CN104770573A - Application of natamycin in preparation of liquid feed - Google Patents

Abstract

The invention discloses the application of natamycin in the preparation of liquid feed, and the use of said natamycin in the liquid feed for mold prevention, usually the dosage of natamycin alone in the liquid feed is 10mg /L. The liquid feed of the present invention may also include sodium diacetate, and the compounding ratio of natamycin and sodium diacetate is 4mg/kg: 3g/L. In the application of liquid feed, natamycin effectively solves the problem that natamycin is difficult to diffuse in solid feed. Natamycin can be dissolved in liquid feed and has a good antibacterial effect on it.

Description

Application of Natamycin in Preparation of Liquid Feed

technical field

The invention belongs to the technical field of animal feed, and in particular relates to the application of natamycin in the preparation of liquid feed.

Background technique

As a new type of biological antifungal agent, natamycin can specifically inhibit yeast and mold, and has good physical and chemical stability. It has become a natural biological food additive widely used in more than 30 countries. my country's GB2760-2007 also approves natamycin as a food additive, and its trade name is NatamaxinTM. Currently, there are only three biological preservatives approved for use in the world: Nisin, Natamycin and s-poly-lysine. Currently, only nisin and natamycin are allowed to be used in our country. Studies have shown that most molds can be inhibited by natamycin with a mass concentration of (1.0～6.0)×10-3g/L, and very few molds can be inhibited by natamycin with a mass concentration of (1.0～2.5)×10-2g/L. Mycin inhibition. In addition to being used as a food preservative, natamycin can also be used as a feed additive and biological pesticide in animal husbandry and agriculture. There are not many reports on the use of natamycin for anti-mildew in feed. Only in 2004, the U.S. Medicine and Food Administration (FDA) approved the addition of natamycin in silage to prevent poultry fungal diseases. The reason is that in addition to the cost of anti-mildew, the water content in the solid feed should not be too high (water is listed as a restrictive component in the nutrient composition of the feed, and no more than 14.4% is allowed) and the low content of natamycin Solubility may limit its widespread use. Liquid feed has been widely used in pig breeding in EU countries. 50% of pigs in the Netherlands use wet mix, and more than 30% of sows in Denmark use fermented liquid feed, and more than 70% of sows also use fermented feed during lactation. liquid feed.

In recent years, there have been some reports on the application of liquid feed in China. In the use of liquid feed, there will be problems such as the fact that the raw materials do not contain bacteria suitable for fermentation, and the feeding system contains a large number of miscellaneous bacteria, which leads to mildew of the feed. This application takes liquid feed as the research object, and tries to compound natamycin and sodium diacetate to avoid the above-mentioned obstacles and carry out anti-mold test, so as to expand the application range of natamycin in feed anti-mold.

Contents of the invention

The purpose of the present invention is to provide the application of natamycin in the preparation of liquid feed, and the compounding of natamycin and sodium diacetate as a liquid feed preservative.

The present invention is specifically realized through the following technical solutions:

The invention provides the application of natamycin in the preparation of liquid feed, and the application of the natamycin in the liquid feed for mold prevention.

Usually, the dosage of natamycin alone in liquid feed is 10mg/L.

The liquid feed of the present invention may also include sodium diacetate, and the sodium diacetate is used for mildew prevention in the liquid feed.

The compounded ratio of described natamycin and sodium diacetate is 4mg/kg:3g/L.

The liquid feed of the present invention can be prepared by those skilled in the art through conventional methods.

The beneficial effects of the present invention are: in the application of natamycin in liquid feed, the problem that natamycin is difficult to diffuse in solid feed is effectively solved, and natamycin can be dissolved in liquid feed and has a great effect on it. Good antibacterial effect.

Description of drawings

Figure 1 is the destructive storage experiment of Oerlikon pet feed under different natamycin concentrations;

Fig. 2 is coral feed destructive storage experiment;

Figure 3 is the destructive storage experiment of Oerlikon pet food.

Detailed ways

The present invention will be further described below in conjunction with the embodiments. The following descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention to other forms. Changes to equivalent embodiments with equivalent changes. Any simple modifications or equivalent changes made to the following embodiments according to the technical essence of the present invention without departing from the solution content of the present invention fall within the protection scope of the present invention.

1. Materials and reagents

Culture medium: tiger red medium (Guangzhou Huankai Microbial Technology Co., Ltd.), Cha's medium (Guangzhou Huankai Microbial Technology Co., Ltd.)

Reagents: natamycin standard (Qianjiang Biochemical Products), sodium diacetate (Aladdin), Olikang pet liquid feed (Baotou Kangmu Feed Co., Ltd.); coral growth food Plankton-1 (Beijing Songtao Hengye International trade co., LTD);

2. Instruments and equipment

Mold incubator model: MJX-160B-Z (Shanghai Boxun), disposable bacterial filter, model: JJJ50G (Beijing Zhongxi Yuanda Technology Co., Ltd.)

3. Test conditions

Solid medium dilution method: Inhibition spectrum and minimum inhibitory concentration tests are used. Add different concentrations of antifungal agents (filtered with a bacterial filter) to the tiger bengal medium at 45°C, mix evenly, and pour into the plate. Inoculate Saccharomyces cerevisiae, Rhizopus, Mucor, Aspergillus niger, Penicillium, Miscellaneous molds (mixed with concentrations of Rhizopus, Mucor, Aspergillus niger, Penicillium, etc.) in the above medium, culture in a mold incubator at 28°C for 3 days and observe The growth of the tested bacteria.

Feed storage destructive test: Take 500ml samples respectively in 5 conical flasks with the same volume, labeled as 1, 2, 3, 4, 5. Wherein No. 1 is a blank control group, No. 2 and No. 3 are control experimental groups added with 10 mg/L natamycin standard product, and No. 4 and No. 5 are controlled experimental groups added with 10 mg/L natamycin product. Place the openings of five Erlenmeyer flasks in a constant temperature water bath at 30°C. Take a sample every three days, use the coating method to measure the total number of molds in the liquid feed on the Cha's medium, and observe the apparent mildew of the liquid feed.

Feed storage destructive concentration gradient test: Take 500ml samples respectively in 5 conical flasks with the same volume, labeled as 1, 2, 3, 4. Wherein No. 1 is the blank control group, and No. 2, 3, and 4 are the experimental groups added with 10, 20, and 30 mg/L natamycin standard products respectively. Place the openings of the four Erlenmeyer flasks at room temperature. Samples were taken every three days, and the total number of fungi in each milliliter of liquid feed was measured by the mold yeast test piece method.

Embodiment 1 spectrum of inhibition and minimum inhibitory concentration test

It is known that the effective inhibitory concentration of natamycin to 500 kinds of molds is 1-100mg/kg. The concentration of natamycin in kg was inhibited; most yeasts were inhibited in the concentration of natamycin in the range of 1-5mg/kg.

It can be seen from Table 1 that the minimum inhibitory concentration of natamycin to several common molds is between 3g/kg-6mg/kg, which is consistent with the results reported in the literature. The minimum inhibitory concentration of sodium diacetate is nearly 1000 times that of natamycin. Therefore, natamycin has an incomparable superiority over chemical antifungal agents in terms of feed antifungal performance. The problem is that the cost of using natamycin alone is too high, and when the concentration is high, the solubility of natamycin is not good, which affects the use effect.

Table 1 Natamycin minimum inhibitory concentration test results

Table 2 sodium diacetate to the experimental results of the minimum inhibitory concentration of miscellaneous molds

Embodiment 2 natamycin and sodium diacetate composite test

As shown in Table 3, an appropriate compound combination (combination 5 in Table 3) can effectively reduce the concentration of natamycin and sodium diacetate, which can not only reduce the cost of mold prevention, but also reduce the palatability of sodium diacetate to feed. sexual influence.

Table 3 Natamycin and sodium diacetate composite antibacterial experimental results

Embodiment 3 feed destructive storage test

Figure 1 shows the results of Oerlikon’s pet food destructive storage experiments. The concentrations of natamycin used were 0, 10, 20, and 30 mg/L, respectively. When natamycin standard is used as antifungal agent for liquid feed (Olikon), it can effectively prevent mold, and the number of colonies per milliliter of feed is reduced by more than 3 orders of magnitude compared with the control. When a higher concentration of natamycin was used, the anti-mold effect was slightly better than that of a lower concentration, but the difference was not significant. This is related to the low solubility of natamycin in solution, which is not conducive to diffusion. The number of colonies in the control decreased after the 24th day, probably because the number of bacteria was too high, the nutrients in the test feed were exhausted, and some bacteria died. It is reported in the literature that the allowable residual amount of natamycin is 10 mg/L, taking into account the anti-mold effect, the cost of anti-mold and the allowable residual amount, 10 mg/L natamycin is used as the anti-mold agent in the following experiments.

Figure 2 and Figure 3 show the results of the destructive storage test of coral feed and the destructive storage test of Oerlikon pet feed when the concentration of natamycin is 10 mg/L, respectively. The results showed that 10mg/L natamycin could effectively control the growth of mold during the storage of the two liquid feeds, and the number of mold was 3 orders of magnitude lower than that of the control. The number of mold colonies in Oerlikon pet feed is slightly different from that in coral liquid feed, which may be due to the different nutrients contained in the two, or because Oerlikon pet feed contains beneficial microorganisms, which partially inhibit the growth of miscellaneous bacteria. The visual observation results of the destructive storage tests of the two feeds shown in Table 4 and Table 5 also confirmed the good anti-mold effect of natamycin, and the days of controlling the sterile film reached 18 days and 24 days respectively.

Table 4 Oerlikon pet feed destructive storage test results of visual observation (natamycin concentration 10mg/L)

The results of the destructive storage experiment of table 5 coral growth grain (natamycin concentration 10mg/L)

In summary, when natamycin is used alone, the minimum inhibitory concentration range is 3-6 mg kg-1, and when it is used in combination with the chemical antifungal agent sodium diacetate, the minimum inhibitory concentration of the antifungal agent can be reduced. From the perspective of food safety, the compounding ratio should be 4mg·kg-1:3g·L-1, which not only ensures the safety of food and feed, but also increases the inhibitory effect of antifungal agents. It can be seen from the destructive test that different concentrations of natamycin have a significant anti-mold effect on the liquid feed, and the total number of fungi is greatly reduced compared with the blank control group. From the comprehensive consideration of anti-mold effect and economic point of view, choose natamycin 10mg/L. In the destructive appearance experiment, the liquid feed added with natamycin had no obvious change in appearance after being exposed to the air for a long time, while the liquid feed of the blank control group had formed a layer of bacteria on the liquid surface in the first three days. membrane. In summary, the application of natamycin in liquid feed effectively solves the problem that natamycin is difficult to diffuse in solid feed. Natamycin can be dissolved in liquid feed and has a good effect on it. Antibacterial effect.

Claims (5)

1. The application of natamycin in the preparation of liquid feed. 2. The application according to claim 1, characterized in that: said natamycin is used for mildew prevention in liquid feed. 3. application according to claim 2, is characterized in that: the consumption of natamycin in liquid feed is 10mg/L. 4. The application of natamycin and sodium diacetate composition in the preparation of liquid feed. 5. The application according to claim 4, characterized in that: the ratio of the compounded natamycin and sodium diacetate is 4mg/kg: 3g/L.