among which the survival rates of Examples 2-4 were relatively high, and the survival rate of Example 4 was comparable to that of Comparative Example 1; the survival rate of Comparative Example 3 using the basic feed supplemented with 400 mg / kg was lower, comparable to that of Comparative Example 2. This indicates that in terms of growth performance, especially survival rate, an appropriate amount of proanthocyanidin feed additive has a smaller effect on tilapia, while brittle feed or feed additives containing higher amounts of proanthocyanidins have a greater effect on tilapia.

[0093] As can be seen from Table 2, compared with Examples 1-6, Comparative Examples 1 and 3, the levels of alanine aminotransferase and aspartate aminotransferase in Comparative Example 2 using the brittle feed were higher, and the increase in aspartate aminotransferase and alanine aminotransferase is an important indicator for evaluating liver stress damage, which fully demonstrates that brittle feed can significantly aggravate liver stress damage. It also shows that the proanthocyanidin feed additive of the present invention does not affect the health level of tilapia liver. However, when the proanthocyanidin content is high, such as reaching 400 mg / kg basal feed, its effect begins to decline, that is, the effect of Comparative Example 3 is not obvious compared with Comparative Example 1.

[0094] As shown in Table 3, compared with Examples 1-6, as well as Comparative Examples 2 and 3, Comparative Example 1, which used only the basal feed, had lower crude protein and hydroxyproline contents and higher crude fat content. Hydroxyproline is the main component of collagen, and low fat and high protein are important indicators for evaluating the nutritional content of muscle. This shows that the proanthocyanidin feed additive of the present invention can improve the nutritional content of tilapia muscle, just like the embrittled feed. However, when the proanthocyanidin content is high, such as reaching 400 mg / kg of basal feed, its effect begins to decline, that is, Comparative Example 3 does not have an advantage over Example 6.

[0095] As can be seen from Table 4, compared with Examples 1-6, as well as Comparative Examples 2 and 3, Comparative Example 1, which used only the basal feed, had significantly lower muscle hardness, chewiness, and adhesiveness. Examples 1-6 had a hardness of 1167 g or more, with a maximum of 1521 g; chewiness of 189 g or more, with a maximum of 267 g; and adhesiveness of 378 g or more, with a maximum of 600 g. This indicates that the feed additive of the present invention can significantly improve the muscle texture properties of tilapia compared to the basal feed, and is comparable to that of the brittle feed. However, when the proanthocyanidin content is high, such as 400 mg / kg basal feed, the effect begins to decline, meaning that Comparative Example 3 does not have an advantage over Example 6.

[0096] In summary, adding 20-320mg of proanthocyanidins to 1kg of basal feed can effectively improve tilapia muscle hardness, chewiness, and adhesiveness, significantly enhancing the muscle texture of tilapia. This can achieve similar effects to those of brittle feed, while not degrading the health of tilapia compared to ordinary feed. Compared to brittle feed, it can significantly improve the health of tilapia, especially liver stress damage.

[0097] The above description is only a preferred specific 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 thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. An application of proanthocyanidins in improving tilapia muscle quality, characterized in that: Proanthocyanidins are used as an effective ingredient of the feed additive, and the content of proanthocyanidins in the feed additive is above 98% based on the mass percentage.

2. The application according to claim 1, characterized in that The muscle quality parameters include hardness, chewiness and gelatinization.

3. The application according to claim 2, characterized in that: The hardness is greater than 1167 g, the chewiness is greater than 189 g, and the adhesiveness is greater than 378 g.

4. The application according to claim 1, characterized in that After the proanthocyanidins are passed through an 80-mesh sieve, the undersize material is directly used as the active ingredient of the feed additive.

5. The application according to claim 4, characterized in that: The feed additive and bran are uniformly mixed to obtain a mixture, and the mixture is added to a basic feed for tilapia to feed the tilapia.

6. The application according to claim 5, characterized in that Calculated by mass percentage, the content of proanthocyanidins in the mixture is 2-32%, and the rest is bran.

7. The use according to claim 5, characterized in that The mixed material is added to the basic feed of tilapia to make the proanthocyanidin content be 20-320 mg / kg of the basic feed.

8. The application according to claim 7, characterized in that: The proanthocyanidin content is 80-160 mg / kg of basic feed.

9. The use according to claim 5, characterized in that: The production and use of the basic feed meet the requirements of the national standard "Aquatic Formula Feed Part 10: Tilapia Formula Feed" (GB / T 22919.10-2024).

10. The use according to claim 5, characterized in that: The feeding is a daily feeding amount of 2-3% of the fish body weight, and is fed 2-3 times a day.