Method for rapidly degrading apple pomace fibers to improve nutrient digestibility and fermented feed

Abstract

The invention relates to the technical field of biology, in particular to a method for rapidly degrading apple pomace fibers to improve nutrient digestibility and a fermented feed. The method comprises the following steps: uniformly mixing apple pomace with wheat bran and urea to obtain a fermentation material; adjusting the water content of the fermented material to 65-70%, inoculating 5-12% of lactobacillus plantarum, 1-10% of saccharomyces cerevisiae and 1-5% of bacillus subtilis, adding 1-1.5% of cellulase, 0.5-1% of pectinase, 0.5-1% of xylanase and 0.1-0.5% of beta-glucanase, and carrying out solid-state fermentation at 30-35 DEG C for more than or equal to 48 hours. According to the method disclosed by the invention, the content of crude protein is remarkably increased, and the fiber degradation rate and the nutrient digestibility are also remarkably improved. According to the method, the apple pomace can be converted into the high-digestibility feed, and an important foundation is laid for applying the apple pomace as a feed grain substitute raw material to the feed in a large scale.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, and in particular to a method for rapidly degrading apple pomace fiber to improve nutrient digestibility and a fermented feed. Background Art

[0002] Apple pomace is the main by-product in the apple processing process, commonly found in apple deep processing industries such as juice production and canned food production. After apples go through processes such as crushing, juicing, and filtering, the remaining solid matter is apple pomace, which is mainly composed of fruit peel, fruit core, pulp fiber, and a small amount of incompletely extracted juice, usually presenting as a light brown or brown wet residue with a soft texture and certain viscosity. Apple pomace contains various nutrients, mainly including protein, crude fiber, crude fat, organic acids, soluble sugars, phosphorus, polyphenols, flavonoids, as well as various vitamins and trace elements, and has currently been widely used in the production of pigs, ruminants, and poultry. However, due to its high proportion of lignocellulose and the presence of anti-nutritional factors such as tannins, the addition amount of apple pomace in animal feed cannot be too much to avoid affecting the animal's nutritional balance and health.

[0003] Wang Xiaoli et al. used apple pomace and brewer's grains as fermentation substrates, and Trichoderma reesei, Aspergillus niger, and Candida utilis as fermentation strains. The crude protein content of the fermented feed obtained by solid-state fermentation under optimal conditions increased by 34.52%, and the acidic and neutral cellulose contents decreased by 22.93% and 9.08% respectively. Although this method can increase the crude protein content, its effect on the degradation of neutral fiber is limited.

[0004] Chang Liang et al. selected Geotrichum candidum, Saccharomyces cerevisiae, Rhizopus sp., Bacillus subtilis, Trichoderma viride, etc. as fermentation strains, and fermented apple pomace with different mixing ratios of single strain, two strains, 5 strains, etc. The results showed that the ratio of Geotrichum candidum:Saccharomyces cerevisiae:Rhizopus sp.:Bacillus subtilis:Trichoderma viride of 2.0:2.0:0.5:0.5:1.0, fermented at 31°C for 72 h under natural pH conditions, had the best effect, and the protein content in the fermentation product could reach up to 15.15%, an increase of 89.72% compared with that before fermentation. Although this method can better increase the crude protein content, its effect on the degradation of fiber in apple pomace is not clear.

[0005] Currently, although a large number of studies on apple pomace fermented feed have been carried out, due to different sources, combination methods, and ratios of strains, there are significant differences in fermentation conditions and fermentation effects, and most of the existing studies aim mainly at increasing the crude protein content in apple pomace fermented feed.

[0006] To promote the large - scale application of apple pomace as a substitute raw material for feed grains in feed, it is necessary not only to increase the content of nutrients such as crude protein, but also to significantly reduce the content of lignocellulose. Therefore, there is still an urgent need for an effective method to improve the fiber degradation rate and nutrient digestibility of apple pomace. Summary of the Invention

[0007] The main purpose of the present invention is to provide a method and fermented feed for rapidly degrading apple pomace fiber and improving nutrient digestibility. The method of the present invention uses Lactobacillus plantarum, Saccharomyces cerevisiae and Bacillus subtilis as fermentation inoculants, and cooperates with non - starch polysaccharide enzyme complex to carry out solid - state fermentation on apple pomace. In the obtained fermented feed, not only the crude protein content increases significantly, but also the fiber degradation rate and nutrient digestibility are both significantly improved. The present invention lays an important foundation for the large - scale application of apple pomace as a substitute raw material for feed grains in feed.

[0008] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0009] In the first aspect of the present invention, a bacterial - enzyme complex preparation for rapidly degrading apple pomace fiber and improving nutrient digestibility is provided. Calculated by weight, the bacterial - enzyme complex preparation includes the following components: 5 - 12 parts of Lactobacillus plantarum, 1 - 10 parts of Saccharomyces cerevisiae, 1 - 5 parts of Bacillus subtilis, 1 - 1.5 parts of cellulase, 0.5 - 1 part of pectinase, 0.5 - 1 part of xylanase, and 0.1 - 0.5 part of β - glucanase.

[0010] In the second aspect of the present invention, a method for rapidly improving the fiber degradation rate and nutrient digestibility of apple pomace is provided. The method includes fermenting apple pomace with the bacterial - enzyme complex preparation described in the first aspect.

[0011] Further, the method includes the following steps: uniformly mixing apple pomace with wheat bran and urea to obtain a fermentation material; adjusting the water content of the fermentation material to 65% - 70%, inoculating 5% - 12% of Lactobacillus plantarum, 1% - 10% of Saccharomyces cerevisiae and 1% - 5% of Bacillus subtilis, adding 1% - 1.5% of cellulase, 0.5% - 1% of pectinase, 0.5% - 1% of xylanase, and 0.1% - 0.5% of β - glucanase, and carrying out solid - state fermentation at 32 - 36 °C for ≥48 h.

[0012] The present invention selects the above-mentioned enzyme-bacteria complex preparation in the first aspect to ferment apple pomace. The enzyme used is non-starch polysaccharide enzyme. Through screening, it is found that the combination of cellulase, pectinase, xylanase and β-glucanase in non-starch polysaccharide enzyme has the best effect on the degradation of apple pomace fiber. Taking the degradation rate of neutral detergent fiber (NDF) as the response index, six factors including fermentation temperature, fermentation time, water content of the fermentation material, inoculation amount of Saccharomyces cerevisiae, inoculation amount of Bacillus subtilis, and inoculation amount of Lactobacillus plantarum are screened. It is found that the three factors of water content of the fermentation material, inoculation amount of Saccharomyces cerevisiae and inoculation amount of Lactobacillus plantarum have the most significant influence on the NDF degradation rate. By screening, within the above-mentioned ranges of water content of the fermentation material, inoculation amount of Saccharomyces cerevisiae and inoculation amount of Lactobacillus plantarum, the NDF degradation rate in apple pomace can be significantly increased, and the crude protein content and the digestibility of various nutrients can be improved.

[0013] In the third aspect of the present invention, there is provided a fermented feed prepared by the method described in the first aspect above.

[0014] Compared with the prior art, the present invention has the following technical advantages:

[0015] The method of the present invention can significantly improve the fiber degradation rate and nutrient digestibility in apple pomace. By fermenting with the above-mentioned enzyme-bacteria complex preparation, the degradation rate of neutral detergent fiber in the apple pomace can be as high as 39.60%, and the degradation rate of acid detergent fiber is 33.84%. The nutritional value of the obtained fermented feed is evaluated by in vitro rumen fermentation experiment. After 24 hours of in vitro rumen fermentation, its dry matter digestibility is 62.89%, neutral detergent fiber digestibility is 50.87%, acid detergent fiber digestibility is 38.56%, and crude protein digestibility is 75.10%, which are increased by 22.88%, 34.04%, 42.92% and 61.54% respectively compared with before fermentation; moreover, compared with before fermentation, the crude protein content after fermentation is increased by 104%. In addition, the fermentation cycle of the method of the present invention is relatively short, and the above-mentioned effects can be achieved only after 48 hours of fermentation. The method of the present invention can convert apple pomace into feed with high digestibility, which is beneficial to alleviating the shortage of protein resources in animal husbandry and reducing the pollution of fruit and vegetable processing waste at the same time. Detailed implementation manners

[0016] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0017] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should also be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, and / or combinations thereof.

[0018] To solve the problems described in the background art, a first aspect of the present invention provides a bacterial enzyme complex preparation for rapidly degrading apple pomace fibers and improving nutrient digestibility. In parts by weight, the bacterial enzyme complex preparation includes the following components: 5-12 parts of Lactobacillus plantarum, 1-10 parts of Saccharomyces cerevisiae, 1-5 parts of Bacillus subtilis, 1-1.5 parts of cellulase, 0.5-1 part of pectinase, 0.5-1 part of xylanase, and 0.1-0.5 part of β-glucanase.

[0019] As a preferred embodiment, the viable cell counts of Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis are 1×10 7 -1×10 8 CFU / mL.

[0020] A second aspect of the present invention provides a method for rapidly degrading apple pomace fibers and improving nutrient digestibility. The method includes fermenting apple pomace with the bacterial enzyme complex preparation described in the first aspect.

[0021] As a preferred embodiment, the method includes the following steps: uniformly mixing apple pomace with wheat bran and urea to obtain a fermentation material; adjusting the water content of the fermentation material to 65%-70%, inoculating 5%-12% of Lactobacillus plantarum, 1%-10% of Saccharomyces cerevisiae, and 1%-5% of Bacillus subtilis, adding 1%-1.5% of cellulase, 0.5%-1% of pectinase, 0.5%-1% of xylanase, and 0.1%-0.5% of β-glucanase, and performing solid-state fermentation at 32-36°C for ≥48 h.

[0022] As a preferred embodiment, the water content of the fermentation product is adjusted to 67%-70%, the inoculation amount of Lactobacillus plantarum is 10%-12%, the inoculation amount of Saccharomyces cerevisiae is 1%-10%, the inoculation amount of Bacillus subtilis is 2%, 1.2% of cellulase, 0.7% of pectinase, 0.5% of xylanase, and 0.3% of β-glucanase are added, and solid-state fermentation is performed at 32-36°C for 48-96 h.

[0023] As a preferred embodiment, the mass ratio of apple pomace to wheat bran is 5-10:1-3.

[0024] As a preferred embodiment, the urea addition amount is 1%-5%.

[0025] As a preferred embodiment, before inoculation, it further includes sterilizing the fermented material.

[0026] As a preferred embodiment, adjust the water content of the fermented product to 67%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 10%, and perform solid-state fermentation at 32 °C for 48 h.

[0027] As a preferred embodiment, adjust the water content of the fermented product to 70%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 1%, and perform solid-state fermentation at 36 °C for 96 h.

[0028] As a preferred embodiment, adjust the water content of the fermented product to 65%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 3%, and perform solid-state fermentation at 32 °C for 48 h.

[0029] As a preferred embodiment, adjust the water content of the fermented product to 65%, the inoculation amount of Lactobacillus plantarum to 8%, the inoculation amount of Saccharomyces cerevisiae to 5%, and perform solid-state fermentation at 32 °C for 48 h.

[0030] The present invention also provides the fermented feed prepared by the above-mentioned method.

[0031] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with specific examples.

[0032] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods.

[0033] Unless otherwise specified, the materials, reagents, etc. used in the following examples can all be obtained from commercial channels.

[0034] In the following examples, unless otherwise specified, the percentage (%) refers to the weight percentage relative to the composition.

[0035] Cellulase (10000 U / g), pectinase (60000 U / g), xylanase (100000 U / g), and β-glucanase (50000 U / g) are all commercial enzymes.

[0036] The Lactobacillus plantarum used in the following examples was purchased from the General Microbiology Center of the China Committee for Culture Collection of Microorganisms, and the viable count of the inoculated Lactobacillus plantarum was 3.15×10 7 CFU / mL; the commercial number of the Saccharomyces cerevisiae used was BNCC 300560, purchased from Beina Chuanglian Biotechnology Co., Ltd. in the mall, and the viable count of the inoculated Saccharomyces cerevisiae was 2.5×10 7CFU / mL; Bacillus subtilis, purchased from the General Microbiology Center of the China Committee for Culture Collection of Microorganisms, with the preservation number CGMCC 1.9086, and the viable count of Bacillus subtilis inoculated was 2.2×10 7 CFU / mL.

[0037] Example 1

[0038] A method for rapidly degrading apple pomace fiber to improve nutrient digestibility, the method comprising: mixing apple pomace and wheat bran in a mass ratio of 8:2, adding 2% urea, mixing evenly to obtain a fermentation material, and sterilizing the obtained fermentation material; adjusting the water content of the fermentation material to 67%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 10%, the inoculation amount of Bacillus subtilis to 2%, adding 1.2% cellulase, 0.7% pectinase, 0.5% xylanase, 0.3% β-glucanase, and performing solid-state fermentation at 32 °C for 48 h.

[0039] Example 2

[0040] A method for rapidly degrading apple pomace fiber to improve nutrient digestibility, the method comprising: mixing apple pomace and wheat bran in a mass ratio of 8:2, adding 2% urea, mixing evenly to obtain a fermentation material, and sterilizing the obtained fermentation material; adjusting the water content of the fermentation material to 70%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 1%, the inoculation amount of Bacillus subtilis to 2%, adding 1.2% cellulase, 0.7% pectinase, 0.5% xylanase, 0.3% β-glucanase, and performing solid-state fermentation at 36 °C for 96 h.

[0041] Example 3

[0042] A method for rapidly degrading apple pomace fiber to improve nutrient digestibility, the method comprising: mixing apple pomace and wheat bran in a mass ratio of 8:2, adding 2% urea, mixing evenly to obtain a fermentation material; adjusting the water content of the fermentation material to 65%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 3%, the inoculation amount of Bacillus subtilis to 2%, adding 1.2% cellulase, 0.7% pectinase, 0.5% xylanase, 0.3% β-glucanase, and performing solid-state fermentation at 32 °C for 48 h.

[0043] Example 4

[0044] A method for rapidly degrading apple pomace fiber to improve nutrient digestibility, the method comprising: mixing apple pomace and wheat bran in a mass ratio of 8:2, adding 2% urea, and mixing evenly to obtain a fermentation material; adjusting the water content of the fermentation material to 65%, the inoculation amount of Lactobacillus plantarum to 8%, the inoculation amount of Saccharomyces cerevisiae to 5%, the inoculation amount of Bacillus subtilis to 2%, adding 1.2% cellulase, 0.7% pectinase, 0.5% xylanase, and 0.3% β-glucanase, and performing solid-state fermentation at 32°C for 48 h.

[0045] Control Example 1

[0046] The difference from Example 1 is that the water content of the fermentation material is adjusted to 60%, the inoculation amount of Lactobacillus plantarum is 10%, the inoculation amount of Saccharomyces cerevisiae is 1%, and the others are the same as in Example 1.

[0047] Control Example 2

[0048] The difference from Example 1 is that the water content of the fermentation material is adjusted to 50%, the inoculation amount of Lactobacillus plantarum is 2%, the inoculation amount of Saccharomyces cerevisiae is 2%, the inoculation amount of Bacillus subtilis is 10%, and solid-state fermentation is performed at 36°C for 96 h, and the others are the same as in Example 1.

[0049] Control Example 3

[0050] The difference from Example 1 is that the water content of the fermentation material is adjusted to 50%, and solid-state fermentation is performed at 36°C for 96 h, and the others are the same as in Example 1.

[0051] Test Example

[0052] 1. Determination of NDF degradation rate

[0053] The NDF degradation rate of the fermented feed prepared by the methods described in Examples 1-4 and Control Examples 1-3 was measured, and the results are shown in Table 1 below.

[0054] Among them, the determination of neutral detergent fiber refers to GB / T 20806-2022, and the calculation formulas for the mass fraction of NDF and the NDF degradation rate are as follows:

[0055] (1)

[0056] (2)

[0057] Table 1 NDF degradation rate of each group

[0058] Group DNF Degradation Rate % Example 1 39.60 Example 2 35.65 Example 3 29.31 Example 4 28.49 Comparative Example 1 18.96 Comparative Example 2 14.97 Comparative Example 3 20.53

[0059] As can be seen from Table 1, the NDF degradation rates of the fermented feeds prepared by the methods described in Examples 1-4 of the present invention are all higher than those of Comparative Examples 1-3, and the NDF degradation rate in the group of Example 1 of the present invention can be as high as 39.60%.

[0060] Furthermore, the total crude protein content, acid detergent fiber, dry matter, etc. of the fermented feed obtained in Example 1 were measured and compared with the sample before fermentation. The results are shown in Table 2 below. Among them, the sample before fermentation is denoted as AP before fermentation; the sample after fermentation by the method described in Example 1 is denoted as AP after fermentation.

[0061] Table 2 Nutrient contents of the samples

[0062] Sample Name CP / % NDF / % ADF / % DM / % AP Before Fermentation <![CDATA[8.69±0.05 b > <![CDATA[54.50±0.34 b > <![CDATA[35.96±0.25 b > <![CDATA[98.46±0.11 b > AP After Fermentation <![CDATA[17.72±0.04 a > <![CDATA[32.92±0.43 a > <![CDATA[23.79±0.23 a > <![CDATA[97.16±0.03 a >

[0063] Note: Independent sample t-tests were used to analyze the differences between the two groups of data. The data in the table are presented in the form of mean ± standard deviation. Different superscripts (a, b) of the same column indicate significant differences between the two groups of data at the p < 0.05 level.

[0064] As can be seen from Table 2 above, compared with before fermentation, the crude protein content in the fermented feed obtained after fermentation by the method described in Example 1 increased by 104%, and the acid detergent fiber degradation rate was 33.84%.

[0065] 2. Nutritional value evaluation of apple pomace before and after fermentation

[0066] (1) Test materials

[0067] The method described in Example 1 was used to ferment apple pomace in the test. Among them, the sample before fermentation is denoted as AP before fermentation; the sample after fermentation by the method described in Example 1 is denoted as AP after fermentation; the nutritional values of the two raw materials before and after fermentation are shown in Table 2.

[0068] (2) Test methods

[0069] Treatment of samples:

[0070] The samples of apple pomace before and after fermentation were placed in an oven at 65 °C for 24 hours, taken out and left at room temperature for one day, then pulverized with a pulverizer and sieved (40 mesh) for standby.

[0071] According to the experimental grouping, 100 mL culture bottles were numbered, and 1 g of the sample was weighed and placed at the bottom of the culture bottle.

[0072] Preparation of the culture medium

[0073] The Menke culture medium formula was adopted, and the specific steps are as follows:

[0074] Trace element solution (Solution A): 13.2 g of CaCl2·2H2O, 10.0 g of MnCl2·4H2O, 1.0 g of CoCl2·6H2O, 8.0 g of FeCl3·6H2O, dissolved in deionized water and made up to 100 mL, stored at 4°C.

[0075] Buffer solution (Solution B): 4.0 g of NH4HCO3, 35.0 g of NaHCO3, dissolved in deionized water and made up to 1000 mL, stored at 4°C.

[0076] Macronutrient solution (Solution C): 9.45 g of Na2HPO4·12H2O, 6.2 g of KH2PO4, 0.6 g of MgSO4·7H2O, dissolved in deionized water and made up to 1000 mL, stored at 4°C.

[0077] Resazurin solution (Solution D): 100 mg of resazurin dissolved in 100 mL of deionized water, stored at 4°C in a sealed container protected from light.

[0078] Reducing agent solution (Solution E): 625 mg of L-cysteine hydrochloride, 4.0 mL of 1 M NaOH, 625 mg of Na2S·9H2O, dissolved in 95 mL of distilled water, prepared freshly before use.

[0079] Add Solutions A, B, C, D and distilled water to the culture flask according to Table 3, heat to boiling in a microwave oven for 10 minutes, pass in CO2 gas, adjust the pH to 6.8, add the reducing agent solution (Solution E), and finally add the filtered rumen fluid.

[0080] Table 3 Culture medium formula

[0081] Sequence Stock Solution Volume (mL) 1 Solution B 208.1 2 Solution C 208.1 3 Solution A 0.1 4 Solution D 1.0 5 Distilled Water 520.2 6 Solution E 62.4

[0082] Collection and treatment of rumen fluid

[0083] Collection of rumen fluid: Two hours before morning feeding, collect rumen fluid from the sheep rumen using a negative pressure device and store it in a collection bottle filled with CO2.

[0084] Treatment of rumen fluid: Stir and mix the rumen fluid, filter it through four layers of gauze, and mix it with the culture medium in a ratio of 1:2 to prepare an artificial rumen culture solution.

[0085] In vitro fermentation experiment of rumen fluid

[0086] Blank control: Set up 3 blank controls, without adding substrate, only adding rumen fluid and culture medium.

[0087] Fermentation culture: The mixed artificial rumen culture solution was aliquoted into 180 mL culture bottles, 100 mL per bottle. After sealing, it was placed in a constant temperature shaker at 39 °C for culture, with a shaking frequency of 150 rpm for 24 h.

[0088] Nutrient analysis method

[0089] The determination of the dry matter content in the samples and residues was carried out with reference to GB / T 6435-2014. The determination methods for neutral detergent fiber content and acid detergent fiber content were the same as in 2.1. The determination of crude protein was carried out with reference to GB / T 18868-2024.

[0090] (3) Data processing

[0091] By analyzing the changes in the dry matter content, cellulose and other components of the substrate before and after in vitro rumen fermentation, the degradation rate of the substrate was calculated. Excel was used to process the data. The independent-samples t-test analysis was performed on the nutrient digestibility of apple pomace before and after fermentation using SAS software.

[0092] The calculation formula for dry matter digestibility (Dry Matter Digestibility, DMD) is as follows:

[0093] (3)

[0094] The calculation formula for crude protein digestibility (Crude Protein Digestibility, CPD) is as follows:

[0095] (4)

[0096] The calculation formula for neutral detergent fiber digestibility (Neutral Detergent Fiber Digestibility, NDFD) is as follows:

[0097] (5)

[0098] The calculation formula for acid detergent fiber digestibility (Acid Detergent Fiber Digestibility, ADFD) is as follows:

[0099] (6)

[0100] (4) Results and analysis

[0101] The digestibility of each substance in apple pomace before and after fermentation is shown in Table 4 below.

[0102] Table 4 Digestibility of each substance in apple pomace before and after fermentation

[0103] Sample Name DM Digestibility / % CP Digestibility / % NDF Digestibility / % ADF Digestibility / % AP Before Fermentation <![CDATA[51.18±3.27 b > <![CDATA[46.49±0.71 b > <![CDATA[37.95±3.56 b > <![CDATA[26.98 ± 2.71 b > AP After Fermentation <![CDATA[62.89±1.62 a > <![CDATA[75.10±1.43 a > <![CDATA[50.87±0.85 a > <![CDATA[38.56 ± 1.03 a >

[0104] Note: Independent sample t-tests were used to analyze the differences between the two groups of data. The data in the table are presented in the form of mean ± standard deviation. Different superscripts (a, b) indicate significant differences between the two groups of data at the p < 0.05 level.

[0105] As can be seen from Table 4, after treatment with the method described in Example 1 of the present invention, the dry matter digestibility of the fermentation product was 62.89%, which was 22.88% higher than that before fermentation; the crude protein digestibility was 75.10%, which was 61.54% higher than that before fermentation; the neutral detergent fiber digestibility was 50.87%, which was 34.04% higher than that before fermentation; the acid detergent fiber digestibility was 38.56%, which was 42.92% higher than that before fermentation. It can be seen that the method of the present invention improves the digestibility of nutrients in apple pomace, can convert apple pomace into feed with high digestibility, alleviates the shortage of protein resources in animal husbandry, and at the same time reduces the pollution of fruit and vegetable processing waste.

[0106] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A bacterial enzyme complex preparation for rapidly degrading apple pomace fiber and improving nutrient digestibility, characterized in that, Comprising the following components by weight parts: Lactobacillus plantarum 5 - 12 parts, Saccharomyces cerevisiae 1 - 10 parts, Bacillus subtilis 1 - 5 parts, cellulase 1 - 1.5 parts, pectinase 0.5 - 1 part, xylanase 0.5 - 1 part, β-glucanase 0.1 - 0.5 part.

2. The enzyme complex preparation for rapidly degrading apple pomace fiber and improving nutrient digestibility according to claim 1, wherein The viable counts of Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis are 1×10 7 -1×10 8 CFU / mL.

3. A method for rapidly degrading apple pomace fiber to improve nutrient digestibility, characterized in that, Using the enzyme-bacteria complex preparation described in claim 1 or 2 to ferment apple pomace.

4. The method for rapidly degrading apple pomace fiber to improve nutrient digestibility according to claim 3, characterized in that The method comprises the following steps: uniformly mixing apple pomace with wheat bran and urea to obtain a fermentation material; adjusting the water content of the fermentation material to 65% - 70%, inoculating 5% - 12% of Lactobacillus plantarum, 1% - 10% of Saccharomyces cerevisiae and 1% - 5% of Bacillus subtilis, adding 1% - 1.5% of cellulase, 0.5% - 1% of pectinase, 0.5% - 1% of xylanase, 0.1% - 0.5% of β-glucanase, and performing solid-state fermentation at 32 - 36°C for ≥48 h.

5. The method for rapidly degrading apple pomace fiber to improve nutrient digestibility according to claim 4, characterized in that, Adjusting the water content of the fermentation product to 67% - 70%, the inoculation amount of Lactobacillus plantarum to 10% - 12%, the inoculation amount of Saccharomyces cerevisiae to 1% - 10%, the inoculation amount of Bacillus subtilis to 2%, adding 1.2% of cellulase, 0.7% of pectinase, 0.5% of xylanase, 0.3% of β-glucanase, and performing solid-state fermentation at 32 - 36°C for 48 - 96 h.

6. The method for rapidly degrading apple pomace fiber to improve nutrient digestibility according to claim 4, wherein The mass ratio of apple pomace to wheat bran is 5 - 10:1 - 3.

7. The method for rapidly degrading apple pomace fiber to improve nutrient digestibility according to claim 4, characterized in that, The addition amount of urea is 1% - 5%.

8. The method for rapidly degrading apple pomace fiber to improve nutrient digestibility according to claim 4, characterized in that, Before inoculation, it further includes sterilizing the fermentation material.

9. The method for rapidly improving the degradation rate of apple pomace fiber and nutrient digestibility according to claim 5, characterized in that, Adjusting the water content of the fermentation product to 67%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 10%, and performing solid-state fermentation at 32°C for 48 h; Or, adjusting the water content of the fermentation product to 70%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 1%, and performing solid-state fermentation at 36°C for 96 h; Or, adjusting the water content of the fermentation product to 65%, the inoculation amount of Lactobacillus plantarum to 10%, the inoculation amount of Saccharomyces cerevisiae to 3%, and performing solid-state fermentation at 32°C for 48 h; Or, adjusting the water content of the fermentation product to 65%, the inoculation amount of Lactobacillus plantarum to 8%, the inoculation amount of Saccharomyces cerevisiae to 5%, and performing solid-state fermentation at 32°C for 48 h.

10. The fermented feed prepared by the method according to any one of claims 3 - 9.