Method for producing fish feed by using kitchen residues

Abstract

The invention discloses a method for producing fish feed by using kitchen residues, and belongs to the technical field of aquaculture feed. The method comprises the following steps: (1) performing flotation on the kitchen waste to remove plastic impurities, and realizing efficient separation by adjusting the surface tension of flotation liquid, the solid-liquid ratio, the temperature and the stirring speed; (2) soaking the materials subjected to flotation at 60 DEG C for 3 days, and separating oil-containing and salt-containing wastewater; (3) drying, dehydrating and crushing; (4) adding alkaline protease for enzymolysis for 2 days, wherein the decomposed components are easily absorbed proteins; (5) culturing chlorella, nostoc globosa or euglena by using the oil-containing and salt-containing wastewater, drying and grinding; and (6) mixing the algae powder with the enzymolysis product, rice bran, rice husk and bacillus amyloliquefaciens, and granulating to obtain a finished product. Through cooperative treatment of kitchen waste recycling and algae culture, the feed cost is remarkably reduced, the utilization rate of organic matter and microelements is increased, and the obtained feed is balanced in nutrition and environmentally friendly, meets market requirements and has market prospects.

Description

Technical Field

[0001] The invention relates to the field of aquaculture feed production, and in particular to a method for producing fish feed by utilizing kitchen waste. Background Art

[0002] Problems with existing fish feed production methods include: (1) High dependence on natural resources. Traditional fish feed production often relies on large amounts of marine biological resources such as fish meal and fish oil. With the gradual reduction of fishery resources and the focus on sustainable development, this dependence faces the challenge of resource shortage. (2) High cost. High-quality fish meal and fish oil are expensive, which makes the production cost of fish feed high. This not only increases the economic burden of farmers, but also restricts the development of aquaculture to a certain extent. In addition, some special nutritional additives and processing technologies will also increase the cost of feed. (3) Complex production process and low efficiency. Some traditional feed production processes involve multiple complex steps, such as fine grinding, mixing, granulation, etc., which require a lot of time and energy. Moreover, some processes have high requirements for equipment and high equipment maintenance costs, resulting in low overall production efficiency.

[0003] In addition, existing fish feeds also have limitations in terms of nutritional composition, such as (1) Unbalanced organic matter content. Some existing fish feeds may have an imbalance in the content of organic matter such as protein and carbohydrates. For example, some feeds may have too high a protein content, which the fish cannot fully absorb and utilize, resulting in waste and water pollution. Or the type and content of carbohydrates are inappropriate and cannot meet the energy needs of fish at different growth stages. (2) Deficiency of trace elements and insufficient types and content of vitamins. Some important trace elements such as zinc, iron, selenium and vitamins are not present in sufficient amounts in some fish feeds. These deficiencies may lead to problems such as slow fish growth. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for producing fish feed using kitchen waste, which can effectively solve the problems raised in the above background technology.

[0005] To solve the above problems, the technical solution adopted by the present invention is: a method for producing fish feed using kitchen waste, comprising the following steps: S1. Raw material pretreatment: Place food waste in a flotation machine, add flotation fluid, adjust the surface tension of the flotation fluid to a solid-liquid ratio of 1:5-1:20, set the flotation temperature at 10-80°C, and stir at 100-2000 rpm. Perform flotation to remove floating debris. S2. Soaking for oil removal and desalination: Soak the flotation kitchen waste at 60°C for 3 days, and separate the oily and salty wastewater through an oil-water separation device; S3 drying and crushing: the deoiling and desalting of the food waste into the dryer for drying and dehydration at a temperature of 50-80 ° C for 2 days, and then into the grinder to a particle size of 20-100 mesh; S4. Enzymatic hydrolysis: alkaline protease was added to the pulverized food waste and treated at 35°C and pH 8 for 2 days; S5 algae culture: the oily and salty wastewater of step S2 is put into an algae culture container, inoculated with at least one of Chlorella, Nostoc spherical or Euglena, and cultured until the algae biomass reaches the standard and then collected and dried; S6. Mixing and granulation: Grind the dried algae and mix it with the enzymatically hydrolyzed food waste debris, add rice bran, rice husks and Bacillus amyloliquefaciens, stir and mix evenly, then put it into a granulator and granulate it at 50-90℃ and 0.1-2 MPa pressure to obtain the finished fish liquid feed.

[0006] Choosing food waste as fish feed offers significant advantages. First, it is widely available and low-cost. Food waste comes from various sources, including homes, restaurants, and canteens, generating significant amounts of waste daily. Using this waste as a raw material not only solves waste disposal issues but also reduces feed production costs. Compared to traditional ingredients like fish meal and fish oil, food waste is a virtually free resource, requiring only proper processing. Second, it is rich in nutrients. Food waste contains a wealth of organic matter, such as protein, carbohydrates, and fat. These nutrients, after processing, can provide comprehensive nutritional support for fish. For example, protein meets fish growth and development needs, carbohydrates provide energy, and the unsaturated fatty acids in fat are crucial for fish health. Using food waste to produce fish feed aligns with the concept of sustainable development. It reduces reliance on natural fishery resources, while also repurposing waste and reducing environmental impact. This recycling model contributes to a more environmentally friendly and sustainable aquaculture system.

[0007] Compared with the prior art, the present invention provides a method for producing fish feed using kitchen waste, which has the following beneficial effects: (1) Improve the utilization rate of organic matter. The present invention reuses the organic matter, salts and trace elements rich in kitchen waste, effectively improving the utilization rate of various substances in the kitchen waste and reducing resource waste.

[0008] (2) Rich in nutrients. The prepared feed has a high content of organic matter, trace elements, and vitamins. It is rich in organic matter such as amino acids, vitamins, short-chain starch, etc. that are essential for fish growth and are easily absorbed. It also contains rich trace elements and can meet the nutritional needs of fish at different growth stages.

[0009] (3) Low cost and easy to promote. This invention uses kitchen waste as raw material, which is widely available and low cost. The process is simple, the required equipment is relatively cheap, and the cost is low, making it easy to promote on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the processing flow of the present invention. DETAILED DESCRIPTION

[0011] If "and / or" or "and / or" appears in the full text, its meaning includes three parallel options. Taking "A and / or B" as an example, it includes option A, or option B, or options in which A and B are satisfied at the same time.

[0012] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0013] Reference Figure 1 The present invention provides a method for producing fish feed using kitchen waste, comprising the following steps: S1. Raw material pretreatment: Place food waste in a flotation machine, add flotation fluid, adjust the surface tension of the flotation fluid to a solid-liquid ratio of 1:5-1:20, set the flotation temperature at 10-80°C, and stir at 100-2000 rpm. Perform flotation to remove floating debris. S2. Soaking for oil removal and desalination: Soak the flotation kitchen waste at 60°C for 3 days, and separate the oily and salty wastewater through an oil-water separation device; S3 drying and crushing: the deoiling and desalting of the food waste into the dryer for drying and dehydration at a temperature of 50-80 ° C for 2 days, and then into the grinder to a particle size of 20-100 mesh; S4. Enzymatic hydrolysis: alkaline protease was added to the pulverized food waste and treated at 35°C and pH 8 for 2 days; S5 algae culture: the oily and salty wastewater of step S2 is put into an algae culture container, inoculated with at least one of Chlorella, Nostoc spherical or Euglena, and cultured until the algae biomass reaches the standard and then collected and dried; S6. Mixing and granulation: Grind the dried algae and mix it with the enzymatically hydrolyzed food waste debris, add rice bran, rice husks and Bacillus amyloliquefaciens, stir and mix evenly, then put it into a granulator and granulate it at 50-90℃ and 0.1-2 MPa pressure to obtain the finished fish liquid feed.

[0014] As a further preferred embodiment of the present invention, in step S1, the flotation liquid is an aqueous solution containing a surfactant, the solid-liquid ratio is 1:10, the flotation temperature is 40-60° C., and the stirring speed is 800-1500 rpm.

[0015] As a further preferred embodiment of the present invention, in step S3, the moisture content of the food waste after drying and dehydration is ≤10%, and the crushed particle size is 40-80 mesh.

[0016] As a further preferred embodiment of the present invention, in step S4, the amount of alkaline protease added is 0.5-2.0% of the dry weight of the kitchen waste.

[0017] As a further preferred embodiment of the present invention, in step S5, the culture is terminated when the algae culture density reaches 1×10^6-5×10^6 cells / mL, and the particle size of the algae powder after drying is 100-200 mesh.

[0018] As a further preferred embodiment of the present invention, in step S6, the mass ratio of the mixed materials is: 60-80% of enzymatically hydrolyzed food waste scraps, 10-20% of algae powder, 5-15% of rice bran, 3-8% of rice husk, and 0.1-0.5% of Bacillus amyloliquefaciens.

[0019] As a further preferred embodiment of the present invention, the granulation pressure in step S6 is 0.5-1.5 MPa, and the granulation temperature is 60-80°C.

[0020] As a further preferred embodiment of the present invention, the particle size of the finished fish liquid feed is 0.5-3 mm, and the moisture content is ≤8%.

[0021] As a specific embodiment of the present invention: Raw material processing process First, the food waste is floated to remove unusable waste, such as plastics. The flotation process effectively separates floating debris, such as plastics, from the food waste by adjusting flotation fluid composition, temperature, and agitation speed. The food waste is then soaked for oil removal and desalination at 60°C for three days. After soaking, the oil and water are separated using an oil-water separator, and the resulting oily and salty wastewater is collected for future use. The deoiled and desalinated food waste is then dried, dehydrated, and pulverized to a particle size of 20-100 mesh. The pulverized food waste is then mixed with protease and ground, and treated with the protease at 35°C in a weakly alkaline environment for two days.

[0022] Algae cultivation and mixing: Microorganisms such as Chlorella vulgaris, Nostoc sphaeroides, and Euglena are added to the oily and saline wastewater for cultivation. The cultivation process is monitored by regularly monitoring algae growth density, oil decomposition, and other indicators. After growth, the algae are collected, dried, ground, and added to the treated food waste in appropriate proportions.

[0023] 1. Flotation steps Put the collected food waste into the flotation machine, add an appropriate amount of flotation liquid [adjust the surface tension of the flotation liquid, solid-liquid ratio (1:5-1:20) and other conditions], adjust the temperature of the flotation machine to (10-80 ℃), and the stirring speed to (100-2000rpm), and perform flotation operation to remove floating objects such as plastic waste.

[0024] 2. Soaking degreasing and desalting steps The flotation kitchen waste was placed in a soaking container, emulsion was added, and the waste was soaked at 60 °C for 3 days. The oil and water were then separated by an oil-water separation device, and the oily and salty wastewater was collected for later use.

[0025] 3. Drying, dehydration and crushing steps The degreased and desalted food waste is placed in a dryer for drying and dehydration according to the dryer's operating parameters (e.g., temperature of 50-80°C, drying time of 2 days), and then placed in a grinder to reduce the particle size to 20-100 mesh.

[0026] 4. Protease treatment step Put the crushed food waste into a container, add alkaline protease, adjust the temperature to 35°C and the pH value to 8, and treat for 2 days.

[0027] 5. Algae cultivation steps Put the oily and salty wastewater into an algae cultivation container, add microorganisms such as Chlorella, Nostoc sphaeroides, and Nasturtium, and regularly test the growth density of the algae, the decomposition of oil and salt, and when the algae reproduce to an appropriate degree, collect and dry them.

[0028] 6. Mixing step Grind the dried algae and add it to the processed food waste in proportion. Then add a certain proportion of rice bran, rice husk and a small amount of Bacillus amyloliquefaciens and mix them evenly according to the working parameters of the blender (such as the stirring speed (100-1000rpm)).

[0029] 7. Granulation and packaging steps Put the evenly mixed materials into the pelletizer and pelletize them according to the working parameters of the pelletizer (such as pelletizing temperature of 50-90℃, pelletizing pressure of (0.1-2 Mpa), and then pack and store them to obtain the finished fish liquid feed.

[0030] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for producing fish feed using kitchen waste, characterized in that: The following steps are involved: S1. Raw material pretreatment: Place food waste in a flotation machine, add flotation fluid, adjust the surface tension of the flotation fluid to a solid-liquid ratio of 1:5-1:20, set the flotation temperature at 10-80°C, and stir at 100-2000 rpm. Perform flotation to remove floating debris. S2. Soaking for oil removal and desalination: Soak the flotation kitchen waste at 60°C for 3 days, and separate the oily and salty wastewater through an oil-water separation device; S3 drying and crushing: the deoiling and desalting of the food waste into the dryer for drying and dehydration at a temperature of 50-80 ° C for 2 days, and then into the grinder to a particle size of 20-100 mesh; S4. Enzymatic hydrolysis: alkaline protease was added to the pulverized food waste and treated at 35°C and pH 8 for 2 days; S5 algae culture: the oily and salty wastewater of step S2 is put into an algae culture container, inoculated with at least one of Chlorella, Nostoc spherical or Euglena, and cultured until the algae biomass reaches the standard and then collected and dried; S6. Mixing and granulation: Grind the dried algae and mix it with the enzymatically hydrolyzed food waste debris, add rice bran, rice husks and Bacillus amyloliquefaciens, stir and mix evenly, then put it into a granulator and granulate it at 50-90℃ and 0.1-2 MPa pressure to obtain the finished fish liquid feed.

2. The method for producing fish feed using kitchen waste according to claim 1, wherein: In step S1, the flotation liquid is an aqueous solution containing a surfactant, the solid-liquid ratio is 1:10, the flotation temperature is 40-60° C., and the stirring speed is 800-1500 rpm.

3. The method for producing fish feed using kitchen waste according to claim 1, wherein: In the step S3, the moisture content of the food waste after drying and dehydration is ≤10%, and the crushed particle size is 40-80 mesh.

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