Preparation method and application of long-lasting antibacterial fiber functional feed

Abstract

The present invention discloses a method for preparing a long-acting antibacterial fiber functional feed, which belongs to the technical field of biomass resource development and utilization. The present invention first mixes and stirs the agricultural and forestry wood fibers after crushing and screening with an ammoniating agent solution to obtain an ammoniated wood fiber pulp, which is dried to form an ammoniated wood fiber powder; then the ammoniated wood fiber powder is mixed and stirred with a citral solution to obtain a citral composite fiber pulp, which is dried after recovering the solvent to obtain a fiber functional feed. The present invention controls the degree of ammonia of the agricultural and forestry fibers and the amount of citral added and the moisture content, so that the fiber functional feed prepared has good stability, long-acting antibacterial properties and sustained release properties, and can effectively achieve the long-term shelf life of the fiber; at the same time, the fiber has good dispersibility and good storage stability at room temperature, can be added to fluids, semi-fluids and solids, has a wide range of applications, and has good application prospects in the fields of agricultural and forestry biomass resource development and utilization, feed processing industry, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass resource development and utilization, and particularly relates to a preparation method and application of a long-acting antibacterial fiber functional feed. Background Art

[0002] Vigorously developing agricultural and forestry fiber for food and feed production, using agricultural and forestry fiber as raw materials, is of strategic importance for further increasing the high-value utilization of agricultural and forestry biomass and partially replacing grain and feed. Agricultural and forestry wood fiber is primarily composed of cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are widely utilized by microorganisms. Therefore, fiber feeds are highly susceptible to environmental microbial attack during storage and transportation, leading to mold and deterioration, seriously impacting subsequent processing and utilization as food and feed. Therefore, developing efficient agricultural and forestry fiber preservation technologies is crucial for promoting the utilization of agricultural and forestry fiber for food and feed production.

[0003] Currently, feed preservation and freshness-keeping technologies primarily include the addition of chemical preservatives, vacuum packaging, and the addition of natural antimicrobials. As the harmful effects of chemical preservatives continue to be recognized, regulations regarding their use and dosage have become increasingly stringent in recent years. Once vacuum packaging is opened, the risk of spoilage persists over extended feeding cycles, effectively preventing the long-term preservation of feed. Natural plants and their extracts offer advantages as natural antimicrobial preservatives, including abundant resources, comprehensive functionality, high safety, minimal side effects, and a low risk of developing drug resistance. Compared to chemical preservatives, natural plants employ a more holistic, multi-target / multi-component antimicrobial mechanism, making them safer and more effective in treating complex diseases or disorders. Consequently, they offer significant advantages in comprehensively improving animal health, preventing disease, enhancing production performance, and improving product quality. Natural plant extracts can be broadly categorized based on their chemical structure into polyphenols, polysaccharides, terpenes, and alkaloids, sharing both common and unique characteristics in the aquaculture industry. Among them, plant polyphenols and essential oils have broad-spectrum bactericidal properties and are most widely used in feed preservation. Currently, oregano oil, carvacrol, thymol, cinnamaldehyde, lemon oil, chili oil, etc. are more commonly used. These ingredients have the functions of regulating enzyme activity, protecting intestinal villi, improving feed conversion efficiency, inhibiting the growth of harmful microorganisms, stimulating the reproduction of beneficial microorganisms, and improving the antioxidant capacity and storage time of meat.

[0004] Natural citral consists primarily of two configurations: α-citral (neral) and β-citral (geranial). These citral are primarily derived from oils such as Cymbopogon winterianus and Litsea cubeba. Litsea cubeba is a unique forest-derived spice resource in China, boasting an abundance of natural resources. The relative content of natural citral in Litsea cubeba oil can reach over 70%. Citral has a wide range of applications in food additives, plant growth hormones, daily chemicals, and pharmaceutical intermediates, exhibiting flavor enhancement, appetite attractant, antibacterial properties, and pheromone properties. Therefore, the introduction of citral as a fiber feed preservative offers advantages in terms of safety and multifunctionality. However, citral is highly volatile and chemically active, easily undergoing redox reactions to form geranic acid or geraniol / nerol. Consequently, its stability limits its widespread application.

[0005] Pretreating wood fiber with ammonia and its derivatives effectively disrupts the fiber structure and forms ammoniated lignin, which adsorbs into the fiber, forming an ammoniated wood fiber mixture (hereinafter collectively referred to as ammoniated wood fiber). Ammoniated lignin has amino and amide structures, which can form more stable Schiff base complexes with aldehyde groups. This invention uses agricultural and forestry wood fiber as raw material and citral as the primary antibacterial activator. By utilizing ammoniated treatment of the wood fiber and an aldehyde-amino Schiff base reaction, a more stable ammoniated wood fiber citral-Schiff base complex is obtained. This complex can be further decomposed into fiber and citral in an acidic environment and exhibits sustained-release citral. The invention also develops a method for preparing a long-lasting antibacterial citral fiber functional feed, which is beneficial for improving the efficient utilization of agricultural and forestry wood fiber and citral. The prepared fiber feed has excellent stability, long-lasting antibacterial properties, and sustained-release properties. It can also effectively extend the shelf life of agricultural and forestry fibers and has potential as an animal food attractant. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing a long-lasting antibacterial fiber functional feed. The method is simple, environmentally friendly, has good process stability, can be added to fluids, semi-fluids and solids, has a wide range of applications, and has good application prospects in the fields of agricultural and forestry biomass resource development and utilization, feed processing industry, etc.; another technical problem to be solved by the present invention is to provide an application of a fiber functional feed, which can be added to various formula feeds or used as a single feed.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] A method for preparing a long-lasting antibacterial fiber functional feed comprises the following steps: mixing crushed and screened agricultural and forestry wood fibers with an ammoniating agent solution to obtain an ammoniated wood fiber pulp, which is then dried to obtain an ammoniated wood fiber powder; then mixing the ammoniated wood fiber powder with a citral solution to obtain a citral composite fiber pulp, and recovering the solvent before drying to obtain the fiber functional feed.

[0009] Furthermore, the agricultural and forestry wood fibers include bamboo shoot shells, corn straw, caragana, and poplar; and the particle size after crushing and screening is 0.02-2 mm.

[0010] Furthermore, the type of the aminating agent is selected from one or more of urea, ammonium carbonate, ammonium bicarbonate, and ammonia water.

[0011] Furthermore, the mass ratio of the agricultural and forestry wood cellulose to the ammoniating agent solution is 1:0.05~0.2; the reaction temperature of the agricultural and forestry wood fiber and the ammoniating agent solution is 100~140°C, the closed fumigation reaction time is 0.5~4 hours; and the drying temperature of the ammoniated wood fiber pulp is 50~90°C.

[0012] Furthermore, the solid content of the ammoniated wood fiber pulp accounts for 18% to 27% of the total content; the pH of the ammoniated wood fiber pulp is 8 to 11; and the water content of the ammoniated wood fiber powder accounts for 1% to 10% of the total content.

[0013] Furthermore, the mass ratio of the ammoniated wood fiber powder to the citral solution is 1:0.005-0.05; the reaction temperature of the ammoniated wood fiber powder and the citral solution is 80-120°C, and the closed fumigation reaction time is 0.5-6 h.

[0014] Furthermore, the solvent of the citral solution is selected from one or more of ethanol and ethyl acetate; and the mass fraction of the citral solution is 10% to 50%.

[0015] Furthermore, the drying temperature of the citral composite fiber pulp is 50-80° C.; and the moisture content of the fiber functional feed accounts for 1%-10% of the total content.

[0016] Furthermore, any of the above-mentioned methods for preparing long-acting antibacterial fiber functional feed can produce fiber functional feed.

[0017] Furthermore, the fiber functional feed can be added to various formula feeds or used as a single feed.

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

[0019] (1) The present invention utilizes agricultural and forestry fibers, which are abundant in source and low in price, as raw materials. The production process is simple and easy, which is conducive to the high-value utilization of agricultural and forestry biomass resources.

[0020] (2) The preparation method of the present invention is simple, environmentally friendly, and has good process stability. By controlling the degree of ammoniaization of agricultural and forestry fibers and the amount of citral added and the moisture content, the prepared fiber functional feed has good stability, long-term antibacterial properties, and sustained release properties, which can effectively achieve the long-term shelf life of the fiber.

[0021] (3) The fiber of the present invention has good dispersibility and good storage stability at room temperature. It can be added to fluids, semi-fluids and solids and has a wide range of applications.

[0022] (4) The main raw materials used in the present invention meet the requirements of feed raw materials and additives. The prepared fiber functional feed has rich ammonia nitrogen content and can be mainly used in the field of feed for ruminants such as cattle and sheep. The present invention has good application prospects in the fields of agricultural and forestry biomass resource development and utilization, feed processing industry, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an infrared comparison image of the long-acting antibacterial fiber functional feed prepared in Example 1 of the present invention and its intermediate products and raw materials;

[0024] Figure 2 This is an infrared comparison image of the long-acting antibacterial fiber functional feed and its intermediates and raw materials prepared in Example 2 of the present invention;

[0025] Figure 3 This is an infrared comparison image of the long-acting antibacterial fiber functional feed and its intermediates and raw materials prepared in Example 3 of the present invention;

[0026] Figure 4 This is an infrared comparison image of the long-acting antibacterial fiber functional feed and its intermediates and raw materials prepared in Example 4 of the present invention;

[0027] Figure 5 This is a diagram showing the release of citral from the long-acting antibacterial fiber functional feed prepared in Examples 1-4 of the present invention in artificial simulated rumen fluid;

[0028] Figure 6 This is a graph showing the changes in the total mold count of the long-acting antibacterial fiber functional feed prepared in Examples 1-4 of the present invention and its raw materials during open storage. DETAILED DESCRIPTION

[0029] The present invention will be further illustrated below with reference to specific examples. The examples are implemented based on the technical solutions of the present invention. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0030] Example 1

[0031] 50 g (calculated on a dry basis) of crushed and sieved corn straw powder with a particle size of 0.05-1 mm was slowly added to 300 mL of a 2% ammonia solution and fumigated in a sealed container at 120°C for 1 h to obtain an ammoniated wood fiber pulp with a solid content of 18% and a pH value of approximately 11. The pulp was further hot-air dried at 70°C to obtain approximately 59 g of ammoniated wood fiber powder with a moisture content of 5%. Subsequently, 12.5 mL of a 20% citral ethanol solution was added and fumigated in a sealed container at 100°C for 2 h. The pulp was dried at 60°C to a moisture content of 5%, resulting in approximately 60 g of a fiber-functional feed (derived from corn straw) with long-lasting shelf life.

[0032] Example 2

[0033] 100 g (calculated on a dry basis) of crushed and sieved bamboo shoot shell powder with a particle size of 0.02-0.5 mm was slowly added to 500 mL of a 4% urea and 1% ammonia solution, and the mixture was fumigated in a closed manner at 140°C for 0.5 h to obtain an ammoniated wood fiber pulp with a solid content of 25% and a pH value of approximately 9. The mixture was further hot-air dried at 50°C to obtain approximately 136 g of ammoniated wood fiber powder with a moisture content of 10%. Subsequently, 4 mL of a 50% citral ethyl acetate solution was added and the mixture was fumigated in a closed manner at 80°C for 6 h. The mixture was dried at 80°C to a moisture content of 10%, resulting in approximately 137 g of a fiber-functional feed (derived from bamboo shoot shells) with long-lasting shelf life.

[0034] Example 3

[0035] 20 g (calculated on a dry basis) of crushed and sieved caragana powder with a particle size of 0.1-2 mm was slowly added to 100 mL of an aqueous solution containing 1% ammonium carbonate and 1% urea. The mixture was fumigated in a closed manner at 100°C for 4 h to obtain an ammoniated wood fiber pulp with a solid content of 22% and a pH value of approximately 8. The pulp was further hot-air dried at 90°C to obtain approximately 22 g of ammoniated wood fiber powder with a moisture content of 1%. Subsequently, 1 mL of a 10% citral ethanol solution was added and the mixture was fumigated in a closed manner at 120°C for 0.5 h. The pulp was dried at 90°C to a moisture content of 1%, resulting in approximately 22 g of a fiber-functional feed (derived from caragana) with long-lasting shelf life.

[0036] Example 4

[0037] 1 kg (calculated on a dry basis) of crushed and sieved poplar wood powder with a particle size of 0.05-2 mm was slowly added to 4 L of a 1% ammonium bicarbonate and 1% ammonia solution, and fumigated in a closed manner at 130°C for 2 hours to obtain an ammoniated wood fiber pulp with a solid content of 27% and a pH value of approximately 10. The pulp was further hot-air dried at 80°C to obtain approximately 1.1 kg of ammoniated wood fiber powder with a moisture content of 4%. Subsequently, 100 mL of a 25% citral ethanol solution was added and fumigated in a closed manner at 100°C for 3 hours. The pulp was dried at 80°C to a moisture content of 4%, resulting in approximately 1.12 kg of a fiber-functional feed (from poplar wood) with long-lasting shelf life.

[0038] Example 5

[0039] The infrared spectra of the fiber functional feed with long-term shelf life and its corresponding raw materials and intermediate products obtained in Examples 1-4 above are as follows: Figure 1-4 As shown, the following characterization analyses were performed:

[0040] By the attached Figure 1-4 It can be seen that the infrared absorption peaks of wood fiber before and after ammoniation are similar, but the absorption intensities are different. The fiber functional feed with long-term shelf life prepared after citral treatment has greater differences. Specifically, after ammoniation of wood fiber, the absorption peaks at 1720 cm -1 The carbonyl absorption peaks in the surrounding areas are all weakened, indicating that the carbonyl groups in the wood fiber are reduced after amination. -1 The spectral band at 1630-1680 cm is weakened, indicating that the methoxy content is reduced. -1 The region is a typical Schiff base bond (C=N) absorption peak. Figure 1-4 In this region, there is an obvious absorption peak enhancement, which proves the formation of citral wood fiber Schiff base structure; at 1420 cm -1 Carbon-nitrogen bond (CN) stretching vibration absorption bands appeared in the nearby areas, suggesting that by-products such as amide structures may have been formed at the same time.

[0041] Example 6

[0042] The fiber functional feed with long-term shelf life obtained in Examples 1-4 was subjected to an in vitro simulated release test. Figure 5 As shown, the analysis is as follows:

[0043] Feed typically remains in the rumen of cattle for no more than 24 hours. An artificial rumen fluid system was used to simulate the initial digestive environment of ruminants to investigate the 24-hour release of citral from fiber-functionalized feeds with long-lasting shelf life. The artificial rumen fluid system was based on ELITE-MEDIA clarified bovine rumen fluid, with the addition of a complex enzyme system (including cellulase, xylase, pectinase, amylase, and protease) to simulate the initial digestive environment of cattle. Specific conditions included a pH adjustment between 6.0 and 6.5, a constant temperature of 39°C, and continuous oscillation at 1 to 3 times per minute to simulate rumen peristalsis. Results showed that citral from the four fiber-functionalized feeds with long-lasting shelf life was primarily released at a uniform rate over 24 hours, with no "burst release" observed. The corn straw-derived fiber-functionalized feed had the highest cumulative citral release rate, reaching 80.5%, followed by the poplar wood and bamboo shoot shell-derived fiber-functionalized feeds. The caragana-derived fiber-functionalized feed had the lowest cumulative citral release rate, at 61.2%.

[0044] Example 7

[0045] The antibacterial effect of the fiber functional feed with long-term shelf life obtained in Examples 1-4 above was studied in open storage. Figure 6 As shown, the analysis is as follows:

[0046] According to GB13078-2017 National Feed Hygiene Standard for Microbial Contaminants in Cereals and Other Processed Products, the total number of molds is less than 4×10 4 CFU / g. The total mold count is the most important microbial indicator affecting the quality of fiber feed. A comparison was made of the fiber functional feeds with long-term shelf life obtained from four wood fiber sources using Examples 1-4 of the present invention. The results showed that the total mold counts of the four fiber functional feeds prepared by the present invention were far below the national standard of 4×10- 4 The total number of molds in the four wood fiber raw materials exceeded the limit after 30 days of open storage.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a long-lasting antibacterial fiber functional feed, characterized by: The crushed and screened agricultural and forestry wood fiber is mixed and stirred with an ammoniating agent solution to obtain an ammoniated wood fiber pulp, which is dried to obtain an ammoniated wood fiber powder; the ammoniated wood fiber powder is then mixed and stirred with a citral solution to obtain a citral composite fiber pulp, and the solvent is recovered and dried to obtain a fiber functional feed; the mass ratio of the agricultural and forestry wood fiber to the ammoniating agent solution is 1:0.05-0.2, the reaction temperature of the agricultural and forestry wood fiber and the ammoniating agent solution is 100-140°C, the closed fumigation reaction time is 0.5-4 h, and the drying temperature of the ammoniated wood fiber pulp is 50-90°C; the solid content of the ammoniated wood fiber pulp accounts for 18%-27% of the total content; the pH of the ammoniated wood fiber pulp is 8-11; the water content of the ammoniated wood fiber powder accounts for 1%-10% of the total content; the mass ratio of the ammoniated wood fiber powder to the citral solution is 1:0.005-0.05, and the reaction temperature of the ammoniated wood fiber powder and the citral solution is 80-120 ℃, the closed fumigation reaction time is 0.5~6 h.

2. The method for preparing a long-acting antibacterial fiber functional feed according to claim 1, characterized in that: The agricultural and forestry wood fibers include bamboo shoot shells, corn straw, caragana, and poplar wood; and the particle size after crushing and screening is 0.02-2 mm.

3. The method for preparing a long-acting antibacterial fiber functional feed according to claim 1, characterized in that: The type of the aminating agent is selected from one or more of urea, ammonium carbonate, ammonium bicarbonate, and ammonia water.

4. The method for preparing a long-acting antibacterial fiber functional feed according to claim 1, characterized in that: The solvent of the citral solution is selected from one or more of ethanol and ethyl acetate; the mass fraction of the citral solution is 10% to 50%.

5. The method for preparing a long-acting antibacterial fiber functional feed according to claim 1, characterized in that: The drying temperature of the citral composite fiber pulp is 50-80° C.; the moisture content of the fiber functional feed accounts for 1%-10% of the total content.

6. The method for preparing a long-acting antibacterial fiber functional feed according to any one of claims 1 to 5, wherein the fiber functional feed is prepared.

7. Use of the fiber functional feed according to claim 6 in addition to various formula feeds or as a single feed.

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