Method for preparing functional fish feed based on synergy of saccharomycetes and sodium gluconate, feed prepared by method and application of feed

Abstract

The invention discloses a method for preparing a functional fish feed based on synergy of saccharomycetes and sodium gluconate as well as the prepared feed and application thereof, and belongs to the technical field of aquatic feed processing. The invention discloses a method for preparing a functional fish feed based on synergy of yeast thalli and sodium gluconate. The fish feed is prepared by combining the yeast thalli fermented by erythritol, the sodium gluconate and modified starch. According to the method for preparing the functional fish feed based on the synergy of the saccharomycetes and the sodium gluconate, the feed utilization rate is increased by 5-10%, and the weight gain rate reaches 7-9%.

Description

Technical Field

[0001] The present invention relates to the technical field of aquatic feed processing, and more specifically, to a method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, the feed prepared thereby, and its applications. Background Art

[0002] Freshwater fish, as one of the important aquatic products in China, play an important role in ensuring the supply of national aquatic products, increasing farmers' income, and promoting the development of rural economy. With the improvement of people's living standards, the demand for freshwater fish is increasing continuously, especially the demand for high-quality, green, and safe aquatic products is becoming increasingly prominent. The market scale is huge and has been growing continuously in recent years. According to market research data, the annual output of freshwater fish in China has exceeded 10 million tons, accounting for half of the total global freshwater fish production. With the increase in domestic consumption demand and the expansion of the export market, the market scale is expected to continue to maintain a stable growth trend.

[0003] In fish farming, the feed cost accounts for 60%-70% of the total production cost, and traditional feeds have the following core problems: High protein source dependence: mainly relying on high-cost raw materials such as fish meal and soybean meal, resulting in high costs. Insufficient functionality: ordinary feeds only meet basic nutritional needs, lack functions such as immune enhancement and antioxidant properties, and are prone to growth stagnation due to diseases or stress responses. Adhesive defects: traditional adhesives (such as carboxymethyl cellulose) have high costs and may leave chemical residues, affecting the health of fish.

[0004] The yeast cells (OD600≥50) generated during the production process of erythritol are usually directly discarded, but they are rich in protein (40-50%), nucleic acid, and β-glucan (10%-30%), resulting in serious waste of resources. Traditional erythritol fermentation processes require inactivation treatment of the cells, increasing energy consumption and costs.

[0005] Sodium gluconate is a colorless crystal or white powder obtained by enzymatic conversion from corn starch. It is easily soluble in water and slightly soluble in ethanol. Chemically, it belongs to carbohydrate derivatives and has various uses, especially in the food industry and the pharmaceutical field. Sodium gluconate is not only an effective food additive but also used in the manufacture of various nutritional supplements due to its good solubility and stability.

[0006] Therefore, it is an urgent problem for those skilled in the art to provide a method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, the feed prepared thereby, and its applications. Summary of the Invention

[0007] In view of this, the present invention provides a method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, as well as the feed prepared thereby and its application, which combines yeast cells after erythritol fermentation, sodium gluconate and modified starch to prepare fish feed.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, comprising the following steps: (1) Cell pretreatment: Take the erythritol fermentation broth and filter it through a ceramic membrane with a pore size of 0.1 μm to obtain the retained concentrated cell suspension with an OD600 of 150 - 200 and a pH value of 3.5 - 4.5; add 0.5 - 1% (mass / volume ratio) of sodium gluconate to the concentrated cell suspension, stir and mix evenly to obtain a mixed solution; (2) Construction of a highly viscous matrix: Add 6 - 10% (mass / volume ratio) of modified starch to the mixed solution, gelatinize it at 95 - 98 °C for 15 - 20 minutes to form a uniform colloid, and obtain a gelatinized material; (3) Drying and shaping: Spread the gelatinized material on a tray and place it in an oven at 50 - 70 °C for drying for 12 - 16 hours, controlling the final moisture content ≤ 10%; (4) Crush it to 30 - 60 meshes to obtain fish feed with uniform particles.

[0009] Further, the erythritol fermentation broth in step (1) is obtained by fermentation with Candida lipolytica.

[0010] Further, the modified starch in step (2) is phosphate starch.

[0011] Further, the functional fish feed prepared by the above method.

[0012] Further, the application of the functional fish feed in improving feed utilization rate and weight gain.

[0013] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, as well as the feed prepared thereby and its application, having the following beneficial effects: (1) Efficient resource utilization: The ceramic membrane directly retains live cells, avoids the sterilization step, retains the active components of the cells, and realizes the high-value utilization of the by-products of erythritol fermentation.

[0014] (2) Functional Synergy: Sodium gluconate can act as a biological cycle regulator, affecting the metabolism and biochemical reactions in cultured organisms by adjusting the water environment, thereby enhancing the resistance of cultured organisms and reducing the incidence of diseases. In addition, sodium gluconate can also enhance the immunity and antioxidant capacity of cultured organisms. The addition of sodium gluconate promotes the cross-linking of bacterial protein and modified starch to form a stable colloid, while enhancing the calcium and phosphorus absorption and digestion functions of fish.

[0015] (3) Cost and Safety Optimization: Replacing traditional adhesives with modified starch reduces raw material costs by 20-30% and has no risk of chemical residues.

[0016] (4) The feed utilization rate is increased by 5-10%, and the weight gain rate reaches 7-9%. Specific Embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] Erythritol Fermentation Broth: Refer to Patent 202111453794.3. When the glucose content in the fermentation broth ≤ 0.2 g / 100 mL, the fermentation ends (at this time it is erythritol fermentation broth), and erythritol is prepared.

[0019] Example 1 A method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, comprising the following steps: (1) Cell Pretreatment: Take the erythritol fermentation broth and filter it through a ceramic membrane with a pore size of 0.1 μm to obtain 200 mL of the retained concentrated bacterial liquid with an OD600 of 150 and a pH value of 3.5; add 1 g of sodium gluconate, stir for 5 min, and mix evenly to obtain a mixed solution.

[0020] (2) Construction of High-Viscosity Matrix: Add 12 g of phosphate starch to the mixed solution and gelatinize it at 95 °C for 15 minutes to form a transparent colloidal state, obtaining a gelatinized material.

[0021] (3) Drying and Crushing: Spread the gelatinized material on a tray, dry it in an oven at 50 °C for 16 hours, and crush it to 30-60 mesh to obtain feed pellets with a moisture content of 9.2%.

[0022] Through the breeding experiment (carp, 30 days), the feed utilization rate is increased by 5.1%, and the weight gain rate is increased by 7.3%.

[0023] Example 2 A method for synergistically preparing functional fish feed based on yeast cells and sodium gluconate, comprising the following steps: (1) Pretreatment of cells: Take the erythritol fermentation broth and filter it through a ceramic membrane with a pore size of 0.1 μm to obtain 200 mL of the retained concentrated cell solution with an OD600 of 170 and a pH value of 4.0; add 1.5 g of sodium gluconate, stir for 5 min, and mix evenly to obtain a mixed solution.

[0024] (2) Construction of high-viscosity matrix: Add 16 g of phosphate starch to the mixed solution and gelatinize it at 96 °C for 17 minutes to form a transparent colloidal state, obtaining a gelatinized material.

[0025] (3) Drying and pulverization: Spread the gelatinized material on a tray, place it in an oven and dry it at 60 °C for 14 hours, and pulverize it to 30 - 60 mesh to obtain feed particles with a moisture content of 8.2%.

[0026] Through the feeding experiment (carp, 30 days), the feed utilization rate is increased by 10.1%, and the weight gain rate is increased by 8.8%.

[0027] Example 3 A method for synergistically preparing functional fish feed based on yeast cells and sodium gluconate, comprising the following steps: (1) Take the erythritol fermentation broth and filter it through a ceramic membrane with a pore size of 0.1 μm to obtain 200 mL of the retained concentrated cell solution with an OD600 of 200 and a pH value of 4.5; add 2 g of sodium gluconate, stir for 5 min, and mix evenly to obtain a mixed solution.

[0028] (2) Construction of high-viscosity matrix: Add 20 g of phosphate starch to the mixed solution and gelatinize it at 98 °C for 20 minutes to form a transparent colloidal state, obtaining a gelatinized material.

[0029] (3) Drying and pulverization: Spread the gelatinized material on a tray, place it in an oven and dry it at 70 °C for 12 hours, and pulverize it to 30 - 60 mesh to obtain feed particles with a moisture content of 9.5%.

[0030] Through the feeding experiment (carp, 30 days), the feed utilization rate is increased by 7.6%, and the weight gain rate is increased by 7%.

[0031] Description of comparative experimental data: Experimental group: Feed the yeast cell - sodium gluconate functional fish feed prepared in Examples 1 - 3.

[0032] Control group: Feed the conventional carp expanded pellet feed (purchased from Tianjin Zhanwang Feed Co., Ltd.).

[0033] Sample size: Each group releases 10 healthy carps (weight 300 - 500 g, similar total weight), and they are separately raised in independent experimental ponds to avoid cross - interference.

[0034] Feeding method: Fixed-point feeding is carried out by an automatic bait feeder, feeding regularly at 8:00, 13:00, and 18:00 every day. The feeding rate for the first time each day (the percentage of the amount of feed fed to the total weight of the fish) is 3%, and the feeding rates for the next two times are 1% respectively. The water temperature is maintained at 22 - 25 °C. After 30 days of feeding, record and calculate the relevant parameters of each group of carp (10 tails), and the results are shown in Table 1.

[0035] Table 1

[0036] Feed utilization rate (FER) = average weight gain / feed consumption.

[0037] Feed improvement rate = (FER of the experimental group - FER of the control group) / FER of the control group * 100%.

[0038] Weight gain rate = (average weight gain of the experimental group - average weight gain of the control group) / average weight gain of the control group * 100%.

[0039] As can be seen from Table 1, the feed improvement rates of Examples 1 - 3 of the present invention are 5 - 10%, and the weight gain rates are 7 - 9%.

[0040] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate, characterized in that, Comprising the following steps: (1) Bacterial cell pretreatment: Take the erythritol fermentation broth and filter it through a ceramic membrane with a pore size of 0.1 μm to obtain the retained concentrated bacterial liquid with an OD600 of 150 - 200 and a pH value of 3.5 - 4.5; add 0.5 - 1% (mass / volume ratio) of sodium gluconate to the concentrated bacterial liquid, stir and mix evenly to obtain a mixed liquid; (2) Construction of high-viscosity matrix: Add 6 - 10% (mass / volume ratio) of modified starch to the mixed liquid, gelatinize it at 95 - 98 °C for 15 - 20 minutes to form a uniform colloid, and obtain the gelatinized material; (3) Drying and shaping: Spread the gelatinized material on a tray and place it in an oven at 50 - 70 °C for drying for 12 - 16 hours, controlling the final moisture content ≤ 10%; (4) Crush to 30 - 60 mesh to obtain fish feed with uniform particles.

2. The method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate according to claim 1, characterized in that, The erythritol fermentation broth described in step (1) is obtained by fermenting Candida lipolytica.

3. A method for synergistically preparing a functional fish feed based on yeast cells and sodium gluconate according to claim 1, characterized in that, The modified starch described in step (2) is phosphate starch.

4. A functional fish feed prepared by the method according to any one of claims 1 - 3.

5. Use of the functional fish feed according to claim 4 in improving feed utilization rate and weight gain.

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