Composition for increasing nutrient content of living oysters and temporary culture method thereof

Abstract

The invention discloses a composition for increasing the nutrient content of living oysters and a temporary culture method of the composition, and belongs to the technical field of aquaculture. The corn oligopeptide powder, the molasses powder, the spirulina powder, the green alga powder, the photosynthetic bacteria and the EM bacteria are simultaneously added into the composition for increasing the nutrient content of the living oysters, the components have good interaction, when the composition is applied to temporary culture of the living oysters, the nutrient content of the living oysters can be increased by adding the composition with a certain mass volume concentration, and the nutrient content of the living oysters can be increased. According to the method, the content of delicious amino acid and the content of polyunsaturated fatty acid in the living oysters in the temporary rearing period can be effectively increased, the delicious characteristic and the nutritional characteristic of the oysters are strengthened, no chemical additive which is artificially synthesized or harmful to the human body is used in the temporary rearing period, and the eating safety can be guaranteed while the quality of the oysters is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and in particular relates to a composition for improving the nutrient content of living oysters and a temporary culture method thereof. Background Art

[0002] Oysters are high in protein and low in fat, earning them the reputation of “sea milk.” The amino acid and polyunsaturated fatty acid composition and content of the soft part of oysters are important indicators for evaluating the nutritional value of oysters and are also the main contributors to oyster flavor. In particular, as the main raw material for oyster sauce, the content of umami amino acids (aspartic acid, glycine, glutamic acid, and alanine) in the soft part of oysters has a significant impact on the quality of the sauce, and increasing the content of these amino acids is often the primary goal in the preparation of oyster sauce. Polyunsaturated fatty acids are a type of fatty acid beneficial to the human body, and a method for increasing the content of ω-3 polyunsaturated fatty acids by cultivating oysters in specific sea areas has been proposed (Publication No. CN117223659A). Therefore, developing efficient, low-cost, and synergistically controlled technologies for increasing the content of umami amino acids and polyunsaturated fatty acids in the soft part of living oysters can artificially improve the nutrition and flavor of oysters, contributing to the production of high-quality oyster sauce and the creation of high-end oyster brands.

[0003] The difference in taste and flavor of oysters mainly depends on the growth environment, such as water temperature, salinity, food source and other factors. The top French oyster, the "Belon oyster", has moved to different habitats many times during its life history, which has created a unique flavor; the fresh seawater in California, USA makes the farmed Kumamoto oysters taste refreshing, sweet and unique. At present, domestic research on oyster amino acids and polyunsaturated fatty acids is mostly seen in nutritional analysis and evaluation, and there is very little research on artificial regulation technology. By artificially regulating the nutrition and flavor of oysters, the economic value of oysters can be improved, while the nutritional content of oyster processed products can be increased, and processing efficiency can be improved. Therefore, a low-cost, fast-acting composition and method of use for synergistically improving the content of umami amino acids and polyunsaturated fatty acids in living oysters are urgently needed. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the prior art and provide a composition and a temporary culture method thereof that can effectively increase the content of umami amino acids and polyunsaturated fatty acids in the temporary culture of live oysters.

[0005] To achieve the above objectives, in a first aspect of the present invention, a composition for increasing the nutritional content of living oysters is provided, the composition comprising the following components:

[0006] Corn oligopeptide powder, molasses powder, spirulina powder, green algae powder, photosynthetic bacteria and EM bacteria.

[0007] The composition for increasing the nutritional content of living oysters provided by the present invention is characterized by the simultaneous addition of the above six components, which have good interaction between the components, thereby effectively increasing the content of umami amino acids and polyunsaturated fatty acids in the living oysters.

[0008] Specifically, corn oligopeptide powder can be directly filtered and absorbed by oysters, providing them with essential amino acids for survival and enhancing their immunity. Molasses powder is rich in carbohydrates and can serve as a carbon source for oysters. It can also serve as a carbon source for photosynthetic bacteria and EM bacteria. Spirulina powder and green algae powder have high nutritional value and high protein content and can be directly filtered and consumed by oysters. Photosynthetic bacteria and EM bacteria can effectively improve water quality, improve the oyster intestine, and enhance the oyster's immune capacity. The above components also interact well with each other. For example, molasses powder, spirulina powder, and green algae powder can serve as nutrients for photosynthetic bacteria and EM bacteria, thereby coordinating their interactions and jointly improving the nutrient content in oysters.

[0009] As a preferred embodiment of the composition of the present invention, the composition comprises the following components in parts by mass: 3-7 parts of corn oligopeptide powder, 0.5-3.5 parts of molasses powder, 0.5-3.5 parts of spirulina powder, 2-4 parts of green algae powder, 0.001-0.003 parts of photosynthetic bacteria, and 0.001-0.003 parts of EM bacteria.

[0010] The present invention has found that the mass fractions of the components in the composition affect the interactions between the components, thereby affecting the growth of live oysters. When the mass fractions of the components in the composition are further selected to be within the above range, the content of umami amino acids and polyunsaturated fatty acids in the live oysters obtained after temporary cultivation is higher.

[0011] As a preferred embodiment of the composition of the present invention, the spirulina powder includes Spirulina platensis powder.

[0012] For example, the Spirulina platensis powder can be Spirulina powder (feed grade) from Dongtai Cibainian Bioengineering Co., Ltd., Spirulina powder (food grade) from Henan China Resources Biotechnology Co., Ltd., Spirulina powder (food grade) from Fuqing Xindaze Spirulina Co., Ltd. When the Spirulina platensis powders from these different manufacturers are used under the same conditions, no significant differences in the effects obtained are observed in the technical solution of the present invention.

[0013] The present invention has found that the preferred spirulina powder is Spirulina platensis powder, which can better help improve the nutritional content of oysters after temporary culture. Specifically, the present invention speculates that, on the one hand, Spirulina platensis powder itself has relatively excellent nutritional components and good ecological benefits; on the other hand, it also interacts better with the remaining components. Therefore, when it is subsequently used in the temporary culture of live oysters, the quality of the resulting oysters is better.

[0014] As a preferred embodiment of the composition of the present invention, the green algae powder includes at least one of Chlorella powder and Nannochloropsis powder.

[0015] For example, the chlorella powder can be pyrenoid chlorella powder (food grade) from Shanghai Xintai Industrial Co., Ltd., pyrenoid chlorella powder (food grade) from Yunnan Baoshan Zeyuan Algae Health Technology Co., Ltd., or pyrenoid chlorella powder (food grade) from Guangdong Huasheng Food Co., Ltd. When the chlorella powders from the above-mentioned different manufacturers are used under the same conditions in the technical solution of the present invention, no significant difference in the effects is obtained.

[0016] The Nannochloropsis algae powder can be Nannochloropsis algae powder (cis-5,8,11,14,17-eicosapentaenoic acid EPA ≥ 3%) from Qingdao Kangyuan Microalgae Biotechnology Co., Ltd., Nannochloropsis algae powder (EPA ≥ 2%) from Shaanxi Guben Biotechnology Co., Ltd., or Nannochloropsis parasitica powder from Xiamen Bolu Biotechnology Co., Ltd. When the Nannochloropsis algae powders from the above-mentioned different manufacturers were used under the same conditions, no significant differences in the effects were observed.

[0017] The present invention has found that Chlorella powder and Nannochloropsis powder not only have relatively excellent photosynthesis and oxygen production capabilities, but also have relatively excellent nutritional value and the ability to regulate water quality. Therefore, when the green algae powder is further selected to include at least one of Chlorella powder and Nannochloropsis powder, the temporary culture effect of oysters can be better improved, and the content of umami amino acids and polyunsaturated fatty acids in the obtained temporary cultured oysters is higher.

[0018] As a preferred embodiment of the composition of the present invention, the photosynthetic bacteria include Rhodopseudomonas palustris.

[0019] The present invention has found that Rhodopseudomonas palustris can effectively purify water quality and degrade residual feed, excrement, etc. in the water. At the same time, it can also better promote the growth of oysters and promote the production and accumulation of nutrients in oysters. In addition, it can also effectively enhance the immunity of oysters and improve the health of oysters. When photosynthetic bacteria are further selected to include Rhodopseudomonas palustris, the quality of the temporarily cultured oysters is better.

[0020] For example, the Rhodopseudomonas palustris strain can be Q / 370683BZYSW002 from Yantai Beizhiyuan Biotechnology Co., Ltd. or Q / 320114NJRM013 from Nanjing Runmiao Biotechnology Co., Ltd.; when the present invention's technical solution uses Rhodopseudomonas palustris strains from these different manufacturers under the same conditions, the effects obtained are not significantly different.

[0021] It should be noted that the bacterial content of the photosynthetic bacteria is 300 million / mL-400 million / mL.

[0022] As a preferred embodiment of the composition of the present invention, the EM bacteria include at least one of Lactobacillus plantarum, Pediococcus pentosaceus, yeast, and Clostridium butyricum.

[0023] Preferably, the EM bacteria include Lactobacillus plantarum, yeast and Clostridium butyricum.

[0024] Preferably, the EM bacteria include Lactobacillus plantarum and Pediococcus pentosaceus.

[0025] For example, the EM bacteria may be Q / 320115NJHZ001 of Nanjing Haizhou Biotechnology Co., Ltd., Q / 370902SBL232 of Shandong Baolaililai Bioengineering Co., Ltd., etc.; when the technical solution of the present invention uses EM bacteria from different manufacturers under the same conditions, there is no significant difference in the effects obtained.

[0026] It should be noted that the bacterial content of the EM bacteria is 300 million / mL-400 million / mL.

[0027] In a second aspect of the present invention, the present invention provides use of the composition for increasing the nutritional content of living oysters.

[0028] As a preferred embodiment of the application of the present invention, the nutritional components include at least one of umami amino acids and polyunsaturated fatty acids.

[0029] Exemplarily, the umami amino acids include aspartic acid, glutamic acid, glycine, and alanine.

[0030] The polyunsaturated fatty acids include linoleic acid (C18:2n6c), α-linoleic acid (C18:3n3), cis-11,14-eicosatrienoic acid (C20:2), cis-11,14,17-eicosatrienoic acid (C20:3n3), cis-8,11,14,-eicosatrienoic acid (C20:3n6), arachidonic acid (C20:4n6), cis-5,8,11,14,17-eicosapentaenoic acid (C20:5n3), and arachidonic acid (C20:4n6).

[0031] It should be noted that the nutrient content of the oyster refers to the nutrient content of the soft part of the oyster. Specifically, the soft part includes all parts except the shell, including the gills, mantle, adductor muscle, gonads, digestive glands, etc.

[0032] In a third aspect, the present invention provides a method for temporarily culturing live oysters, comprising the following steps: cleaning oysters from natural sea areas and placing them in aquaculture water, adding the composition of the present invention to the aquaculture water for aquaculture; and a single addition amount of the composition is 6-19 g / L based on the volume of the aquaculture water.

[0033] The present invention has found that the temporary culture method provided by the present invention can effectively increase the content of umami amino acids and polyunsaturated fatty acids in living oysters after temporary culture, and in particular can effectively improve the nutritional quality of oysters.

[0034] It should be noted that temporary culture refers to the indoor culture of oysters for a certain period of time after they have grown to commercial specifications and have been harvested and cleaned.

[0035] Preferably, the fineness of the composition is ≥500 mesh, that is, the composition needs to be crushed and sieved after mixing to control the fineness of the composition to be ≥500 mesh.

[0036] As a preferred embodiment of the preparation method of the present invention, the salinity of the aquaculture water is 30-35.

[0037] It should be noted that the salinity of the aquaculture water refers to the total amount of dissolved salts in the water, which is obtained by testing with a salinometer.

[0038] It should be noted that aquaculture water within the above salinity range can be achieved by adding sea salt, inland salt or sodium chloride to the water.

[0039] The present invention has found that by selecting the salinity of aquaculture water within the above range, the survival of oysters can be better guaranteed, and the stress response caused by environmental changes in oysters after being caught from natural sea areas or aquaculture areas and placed in temporary holding ponds can be avoided; further, the addition of the composition in accordance with the single composition addition amount provided by the present invention can alleviate the impact of environmental changes on oysters, and can also better improve the growth ability of oysters and increase the content of nutrients in their bodies.

[0040] As a preferred embodiment of the preparation method of the present invention, during the breeding process, the composition is fed twice a day, and the interval between single feedings is 10-14 hours.

[0041] As a preferred embodiment of the preparation method of the present invention, when the temporary culture time is greater than 2 days, the water is changed every 2 days, and the volume of the changed water is 45-55% of the total volume of the culture water.

[0042] As a preferred embodiment of the preparation method of the present invention, the cleaning comprises: washing the oysters in the natural sea area to remove the surface mud and sand, intact organisms and algae, and eliminating dead individuals.

[0043] As a preferred embodiment of the preparation method of the present invention, the oyster farming density is 200-500 per cubic meter of water based on the volume of the farming water.

[0044] As a preferred embodiment of the preparation method of the present invention, oxygenation is continuously performed during the cultivation process.

[0045] Preferably, the oxygenation rate is 2-5 L air / min / cubic water.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The composition for improving the nutritional content of living oysters provided by the present invention is prepared by simultaneously adding corn peptide, molasses powder, spirulina powder, green algae powder, photosynthetic bacteria and EM bacteria. The components have good interaction. When the composition is applied to the temporary culture of living oysters, the addition of the composition at a certain mass volume concentration can effectively improve the content of umami amino acids and polyunsaturated fatty acids in the living oysters during the temporary culture period, thereby enhancing the umami characteristics and nutritional characteristics of the oysters. Moreover, no artificially synthesized or chemical additives harmful to the human body are used during the temporary culture period, thereby ensuring the edible safety of the oysters while improving the quality of the oysters. DETAILED DESCRIPTION

[0048] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0049] Unless otherwise specified, the reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in the art; and unless otherwise specified, the raw materials used in parallel experiments are from the same batch of raw materials.

[0050] Corn oligopeptide powder: purchased from Guangzhou Hecheng Industrial Co., Ltd.

[0051] Molasses powder: molasses fermentation concentrate dry powder (Type I) purchased from Guangxi Wanwei Biomass Technology Co., Ltd.

[0052] Spirulina powder 1: Spirulina platensis powder;

[0053] Spirulina powder 2: Maximal Spirulina powder, commercially available;

[0054] Green algae powder 1: Nannochloropsis powder;

[0055] Green algae powder 2: Chlorella powder;

[0056] Photosynthetic bacteria 1: Rhodopseudomonas palustris, purchased from Yantai Beizhiyuan Biotechnology Co., Ltd., product standard number Q / 370683BZYSW002-2025;

[0057] Photosynthetic bacteria 2: Rhodopseudomonas capsulatus, commercially available;

[0058] EM bacteria: The effective microbial community includes Lactobacillus plantarum, yeast and Clostridium butyricum, which were purchased from Nanjing Haizhou Biotechnology Co., Ltd. with the product standard number Q / 320115NJHZ001.

[0059] Live oysters: Omi oysters cultured in Laizhou ponds were caught, washed to remove surface sediment, intact organisms and algae, and dead individuals were eliminated. Oysters were then classified by size, and oysters of the same size were selected as the cleaned live oysters for the experiment of the present invention.

[0060] Examples 1-6 and Comparative Examples 1-4

[0061] The examples and comparative examples of the present invention provide a composition, the components (parts by mass) of the composition are shown in Table 1;

[0062] Table 1

[0063]

[0064]

[0065] The preparation method of the composition provided in Example 1 is: mixing the components uniformly to obtain the composition.

[0066] The synthesis methods of the compositions provided in Examples 2-6 and Comparative Examples 1-4 are consistent with that in Example 1, and if relevant components are not present, they may be omitted.

[0067] Application Example 1

[0068] An application example of the present invention provides a temporary culture method for live oysters, the temporary culture method comprising the following steps:

[0069] Preparation of aquaculture water: Sodium chloride was added to water to obtain aquaculture water with a salinity of 33, and then the composition was added to the aquaculture water (the composition prepared in Example 1, based on the volume of the aquaculture water, the single addition amount of the composition was 12.004 g / L). The cleaned live oysters were then placed in a temporary holding pond at a stocking density of 200 oysters / cubic meter of water for temporary stocking. During the stocking period, oxygen was continuously supplied at a rate of 3 L of air / min / cubic meter of water. The stocking period was 2 days. During the stocking process, dead individuals were checked and picked out every day, and the composition was fed every 12 hours.

[0070] Application Example 2

[0071] The application example of the present invention provides a temporary culture method for live oysters. The difference between the temporary culture method and the application example 1 is that the composition used is the composition prepared in Example 2, and the addition amount of the single composition is 11.004.

[0072] Application Example 3

[0073] The application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from the application example 1 in that the composition used is the composition prepared in Example 3, and the addition amount of the composition for a single time is 13.004.

[0074] Application Example 4

[0075] The application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Example 4.

[0076] Application Example 5

[0077] The application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Example 5.

[0078] Application Example 6

[0079] The application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Example 6.

[0080] Application Example 7

[0081] The application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of application example 1 in that the temporary culture period is 30 days, the water is changed every 2 days, and the replacement water volume is 50% of the total volume of the aquaculture water.

[0082] Comparative Application Example 1

[0083] The comparative application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Comparative Example 1.

[0084] Comparative Application Example 2

[0085] The comparative application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Comparative Example 2.

[0086] Comparative Application Example 3

[0087] The comparative application example of the present invention provides a temporary culture method for live oysters. The temporary culture method differs from that of Application Example 1 in that the composition used is the composition prepared in Comparative Example 3.

[0088] Control group 1

[0089] The control group of the present invention provides a temporary culture method for living oysters. The temporary culture method differs from that of Application Example 1 in that the aquaculture water used is the natural seawater in which the oysters originally live, and the composition is the composition prepared in Comparative Example 4.

[0090] Control group 2

[0091] The control group of the present invention provides a temporary culture method for living oysters. The difference between the temporary culture method and Application Example 7 is that the aquaculture water used is the natural seawater where the oysters originally live, and the composition is the composition prepared in Comparative Example 4.

[0092] Effect Examples

[0093] The present invention provides an effective example to test the content of umami amino acids and unsaturated fatty acids in the soft part of oysters after temporary culture in an application example, a comparative application example, and a treatment group; specifically, the following steps are included:

[0094] After temporary culture, the soft parts of the oysters were dissected and removed. Three oysters were collected in a group, with two parallel groups. The types, composition, and content of acid-hydrolyzed amino acids in the samples were determined according to GB 5009.1244-2016, "National Food Safety Standard - Determination of Amino Acids in Foods." The types, composition, and content of polyunsaturated fatty acids in the samples were determined according to GB 5009.168-2016, "National Food Safety Standard - Determination of Fatty Acids in Foods." The flavor characteristics of the amino acids were evaluated using the flavor intensity value (TAV), which is the ratio of the amino acid content to the amino acid taste threshold. The amino acid content (g / 100g) and TAV values ​​are shown in Table 2, and the unsaturated fatty acid content (g / 100g) is shown in Table 3.

[0095] Table 2

[0096]

[0097] Table 3

[0098]

[0099]

[0100] As can be seen from Tables 2-3, when the composition of the present invention is used for the corresponding temporary culture, the quality of the obtained oysters is significantly improved, as reflected in the significant increase in the content of umami amino acids and polyunsaturated fatty acids;

[0101] As can be seen from Application Examples 1-6, the mass fraction of the components in the composition and the specific types of the components in the composition will affect, to a certain extent, the content of umami amino acids and polyunsaturated fatty acids in the soft parts of the oysters after temporary culture. As can be seen from Application Example 1 and Comparative Application Examples 1-3, when a certain component is missing from the composition, the content of nutrients in the temporary cultured oysters cannot be effectively increased. As can be seen from Application Examples 1, Application Example 7 and Control Groups 1-2, the temporary culture method provided by the present invention can relatively effectively increase the content of umami amino acids and polyunsaturated fatty acids in the oysters after temporary culture, both in short-term and relatively long-term culture.

[0102] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A composition for increasing the nutritional content of living oysters, characterized in that: The composition comprises the following components: Corn oligopeptide powder, molasses powder, spirulina powder, green algae powder, photosynthetic bacteria and EM bacteria.

2. The composition according to claim 1, characterized in that The composition comprises the following components in parts by weight: 3-7 parts of corn oligopeptide powder, 0.5-3.5 parts of molasses powder, 0.5-3.5 parts of spirulina powder, 2-4 parts of green algae powder, 0.001-0.003 parts of photosynthetic bacteria, and 0.001-0.003 parts of EM bacteria.

3. The composition according to claim 1, characterized in that The spirulina powder includes Spirulina platensis powder; And / or, the green algae powder includes at least one of Chlorella powder and Nannochloropsis powder; and / or, the photosynthetic bacteria include Rhodopseudomonas palustris; And / or, the EM bacteria include at least one of Lactobacillus plantarum, Pediococcus pentosaceus, yeast, and Clostridium butyricum.

4. Use of the composition according to any one of claims 1 to 3 for increasing the nutritional content of living oysters.

5. The use according to claim 4, characterized in that The nutritional components include at least one of umami amino acids and polyunsaturated fatty acids.

6. A method for temporarily culturing live oysters, characterized in that: The temporary culture method comprises the following steps: cleaning oysters from natural sea areas and placing them in culture water, and adding the composition according to any one of claims 1 to 3 to the culture water for culture; Calculated based on the volume of the aquaculture water, the addition amount of the composition for a single time is 6-19 g / L.

7. The temporary raising method according to claim 6, wherein: The salinity of the aquaculture water is 30-35.

8. The temporary raising method according to claim 6, wherein: During the breeding process, the composition is fed twice a day, and the interval between single feedings is 10-14 hours.

9. The temporary raising method according to claim 6, wherein: When the temporary culture time is greater than 2 days, the water should be changed every 2 days, and the volume of water changed should be 45-55% of the total culture water volume.

10. The temporary raising method according to claim 6, characterized in that: Calculated by the volume of aquaculture water, the oyster farming density is 200-500 per cubic meter of water.

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