Application of procyanidins in improving muscle quality of tilapia

Abstract

The application relates to application of procyanidine in improving muscle quality of tilapia, and belongs to the technical field of aquaculture, and solves the technical problem of the decrease of muscle quality of tilapia, especially the decrease of muscle hardness, and can also improve the health level of the brittle tilapia in the breeding process, especially relieve the oxidative stress of the tilapia under the condition of high-density breeding. The application of the procyanidine in improving the muscle quality of the tilapia takes the procyanidine as an effective component of a feed additive, and the content of the procyanidine in the feed additive is more than 98% in terms of mass percentage. The raw material of the feed additive is widely present in plants, does not need to be artificially synthesized, is safe and has no toxic side effect, does not pollute the environment, and is stably supplied in source and has a simple production process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aquaculture, and particularly relates to application of procyanidins in improving muscle quality of tilapia. BACKGROUND

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

[0003] The most widely used method to improve the muscle quality of tilapia is to feed with crisp feed added with beans, commonly known as crisp tilapia. However, beans contain different proportions of anti-nutritional factors such as phenolic substances, tannins, trypsin inhibitors and phytic acid, which have a negative impact on fish health. Further, in order to avoid the negative impact of beans, researchers have made various explorations, such as the pH value and salinity of the breeding environment, adding a small amount of vitamins, lactic acid bacteria, mannose oligosaccharides, yeast polysaccharides, spirulina, citric acid, etc. in the feed, but these substances have some or other shortcomings in different aspects and to different degrees, such as poor stress resistance, slow action, high price, etc.

[0004] Patent CN118216626A proposes a feed for reducing the crisp damage of tilapia and improving muscle quality, specifically a beta-glucan and bean powder compound feed, which can improve the growth performance of tilapia, improve 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 body; patents CN101548728A, CN108371231A, etc. provide various Chinese herbal medicine additives in tilapia feed for improving the disease resistance and muscle quality of tilapia; patent CN118160829A proposes a feed additive for improving the muscle hardness and health level of crisp tilapia and application, specifically a composite feed additive for tilapia prepared by mixing rutin, sodium butyrate and yeast powder as raw materials, which is used to relieve oxidative stress of tilapia, improve the hardness of muscle of crisp tilapia, and improve the health level of crisp tilapia.

[0005] However, some related patents are compound feeds containing multiple components, such as patent CN118216626A, etc., which must be fed according to the formula feed to achieve the desired technical effect, which poses a considerable challenge to the selection of different breeding environments, different breeds, and different basic feeds and feeding methods based on cost considerations. Some are feed additives, such as patents CN108371231A, CN101548728A, and CN118160829A, which can be used with different feeds, but the additives themselves require several, even dozens of raw materials to be used together, and the preparation process is complex.

[0006] Therefore, based on the requirement to improve the muscle quality of tilapia, while not affecting the healthy growth of tilapia, it is necessary to find one or more simple, effective, low-cost, and convenient for on-site feeding operations of the feed additive, which is a technical problem that needs to be solved by the technical personnel in this field. SUMMARY

[0007] To solve the above technical problems, the present application provides the use of procyanidins in improving the muscle quality of tilapia, which can at least solve the problem of decreased muscle quality of tilapia, especially reduced muscle hardness, and also improve the health level of brittle tilapia during breeding, especially alleviate the oxidative stress of tilapia under high-density breeding conditions.

[0008] The purpose of the present application is mainly realized by the following technical solutions:

[0009] The present application provides the use of procyanidins in improving the muscle quality of tilapia, which uses procyanidins as an effective component of a feed additive, and the content of procyanidins in the feed additive is more than 98% by mass percentage.

[0010] Further, the muscle quality parameters include hardness, chewiness, and gumminess.

[0011] Further, the hardness is more than 1167g, the chewiness is more than 189g, and the gumminess is more than 378g.

[0012] Further, the procyanidins are sieved through an 80-mesh sieve, and the undersize material is directly used as an effective component of a feed additive.

[0013] Further, the feed additive and bran are uniformly mixed to obtain a mixture, and the mixture is added to the basic feed of tilapia for feeding tilapia.

[0014] Further, the content of procyanidins in the mixture is 2-32% by mass percentage, and the rest is bran.

[0015] Further, the mixture is added to the tilapia basic feed, so that the procyanidin content is 20-320 mg / kg of the basic feed.

[0016] Further, the procyanidin content is 80-160 mg / kg of the basic feed.

[0017] Further, the production and use of the basic feed meet the requirements of the national standard "Aquatic Compound Feed Part 10: Tilapia Compound Feed" (GB / T 22919.10-2024).

[0018] Further, the feeding is 2-3% of the fish body weight per day, and the feeding is 2-3 times a day.

[0019] Compared with the prior art, the present application can at least achieve one of the following technical effects:

[0020] (1) For improving the muscle quality of tilapia, the most widely used is to feed with crisp feed added with chickpea, commonly known as crisp tilapia. The existing crisp tilapia is fed with crisp feed, which usually needs to add more than 60% chickpea as the core raw material. Chickpea contains different proportions of anti-nutritional factors such as phenolic substances, tannins, trypsin inhibitors and phytic acid, etc., which causes the proportion of protein source, fat source and other functional ingredients in the formula to be severely compressed, and there are inherent defects such as limited raw material selection and difficulty in nutritional balance adjustment, which has a negative impact on the health of fish. Unlike the prior art, the present application can significantly improve the muscle hardness, chewability, gumming and other key quality indicators of tilapia without relying on high proportion of chickpea, and achieve muscle texture effect comparable to crisp feed.

[0021] (2) The feed additive of the present application can make the muscle hardness of tilapia reach 1167g or more, and the highest is 1521g, the chewability is 189g or more, and the highest is 267g, and the gumming is 378g or more, and the highest is 600g, which can achieve the effect similar to crisp feed.

[0022] (3) The use of the feed additive of the present application to feed tilapia has no difference in the levels of glutathione and glutathione transaminase from tilapia fed with conventional basic feed, and the liver of tilapia is healthy, unlike crisp feed which can significantly worsen liver stress damage.

[0023] (4) The procyanidin content of the present application is controlled to be 20-320 mg / kg of the basic feed, which avoids the influence of the survival rate and the effect of improving the muscle quality of tilapia. When the procyanidin content exceeds 320 mg / kg of the basic feed, the survival rate and the effect of improving the muscle quality of tilapia will decrease.

[0024] (5) The present application can add 2-32% of procyanidin by mass percentage to the basic feed, which can improve the muscle quality of tilapia without relying on high proportion of chickpea.cyanine When the proanthocyanidins and bran are evenly mixed and added to the tilapia base feed, they work synergistically to improve the muscle quality of tilapia. At the same time, the bran can evenly disperse the proanthocyanidins into the feed, which is beneficial for the tilapia to feed evenly in a group.

[0025] (6) The raw materials used in the feed additive of the present invention are widely found in plants, do not require artificial synthesis, are safe and have no toxic side effects, do not pollute the environment, have a stable supply, and have a simple production process.

[0026] (7) The feed additive of the present invention increases the cost of ordinary feed by about RMB 100 / ton, while feed using broad beans is about RMB 1500 / ton more expensive than ordinary feed. Therefore, the present invention is about RMB 1400 / ton cheaper than crispy feed using broad beans. This technology breaks through the limitations of formula design, allowing farmers to flexibly adjust the proportion of raw materials such as soybean meal, fish meal, and grains according to cost fluctuations, or add targeted auxiliary ingredients such as immune enhancers and palatability enhancers, so as to achieve the synergistic goals of optimizing nutritional ratios, controlling production costs, and expanding functionality while ensuring meat quality. Detailed Implementation

[0027] The following detailed description, in conjunction with specific embodiments, illustrates the application of a proanthocyanidin in improving the muscle quality of tilapia. These embodiments are for comparative and illustrative purposes only, and the present invention is not limited to these embodiments.

[0028] Proanthocyanidins are a general term for a large class of polyphenolic compounds widely found in plants. They are widely distributed and present in the bark, shell, seeds, kernels, flowers, and leaves of many plants, such as grape seeds and pine bark. Feed additives, as a core regulatory tool in aquaculture, can optimize the composition and improve fish quality without altering the basic feed formula. Therefore, feed additives can be flexibly combined with different basic feed formulas according to actual needs.

[0029] In view of the above-mentioned current technology, after multiple experiments, an application of proanthocyanidins in improving the muscle quality of tilapia was proposed. Proanthocyanidins were used as the effective ingredient in tilapia feed additives. The proanthocyanidin content in the feed additives was above 98% by mass percentage, with the remainder being impurities.

[0030] The muscle quality parameters of tilapia include hardness, chewiness, and adhesiveness. Using the feed additive of this invention can make the muscle hardness of tilapia above 1167g, the chewiness above 189g, and the adhesiveness above 378g.

[0031] The feed additive of the present application only contains one procyanidin effective component, and the procyanidin has the effects of improving the muscle quality of the tilapia, enhancing the liver function and promoting the nutrient absorption, so the feed additive of the present application is a simple, low-cost and convenient on-site feeding operation feed additive, which can not only improve the muscle hardness, chewability and gumming of the tilapia, but also improve the health level of the existing brittle tilapia during feeding.

[0032] It should be noted that the health level of the tilapia includes the evaluation of the growth performance, antioxidant state and immune function of the tilapia, that is, the physical health of the tilapia during the breeding process; and the quality of the fish meat mainly refers to the eating taste of the fish meat, including hardness, chewability and gumming. The existing breeding technology of the brittle tilapia is to improve the muscle quality on the premise of damaging the health level of the tilapia, and the procyanidin of the present application has the dual effects of maintaining the health level of the tilapia and improving the muscle quality.

[0033] In the application of the procyanidin in improving the muscle quality of the tilapia, the procyanidin is sieved through an 80-mesh sieve, and the undersize material is directly used as the effective component of the feed additive. The content of the procyanidin in the feed additive is more than 98% according to the mass percentage.

[0034] The procyanidin is a monomer or an oligomer with a degree of polymerization of 2-4, such as catechin, epicatechin, and dimers, trimers and tetramers formed by catechin and / or epicatechin. The procyanidin can be the most common procyanidin in various foods, or the relatively rare procyanidin existing in some special plants.

[0035] Specifically, the procyanidin can be from Shanghai Yuanye Biotechnology Co., Ltd., with a product number of S30598, a BR grade and a purity of 95%.

[0036] It should be noted that in order to match the particle size of the procyanidin with the particle size of the feed, the procyanidin needs to be sieved through an 80-mesh sieve, and the undersize material is used as the feed additive, and in order to ensure the actual effect of the feed additive, the content of the procyanidin in the feed additive is limited to more than 98%.

[0037] The above-mentioned feed additive and bran are mixed and added to the basic feed of the tilapia for feeding the tilapia. The synergistic effect of the procyanidin and the bran further improves the muscle quality of the tilapia.

[0038] The muscle quality referred to in the present application is muscle hardness, chewiness and gumminess. Muscle hardness, chewiness and gumminess are important indicators for evaluating the muscle quality of tilapia. These qualities are closely related to crude protein, crude fat, hydroxyproline, moisture content and the like. Unlike the effects of proanthocyanidins in the prior art in terms of antioxidant, anti-inflammatory and immune and the like, the present application can realize the regulation of the crude protein, crude fat, hydroxyproline (main component of collagen) and moisture content in the muscle by controlling the proanthocyanidin content in the proanthocyanidin and bran mixture to 2-32%, so as to improve the muscle quality.

[0039] When in use, the mixture can be added to the tilapia basic feed, so that the proanthocyanidin content is 20-320 mg / kg of the basic feed. The content of proanthocyanidin in the basic feed should not be too high, and when the proanthocyanidin content is high, such as reaching 400 mg / kg of the basic feed, its effect begins to decline. Preferably, the proanthocyanidin content is 80-160 mg / kg of the basic feed, and within this range, the hardness is more than 1255.75 g, the chewiness is more than 209 g, and the gumminess is more than 421 g.

[0040] Specifically, the above-mentioned feed additive and bran are mixed and then added to the tilapia basic feed, including the following steps:

[0041] Step S1, uniformly mixing proanthocyanidin and bran, the proanthocyanidin content is 2-32% by mass percentage, and the rest is bran, such as uniformly mixing 16% of proanthocyanidin and 84% of bran;

[0042] Step S2, adding the mixture of step S1 to the tilapia basic feed, so that the proanthocyanidin content is 20-320 mg / kg of the basic feed, such as the proanthocyanidin content being 40 mg / kg of the basic feed, 60 mg / kg of the basic feed, 80 mg / kg of the basic feed, 100 mg / kg of the basic feed, 120 mg / kg of the basic feed, 140 mg / kg of the basic feed, 160 mg / kg of the basic feed, 180 mg / kg of the basic feed, 200 mg / kg of the basic feed, 240 mg / kg of the basic feed, 260 mg / kg of the basic feed, 280 mg / kg of the basic feed, 300 mg / kg of the basic feed, preferably 80-160 mg / kg of the basic feed, and uniformly mixing for feeding tilapia.

[0043] It should be noted that in step S1, by adjusting the content of bran, the addition amount of proanthocyanidin is adjusted, the ratio of the two is controlled, and the bran can uniformly disperse the proanthocyanidin in the feed, which is beneficial to the uniform distribution of tilapia population.

[0044] In step S2, the production and use of the basic feed meet the requirements of the national standard "Aquatic Compound Feed Part 10: Tilapia Compound Feed" (GB / T 22919.10-2024), specifically, the raw materials of the basic feed include, in terms of mass percentage: 20% of soybean meal, 30% of cassava starch, 30% of rapeseed meal, 3.65% of cottonseed meal, 5% of fish meal, 4.5% of soybean oil, 1% of bentonite, 2% of calcium dihydrogen phosphate, 1.6% of methionine, 0.25% of choline chloride, 1% of vitamin premix, 1% of mineral premix, wherein 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, 120mg of niacin, 10mg of calcium pantothenate, 1mg of folic acid, and 0.1mg of biotin per kilogram of feed; and 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, 1500mg of KCl, 2mg of CuCl2, 16mg of MnSO4, 20mg of CoCl2, and 60mg of ZnSO4 per kilogram of feed.

[0045] The feeding amount is adjusted according to the feeding condition every day, the daily feeding amount is 2-3% of the fish weight, and the fish is fed 2-3 times a day. The single feeding lasts for 30 minutes, and the un-fed feed is recycled, dried at 65 DEG C and weighed. The fish is fed for 10 weeks, and the fish body is weighed every two weeks to adjust the feeding amount.

[0046] It should be noted that the addition of 20-320mg of procyanidins in 1kg of basic feed can effectively improve the muscle hardness, chewiness and gumminess of tilapia, and significantly improve the muscle texture properties of tilapia. The effect is similar to that of crisp feed; compared with ordinary feed, the health of tilapia is not deteriorated; compared with crisp feed, the health level of tilapia can be significantly improved, especially the stress damage of the liver of tilapia. When the content of procyanidins exceeds 320mg / kg of basic feed, the survival rate of tilapia and the effect of improving muscle quality will decrease.

[0047] The cost of the present application is increased by about 100 yuan / ton by adding feed additives to ordinary feed, and the cost of the feed using chickpea is about 1500 yuan / ton higher than that of ordinary feed, so the cost of the present application is about 1400 yuan / ton lower than that of the feed using chickpea.

[0048] Example 1

[0049] The breeding experiment was carried out in a pond net cage, the size of the net cage was 2m*1m*1m, the breeding variety was GIFT tilapia, the initial average weight was 763.33±10.41g, 10 fish in each net cage, a total of 3 net cages, 30 fish.

[0050] 20mg of procyanidins was added in 1kg of basic feed for feeding.

[0051] Firstly, the procyanidins were sieved through an 80-mesh sieve, and the undersize material was directly used as the effective component of the feed additive. The procyanidin content in the feed additive was more than 98% by mass percentage. The procyanidins were from Shanghai Yuanye Biotechnology Co., Ltd., with a product code of S30598, BR grade, and a purity of 95%.

[0052] Secondly, the above feed additive and bran were mixed and added to the basic feed of tilapia for feeding tilapia. Specifically, the following steps were included:

[0053] Step S1, 20mg of procyanidins and 980mg of bran were uniformly mixed by mass percentage;

[0054] Step S2, the mixture of step S1 was added to each kilogram of basic feed of tilapia, so that the procyanidin content was 20mg / kg of basic feed, and the mixture was uniformly mixed for feeding tilapia.

[0055] Specifically, the fish were fed 2-3 times a day, and the daily feeding amount was 2%-3% of the body weight of the fish. The raw materials of the basic feed included, by mass percentage: soybean meal 20%, cassava starch 30%, rapeseed meal 30%, cottonseed meal 3.65%, fish meal 5%, soybean oil 4.5%, bentonite 1%, calcium dihydrogen phosphate 2%, methionine 1.6%, choline chloride 0.25%, vitamin premix 1%, and mineral premix 1%. The vitamin premix provided 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, 120mg of niacin, 10mg of calcium pantothenate, 1mg of folic acid, and 0.1mg of biotin per kilogram of feed. The mineral premix provided 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, 1500mg of KCl, 2mg of CuCl2, 16mg of MnSO4, 20mg of CoCl2, and 60mg of ZnSO4 per kilogram of feed.

[0056] During the feeding experiment, the water temperature was 26-33℃, the dissolved oxygen was >5.0 mg / L, the pH was 7.4-7.6, the total ammonia nitrogen was <0.2 mg / L, the natural light was used, and the culture period was 70 days.

[0057] After the end of the culture experiment, relevant performance tests were carried out, and the performance tests included growth performance, serum biochemical indexes, basic nutritional components, and muscle texture. The test parameters were first collected the data of each net cage sample and then averaged, and then the performance test parameters of the three net cages were averaged. All the data results were mean ± standard deviation, i.e. (Mean ± SD, n=3).

[0058] Among them, the growth performance included weight gain rate (WGR), specific growth rate (SGR), feed coefficient (FCR), survival rate (SR), condition factor (CF), hepatosomatic index (HSI) and viscera-somatic index (VSI), and the test results were shown in Table 1:

[0059] Weight gain rate (WGR, %) = (W t -W0) × 100 / W0;

[0060] Specific growth rate (SGR, % / d) = (lnW t -lnW0) × 100 / t

[0061] Feed coefficient (FCR) = F / (W t -W0)

[0062] Survival rate (SR, %) = N t × 100 / N0

[0063] Condition factor (CF, g / cm 3 ) = W × 100 / L 3

[0064] Hepatosomatic index (HSI, %) = W h × 100 / W

[0065] Viscera-somatic index (VSI, %) = W v × 100 / W

[0066] Among them, N t was the final tail number, N0 was the initial tail number; W t was the final body weight, unit: g; W0 was the initial body weight, unit: g; W was the fish body weight, unit: g; t was the culture time, unit: d; F was the total feed intake, unit: g; W h was the liver weight, unit: g; W v was the viscera weight, unit: g; L was the body length, unit: cm.

[0067] The serum biochemical indicators include serum glucose (GLU), glutamic-pyruvic transaminase (ALT), glutamic-oxalacetic transaminase (AST), alkaline phosphatase (ALP), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL) and total cholesterol (T-CHO), which are determined by using a fully automatic biochemical analyzer, and the test results are shown in Table 2.

[0068] The basic nutritional components include water, crude protein, crude fat, ash, hydroxyproline, the water is determined by using a direct drying method (GB 5009.3-2016), the crude protein is determined by using a Kjeldahl method (GB 5009.5-2016), the crude fat is determined by using a Soxhlet extraction method (GB 5009.6-2016), the ash is determined by using a 550℃ muffle furnace burning method (GB 5009.4-2016), and the muscle hydroxyproline content is determined by using a hydroxyproline (Hyp) determination kit produced by Nanjing Jiancheng Biological Engineering Institute. The test results are shown in Table 3.

[0069] The muscle texture includes hardness, elasticity, viscosity, chewiness, cohesiveness, gumminess, adhesiveness and resilience, the muscle at the part above the back of the fish close to the dorsal fin is taken, cut into small pieces with a size of 1.0cm*1.0cm*1.0cm, the TPA test is performed by using a TVT300XP texture analyzer under room temperature conditions, and 5 parallel muscle samples are taken from each fish for determination. The test results are shown in Table 4.

[0070] Example 2

[0071] The difference between this example and Example 1 is that 40mg of procyanidins is added in 1kg of the basic feed, and the rest of the initial average weight, the basic feed, the breeding, the feeding, the performance test are completely same as those of 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.

[0072] 40mg of procyanidins is added in 1kg of the basic feed for feeding.

[0073] Firstly, the procyanidins are passed through an 80-mesh sieve, and the undersize material is directly used as the effective component of the feed additive, and the content of procyanidins in the feed additive is more than 98% in terms of mass percentage. The procyanidins are from Shanghai Yuanye Biological Technology Co., Ltd., with a product number of S30598, a BR grade and a purity of 95%.

[0074] Secondly, the above feed additive and bran are mixed and added to the basic feed of tilapia for feeding the tilapia. Specifically, the steps include the following steps:

[0075] Step S1, 40mg of procyanidins and 960mg of bran are uniformly mixed in terms of mass percentage.

[0076] Step S2, add the mixture of step S1 to each kg of the tilapia basic feed so that the procyanidins content is 40 mg / kg of the basic feed, and mix well for feeding the tilapia.

[0077] Example 3

[0078] The difference between this example and Example 1 is that 80 mg of procyanidins is added to 1 kg of the basic feed, and the rest of the initial average weight, the basic feed, the cultivation, the feeding, and the performance test are the same as 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.

[0079] 80 mg of procyanidins is added to 1 kg of the basic feed for feeding.

[0080] First, the procyanidins is passed through an 80-mesh sieve, and the undersize material is directly used as the effective component of the feed additive. The procyanidins content in the feed additive is more than 98% by mass percentage. The procyanidins is from Shanghai Yuanye Biotechnology Co., Ltd., with the product number S30598, BR grade, and a purity of 95%.

[0081] Second, the above feed additive and bran are mixed and added to the tilapia basic feed for feeding the tilapia. Specifically, the following steps are included:

[0082] Step S1, uniformly mix 80 mg of procyanidins and 920 mg of bran by mass percentage;

[0083] Step S2, add the mixture of step S1 to each kg of the tilapia basic feed so that the procyanidins content is 80 mg / kg of the basic feed, and mix well for feeding the tilapia.

[0084] Example 4

[0085] The difference between this example and Example 1 is that 160 mg of procyanidins is added to 1 kg of the basic feed, and the rest of the initial average weight, the basic feed, the cultivation, the feeding, and the performance test are the same as 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.

[0086] 160 mg of procyanidins is added to 1 kg of the basic feed for feeding.

[0087] Firstly, the procyanidins are sieved through an 80-mesh sieve, and the undersize material is directly used as the effective ingredient of the feed additive. The content of the procyanidins in the feed additive is more than 98% by mass percentage. The procyanidins are from Shanghai Yuan Ye Biotechnology Co., Ltd., with the product number S30598, BR grade, and a purity of 95%.

[0088] Secondly, the feed additive and bran are mixed and added to the basic feed of the tilapia for feeding the tilapia. Specifically, the following steps are included:

[0089] Step S1: 160 mg of procyanidins and 840 mg of bran are uniformly mixed by mass percentage;

[0090] Step S2: The mixture of step S1 is added to each kilogram of the basic feed of the tilapia, so that the content of the procyanidins is 160 mg / kg of the basic feed, and the mixture is uniformly mixed and used for feeding the tilapia.

[0091] Example 5

[0092] The difference between this example and Example 1 is that 240 mg of procyanidins are added to 1 kg of the basic feed. The rest, such as the initial average weight, the basic feed, the cultivation, the feeding, and the performance test, are the same as those 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.

[0093] A feed additive for tilapia, wherein the effective ingredient of the feed additive is procyanidins, and the content of the procyanidins in the feed additive is 98% by mass percentage, and the rest is impurities.

[0094] A preparation method of the above-mentioned feed additive, wherein the procyanidins are sieved through an 80-mesh sieve, and the undersize material is directly used as the feed additive. The procyanidins are from Shanghai Yuan Ye Biotechnology Co., Ltd., with the product number S30598, BR grade, and a purity of 95%.

[0095] 240 mg of procyanidins are added to 1 kg of the basic feed for feeding.

[0096] Firstly, the procyanidins are sieved through an 80-mesh sieve, and the undersize material is directly used as the effective ingredient of the feed additive. The content of the procyanidins in the feed additive is more than 98% by mass percentage. The procyanidins are from Shanghai Yuan Ye Biotechnology Co., Ltd., with the product number S30598, BR grade, and a purity of 95%.

[0097] Secondly, the feed additive and bran are mixed and added to the basic feed of the tilapia for feeding the tilapia. Specifically, the following steps are included:

[0098] Step S1, 240 mg of procyanidins and 760 mg of bran were uniformly mixed according to the mass percentage;

[0099] Step S2, the mixture of step S1 was added to each kg of tilapia basal feed so that the procyanidin content was 240 mg / kg of basal feed, and after mixing, it was used to feed tilapia.

[0100] Example 6

[0101] The difference between this example and Example 1 is that 320 mg of procyanidins is added to 1 kg of basal feed, and the rest of the initial average weight, basal feed, breeding, feeding, performance test is exactly the same as 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.

[0102] 320 mg of procyanidins was added to 1 kg of basal feed for feeding.

[0103] First, the procyanidins were sieved through an 80-mesh sieve, and the undersize material was directly used as the effective ingredient of the feed additive. The procyanidin content in the feed additive was more than 98% according to the mass percentage. The procyanidins were from Shanghai Yuanye Biotechnology Co., Ltd., with a product code of S30598, BR grade, and a purity of 95%.

[0104] Secondly, the above feed additive and bran were mixed and added to the tilapia basal feed for feeding tilapia. Specifically, the following steps are included:

[0105] Step S1, 320 mg of procyanidins and 680 mg of bran were uniformly mixed according to the mass percentage;

[0106] Step S2, the mixture of step S1 was added to each kg of tilapia basal feed so that the procyanidin content was 320 mg / kg of basal feed, and after mixing, it was used to feed tilapia.

[0107] Comparative Example 1

[0108] The difference between this example and Example 1 is that only basal feed is used for feeding, and the rest of the initial average weight, basal feed, breeding, feeding, performance test is exactly the same as 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.

[0109] Comparative Example 2

[0110] The difference between the present comparative example and Example 1 is that the roe fish is fed with the brittle feed, and the initial average weight, breeding, feeding, and performance test are the same as those in Example 1. The brittle feed comprises, in percentage by mass: 20% of soybean meal, 60% of broad bean, 2.05% of cottonseed meal, 5% of fish meal, 4.5% of soybean oil, 1% of bentonite, 2% of calcium dihydrogen phosphate, 3.2% of methionine, 0.25% of choline chloride, 1% of vitamin premix, and 1% of mineral premix, wherein the vitamin premix and the mineral premix are the same as those 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.

[0111] Comparative Example 3

[0112] The difference between the present comparative example and Example 1 is that 400 mg of procyanidins is added to 1 kg of the basic feed, and the initial average weight, the basic feed, breeding, feeding, and performance test are the same as those 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.

[0113] The procyanidins is added to 1 kg of the basic feed.

[0114] First, the procyanidins is sieved through an 80-mesh sieve, and the undersize material is directly used as the effective component of the feed additive. The content of the procyanidins in the feed additive is more than 98% by mass percentage. The procyanidins is from Shanghai Yuanye Biotechnology Co., Ltd., with a product code of S30598, a BR grade, and a purity of 95%.

[0115] Second, the feed additive and bran are mixed and added to the basic feed of the roe fish for feeding the roe fish. The specific steps include the following:

[0116] Step S1, 400 mg of procyanidins and 600 mg of bran are uniformly mixed by mass percentage;

[0117] Step S2, the mixture of Step S1 is added to each kilogram of the basic feed of the roe fish, so that the content of the procyanidins is 400 mg / kg of the basic feed, and the mixture is uniformly mixed and used for feeding the roe fish.

[0118] Table 1 Growth performance test results of the comparative example and the example

[0119] ;

[0120] Table 2 Serum biochemical index test results of the comparative example and the example

[0121] ;

[0122] Table 3. Results of muscle basic nutrient component test of comparative examples and examples

[0123] ;

[0124] Table 4. Results of muscle texture test of comparative examples and examples

[0125] ;

[0126] As shown in Table 1, in general, the survival rate of Comparative Example 1 using only the basic feed is higher; the specific growth rate and the weight gain rate of Comparative Example 2 using the brittle feed are higher, but the survival rate is lower; the survival rates of Examples 1-6 using the basic feed added with 20-320 mg / kg of the procyanidin feed additive are between Comparative Example 1 and Comparative Example 2, in which the survival rates of Examples 2-4 are relatively higher, and the survival rate of Example 4 is equivalent to that of Comparative Example 1; the survival rate of Comparative Example 3 using the basic feed added with 400 mg / kg of the procyanidin feed additive is lower and equivalent to that of Comparative Example 2. It is indicated that the appropriate amount of the procyanidin feed additive has little effect on the growth performance of the tilapia, especially the survival rate, while the brittle feed or the feed additive with a higher content of procyanidin has a greater effect on the tilapia.

[0127] As shown in Table 2, compared with Examples 1-6 and Comparative Examples 1 and 3, the glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase of Comparative Example 2 using the brittle feed are higher, and the increase of the glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase is an important marker for evaluating the stress damage of the liver, which fully indicates that the brittle feed can significantly worsen the stress damage of the liver, and also indicates that the procyanidin feed additive of the present application does not affect the health level of the liver of the tilapia, but when the content of the procyanidin is high, such as reaching 400 mg / kg of the basic feed, the effect starts to decrease, that is, the effect of Comparative Example 3 is not obvious compared with Comparative Example 1.

[0128] As shown in Table 3, compared with Examples 1-6 and Comparative Examples 2 and 3, the crude protein content and the hydroxyproline content of Comparative Example 1 using only the basic feed are lower, and the crude fat content is higher, and the hydroxyproline is the main component of collagen, and low fat and high protein are important indicators for evaluating the high nutrient components of the muscle, so it can be seen that the procyanidin feed additive of the present application can improve the nutrient components of the muscle of the tilapia like the brittle feed. However, when the content of the procyanidin is high, such as reaching 400 mg / kg of the basic feed, the effect starts to decrease, that is, Comparative Example 3 does not have an advantage compared with Example 6.

[0129] As can be seen from Table 4, compared with Examples 1-6 and Comparative Examples 2 and 3, the Comparative Example 1 using only the basic feed is significantly lower in the hardness, chewiness and gumminess of the muscle, wherein the hardness of Examples 1-6 is above 1167 g, the highest being 1521 g, the chewiness is above 189 g, the highest being 267 g, and the gumminess is above 378 g, the highest being 600 g. It is shown that the feed additive of the present application can significantly improve the muscle texture properties of the tilapia relative to the basic feed, and is not inferior to the brittle feed, but when the procyanidin content is high, such as reaching 400 mg / kg of the basic feed, the effect starts to decline, i.e. Comparative Example 3 and Example 6 do not have an advantage.

[0130] In summary, adding 20-320 mg of procyanidin in 1 kg of the basic feed can effectively improve the muscle hardness, chewiness and gumminess of the tilapia, and significantly improve the muscle texture properties of the tilapia. The effect is similar to that of the brittle feed; compared with the ordinary feed, the health of the tilapia is not deteriorated; compared with the brittle feed, the health level of the tilapia can be significantly improved, especially the stress damage of the liver of the tilapia.

[0131] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be covered within the protection scope of the present application.

Claims

1. The application of proanthocyanidins and wheat bran in the preparation of feed to improve the muscle quality of tilapia, characterized in that, The proanthocyanidins are monomers or oligomers with a degree of polymerization of 2-4. After passing the proanthocyanidins through an 80-mesh sieve, the sieved material is used directly as an effective ingredient in the feed additive. The proanthocyanidin content in the feed additive is above 98% by mass percentage. The feed additive and wheat bran are uniformly mixed to obtain a mixture containing 2-32% proanthocyanidins, with the remainder being wheat bran. This mixture is added to the basic feed for tilapia, resulting in a proanthocyanidin content of 120-180 mg / kg of the basic feed. The production and use of the basic feed meet the national standard "Aquatic Compound Feed Part 10: Tilapia Compound Feed" (GB / T). The requirements of 22919.10-2024 are as follows: wherein the bran uniformly disperses proanthocyanidins into the feed; the parameters of muscle quality include hardness, chewiness, and adhesiveness; the feed additive can improve the hardness, chewiness, and adhesiveness of Nile tilapia muscle, wherein the hardness is above 1167g, the chewiness is above 189g, and the adhesiveness is above 378g.

2. The application according to claim 1, characterized in that, The feed additive and bran are mixed evenly to obtain a mixture, which is then added to the Nile tilapia base feed for feeding Nile tilapia.

3. The application according to claim 1, characterized in that, The proanthocyanidin content is 120-160 mg / kg of basal feed.

4. The application according to claim 2, characterized in that, The feeding amount is 2-3% of the fish's body weight per day, and the fish is fed 2-3 times a day.