A method for preparing fermented raw material and its application in eel feed

Abstract

The present invention belongs to the technical field of aquatic feed, and in particular, relates to a method for preparing a fermented raw material, and its application in eel feed. The present invention provides a method for preparing a fermented raw material, the steps of which sequentially include first inoculating a composite koji species and inoculating a composite bacterial liquid, then mixing and anaerobic fermentation, and finally obtaining a fermented raw material product, i.e., fermented sesame meal. The fermented sesame meal has the advantages of low anti-nutritional factors and high protein levels. In addition, the present invention also provides an application of the above-mentioned fermented sesame meal, which can replace 2-4wt% of fish meal in the raw material composition of eel feed, and finally significantly reduces the feed cost of eel farming.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic feed, and in particular relates to a method for preparing a fermented raw material and application of the fermented raw material in eel feed. Background Art

[0002] Sesame meal refers to the by-product of sesame seed oil extraction. Compared with common soybean meal, it has relatively higher content of crude protein and amino acids, and therefore has higher economic value for recycling.

[0003] On the other hand, eels are a common carnivorous fish, and fish meal is an indispensable high-quality protein in the raw material composition of their feed. However, the price of fish meal is relatively high. In order to reduce the cost of eel farming, it is necessary to find new protein sources to replace fish meal.

[0004] The Chinese invention patent with the publication number of CN107183356A and the publication date of September 22, 2017 discloses a preparation method of a bacterial peptide feed rich in taurine produced by fermenting sesame meal with multiple strains: preparation of beef extract peptone culture medium, preparation of potato culture medium, preparation of Cha's culture medium, activation and cultivation of bacterial strains: stirring and mixing the raw materials used for fermenting and producing bacterial peptide feed containing taurine evenly, sterilizing with high-temperature steam at 110-130°C, and cooling to obtain a solid fermentation product, inoculating the seed bacterial suspension prepared in step 2 into the sterilized solid fermentation product at a volume ratio of 4-8%, and culturing for 65-70 hours to obtain a bacterial peptide feed rich in taurine.

[0005] The preparation method in this invention patent relies on the multi-strain fermentation of sesame meal by Bacillus subtilis YS-45 seed suspension, yeast S-78 seed suspension and Aspergillus niger PL-39 seed suspension. These three are mixed with sesame meal, ultimately making the bacterial peptide feed rich in taurine.

[0006] However, the biggest defect of the preparation method in actual production and use, in other words, the technical problem to be solved by the present invention, is that it is impossible to significantly degrade the content of anti-nutritional factors in sesame meal. Anti-nutritional factors refer to substances that have adverse effects on the digestion, absorption and utilization of nutrients in feed, and cause adverse physiological reactions in humans and animals. This is reflected in sesame meal, that is, the content of crude fiber and oxalic acid cannot be significantly reduced, both of which will significantly interfere with the absorption capacity of livestock, poultry, fish and animals for feed nutrients.

[0007] So in summary, there is an urgent need for a new fermentation method that can effectively degrade anti-nutritional factors and increase the protein level in sesame meal. Summary of the invention

[0008] The invention provides a method for preparing a fermentation raw material, wherein the steps include first inoculating a composite koji and a composite bacterial solution, then mixing and anaerobic fermentation, and finally obtaining a fermentation raw material product, namely, fermented sesame meal. The fermented sesame meal has the advantages of low anti-nutritional factors and high protein level.

[0009] In addition, the present invention also provides an application of the fermented sesame meal, which can replace 2-4wt% of fish meal in the raw material composition of eel feed, ultimately significantly reducing the feed cost of eel farming.

[0010] The technical solution adopted by the present invention to solve the above problem is: a method for preparing a fermentation raw material, which comprises the following steps in sequence:

[0011] S1-a, inoculating compound koji: adding sesame meal, additives, and compound koji into a fermentation tank, and obtaining koji fermented sesame meal after aerobic fermentation;

[0012] S1-b, inoculating composite bacterial solution: adding sesame meal, additives, and composite bacterial solution into another fermentation tank, and obtaining bacterial solution fermented sesame meal after facultative anaerobic fermentation;

[0013] S2, mixed anaerobic fermentation: adding the koji fermented sesame meal and the bacterial liquid fermented sesame meal into the third fermentation tank, and then drying after anaerobic fermentation to obtain the final fermented sesame meal product with low anti-nutritional factors and high protein level.

[0014] In the present invention, there is no order between S1-a and S1-b, as long as they are before S2.

[0015] A further preferred technical solution is that in S1-a, the composite koji contains Mucor racemosus and Rhizopus oryzae, and the inoculation amount is 0.6-1.2wt%; in S1-b, the composite bacterial liquid contains Bacillus coagulans and yeast, and the inoculation amount is 0.5-1.5wt%.

[0016] In the present invention, the yeast is any one of Candida albicans, Candida tropicalis, or Candida glabrata.

[0017] A further preferred technical solution is that in S1-a and S1-b, the auxiliary agents are water, Hericium erinaceus polysaccharide, and molasses, the weight ratio of water to sesame meal is (0.8-1):1, the addition amount of Hericium erinaceus polysaccharide is 5-8wt%, and the addition amount of molasses is 6-10wt%.

[0018] In the present invention, the molasses is beet molasses, sugarcane molasses, grape molasses, or any one or more mixtures of corn molasses.

[0019] A further preferred technical solution is that in S1-a, the temperature of aerobic fermentation is 26-30°C and the time is 2-4 days; in S1-b, the temperature of facultative anaerobic fermentation is 26-30°C and the time is 2-3 days.

[0020] A further preferred technical solution is that in S2, the weight ratio of the sesame meal fermented with koji and the sesame meal fermented with bacterial liquid is 1:(2-5).

[0021] A further preferred technical solution is that in S2, the temperature of anaerobic fermentation is 34-38°C and the time is 4-6 days.

[0022] In S2 of the present invention, the material temperature of the drying operation is 65-75°C.

[0023] In addition, the drying operation is carried out in a fluidized bed, and the fluidized bed drying includes primary drying and secondary drying. The inlet air temperature of the primary drying is 130-150°C, and the moisture content of the material does not exceed 20wt%; the inlet air temperature of the secondary drying is 120-130°C, and the moisture content of the material is 8-10wt%.

[0024] A further preferred technical solution is that: in S1-a, the total number of spores in the composite strain is ≥ 2×10 9 cfu / g, of which the spore count of Mucor racemosus accounted for 50-70% and the spore count of Rhizopus oryzae accounted for 30-40%.

[0025] A further preferred technical solution is that: in S1-b, the number of viable bacteria of Bacillus coagulans in the composite bacterial solution is ≥ 1.0×10 9 cfu / g, the number of live yeast cells ≥ 1.0×10 9 cfu / g.

[0026] A fermentation raw material is prepared by the preparation method.

[0027] An application of a fermented raw material, wherein the fermented raw material has a replacement rate of 2-4wt% for fish meal in the raw material composition of eel feed. DETAILED DESCRIPTION

[0028] The following descriptions are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] A method for preparing a fermentation raw material comprises the following steps in sequence:

[0031] S1-a, inoculating compound koji: adding sesame meal, additives, and compound koji into a fermentation tank, and obtaining koji fermented sesame meal after aerobic fermentation;

[0032] S1-b, inoculating composite bacterial solution: adding sesame meal, additives, and composite bacterial solution into another fermentation tank, and obtaining bacterial solution fermented sesame meal after facultative anaerobic fermentation;

[0033] S2, mixed anaerobic fermentation: adding the koji fermented sesame meal and the bacterial liquid fermented sesame meal into the third fermentation tank, anaerobic fermentation and then drying to obtain the final fermentation raw material product with low anti-nutritional factors and high protein level, i.e. fermented sesame meal.

[0034] In S1-a, the composite koji contains Mucor racemosus and Rhizopus oryzae, and the inoculation amount is 0.6wt%; in S1-b, the composite bacterial liquid contains Bacillus coagulans and yeast, and the inoculation amount is 0.5wt%.

[0035] In S1-a and S1-b, the auxiliary agents are water, Hericium erinaceus polysaccharide, and molasses, the weight ratio of water to sesame meal is 0.8:1, the addition amount of Hericium erinaceus polysaccharide is 6wt%, and the addition amount of molasses is 8wt%.

[0036] In S1-a, the temperature of aerobic fermentation was 26°C and the time was 4 days; in S1-b, the temperature of facultative anaerobic fermentation was 28°C and the time was 3 days.

[0037] In S2, the weight ratio of the sesame meal fermented with koji and the sesame meal fermented with bacterial liquid is 1:2, the temperature of the material during the drying process is 68°C, and the drying is carried out in a fluidized bed. The fluidized bed drying includes primary drying and secondary drying. The inlet air temperature of the primary drying is 145°C, and the inlet air temperature of the secondary drying is 122°C.

[0038] In S2, the temperature of anaerobic fermentation was 34°C and the time was 5 days.

[0039] In S1-a, the total number of spores in the composite strain was 2.6×10 9 cfu / g, of which the spore counts of Mucor racemosus accounted for 52% and the spore counts of Rhizopus oryzae accounted for 35%.

[0040] In S1-b, the number of viable Bacillus coagulans in the composite bacterial solution was 1.4×10 9 cfu / g, the number of live yeast cells is 1.2×10 9 cfu / g.

[0041] A fermented sesame meal is prepared by the preparation method.

[0042] An application of fermented sesame meal, wherein the fermented sesame meal has a replacement rate of 2.5wt% for fish meal in the raw material composition of eel feed.

[0043] Next, the sesame meal before and after fermentation in this embodiment was tested for four items: crude protein / %, sesamin / %, crude fiber / %, and oxalic acid / % (based on air-dried matter). The results are shown in the table below.

[0044]

[0045] As can be seen from the table above, the preparation method of the fermented sesame meal can not only significantly reduce the anti-nutritional factors in sesame meal, namely crude fiber and oxalic acid, but also significantly increase the crude protein level. In addition, sesamin can regulate the intestinal health of eels, and has multiple functions such as anti-inflammatory and promoting vitamin absorption. The substantial increase in its content also proves the superiority of the preparation method of the fermented sesame meal.

[0046] Then, 480 American eels with an average body weight of 12.81±0.21g were randomly divided into 4 treatment groups. Fermented sesame meal replaced fish meal in the eel feed at 0%, 2%, 3%, and 4%. There were 4 replicates in each group, 30 fish in each replicate, and the experimental period was 70 days. Finally, the growth rate and conventional muscle indicators of eels were tested. The results are shown in the table below.

[0047]

[0048] As can be seen from the above table, the replacement range of 2-4wt% of fish meal by the fermented sesame meal can increase the weight gain rate, crude protein and crude fat content of American eel, so this replacement range is relatively efficient and appropriate.

[0049] Furthermore, the three indicators of protease (U / mg), lipase (U / mg), and amylase (U / mg) were tested on the above four groups. The results are shown in the table below.

[0050]

[0051] It can be seen from the above table that the fermented sesame meal can increase the intestinal protease and lipase activities of American eel in the range of 2-4wt% replacement of fish meal, so this replacement range is relatively efficient and appropriate.

[0052] Finally, the three indicators of T-AOC (U / mg), SOD (U / mg), and MDA (U / mg) were tested on the above four groups. The results are shown in the table below.

[0053]

[0054] As can be seen from the above table, the replacement range of 2-4wt% of fish meal by the fermented sesame meal can increase the antioxidant indicators T-AOC and SOD content of American eels and reduce the MDA level, where MDA refers to malondialdehyde, which is harmful and will aggravate the damage and aging of the eel intestine, so the above replacement range is relatively efficient and appropriate.

[0055] Example 2

[0056] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this embodiment differ from those in Embodiment 1 in only the following three aspects.

[0057] 1. In S1-a, the total number of spores in the composite strain was 2.2×10 9 cfu / g.

[0058] 2. In S1-b, the number of viable Bacillus coagulans in the composite bacterial solution was 1.1×10 9 cfu / g.

[0059] 3. In S1-b, the number of live yeast cells in the composite bacterial solution is 1.5×10 9 cfu / g.

[0060] Example 3

[0061] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this embodiment differ from those in Embodiment 1 in only the following three aspects.

[0062] 1. In S1-a, the total number of spores in the composite strain was 2.7×10 9 cfu / g.

[0063] 2. In S1-b, the number of viable Bacillus coagulans in the composite bacterial solution was 1.5×10 9 cfu / g.

[0064] 3. In S1-b, the number of live yeast cells in the composite bacterial solution was 1.1×10 9 cfu / g.

[0065] Example 4

[0066] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this embodiment differ from those in Embodiment 1 in only the following three aspects.

[0067] 1. In S1-a, the total number of spores in the composite strain was 2.9×10 9 cfu / g.

[0068] 2. In S1-b, the number of viable Bacillus coagulans in the composite bacterial solution was 1.1×109 cfu / g.

[0069] 3. In S1-b, the number of live yeast cells in the composite bacterial solution was 1.1×10 9 cfu / g.

[0070] Next, the fermented sesame meal in Examples 2, 3, and 4 was tested for five items: moisture / %, crude protein / %, sesamin / %, crude fiber / %, and oxalic acid / % (the last four items were measured on an air-dried basis). The results are shown in the table below.

[0071]

[0072] It can be seen from the above table that in the preparation method of the fermented sesame meal, when the three parameters of the total spore count in the composite koji, the live bacteria count of Bacillus coagulans in the composite bacterial liquid, and the live bacteria count of yeast in the composite bacterial liquid are changed within a limited range, the preparation method of the fermented sesame meal still has a high nutritional performance improvement effect.

[0073] Comparative Example 1

[0074] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this comparative example differ from those in Example 1 in only the following two aspects.

[0075] 1. All materials of the same weight as those in Example 1, including: 2 parts of sesame meal, 2 parts of auxiliary agents, 1 part of composite koji, and 1 part of composite bacterial liquid, are added into a fermentation tank at one time, and then dried after facultative anaerobic fermentation to obtain the final fermented sesame meal product.

[0076] 2. The temperature of facultative anaerobic fermentation is 28℃ and the time is 8 days.

[0077] Comparative Example 2

[0078] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this comparative example differ from those in Example 1 in only one respect:

[0079] In S1-a and S1-b, the auxiliary agents are water and molasses, and no Hericium erinaceus polysaccharide is present.

[0080] Comparative Example 3

[0081] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this comparative example differ from those in Example 1 in only one respect:

[0082] In S2, the temperature of the material during the drying process is 80°C.

[0083] Comparative Example 4

[0084] The fermented sesame meal, the method for preparing the fermented sesame meal, and the application of the fermented sesame meal in this comparative example differ from those in Example 1 in only one respect:

[0085] In S2, drying is carried out in a fluidized bed, and the fluidized bed drying includes only one-stage drying, and the air inlet temperature of the first-stage drying is 130°C.

[0086] Next, the three items of crude protein / %, crude fiber / %, and dry matter loss rate % were tested for Example 1 and Comparative Examples 1-4 (the first two items were measured based on air-dried matter). The results are shown in the table below.

[0087]

[0088] As can be seen from the above table, in the preparation method of the fermented sesame meal, the four operating parameters of aerobic fermentation of composite koji and facultative anaerobic fermentation of composite bacterial liquid followed by mixed anaerobic fermentation, Hericium erinaceus polysaccharide in the auxiliary agent, temperature range of 65-75°C during the drying process, and fluidized bed drying including primary drying and secondary drying are all necessary for the final effect of low anti-nutritional factors and high protein levels.

[0089] In other words, any change outside the specified range of the above parameters will significantly reduce the quality of fermented sesame meal, which will be manifested in a significant decrease in crude protein content, a significant increase in crude fiber content, and a significant increase in dry matter loss.

[0090] The above describes the embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Various modifications can be made within the knowledge of ordinary technicians in the technical field without departing from the purpose of the present invention. These are all non-creative modifications and are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a fermentation raw material, characterized in that The following steps are included in sequence: S1-a, inoculating compound koji: adding sesame meal, additives, and compound koji to a fermentation tank, and obtaining koji fermented sesame meal after aerobic fermentation; S1-b, inoculating composite bacterial solution: adding sesame meal, additives, and composite bacterial solution into another fermentation tank, and obtaining bacterial solution fermented sesame meal after facultative anaerobic fermentation; S2, mixed anaerobic fermentation: adding the sesame meal fermented by the koji species and the sesame meal fermented by the bacterial liquid into the third fermentation tank, anaerobic fermentation and then drying to obtain the final fermentation raw material product with low anti-nutritional factors and high protein level. In S1-a, the composite koji contains Mucor racemosus and Rhizopus oryzae, and the inoculation amount is 0.6-1.2wt%; in S1-b, the composite bacterial solution contains Bacillus coagulans and yeast, and the inoculation amount is 0.5-1.5wt%, In S1-a and S1-b, the auxiliary agents are water, Hericium erinaceus polysaccharide, and molasses. The weight ratio of water to sesame meal is (0.8-1):

1. The amount of Hericium erinaceus polysaccharide added is 5-8wt%, and the amount of molasses added is 6-10wt%. In S1-a, the temperature of aerobic fermentation is 26-30℃ and the time is 2-4 days; in S1-b, the temperature of facultative anaerobic fermentation is 26-30℃ and the time is 2-3 days. In S2, the weight ratio of the sesame meal fermented with koji and the sesame meal fermented with bacterial liquid is 1:(2-5), In S2, the temperature of anaerobic fermentation is 34-38℃ and the time is 4-6 days. In S2, the material temperature of the drying operation is 65-75°C, In S2, the drying operation is carried out in a fluidized bed, and the fluidized bed drying includes primary drying and secondary drying. The inlet air temperature of the primary drying is 130-150°C, and the moisture content of the material does not exceed 20wt%; the inlet air temperature of the secondary drying is 120-130°C, and the moisture content of the material is 8-10wt%.

2. The method for preparing a fermentation raw material according to claim 1, characterized in that: In S1-a, the total number of spores in the composite strain is ≥ 2×10 9 cfu / g, of which the spore count of Mucor racemosus accounted for 50-70% and the spore count of Rhizopus oryzae accounted for 30-40%.

3. The method for preparing a fermentation raw material according to claim 1, characterized in that: In S1-b, the number of viable Bacillus coagulans in the composite bacterial solution is ≥ 1.0 × 10 9 cfu / g, the number of live yeast cells ≥ 1.0×10 9 cfu / g.

4. A fermentation raw material, characterized in that: Prepared by the preparation method described in any one of claims 1 to 3.

5. A use of the fermentation raw material according to claim 4, characterized in that: The fermented raw material has a replacement rate of 2-4wt% for fish meal in the raw material composition of eel feed.

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