A seaweed feed additive for improving the body color of shrimp and a preparation method thereof

Abstract

The invention relates to the technical field of feed additives for aquaculture, and discloses a seaweed feed additive for improving the body color of prawns and a preparation method thereof. The seaweed is rich in high protein, carbohydrates and lipids, has high nutritional value and antioxidant capacity; sulfated seaweed polysaccharides extracted from the seaweed by a water extraction method strengthen the intestinal microecological stability and immune function of the shrimp body; a part of microalgae astaxanthin powder extracted from Haematococcus pluvialis by an enzyme extraction method can be used by the shrimp body as a nutrient, and the other part is deposited in the shrimp skin layer, muscle and shell, etc., to improve the problem of abnormal body color of prawns, lighter body color or even blue body color, and has an excellent color enhancement effect; at the same time, an appropriate amount of concentrated cottonseed protein is added to significantly promote the growth of prawns, and the components in the feed additive synergistically enhance the effect, promote the growth of prawns and improve the body color of prawns, and are conducive to the sustainable and healthy development of prawn farming.

Description

Technical Field

[0001] The invention relates to the technical field of feed additives for aquaculture, in particular to a seaweed feed additive for improving the body color of shrimps and a preparation method thereof. Background Art

[0002] The Vannamei shrimp is native to the Pacific coastal waters and is one of the most productive shrimp farmed varieties in the world. It is deeply loved by the public due to its thin shell, fat body, good environmental adaptability and strong disease resistance. It has high economic and nutritional value and can be farmed in a high-density and intensive manner. However, with the rise of factory farming of shrimp, the problem of abnormal body color, lighter or even blue body color of farmed shrimp has also been exposed. With the gradual improvement of people's living standards and the enhancement of health awareness, the requirements for the quality of aquatic products are also getting higher and higher. Therefore, the development of high-quality feed additives to improve the body color, meat quality and flavor of shrimp is an urgent task for the sustainable development of the Vannamei shrimp industry.

[0003] The body color of shrimps is mainly due to the absorption, scattering and refraction of light by the chromatophores in the pigment cells, and the prices of shrimps with normal colors are higher than those with abnormal colors. Astaxanthin is a carotenoid with a ketone end group. A large number of studies have shown that astaxanthin can improve the body color of aquatic products and ensure that aquatic animals have a good market value. In addition, astaxanthin is also a nutrient necessary for the normal growth and survival of these animals. However, shrimps themselves cannot synthesize carotenoids, and the food chain in aquaculture is too single. Therefore, an appropriate amount of astaxanthin needs to be artificially added to aquatic feed to ensure that the astaxanthin content in the animal body is maintained at a normal level. In the prior art, more than 95% of the astaxanthin on the market is chemically synthesized, and artificially synthesized astaxanthin has problems such as low safety, high environmental pollution and low product activity.

[0004] Haematococcus pluvialis is the best astaxanthin source in nature. Extracting astaxanthin from Haematococcus pluvialis has become a research hotspot with good economic benefits and prospects. The present invention extracts astaxanthin from Haematococcus pluvialis by enzymatic hydrolysis, extracts cottonseed meal by ultrasonic extraction, obtains sulfated seaweed polysaccharide by water extraction, and compounds it with chitosan, cellulose, etc. to prepare a seaweed feed additive, which is applied to shrimp feed and has the functions of improving shrimp body color, improving shrimp resistance and growth activity. Summary of the invention

[0005] The technical problems solved by the present invention are:

[0006] In view of the deficiencies of the prior art, the present invention provides a seaweed feed additive for improving the body color of shrimp and a preparation method thereof, and develops a high-quality feed additive that can be used to improve the body color of shrimp and promote the growth of shrimp.

[0007] The technical solution adopted by the present invention is:

[0008] A method for preparing a seaweed feed additive for improving the body color of shrimps. The method is carried out according to the following steps: krill meal, concentrated cottonseed protein, calcium dihydrogen phosphate and complex vitamins are crushed by a crusher, passed through an 80-100 mesh sieve, and then brewer's yeast and sulfated seaweed polysaccharide are added to a mixer for mixed fermentation, then put into a feed mixer for stirring for 10-40 minutes, chitosan and microalgae astaxanthin powder are added in sequence and continued to stir for 1-2 hours, and granulated by a feed granulator to obtain the seaweed feed additive for improving the body color of shrimps.

[0009] Furthermore, in terms of weight, the krill meal is 15-25 parts, the concentrated cottonseed protein is 20-45 parts, the calcium dihydrogen phosphate is 1.5-3 parts, the multivitamins are 2-4 parts, the brewer's yeast is 2-5 parts, the sulfated seaweed polysaccharide is 1-5 parts, the chitosan is 0.5-2 parts, and the microalgae astaxanthin powder is 2-10 parts.

[0010] Furthermore, the vitamin complex includes one or more of vitamin A, vitamin C and vitamin E.

[0011] Furthermore, the preparation method of the concentrated cottonseed protein is carried out according to the following steps: 110-140 parts by weight of a sodium hydroxide aqueous solution with a pH of 11-12 and 100 parts of cottonseed meal powder are added to a reaction flask, stirred evenly, placed in an ultrasonic generator for ultrasonic extraction, after the extraction is completed, filtered while hot, hydrochloric acid is added to adjust the pH to 4.5-5, allowed to stand for 10-20 minutes, protein precipitates are precipitated, centrifuged, and dried to obtain concentrated cottonseed protein.

[0012] Furthermore, the ultrasonic extraction temperature is 55-70°C, and the ultrasonic extraction time is 30-60min.

[0013] Furthermore, the preparation method of the sulfated seaweed polysaccharide is carried out according to the following steps: adding 100 parts of seaweed powder and 80-120 parts of deionized water into a reaction flask, stirring and dispersing them evenly, and performing a water extraction reaction. After the reaction is completed, filtering while hot, collecting the filtrate, extracting the filter residue with 5-6 times the volume of deionized water for 3-8 hours, combining the filtrate, concentrating under reduced pressure, adding ethanol to precipitate, filtering, and drying to obtain the sulfated seaweed polysaccharide.

[0014] Furthermore, the water extraction reaction temperature is 75-100° C., and the water extraction reaction time is 8-16 hours.

[0015] Furthermore, the preparation method of the microalgae astaxanthin powder is carried out according to the following steps: adding 100 parts of Haematococcus pluvialis powder and 150-250 parts of deionized water by weight into a reaction flask, shaking in an oscillator for 20-40 minutes, adjusting the pH to 4-5 with 5-10% citric acid by mass, adding 1-3 parts of cellulase, and performing enzymatic hydrolysis reaction. After the reaction is completed, filtering, ethanol extraction, the extraction temperature is 40-50°C, the extraction time is 30-60 minutes, combining the extracts, concentrating under reduced pressure, and drying to obtain microalgae astaxanthin powder.

[0016] Furthermore, the enzymatic hydrolysis reaction temperature is 35-60°C, and the reaction time is 10-25h.

[0017] Furthermore, the preparation method of the feed is carried out according to the following steps: 15-20 parts by weight of krill meal, 5-10 parts of fish meal, 10-12 parts of peeled soybean meal, 8-10 parts of corn protein meal, 25-30 parts of wheat flour, 3-6 parts of peanut meal, 1-3 parts of soybean lecithin oil, 1-2 parts of fish oil, 0.5-1 parts of choline chloride, 1-2 parts of composite minerals, 0.2-0.5 parts of composite amino acids, 1-2 parts of calcium dihydrogen phosphate and 3-15 parts of seaweed feed additives are mixed uniformly, ground through a 50-80 mesh sieve, added into a twin-screw extruder for extrusion, and then matured in an oven at 50-65° C. for 30-50 minutes, and naturally air-dried to obtain a seaweed feed with improved shrimp body color.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The invention improves the growth performance of prawns by adding additives into feeds, extracts concentrated cottonseed protein from cottonseed meal powder by ultrasonic extraction, then extracts effective components from seaweed by water extraction to obtain sulfated seaweed polysaccharides, then performs enzymatic hydrolysis on Haematococcus pluvialis powder, extracts astaxanthin components by enzyme method to obtain microalgae astaxanthin powder, then mixes the powder with complex vitamins, brewer's yeast and chitosan to obtain a seaweed feed additive for improving the body color of prawns, and finally adds the seaweed additive into feeds consisting of krill meal, fish meal, peeled soybean meal, corn protein powder, wheat flour and the like to obtain a seaweed feed for improving the body color of prawns.

[0020] Seaweed is rich in high protein, carbohydrates and lipids, widely used in different growth stages of shrimp, and is a nutrient necessary for shrimp growth, with high nutritional value, antioxidant capacity and disease resistance. The present invention extracts the effective ingredients in seaweed, exerts the role of microorganisms, and saves costs to the greatest extent. The extracted concentrated cottonseed protein is a new plant protein source made from cottonseed as a raw material, with high protein and low anti-nutritional factors. Appropriate addition can significantly promote the growth of shrimp, enhance the intestinal and intestinal digestive enzyme activity of shrimp, and promote the stability of the physiological function of shrimp; the seaweed polysaccharide extracted from seaweed is rich in sulfate group anion active sites in the molecular structure, has antioxidant and antibacterial effects, and functional seaweed polysaccharides can promote the proliferation of microbial flora in shrimp, improve the stability of intestinal microecology, and combine with adsorption of exogenous pathogens to prevent them from adhering to the inner wall of the digestive tract, thereby reducing the niche of harmful bacteria, inhibiting the massive reproduction of conditional pathogens, and then strengthening the immune function of shrimp, maintaining normal intestinal morphology and restoring intestinal function.

[0021] Chitosan, as an edible high-molecular polysaccharide, can improve the immunity of shrimp and protect the hepatopancreas. Natural astaxanthin has strong antioxidant activity, enhances immunity and has color-developing effects. Astaxanthin is extracted from astaxanthin-rich Haematococcus pluvialis, with a high extraction rate and environmental protection. When shrimp absorb astaxanthin from the feed, part of it can be converted into vitamin A in the shrimp body and used as a nutrient by the shrimp body, and the other part is deposited in the shrimp skin, muscles and shell, improving the abnormal body color of shrimp, the problem of lighter or even blue body color, and has an excellent color-enhancing effect.

[0022] The invention adds an appropriate amount of seaweed additives such as sulfated seaweed polysaccharides and microalgae astaxanthin powder to shrimp feed, and through their synergistic effect, can significantly improve the activity of digestive enzymes, improve the stability of intestinal microecology, promote the growth of shrimps and improve the body color of shrimps, has good economic and social benefits, and is conducive to the sustainable and healthy development of shrimp farming. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] (1) Add 130 parts by weight of a sodium hydroxide aqueous solution with a pH of 11 and 100 parts of cottonseed meal powder to a reaction flask, stir evenly, place in an ultrasonic generator, perform ultrasonic extraction at 65° C. for 45 minutes, filter while hot, add hydrochloric acid to adjust the pH to 5, stand for 15 minutes, precipitate protein, centrifuge, and dry to obtain concentrated cottonseed protein.

[0026] (2) Add 100 parts of seaweed powder and 110 parts of deionized water into a reaction flask, stir and disperse evenly, extract at 85°C for 15 hours, filter while hot, collect the filtrate, extract the residue with 6 times the volume of deionized water for 7 hours, combine the filtrates, concentrate under reduced pressure, add ethanol to precipitate, filter, and dry to obtain sulfated seaweed polysaccharide.

[0027] (3) Add 100 parts of Haematococcus pluvialis powder and 200 parts of deionized water by weight to a reaction flask, shake in an oscillator for 30 minutes, adjust the pH to 4.5 with 8% citric acid, add 2 parts of cellulase, react at 55°C for 24 hours, filter, extract with ethanol, the extraction temperature is 45°C, the extraction time is 40 minutes, combine the extracts, concentrate under reduced pressure, and dry to obtain microalgae astaxanthin powder.

[0028] (4) 20 parts of krill meal, 35 parts of concentrated cottonseed protein, 2 parts of calcium dihydrogen phosphate, 3 parts of vitamin A and vitamin C, measured by weight, were crushed with a grinder and passed through a 90-mesh sieve. Then, 3 parts of brewer's yeast and 1 part of sulfated seaweed polysaccharide were added to a mixer for mixing and fermentation. Then, the mixture was placed in a feed mixer and stirred for 20 minutes. 1.5 parts of chitosan and 2 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 1.5 hours. The mixture was granulated with a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp.

[0029] (5) 20 parts of krill meal, 8 parts of fish meal, 12 parts of dehulled soybean meal, 9 parts of corn gluten meal, 25 parts of wheat flour, 5 parts of peanut meal, 2 parts of soybean lecithin oil, 1 part of fish oil, 0.5 parts of choline chloride, 2 parts of complex minerals, 0.3 parts of complex amino acids, 2 parts of calcium dihydrogen phosphate and 3 parts of seaweed feed additives were mixed uniformly, ground through a 60-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 55° C. for 40 minutes and naturally air-dried to obtain a seaweed feed for improving the body color of shrimp.

[0030] Example 2

[0031] (1) Add 140 parts by weight of a sodium hydroxide aqueous solution having a pH of 12 and 100 parts of cottonseed meal powder to a reaction flask, stir evenly, place in an ultrasonic generator, perform ultrasonic extraction at 55° C. for 60 minutes, filter while hot, add hydrochloric acid to adjust the pH to 4.5, stand for 10 minutes, precipitate protein, centrifuge, and dry to obtain concentrated cottonseed protein.

[0032] (2) Add 100 parts of seaweed powder and 120 parts of deionized water into a reaction flask, stir and disperse evenly, extract with water at 75°C for 16 hours, filter while hot, collect the filtrate, extract the residue with 6 times the volume of deionized water for 8 hours, combine the filtrates, concentrate under reduced pressure, add ethanol for precipitation, filter, and dry to obtain sulfated seaweed polysaccharide.

[0033] (3) Add 100 parts of Haematococcus pluvialis powder and 250 parts of deionized water by weight to a reaction flask, shake in an oscillator for 40 minutes, adjust the pH to 5 with 5% citric acid, add 3 parts of cellulase, react at 35°C for 25 hours, filter, extract with ethanol, the extraction temperature is 40°C, the extraction time is 60 minutes, combine the extracts, concentrate under reduced pressure, and dry to obtain microalgae astaxanthin powder.

[0034] (4) 25 parts of krill meal, 20 parts of concentrated cottonseed protein, 1.5 parts of calcium dihydrogen phosphate, and 2 parts of vitamin E by weight were crushed with a grinder and passed through an 80-mesh sieve. Then, 2 parts of brewer's yeast and 2 parts of sulfated seaweed polysaccharides were added to a mixer and mixed and fermented. Then, the mixture was placed in a feed mixer and stirred for 40 minutes. 2 parts of chitosan and 4 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 1 hour. The mixture was granulated with a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp.

[0035] (5) 15 parts of krill meal, 10 parts of fish meal, 12 parts of dehulled soybean meal, 8 parts of corn gluten meal, 25 parts of wheat flour, 6 parts of peanut meal, 1 part of soybean lecithin oil, 2 parts of fish oil, 0.8 parts of choline chloride, 2 parts of complex minerals, 0.5 parts of complex amino acids, 1 part of calcium dihydrogen phosphate and 6 parts of seaweed feed additives were mixed uniformly, ground through a 70-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 50° C. for 50 min and naturally air-dried to obtain a seaweed feed for improving the body color of shrimp.

[0036] Example 3

[0037] (1) Add 110 parts by weight of a sodium hydroxide aqueous solution with a pH of 12 and 100 parts of cottonseed meal powder to a reaction flask, stir evenly, place in an ultrasonic generator, perform ultrasonic extraction at 70° C. for 30 minutes, filter while hot, add hydrochloric acid to adjust the pH to 5, stand for 10 minutes, precipitate protein, centrifuge, and dry to obtain concentrated cottonseed protein.

[0038] (2) Add 100 parts of seaweed powder and 80 parts of deionized water into a reaction flask, stir and disperse evenly, extract at 100°C for 8 hours, filter while hot, collect the filtrate, extract the residue with 5 times the volume of deionized water for 3 hours, combine the filtrates, concentrate under reduced pressure, add ethanol for precipitation, filter, and dry to obtain sulfated seaweed polysaccharide.

[0039] (3) Add 100 parts of Haematococcus pluvialis powder and 150 parts of deionized water by weight to a reaction flask, shake in an oscillator for 20 minutes, adjust the pH to 4 with 10% citric acid, add 1 part of cellulase, react at 60°C for 10 hours, filter, extract with ethanol, the extraction temperature is 50°C, the extraction time is 30 minutes, combine the extracts, concentrate under reduced pressure, and dry to obtain microalgae astaxanthin powder.

[0040] (4) 15 parts of krill meal, 45 parts of concentrated cottonseed protein, 3 parts of calcium dihydrogen phosphate, 4 parts of vitamin C and vitamin E, measured by weight, were crushed with a grinder and passed through an 85-mesh sieve. Then, 2 parts of brewer's yeast and 3 parts of sulfated seaweed polysaccharides were added to a mixer for mixing and fermentation. Then, the mixture was placed in a feed mixer and stirred for 40 minutes. 0.5 parts of chitosan and 6 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 2 hours. The mixture was granulated with a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp.

[0041] (5) 20 parts of krill meal, 5 parts of fish meal, 10 parts of dehulled soybean meal, 10 parts of corn gluten meal, 30 parts of wheat flour, 3 parts of peanut meal, 3 parts of soybean lecithin oil, 1 part of fish oil, 1 part of choline chloride, 1.5 parts of complex minerals, 0.5 parts of complex amino acids, 1 part of calcium dihydrogen phosphate and 9 parts of seaweed feed additives were mixed uniformly by weight, ground through a 50-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 65° C. for 30 min, and naturally air-dried to obtain a seaweed feed for improving the body color of shrimp.

[0042] Example 4

[0043] (1) Add 125 parts by weight of a sodium hydroxide aqueous solution with a pH of 11 and 100 parts of cottonseed meal powder to a reaction flask, stir evenly, place in an ultrasonic generator, perform ultrasonic extraction at 60° C. for 50 min, filter while hot, add hydrochloric acid to adjust the pH to 4.5, stand for 15 min, precipitate protein, centrifuge, and dry to obtain concentrated cottonseed protein.

[0044] (2) Add 100 parts of seaweed powder and 100 parts of deionized water into a reaction flask, stir and disperse evenly, extract at 95°C for 10 hours, filter while hot, collect the filtrate, extract the residue with 5.5 times the volume of deionized water for 6 hours, combine the filtrates, concentrate under reduced pressure, add ethanol for precipitation, filter, and dry to obtain sulfated seaweed polysaccharide.

[0045] (3) Add 100 parts of Haematococcus pluvialis powder and 220 parts of deionized water by weight to a reaction flask, shake in an oscillator for 25 minutes, adjust the pH to 4 with 8% citric acid, add 2 parts of cellulase, react at 50° C. for 20 hours, filter, extract with ethanol, the extraction temperature is 50° C., the extraction time is 35 minutes, combine the extracts, concentrate under reduced pressure, and dry to obtain microalgae astaxanthin powder.

[0046] (4) 20 parts of krill meal, 35 parts of concentrated cottonseed protein, 2 parts of calcium dihydrogen phosphate, 3 parts of vitamin A, vitamin C and vitamin E by weight were crushed with a grinder and passed through a 90-mesh sieve. Then 3 parts of brewer's yeast and 4 parts of sulfated seaweed polysaccharides were added to a mixer and mixed and fermented. Then, the mixture was placed in a feed mixer and stirred for 25 minutes. 2 parts of chitosan and 8 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 1.5 hours. The mixture was granulated with a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp.

[0047] (5) 15 parts of krill meal, 10 parts of fish meal, 12 parts of dehulled soybean meal, 8 parts of corn gluten meal, 25 parts of wheat flour, 5 parts of peanut meal, 2 parts of soybean lecithin oil, 2 parts of fish oil, 0.5 parts of choline chloride, 2 parts of complex minerals, 0.5 parts of complex amino acids, 1 part of calcium dihydrogen phosphate and 12 parts of seaweed feed additives were mixed uniformly, ground through a 60-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 60° C. for 35 minutes and naturally air-dried to obtain a seaweed feed for improving the body color of shrimp.

[0048] Example 5

[0049] (1) Add 130 parts by weight of a sodium hydroxide aqueous solution with a pH of 11 and 100 parts of cottonseed meal powder to a reaction flask, stir evenly, place in an ultrasonic generator, perform ultrasonic extraction at 65° C. for 55 minutes, filter while hot, add hydrochloric acid to adjust the pH to 5, stand for 20 minutes, precipitate protein, centrifuge, and dry to obtain concentrated cottonseed protein.

[0050] (2) Add 100 parts of seaweed powder and 90 parts of deionized water into a reaction flask, stir and disperse evenly, extract at 85°C for 15 hours, filter while hot, collect the filtrate, extract the residue with 6 times the volume of deionized water for 5 hours, combine the filtrates, concentrate under reduced pressure, add ethanol for precipitation, filter, and dry to obtain sulfated seaweed polysaccharide.

[0051] (3) Add 100 parts of Haematococcus pluvialis powder and 180 parts of deionized water by weight to a reaction flask, shake in an oscillator for 35 minutes, adjust the pH to 5 with 9% citric acid, add 3 parts of cellulase, react at 50°C for 16 hours, filter, extract with ethanol, the extraction temperature is 40°C, the extraction time is 60 minutes, combine the extracts, concentrate under reduced pressure, and dry to obtain microalgae astaxanthin powder.

[0052] (4) 25 parts of krill meal, 25 parts of concentrated cottonseed protein, 2 parts of calcium dihydrogen phosphate, 4 parts of vitamin A and vitamin E, measured by weight, were crushed with a grinder and passed through a 100-mesh sieve. Then, 5 parts of brewer's yeast and 5 parts of sulfated seaweed polysaccharides were added to a mixer for mixing and fermentation. The mixture was then placed in a feed mixer and stirred for 30 minutes. 0.5 parts of chitosan and 10 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 1 hour. The mixture was granulated with a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp.

[0053] (5) 15 parts of krill meal, 5 parts of fish meal, 11 parts of dehulled soybean meal, 9 parts of corn gluten meal, 30 parts of wheat flour, 6 parts of peanut meal, 1 part of soybean lecithin oil, 2 parts of fish oil, 1 part of choline chloride, 2 parts of complex minerals, 0.4 parts of complex amino acids, 2 parts of calcium dihydrogen phosphate and 15 parts of seaweed feed additives were mixed uniformly by weight, ground through a 65-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 55° C. for 40 minutes and naturally air-dried to obtain a seaweed feed for improving the body color of shrimp.

[0054] Comparative Example 1

[0055] (1) 20 parts of krill meal, 35 parts of concentrated cottonseed protein, 2 parts of calcium dihydrogen phosphate, 3 parts of vitamin A and vitamin C, measured by weight, were crushed with a grinder, passed through a 90-mesh sieve, and then 3 parts of brewer's yeast were added to a mixer for mixed fermentation. Then, the mixture was put into a feed mixer and stirred for 20 minutes. 1.5 parts of chitosan and 2 parts of microalgae astaxanthin powder were added in sequence and continued to be stirred for 1.5 hours. The mixture was granulated with a feed granulator to obtain a feed additive for improving the body color of shrimp.

[0056] (2) 20 parts of krill meal, 8 parts of fish meal, 12 parts of dehulled soybean meal, 9 parts of corn gluten meal, 25 parts of wheat flour, 5 parts of peanut meal, 2 parts of soybean lecithin oil, 1 part of fish oil, 0.5 parts of choline chloride, 2 parts of complex minerals, 0.3 parts of complex amino acids, 2 parts of calcium dihydrogen phosphate and 3 parts of feed additives were mixed uniformly by weight, ground through a 60-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 55° C. for 40 minutes and naturally air-dried to obtain a feed for improving the body color of shrimp.

[0057] Comparative Example 2

[0058] (1) 20 parts of krill meal, 35 parts of concentrated cottonseed protein, 2 parts of calcium dihydrogen phosphate, 3 parts of vitamin A and vitamin C, measured by weight, are crushed by a grinder and passed through a 90-mesh sieve. Then, 3 parts of brewer's yeast and 1 part of sulfated seaweed polysaccharide are added to a mixer for mixing and fermentation. Then, the mixture is put into a feed mixer and stirred for 20 minutes. 1.5 parts of chitosan are added and stirred for 1.5 hours. The mixture is granulated by a feed granulator to obtain a feed additive for improving the body color of shrimp.

[0059] (2) 20 parts of krill meal, 8 parts of fish meal, 12 parts of dehulled soybean meal, 9 parts of corn gluten meal, 25 parts of wheat flour, 5 parts of peanut meal, 2 parts of soybean lecithin oil, 1 part of fish oil, 0.5 parts of choline chloride, 2 parts of complex minerals, 0.3 parts of complex amino acids, 2 parts of calcium dihydrogen phosphate and 3 parts of feed additives were mixed uniformly by weight, ground through a 60-mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 55° C. for 40 minutes and naturally air-dried to obtain a feed for improving the body color of shrimp.

[0060] The body weight of the vannamei shrimp used in the experiment was (6.82+0.03) g. It was first temporarily cultured in a laboratory culture barrel for 7 days, and then 700 juvenile shrimps with uniform body length, healthy physique and equivalent size were randomly selected for the experiment, and 7 experimental groups were set up, and the feeds of the embodiment and the comparative example were fed respectively; each experimental group was set up with 5 replicates, each replicate had 20 shrimps, and the culture time was 8 weeks.

[0061] During the breeding process, the shrimp's food intake is calculated as 8-10% of its body weight, and is also adjusted according to the weather, water quality, water temperature and shrimp vitality. Feeding is done regularly every day, at 07:00, 12:00, 17:30 and 21:30 respectively. When feeding, the feed is evenly spread on the bottom of the breeding bucket. After feeding for 40-60 minutes, the shrimp's feeding situation and the residual feed are observed. After each feeding for 2 hours, the feces and residual feed in the water body are siphoned out. The water is changed every day, and the amount of water changed is 1 / 3 to 1 / 2 of the water volume in the breeding bucket; during the breeding period, the breeding water body is continuously oxygenated, the water temperature in the system is 26-28℃, the salinity fluctuation range is 26-28, the ammonia nitrogen mass concentration is less than 0.3mg / L, the pH value range is 7.7-8.0, and the dissolved oxygen mass concentration is higher than 6mg / L.

[0062] Data statistics: SPSS 19.0 software was used for statistics, and the data are expressed as mean ± standard error

[0063] Shrimp body component test: The shrimp samples were dried at 105°C to constant mass to determine the moisture content, the crude protein was determined using a fully automatic Kjeldahl nitrogen analyzer, the crude fat was determined using the chloroform-methanol method, and the crude ash was determined using a 550°C muffle furnace ignition method.

[0064] Crude protein (%) Crude fat (%) Crude ash (%) Example 1 73.65±1.16 13.95±0.24 11.41±0.32 Example 2 74.78±1.18 14.16±0.50 11.56±0.30 Example 3 75.65±0.81 14.39±0.45 11.88±0.27 Example 4 75.09±1.23 14.52±0.12 12.04±0.54 Example 5 73.68±1.30 14.46±0.26 12.00±0.36 Comparative Example 1 71.51±1.56 11.10±1.21 10.56±0.39 Comparative Example 2 70.32±1.47 10.32±1.35 10.32±0.84

[0065] It can be seen from the test results in the above table that after adding an appropriate amount of sulfated seaweed polysaccharides and microalgae astaxanthin powder to the feed, the crude protein, crude fat and crude ash contents in the body components of the shrimp in the embodiment are higher than those in the comparative example, indicating that the addition of seaweed-type feed additives can effectively improve the growth performance of shrimp. This is because sulfated seaweed polysaccharides and concentrated cottonseed protein are rich in various mineral elements, organic acids, polysaccharides and natural antibiotics. These rich active substances help to enhance protein synthesis in the shrimp body, thereby promoting growth. Comparative Example 2 does not contain microalgae astaxanthin powder, and its body component content is lower than that in the embodiment.

[0066] Shrimp body color test: Put the shrimp in an ice water bucket until they die, and then use the NR-200 colorimeter to measure the body color of the shrimp's carapace (2-3 abdominal segments). The shrimp body color is expressed by L* (brightness value), a* (red value), and b* (yellow value) according to the standards of the International Commission on Luminous Illumination.

[0067]

[0068]

[0069] From the test data in the above table, it can be seen that with the addition of seaweed feed additives, the brightness value of the shrimp abdominal carapace shows a downward trend, there is no obvious difference in the red value, and the yellow value shows a downward trend. In the L*a*b* color system, the smaller the L*, the darker the color; the larger the a*, the more the color tends to red; the smaller the b*, the more the color tends to blue; from the body color of the shrimp, with the increase of the addition content of seaweed feed, its L* gradually decreases and the body color becomes darker, indicating that the green-gray color of the raw shrimp tends to gradually darken, improving the body color of the shrimp; this is because the prepared feed additive contains astaxanthin, which is a highly efficient free radical scavenger that can remove free radicals accumulated inside cells. The presence of hydroxyl and ketone groups in the structure makes the polar structure of astaxanthin easy to oxidize, thereby giving it antioxidant properties to cells. When the shrimp absorbs astaxanthin from the feed, part of it can be converted into vitamin A in the shrimp body and used as a nutrient by the shrimp body, and the other part is deposited in the shrimp skin, muscle and shell, thereby changing the color of the shrimp.

[0070] Serum biochemical indexes and enzyme activity test: The intestinal tissue was washed with pre-cooled PBS (0.01 M, pH = 7.4), PBS solution (1:9) was added and mixed, the intestinal tissue was ground on ice, the homogenate was centrifuged at 5000 r / min for 5 minutes, the supernatant was extracted, and the serum biochemical indexes and enzyme activity were measured using a microplate photometer and UV-visible spectrophotometer. Each sample was tested three times in parallel.

[0071]

[0072]

[0073] Serum biochemistry is an important physiological indicator of shrimp body function. The antioxidant capacity in serum is an important factor in removing metabolic waste and maintaining the balance of the internal environment. Superoxide dismutase SOD is an important antioxidant enzyme in the body, catalyzing the dismutation reaction of free radicals and playing an important role in maintaining the body's antioxidant stability. Catalase CAT is a marker enzyme of peroxisomes, decomposing hydrogen peroxide to prevent hydrogen peroxide from damaging the body. Phenoloxidase PO is mainly involved in some resistance-related antioxidant enzyme reactions in the phenolic metabolic system, and plays an important role in resisting the invasion of pathogenic microorganisms. Alkaline phosphatase AKP and acid phosphatase ACP are the main indicators of shrimp growth and immune function, playing an important role in cell regulation and nutrient transport, and improving the growth performance of shrimp.

[0074] It can be seen from the test results in the above table that with the addition of seaweed additives in the feed, the serum biochemical indicators in the embodiment are significantly increased compared with the control example, indicating that the addition of seaweed additives enhances the nonspecific immune activity in the serum of shrimp and plays a very important role in maintaining the antioxidant stability of the body.

[0075]

[0076] The digestive function depends on the mechanical movement of gastrointestinal tissue and the chemical digestion of digestive enzymes. The digestive tract of shrimp is relatively simple and its digestive ability is weak. Digestive enzymes play a key role in food digestion and nutrient absorption. The polysaccharides contained in sulfated seaweed polysaccharides cannot be digested and absorbed by shrimp, but can be decomposed by microorganisms in the intestine. Sulfated seaweed polysaccharides can promote the proliferation of microbial flora in shrimp and improve the stability of intestinal microecology. At the same time, they can combine and adsorb exogenous pathogens to prevent them from adhering to the inner wall of the digestive tract, thereby reducing the ecological niche of harmful bacteria and inhibiting the massive reproduction of conditional pathogens, thereby strengthening the immune function of shrimp, maintaining normal intestinal morphology and restoring intestinal function, so that the growth performance and intestinal digestion ability of shrimp are improved.

[0077] It can be seen from the test results in the above table that the addition of seaweed feed additives enhances the activity of digestive enzymes in the shrimp intestine. Comparative Example 1 does not contain sulfated seaweed polysaccharides, and Comparative Example 2 does not contain microalgae astaxanthin powder, and their intestinal enzyme activities are not as good as those in the examples.

[0078] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. An application of a seaweed feed additive for improving the body color of shrimp in feed, characterized in that: The preparation method of the feed is carried out according to the following steps: 15-20 parts by weight of krill meal, 5-10 parts of fish meal, 10-12 parts of peeled soybean meal, 8-10 parts of corn protein meal, 25-30 parts of wheat flour, 3-6 parts of peanut meal, 1-3 parts of soybean lecithin oil, 1-2 parts of fish oil, 0.5-1 parts of choline chloride, 1-2 parts of composite minerals, 0.2-0.5 parts of composite amino acids, 1-2 parts of calcium dihydrogen phosphate and 3-15 parts of seaweed feed additives are mixed uniformly, ground through a 50-80 mesh sieve, added into a twin-screw extruder for extrusion, and then aged in an oven at 50-65° C. for 30-50 minutes, and naturally air-dried to obtain the seaweed feed with improved shrimp body color; The preparation method of the seaweed feed additive is carried out according to the following steps: krill meal, concentrated cottonseed protein, calcium dihydrogen phosphate, and complex vitamins are crushed by a crusher, passed through an 80-100 mesh sieve, and then brewer's yeast and sulfated seaweed polysaccharide are added to a mixer for mixed fermentation, and then put into a feed mixer for stirring for 10-40 minutes, chitosan and microalgae astaxanthin powder are added in sequence and continued to stir for 1-2 hours, and granulated by a feed granulator to obtain a seaweed feed additive for improving the body color of shrimp; The preparation method of the concentrated cottonseed protein is carried out according to the following steps: adding 110-140 parts by weight of a sodium hydroxide aqueous solution with a pH of 11-12 and 100 parts of cottonseed meal powder into a reaction flask, stirring evenly, placing in an ultrasonic generator for ultrasonic extraction, filtering while hot after the extraction is completed, adding hydrochloric acid to adjust the pH to 4.5-5, standing for 10-20 minutes, precipitating protein, centrifuging, and drying to obtain concentrated cottonseed protein; The preparation method of the sulfated seaweed polysaccharide is carried out according to the following steps: adding 100 parts of seaweed powder and 80-120 parts of deionized water into a reaction flask, stirring and dispersing them evenly, and performing water extraction reaction. After the reaction is completed, filtering while hot, collecting the filtrate, extracting the filter residue with 5-6 times the volume of deionized water for 3-8 hours, combining the filtrate, concentrating under reduced pressure, adding ethanol for precipitation, filtering, and drying to obtain the sulfated seaweed polysaccharide; The preparation method of the microalgae astaxanthin powder is carried out according to the following steps: adding 100 parts by weight of Haematococcus pluvialis powder and 150-250 parts of deionized water into a reaction flask, shaking in an oscillator for 20-40 minutes, adjusting the pH to 4-5 with 5-10% citric acid by mass, adding 1-3 parts of cellulase, performing enzymatic hydrolysis, filtering after the reaction, extracting with ethanol, the extraction temperature is 40-50° C., the extraction time is 30-60 minutes, combining the extracts, concentrating under reduced pressure, and drying to obtain the microalgae astaxanthin powder; The vitamin complex includes one or more of vitamin A, vitamin C and vitamin E.

2. The use of the seaweed feed additive for improving the body color of shrimp according to claim 1, characterized in that: In the preparation method of the seaweed feed additive, by weight, krill powder is 15-25 parts, concentrated cottonseed protein is 20-45 parts, calcium dihydrogen phosphate is 1.5-3 parts, complex vitamins are 2-4 parts, brewer's yeast is 2-5 parts, sulfated seaweed polysaccharide is 1-5 parts, chitosan is 0.5-2 parts, and microalgae astaxanthin powder is 2-10 parts.

3. The use of the seaweed feed additive for improving the body color of shrimp according to claim 1, characterized in that: The ultrasonic extraction temperature is 55-70°C, and the ultrasonic extraction time is 30-60min.

4. The use of the seaweed feed additive for improving the body color of shrimp according to claim 1, characterized in that: The water extraction reaction temperature is 75-100° C., and the water extraction reaction time is 8-16 hours.

5. The use of the seaweed feed additive for improving the body color of shrimp according to claim 1, characterized in that: The enzymatic hydrolysis reaction temperature is 35-60° C., and the reaction time is 10-25 h.

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