Preparation method of lactobacillus fermented feed for improving flavor and meat quality of duck meat

Abstract

The invention discloses a preparation method of a lactobacillus fermented feed for improving flavor and meat quality of duck meat, which comprises the following steps: S1, premixing the following raw materials of self-made duck feed in percentage by mass: 30-60% of corn, 5-15% of wheat bran, 20-40% of soybean meal, 1-5% of stone powder and 14-20% of soybean oil to obtain a premix; and S2, crushing the premix, adding lactic acid bacteria fermentation liquor, stirring, fermenting, and performing cold granulation to obtain the lactic acid bacteria fermented feed. According to the method, the activity and quantity of lactic acid bacteria in the obtained lactic acid bacteria fermented feed can be ensured to the greatest extent, and the palatability of the feed is improved. Results show that in the actual feeding process, the death rate of the meat ducks in antibiotic-free breeding can be remarkably reduced by feeding the meat ducks with the feed containing the lactic acid bacteria fermented feed, meanwhile, the flavor and the meat quality of the obtained duck meat are remarkably improved, and therefore the preparation method has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of biological fermented feed, and in particular relates to a method for preparing lactic acid bacteria fermented feed for improving duck meat flavor and meat quality. Background Art

[0002] In recent years, although duck meat has steadily increased in global consumption, making it one of the important sources of meat. But it is well known that a key factor limiting duck meat consumption is the lack of meat quality and flavor compared to other traditional meats such as beef, pork and chicken. For example, the sensory score of duck meat is significantly lower than that of chicken, resulting in a downward trend in consumer preference. Duck meat has a special fishy smell, which usually requires complex cooking techniques to cover up this smell. These professional cooking techniques are difficult to master, and the unavoidable use of antibiotics in the breeding process of meat ducks makes consumers feel uneasy about the meat of this fast-growing commercial meat duck. Therefore, it is necessary to produce better quality duck meat.

[0003] Fermented feed is feed processed by microbial fermentation, which can enhance nutritional value, improve palatability, and reduce harmful substances. Fermented feed can promote the beneficial proliferation of animal intestinal microorganisms, has the potential to replace antibiotics, and can be widely used in poultry farming. However, there are few reports on the use of lactic acid bacteria fermented feed in duck farming, and it has not been used to enhance the flavor and improve the quality of duck meat. In view of this, the present invention proposes a preparation method of lactic acid bacteria fermented feed for improving the flavor and quality of duck meat. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing lactic acid bacteria fermented feed for improving the flavor and quality of duck meat, which aims to solve the problems that the existing poultry fermented feed cannot improve the flavor and quality of duck meat.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] The present invention provides a method for preparing a lactic acid bacteria fermented feed for improving the flavor and quality of duck meat, comprising the following steps:

[0007] S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 30%-60% corn, 5%-15% wheat bran, 20%-40% soybean meal, 1-5% stone powder, and 14%-20% soybean oil to obtain a premix, i.e. homemade duck feed;

[0008] S2. The obtained premix is ​​crushed, and then lactic acid bacteria fermentation liquid is added, stirred and mixed, fermented, and cold granulated to obtain lactic acid bacteria fermented feed.

[0009] Preferably, in step S2, the mass volume ratio of the premix to the lactic acid bacteria fermentation broth is 800-1500 g:5-10 mL.

[0010] Preferably, the lactic acid bacteria fermentation liquid contains lactobacillus at a concentration of 2*10 8 -2*10 10 CFU / mL.

[0011] Preferably, in step S2, the fermentation temperature is 30-40°C, and the fermentation time is 48-80h.

[0012] Preferably, the stirring time is 10-20 min.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The fermentation bacteria selected in the present invention are lactic acid bacteria, and the lactic acid bacteria fermented feed containing live bacteria is prepared through a cold granulation process by controlling the lactic acid bacteria addition ratio, fermentation temperature, and fermentation time. The preparation method of the present invention can ensure the activity and quantity of lactic acid bacteria in the obtained lactic acid bacteria fermented feed to the greatest extent, and improve the palatability of the feed; the experimental results show that in the actual feeding process, by feeding meat ducks with feeding feed containing lactic acid bacteria fermented feed and controlling the addition amount of lactic acid bacteria fermented feed (20-60%), the mortality rate of meat ducks in antibiotic-free breeding can be significantly reduced, and the flavor and quality of duck meat can be significantly improved, which provides powerful help for the flavor and quality improvement of meat ducks in antibiotic-free breeding of meat ducks, and therefore has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a graph showing the results of determining the lactic acid bacteria content in the lactic acid bacteria fermented feed and homemade duck feed prepared in Example 1. DETAILED DESCRIPTION

[0017] In the following description, specific details such as specific system structures and technologies are provided for illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may also be implemented in other embodiments without these specific details.

[0018] Example 1

[0019] A method for preparing a lactic acid bacteria fermented feed for improving the flavor and quality of duck meat, comprising the following steps:

[0020] S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 40% corn, 10% wheat bran, 25% soybean meal, 3% stone powder, and 17% soybean oil to obtain a premix, i.e., homemade duck feed;

[0021] S2. The obtained premix is ​​crushed into powder, and then lactic acid bacteria fermentation liquid (the fermentation liquid contains lactobacillus with a concentration of 2*10 9 CFU / mL), and continued stirring for 15 minutes after the addition was completed. Then, it was transferred to a fermentation tank and fermented at 35°C for 64 hours. After the fermentation was completed, it was stirred for 25 minutes and granulated to obtain lactic acid bacteria fermented feed.

[0022] Example 2

[0023] The steps are basically the same as those in Example 1, except that the fermentation temperature in this example is 30°C.

[0024] Example 3

[0025] The steps are basically the same as those in Example 1, except that the fermentation temperature in this example is 40°C.

[0026] Example 4

[0027] The steps are basically the same as those in Example 1, except that the fermentation temperature in this example is 48 hours.

[0028] Example 5

[0029] The steps are basically the same as those in Example 1, except that the fermentation time in this example is 80 h.

[0030] Example 6

[0031] S1. Premixing the raw materials of homemade duck feed according to the following mass percentages, including 40% corn, 10% wheat bran, 25% soybean meal, 3% stone powder, and 17% soybean oil, to obtain a premix, i.e. homemade duck feed;

[0032] S2. The obtained premix is ​​crushed into powder, and then lactic acid bacteria fermentation liquid (the fermentation liquid contains lactobacillus with a concentration of 2*10 8 CFU / mL), and continued stirring for 15 minutes after the addition was completed. Then, it was transferred to a fermentation tank and fermented at 35°C for 64 hours. After the fermentation was completed, it was stirred for 25 minutes and granulated to obtain lactic acid bacteria fermented feed.

[0033] Example 7

[0034] S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 50% corn, 5% wheat bran, 20% soybean meal, 5% stone powder, and 20% soybean oil, to obtain a premix, i.e., homemade duck feed;

[0035] S2, crush the obtained premix into powder, and then add lactic acid bacteria fermentation liquid (the fermentation liquid contains lactobacillus, the concentration is 2*10 9 CFU / mL), and continued stirring for 15 minutes after the addition was completed. Then, it was transferred to a fermentation tank and fermented at 35°C for 64 hours. After the fermentation was completed, it was stirred for 25 minutes and granulated to obtain lactic acid bacteria fermented feed.

[0036] Example 8

[0037] S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 60% corn, 5% wheat bran, 20% soybean meal, 1% stone powder, and 14% soybean oil, to obtain a premix, i.e., homemade duck feed;

[0038] S2. The obtained premix is ​​crushed into powder, and then lactic acid bacteria fermentation liquid (the bacteria contained in the fermentation liquid are lactobacillus, and the concentration is 2*10 10 CFU / mL), and continued stirring for 15 minutes after the addition was completed. Then, it was transferred to a fermentation tank and fermented at 35°C for 64 hours. After the fermentation was completed, it was stirred for 25 minutes and granulated to obtain lactic acid bacteria fermented feed.

[0039] Example 9

[0040] S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 30% corn, 10% wheat bran, 40% soybean meal, 5% stone powder, and 15% soybean oil to obtain a premix, i.e., homemade duck feed;

[0041] S2, crush the obtained premix into powder, and then add lactic acid bacteria fermentation liquid (the fermentation liquid contains lactobacillus, the concentration is 2*10 10 CFU / mL), and continued stirring for 15 minutes after the addition was completed. Then, it was transferred to a fermentation tank and fermented at 35°C for 64 hours. After the fermentation was completed, it was stirred for 25 minutes and granulated to obtain lactic acid bacteria fermented feed.

[0042] Comparative Example 1

[0043] The steps are basically the same as those in Example 1, except that the fermentation temperature in this example is 25°C.

[0044] Comparative Example 2

[0045] The steps are basically the same as those in Example 1, except that the fermentation temperature in this example is 45°C.

[0046] Comparative Example 3

[0047] The steps are basically the same as those in Example 1, except that the fermentation time in this example is 96 hours.

[0048] Comparative Example 3

[0049] The steps are basically the same as those in Example 1, except that the fermentation time in this example is 144 hours.

[0050] Comparative Example 4

[0051] The steps are basically the same as those in Example 1, except that the fermentation time in this example is 192 h.

[0052] The quality and composition of the lactic acid bacteria fermented feed prepared in Example 1 above were tested, and the specific process was as follows:

[0053] (1) Quantitative detection of the number of lactic acid bacteria in the prepared lactic acid bacteria fermented feed and homemade duck feed (as a control): The gene copy number of lactic acid bacteria in the lactic acid bacteria fermented feed was quantitatively analyzed by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) technology, and commercial duck feed was used as a control. The primers used were 515F (5'-GTGCCAGCMGCCGCGG-3') and 907R (5'-CCGTCAATTCMTTTRAGTTT-3'). The quantitative analysis results are shown in Figure 1 .

[0054] Depend on Figure 1 The results show that the number of lactic acid bacteria gene copies in the lactic acid bacteria fermented feed (FF) prepared in Example 1 of the present invention is significantly higher than that in the homemade duck feed (CF), which means that the lactic acid bacteria content in the lactic acid bacteria fermented feed is significantly higher than that in the duck feed. This result shows that the lactic acid bacteria fermented feed prepared by the present invention contains significantly higher lactic acid bacteria.

[0055] (2) Testing the composition of lactic acid bacteria fermented feed: The composition of the prepared lactic acid bacteria fermented feed and homemade duck feed (as a control) was tested to ensure that the energy and nutrition of the prepared lactic acid bacteria fermented feed could meet the growth requirements of ducks; the results are shown in Table 1.

[0056] Table 1. Results of composition determination of lactic acid bacteria fermented feed and homemade duck feed

[0057]

[0058] As can be seen from the results in Table 1, the energy, total phosphorus content, crude fiber (CF), neutral detergent fiber (NDF), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF) of the lactic acid bacteria fermented feed prepared in Example 1 of the present invention are significantly lower than those of the homemade duck feed. This may be because the added lactic acid bacteria consume part of the energy during the fermentation process. The reduction in fiber content in the lactic acid bacteria fermented feed can improve the palatability of the feed; compared with the homemade duck feed, the methionine content in the lactic acid bacteria fermented feed is significantly increased; the calcium-phosphorus ratio is about 1.51, which is comparable to that of the homemade duck feed.

[0059] The fermented feeds obtained in Examples 1-5 and Comparative Examples 1-4 were tested to study the effects of different fermentation temperatures and fermentation times on the composition, pH and odor of the obtained fermented feeds. The results are shown in Tables 2 and 3.

[0060] Table 2

[0061]

[0062]

[0063] Table 3

[0064]

[0065] From the results in Tables 2 and 3, it can be seen that the total content of crude protein in fermented feed increases with the extension of fermentation time, and microbial protein synthesis increases the total content, but it may decrease due to autolysis in the later stage. The rapid reproduction of lactic acid bacteria consumes oxygen, reduces the pH value (to below 4.0), and inhibits harmful bacteria. The pH value is usually expected to be stable in the range of 3.8-4.5, and too low (<3.5) may affect palatability. Excessive fermentation may produce odorous substances such as butyric acid, and may also cause excessive acidity or nutrient loss (such as vitamin decomposition). At lower temperatures, lactic acid bacteria are less active, fermentation is slow, and mold is easy to grow. At higher temperatures, beneficial bacteria will be inactivated, Bacillus or heat-resistant bacteria will dominate, and ammonia or corruption may be produced, protein decomposition will be accelerated, and volatile fatty acids will be easily lost. Therefore, it is very important to control the fermentation temperature and time. The faster the pH drops, the better the feed preservation is, and the nutritional value of the fermented feed is improved. The energy and nutritional components of the lactic acid bacteria fermented feed obtained by the present invention through controlling the fermentation temperature, time and other conditions can meet the normal needs of meat ducks, and are more palatable than homemade duck feed.

[0066] Feeding method:

[0067] First, the lactic acid bacteria fermented feed prepared in Example 1 and the homemade duck feed were uniformly mixed in a certain mass ratio to obtain a series of feeding feeds with a lactic acid bacteria fermented feed mass fraction of 0%, 20%, 40%, and 60%;

[0068] Then 400 Cherry Valley ducks of 1 day old were selected. In the first stage (1-14 days old), all Cherry Valley ducks were fed with ordinary duckling feed freely every day before 14 days old. In the second stage (15-42 days old), ducklings weighing 0.6-0.8 kg were divided into 4 groups, namely Group 1, Group 2, Group 3, and Group 4, and fed with feed containing lactic acid bacteria fermented feed with a mass fraction of 0%, 20%, 40%, and 60%, respectively. During the period, the environmental factors were kept consistent, and no vaccination or antibiotics were given. After 42 days of feeding, the survival rates of Group 1-Group 4 were determined. The results showed that the survival rates of Group 1-Group 4 were 80%, 92%, 96%, and 94%, respectively, which showed that the addition of a certain amount of lactic acid bacteria fermented feed in the feeding feed can enhance the health of meat ducks and reduce the mortality rate of meat ducks in the process of antibiotic-free breeding. However, too much lactic acid bacteria fermented feed should not be added, because if too much lactic acid bacteria fermented feed is consumed, diarrhea and other phenomena that are not conducive to production may occur.

[0069] One broiler duck was randomly selected from each of the Cherry Valley ducks that survived 42 days of feeding in Groups 1 to 4 and slaughtered to measure the meat quality and flavor-related indices of the broiler ducks. The results are shown in Table 4.

[0070] Table 4. Results of duck meat quality and flavor related indexes

[0071]

[0072]

[0073] From the results in Table 4, it can be seen that the pH value of duck meat in Group 3 (fed with 40% fermented feed) was significantly higher than that in Group 1 (fed with homemade duck feed, i.e., containing 0% fermented feed) at 45 minutes after slaughter, and the pH value was about 6.48. According to existing studies (Md. Shawkat Ali et al., 2007; Yanhan Liu et al., 2018), the normal pH value range of duck meat within 24 hours after slaughter is about 6.0-6.6, and the pH value will decrease with the extension of post-slaughter time. According to existing studies (YaRu Zhang et al., 2018), duck meat within the normal pH range (6.0-6.6) has better quality. If the pH is lower than the normal range, it will promote muscle fiber contraction and lead to more drip loss. This conclusion is confirmed by the results in Table 4 that the cooking loss rate of duck meat in Groups 2, 3, and 4 is significantly lower than that in Group 1 (fed with homemade duck feed).

[0074] The sensory evaluation results in Table 4 show that the duck meat in Groups 2 to 4 scored higher in aroma, flavor, tenderness and juiciness than Group 1 (fed with homemade duck feed), which indicates that the addition of lactic acid bacteria to the feed is beneficial to enhancing the flavor of duck meat. The results of the electronic tongue show that the umami, richness, saltiness and sweetness of the duck meat in Groups 2 to 4 are higher than those in Group 1 (fed with homemade duck feed).

[0075] The above results show that feeding meat ducks with feeding feed containing lactic acid bacteria fermented feed and controlling the amount of lactic acid bacteria fermented feed added (20-60%) can significantly improve the flavor and meat quality of the resulting duck meat, specifically: the fishy smell of duck meat is greatly reduced, the taste is significantly improved, the cooking loss is significantly reduced, and the pH value is significantly increased within the normal range.

[0076] The present invention is not limited to the above-mentioned specific implementation modes. Various changes made by ordinary technicians in this field based on the above-mentioned concepts without creative work are all within the protection scope of the present invention.

Claims

1. A method for preparing lactic acid bacteria fermented feed for improving duck meat flavor and meat quality, characterized in that: The following steps are involved: S1. Premix the raw materials of homemade duck feed according to the following mass percentages, including 30%-60% corn, 5%-15% wheat bran, 20%-40% soybean meal, 1-5% stone powder, and 14%-20% soybean oil to obtain a premix; S2. The obtained premix is ​​crushed, and then lactic acid bacteria fermentation liquid is added, stirred and mixed, fermented, and cold granulated to obtain lactic acid bacteria fermented feed.

2. The method for preparing lactic acid bacteria fermented feed according to claim 1, characterized in that: The mass volume ratio of the premix to the lactic acid bacteria fermentation liquid is 800-1500 g:5-10 mL.

3. The method for preparing lactic acid bacteria fermented feed according to claim 2, characterized in that: The lactic acid bacteria fermentation liquid contains lactobacillus, and the concentration is 2*10 8 -2*10 10 CFU / mL.

4. The method for preparing lactic acid bacteria fermented feed according to claim 1, characterized in that: In step S2, the fermentation temperature is 30-40°C and the fermentation time is 48-80h.

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