A kind of peanut meal and its preparation method and application

Abstract

The present invention discloses a peanut meal and a preparation method and application thereof, and relates to the field of biological fermentation technology. The present invention provides a method for preparing peanut meal, comprising the following steps: (1) crushing the peanut meal, adding water and mixing, and sterilizing to obtain a peanut meal suspension; (2) adding a composite enzyme to the peanut meal suspension obtained in step (1) for enzymolysis to obtain an enzymolysis product; (3) inoculating the activated composite bacterial fermentation liquid into the enzymolysis product of step (2), mixing and fermenting evenly, and drying after the fermentation to obtain the peanut meal. The present invention provides a method for preparing peanut meal. The present invention prepares the peanut meal by a two-step process of composite enzyme and composite bacteria, which reduces the risk of raw material contamination, and improves the nutritional characteristics and flavor characteristics of the peanut meal, so that the peanut meal has a sour and fragrant taste, good palatability for livestock and poultry, and significant cost reduction and efficiency improvement.

Description

Technical Field

[0001] The invention relates to the technical field of biological fermentation, in particular to peanut meal and a preparation method and application thereof. Background Art

[0002] Peanut meal is a byproduct of peanut kernel oil extraction. It is mainly composed of crushed kernels mixed with a small amount of seed coat. It is generally powdery or small pieces, brown in color, and has a strong peanut aroma. Peanut meal has a large output and is the fifth largest meal in the world. As an important plant protein raw material, the crude protein content of peanut meal is higher than that of soybean meal, generally above 46%. In addition, peanut meal is rich in glutamic acid, arginine, and aspartic acid, with glutamic acid and arginine contents as high as 7.52% and 5.2% respectively. Peanut meal has a good taste and is suitable for use in poultry feed. However, the nutritional value defects of peanut meal itself have greatly limited its application in the feed industry, thus preventing it from being fully developed and utilized. The specific defects are: first, it is easily infected by harmful microorganisms, especially Aspergillus flavus that produces aflatoxin (AFB1); second, it lacks high-quality protein and has a low digestion and absorption rate; third, the amino acid distribution is unbalanced, with the lysine content being only 50% of that of soybean meal, and the methionine content is also low, with an arginine / lysine ratio of 3.0-4.0, which is much higher than the ideal ratio of 1.0; fourth, it is rich in anti-nutritional factors such as phytic acid, and phosphorus mostly exists in the form of phytic acid phosphorus that is difficult to utilize.

[0003] In recent years, people have conducted a lot of research on how to improve the nutritional properties of peanut meal, including vacuum high-pressure detoxification, enzyme addition, and fermentation, etc., and have achieved certain results in improving the limiting factors in different aspects. Current research mainly focuses on improving individual feeding quality defects of peanut meal, and does not pay attention to the degradation of the main anti-nutritional factor non-starch polysaccharide, which makes it difficult for the product to replace high-quality protein feeds such as fish meal and soybean meal at a high proportion. In addition, the existing technology is difficult to achieve a balance in eliminating anti-nutritional factors in peanut meal, degrading toxins, and improving the protein quality and amino acid balance of peanut meal. In particular, the ratio of arginine to lysine is high, and there is still a certain gap from the ratio of 1.0. Therefore, there is still room for improvement. Summary of the invention

[0004] Based on this, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a peanut meal and a preparation method and application thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing peanut meal, comprising the following steps:

[0006] (1) crushing peanut meal, adding water and mixing, and sterilizing to obtain a peanut meal suspension;

[0007] (2) adding a composite enzyme to the peanut meal suspension obtained in step (1) for enzymolysis to obtain an enzymolysis product; the composite enzyme is a mixture of glucanase, phytase, neutral xylanase, and papain, and the weight ratio is glucanase: phytase: neutral xylanase: papain = (1-3): (1-3): (1-3): (1-3);

[0008] (3) inoculating the activated composite bacteria fermentation liquid into the enzymatic hydrolyzate of step (2), mixing and fermenting evenly, and drying after the fermentation to obtain the peanut meal; the composite bacteria is a mixture of Lactobacillus bulgaricus and Lactobacillus reuteri, and the weight ratio is Lactobacillus bulgaricus: Lactobacillus reuteri = (10-20): (10-20).

[0009] The invention provides a method for preparing peanut meal. The invention prepares peanut meal by a two-step process of composite enzyme and composite bacteria. First, the first step is to enzymatically hydrolyze the peanut meal with an enzyme preparation, which is beneficial to the degradation of macromolecular nutrients and anti-nutritional factors. Glucanase mainly acts on beta-glucan, neutral xylanase can decompose xylan in the cell wall of peanut meal, and glucanase and neutral xylanase synergistically decompose non-starch polysaccharides in peanut meal to promote the release of effective substances. Neutral xylanase and phytase have a synergistic effect on cell wall degradation. Papain is a thiol protease with a wide substrate specificity, which degrades macromolecular proteins into small molecular peptides or amino acids, and decomposes the peptide bonds of arginine at the same time, reduces the arginine content, and adjusts the amino acid balance. In the second step of the present invention, the composite bacteria are used to treat the peanut meal. Lactobacillus bulgaricus and Lactobacillus reuteri have the advantage of degrading mycotoxins, and can greatly reduce aflatoxin B1 in the peanut meal. Lactobacillus bulgaricus and Lactobacillus reuteri synergistically produce high acid and have inhibitory effects on a variety of pathogenic bacteria, such as Escherichia coli, Salmonella, Proteus mirabilis, and Staphylococcus aureus. And it can further degrade phytic acid, reduce anti-nutritional factors in peanut meal, and further adjust the balance of amino acids; in addition, the secreted organic acids and antibacterial components reduce the risk of raw material contamination on the one hand, and improve the nutritional characteristics and flavor characteristics of peanut meal on the other hand, the taste is sour and fragrant, the palatability of livestock and poultry is good, and the cost reduction and efficiency increase are significant.

[0010] Preferably, the weight ratio of the complex enzyme is glucanase: phytase: neutral xylanase: papain = 1:1:(1-2):(1-2).

[0011] Preferably, the weight ratio of the composite bacteria is Lactobacillus bulgaricus: Lactobacillus reuteri=(10-20):10.

[0012] Preferably, the enzymatic activity of the glucanase is ≥100,000 U / g, the enzymatic activity of the phytase is ≥50,000 U / g, the enzymatic activity of the neutral xylanase is ≥200,000 U / g, and the enzymatic activity of the papain is ≥200,000 U / g.

[0013] The inventor found in the actual experimental process that the weight ratio of beta-glucanase, phytase, neutral xylanase and papain will affect the decomposition effect of the anti-nutritional factors non-starch polysaccharides, macromolecular proteins, etc. in the peanut meal, and the weight ratio of beta-glucanase, phytase, neutral xylanase and papain will affect the balance of amino acids in the peanut meal, and then affect the nutritional indexes and flavor indexes of the peanut meal. The weight ratio of Lactobacillus bulgaricus and Lactobacillus reuteri will affect the aflatoxin B1 content in the peanut meal. At the same time, compound bacteria fermentation can also further degrade macromolecular components and anti-nutritional factors, and further adjust the amino acid balance. The two-step fermentation of compound enzymes and compound bacteria can greatly improve the nutritional value of peanut meal, which is better than simply using one method.

[0014] When the weight ratio of the composite enzyme is glucanase: phytase: neutral xylanase: papain = 1: 1: (1-2): (1-2), and the weight ratio of the composite bacteria is Lactobacillus bulgaricus: Lactobacillus reuteri = (10-20): 10, the nutritional substances of the obtained peanut meal are fully improved, the crude protein, acid-soluble protein (ratio of total protein), small peptides, and effective phosphorus contents are significantly improved, the contents of limiting amino acids lysine, methionine, tryptophan, and threonine are all improved, the arginine / lysine ratio is reduced, the amino acid balance is adjusted, and the content of aflatoxin B1 in the peanut meal is greatly reduced.

[0015] Preferably, in the step (1), the material-water ratio is 1:(10-15), the sterilization method is high-pressure steam sterilization, the pressure of the high-pressure steam sterilization is 0.2-0.25MPa, the temperature of the high-pressure steam sterilization is 121°C, the time of the high-pressure steam sterilization is 10 minutes, and the high-pressure steam sterilization is cooled to 25-30°C to obtain a peanut meal suspension; in the step (2), the inoculation amount of the complex enzyme is 0.1%-0.2%, the temperature of the enzymatic hydrolysis is 50-55°C, the time of the enzymatic hydrolysis is 1-2h, and the pH of the enzymatic hydrolysis is 4.5-5.5; in the step (3), the inoculation amount is 5%-8%, the fermentation temperature is 35-40°C, an aerobic environment is maintained, and the fermentation time is 24-36h.

[0016] Preferably, the moisture content of the peanut meal is ≤10%.

[0017] In addition, the present invention provides peanut meal prepared by the above-mentioned peanut meal preparation method.

[0018] Furthermore, the present invention provides application of the peanut meal in livestock and poultry feed.

[0019] The invention provides a livestock and poultry feed, which comprises the peanut meal, and the weight percentage of the peanut meal in the livestock and poultry feed is 5%-20%.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a method for preparing peanut meal. The present invention prepares peanut meal by a two-step process of composite enzyme and composite bacteria. First, the first step is to enzymatically hydrolyze the peanut meal with an enzyme preparation, which is beneficial to the degradation of macromolecular nutrients and anti-nutritional factors. Glucanase mainly acts on β-glucan, neutral xylanase can decompose the xylan in the cell wall of peanut meal, and glucanase and neutral xylanase synergistically decompose the non-starch polysaccharides in the peanut meal to promote the release of effective substances. Neutral xylanase and phytase have a synergistic effect on cell wall degradation. Papain is a thiol protease with a wide substrate specificity. It degrades macromolecular proteins into small molecular peptides or amino acids, and at the same time decomposes the peptide bonds of arginine to adjust the amino acid balance. In the second step of the present invention, the composite bacteria are used to treat the peanut meal. Lactobacillus bulgaricus and Lactobacillus reuteri have the advantage of degrading mycotoxins, and can greatly reduce aflatoxin B1 in the peanut meal. Lactobacillus bulgaricus and Lactobacillus reuteri synergistically produce high acid and have inhibitory effects on a variety of pathogenic bacteria, such as Escherichia coli, Salmonella, Proteus mirabilis, and Staphylococcus aureus. And it can further degrade phytic acid, reduce anti-nutritional factors in peanut meal, and further adjust the balance of amino acids; in addition, the secreted organic acids and antibacterial components reduce the risk of raw material contamination on the one hand, and improve the nutritional characteristics and flavor characteristics of peanut meal on the other hand, the taste is sour and fragrant, the palatability of livestock and poultry is good, and the cost reduction and efficiency increase are significant. DETAILED DESCRIPTION

[0021] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. In the embodiments, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0022] The sources of raw materials used in the present invention are as follows:

[0023] Glucanase, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 100,000 U / g;

[0024] Phytase, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 50000U / g;

[0025] Neutral xylanase, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 200,000 U / g;

[0026] Papain, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 200,000 U / g;

[0027] Cellulase, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 200,000 U / g;

[0028] Bromelain, purchased from Qingdao Hivison Biotechnology Co., Ltd., enzyme activity ≥ 200,000 U / g;

[0029] Lactobacillus bulgaricus, deposited in the Chinese Institute of Food and Fermentation Industry Science, with the deposit number IFFI 6047;

[0030] Lactobacillus reuteri, deposited in Guangdong Microbiological Culture Collection Center, with the deposit number GDMCCNO.1.1805;

[0031] Lactobacillus paracasei, deposited in Guangdong Microbiological Culture Collection Center, with the deposit number GDMCCNO.1.159;

[0032] Peanut meal was purchased from Foshan Jindaxiang Food Co., Ltd.

[0033] Examples 1-8 and Comparative Examples 1-9

[0034] The present invention provides a peanut meal, wherein the composite enzyme and composite bacteria components and weight portions in the peanut meal preparation process are selected as shown in Table 1. The untreated group is a sample of the peanut meal that is crushed and then passed through a 20-mesh sieve.

[0035] A method for preparing peanut meal of the present invention comprises the following steps:

[0036] (1) 1000 g of peanut meal is crushed and passed through a 20-mesh sieve, and then water is added and mixed, and then sterilized to obtain a peanut meal suspension; wherein the material-water ratio is 1:10, and the sterilization method is high-pressure steam sterilization, the pressure of the high-pressure steam sterilization is 0.2 MPa, the temperature of the high-pressure steam sterilization is 121° C., the steam sterilization time is 10 min, and after the high-pressure steam sterilization, the mixture is cooled to 25° C. to obtain a peanut meal suspension;

[0037] (2) adding a composite enzyme to the peanut meal suspension obtained in step (1) for enzymolysis to obtain an enzymolysis product; wherein the composite enzyme inoculation amount is 0.1%, the enzymolysis temperature is 50° C., the enzymolysis time is 1 h, and the enzymolysis pH is 4.5-5.5;

[0038] (3) inoculating the activated composite bacteria fermentation liquid into the enzymatic hydrolyzate of step (2), mixing and fermenting evenly, and drying at 50° C. after the fermentation to obtain the peanut meal with a moisture content of ≤10%; wherein the composite bacteria inoculation amount is 5%, the fermentation temperature is 37° C., an aerobic environment is maintained, and the fermentation time is 24 hours.

[0039] Table 1 List of components and weight of compound enzymes and compound bacteria

[0040]

[0041] Table 1: Components and weights of composite enzymes and composite bacteria

[0042]

[0043]

[0044] Experiment 1: Peanut meal key index detection

[0045] The nutritional indexes, odor and aflatoxin B1 of the embodiments and comparative examples were evaluated; and amino acid detection and analysis were performed on the embodiments and comparative examples.

[0046] The crude protein detection method refers to the national standard GB / T 6432-2018; the crude fiber detection method refers to the national standard GB / T6434-2022 5.4.1; the non-starch polysaccharide detection method adopts gas chromatography and colorimetry; the acid-soluble protein detection method refers to the industry standard NY / T 3801; the small peptide content detection adopts the trichloroacetic acid precipitation method; the odor is evaluated by nose smell; the aflatoxin B1 detection adopts ELISA kit, which is purchased from ROMER. Amino acid detection refers to the national standard GB / T18246.

[0047] Experimental results: see Table 2-Table 3.

[0048] Table 2 Changes in nutritional indexes, odor indexes, and aflatoxin B1 indexes of peanut meal before and after treatment

[0049]

[0050]

[0051] Note: The smell is evaluated by smelling the nose. +++++ means the smell is very friendly, ++++ means the smell is friendly, +++ means the smell is average, ++ means the smell is poor, and + means poor.

[0052] It can be seen from Table 2 that the effects of the embodiments are better than those of the comparative examples. Among them, the effect of embodiment 1 is the best.

[0053] Table 3 Changes of amino acids in peanut meal before and after treatment (based on dry matter, %)

[0054]

[0055]

[0056] Table 3 Changes of amino acids in peanut meal before and after treatment (based on dry matter, %)

[0057]

[0058] As can be seen from Table 3, the amino acid content of the peanut meal of the embodiment is improved overall, the content of the limiting amino acids lysine, methionine, tryptophan, and threonine are all increased, and the ratio of arginine / lysine is reduced from 3.59 to 1.53, which is close to the ideal ratio of 1.0. This shows that the treatment of the present invention can adjust the amino acid balance and improve the nutritional value of the peanut meal.

[0059] Experiment 2: Effects of peanut meal before and after enzyme treatment on the growth performance of growing pigs.

[0060] The experiment selected 125 growing pigs with an average body weight of (21.7±0.9) kg and randomly divided them into 5 groups, each with 5 replicates and 5 pigs in each replicate. Group 1 was fed a corn-soybean meal type basal diet, Group 2 was fed with untreated peanut meal replacing 50% of soybean meal, Group 3 was fed with enzyme-treated peanut meal prepared in Example 1 replacing 50% of soybean meal, Group 4 was fed with enzyme-treated peanut meal prepared in Example 1 replacing 60% of soybean meal, and Group 5 was fed with enzyme-treated peanut meal prepared in Example 1 replacing 90% of soybean meal. The experimental diets were prepared according to the principle of equal energy and equal nitrogen in reference to the nutritional requirements of growing pigs in NRC (2012). The composition and nutritional level of the experimental diets are shown in Table 4. Since the nutritional level of the experimental diets needs to be consistent, there are slight differences in the raw material components.

[0061] Table 4 Composition and nutritional value of experimental diets (air-dried basis)

[0062] raw material 1 group 2 groups 3 groups 4 groups 5 groups corn,% 75.70 75.78 78.40 79.10 81.15 45% soybean meal,% 20.00 10.00 10.00 8.00 2.00 Peanut meal, % -- 9.48 -- -- -- Example 1 Peanut meal, % -- -- 6.60 7.93 11.87 Soybean oil, % 0.90 1.20 1.50 1.50 1.53 Stone powder, % 0.50 0.50 0.50 0.50 0.50 Calcium hydrogen phosphate, % 1.00 1.00 1.00 1.00 1.00 salt,% 0.30 0.30 0.30 0.30 0.30 Lysine, % 0.41 0.5 0.48 0.47 0.46 Methionine, % 0.12 0.14 0.13 0.12 0.11 Threonine, % 0.07 0.1 0.09 0.08 0.08 Premix, % 1.00 1.00 1.00 1.00 1.00 Nutritional Levels 1 group 2 groups 3 groups 4 groups 5 groups Digestible energy (MJ / kg) 14.11 13.98 14.11 14.09 14.03 Crude protein, % 15.43 15.40 15.39 15.40 15.39 Total phosphorus, % 0.54 0.55 0.56 0.57 0.57 Lysine, % 1.05 1.05 1.05 1.04 1.04 Protein + cysteine, % 0.59 0.61 0.62 0.64 0.64 Threonine, % 0.63 0.64 0.64 0.64 0.64

[0063] Note: Each kg of premix contains: Vitamin A 12000IU; Vitamin D3 1100IU; Vitamin E25IU; Vitamin K4mg; Vitamin B 12 0.04mg; pantothenic acid 28mg; niacin 32mg; choline chloride 8g; MgSO4 100 g; FeSO4 120g; CuSO4 0.45g; MnSO4 2.2g; ZnSO4 5g; Na2SeO3 10mg; KI 40mg; CoCl2 22mg.

[0064] The experimental pigs were raised in a closed pig house with cement floor and good ventilation. During the experiment, they were allowed to eat and drink freely. The pig sty was cleaned regularly every day to keep the light and temperature appropriate. The feeding situation, feces and health status of the pigs were observed every day. Other feeding management followed the conventional management system of the pig farm. The experiment lasted for 28 days.

[0065] Growth performance was determined as follows: the experimental pigs were weighed on an empty stomach in the morning at the beginning and end of the experiment, the feed consumption of each replicate was recorded during the experiment, and the average daily feed intake, average daily weight gain and feed-to-weight ratio were calculated.

[0066] Statistical analysis

[0067] The experimental results were expressed as mean and standard error (SEM). SPSS 21.0 statistical software was used for variance analysis, Duncan's method was used for multiple comparisons, and general linear model was used for regression analysis. P < 0.05 indicated significant differences.

[0068] Results and analysis: as shown in Table 5.

[0069] Table 5 Effect of peanut meal replacing soybean meal on growth performance of growing pigs before and after enzyme and bacterial treatment

[0070]

[0071] Note: Data in the same row with different letters indicate significant differences (P<0.05), while data with the same letters or no letters indicate no significant differences (P>0.05).

[0072] The results of the effect of peanut meal on the growth performance of growing pigs before and after treatment are shown in Table 5. The average daily weight gain of Group 2 is significantly lower than that of Group 1, and the feed-to-weight ratio is significantly higher than that of Group 1, indicating that the untreated peanut meal replacing soybean meal has a certain negative impact on the growth performance of growing pigs; the average daily weight gain of Groups 3-5 is not significantly different from that of Group 1, and the feed-to-weight ratio is significantly lower than that of Group 1, indicating that the peanut meal of Example 1 replaces 50%-90% of soybean meal without adverse effects on the growth performance of growing pigs, and can significantly reduce the feed-to-meat ratio, indicating that the feed utilization rate is higher, which is better than using soybean meal alone in the formula. The enzyme-treated peanut meal of the present invention can replace up to 90% of the soybean meal in the diet.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing peanut meal, characterized in that: The steps include: (1) crushing peanut meal, adding water and mixing, and sterilizing to obtain a peanut meal suspension; (2) adding a composite enzyme to the peanut meal suspension obtained in step (1) for enzymolysis to obtain an enzymolysis product; the composite enzyme is a mixture of glucanase, phytase, neutral xylanase, and papain, and the weight ratio of glucanase: phytase: neutral xylanase: papain is 1:1:(1-2):(1-2); (3) inoculating the activated composite bacteria fermentation liquid into the enzymatic hydrolyzate of step (2), mixing and fermenting evenly, and drying after the fermentation to obtain the peanut meal; the composite bacteria is a mixture of Lactobacillus bulgaricus and Lactobacillus reuteri, and the weight ratio of Lactobacillus bulgaricus: Lactobacillus reuteri is (10-20):

10.

2. The method for preparing peanut meal according to claim 1, characterized in that: The enzymatic activity of the glucanase is ≥100000 U / g, the enzymatic activity of the phytase is ≥50000 U / g, the enzymatic activity of the neutral xylanase is ≥200000 U / g, and the enzymatic activity of the papain is ≥200000 U / g.

3. The method for preparing peanut meal according to claim 1, characterized in that: In the step (1), the material-water ratio is 1:(10-15), the sterilization method is steam sterilization, the steam sterilization pressure is 0.2-0.25 MPa, the steam sterilization temperature is 121° C., the steam sterilization time is 10 minutes, and the peanut meal suspension is obtained after steam sterilization by cooling to 25-30° C.; in the step (2), the compound enzyme inoculation amount is 0.1%-0.2%, the enzymatic hydrolysis temperature is 50-55° C., the enzymatic hydrolysis time is 1-2h, and the enzymatic hydrolysis pH is 4.5-5.5; in the step (3), the inoculation amount is 5%-8%, the fermentation temperature is 35-40° C., and the fermentation time is 24-36h.

4. The method for preparing peanut meal according to claim 1, characterized in that: The moisture content of the peanut meal is ≤10%.

5. Peanut meal prepared by the method for preparing peanut meal according to any one of claims 1 to 4.

6. Use of the peanut meal as claimed in claim 5 in livestock and poultry feed.

7. A livestock and poultry feed, characterized in that: The livestock and poultry feed comprises the peanut meal according to claim 5, and the weight percentage of the peanut meal according to claim 5 in the livestock and poultry feed is 5%-20%.

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