Phytase processing technology

Phytase is an enzyme preparation that uses genetic engineering technology to obtain genetically engineered bacteria and is prepared by a special fermentation process. It was introduced from abroad in the 1980s and produced in the mid-1990s. Currently, domestic manufacturers only produce More than ten. The processing technology is: fermentation liquid - flow metering - computer controlled steam carrier micro-grinding - lifting - high-humidity material mixing - stepless conveying - drying - cooling - finished product mixing - automatic metering - packaging slot A24 phytase for beverage additives, It can effectively decompose phytic acid in feed to release inorganic phosphorus, improve the utilization of phytic acid phosphorus in beverages, reduce phosphorus discharge and protect the environment. In addition, it increases animal utilization of mineral elements and protein digestibility. The role of phytase in livestock and poultry farming is very obvious. Enzyme preparations are added to almost all full-price beverages in the United States, Finland, Sweden, and other countries. In 1999, China's beverage production reached 68.71 million tons, ranking second in the world, of which 5,552 tons of full-price beverages were added. According to the current phytase ratio of 0.1% in the full price, 3,000 tons of phytase can only add 300. The use of 10,000 tons of full-price compound feed is only 5.4% in full-price feed, so the market prospect is very impressive. For the production of 400kg phytase processing equipment, the main workshop covers an area of ​​20 × 10 (M2) equipment costs about 3.1 million yuan, the total installed capacity is about 130kw; phytase sales price of 9,000 yuan / ton, annual profit 324 Ten thousand yuan, the equipment investment recovery period is 0.95 years.

2. Post-processing of phytase

In recent years, phytase has been widely used in feed.

In the production technology of phytase, the production of domestic phytase has reached the international advanced level, and some even far exceed foreign countries; as a post-processing technology, domestic phytase manufacturers have also achieved remarkable results. progress.

At present, the domestic phytase processing methods mainly include adsorption drying, spray drying, granulation and coating.

Adsorption drying is the earliest production method of domestic phytase. At that time, the domestic phytase industry had just started, the fermentation enzyme activity remained at a lower level, and the use of adsorption drying method to produce low-enzyme living products was the most economical production method, and it was also the main production of low-enzyme living products. the way. Adsorption drying is to mix the fermentation broth and corn cob powder in a certain ratio and dry it by two-step airflow. The first step uses hot air at 130 ° C for 10 seconds; the second step uses air at 60 ° C - 80 ° C for 10 seconds. This not only ensures the rapid dehydration of phytase, but also ensures a low loss of enzyme activity. The adsorbed and dried product is greatly affected by the fermentation enzyme activity and the carrier. Quality control must be done to ensure the moisture, particle size and color of the carrier. The products produced by the adsorption drying method have lower cost, but the molecules of the phytase are directly in contact with the outside, and the time of storage in the feed is not as good as that of the granulating and coating type phytase, and the application time is not high. The feed is stored in a place with a good temperature and humidity environment.

Spray drying is currently the main production method of high enzyme activity products in China. For example, a product of 2500 U/g and 5000 U/g is produced by mixing a fermentation liquid and a carrier in a certain ratio, and dispersing into small droplets through a nozzle under a certain pressure. These droplets are instantaneously dehydrated in a stream of hot air to form a granular product. Due to the instantaneous dehydration, the enzyme activity loss is small. At the same time, by adjusting the ratio of the fermentation broth and the carrier, phytase products of different concentration ratios can be produced. The products produced by spray drying should belong to the second generation in China. The utility model has the advantages of beautiful appearance, good dispersibility and high enzyme activity. Use in the feed can create a larger formula space. The disadvantage is that the particle size is not easy to control during the production process, and there is a certain amount of dust when used. At the same time, similar to the adsorbed and dried products, the phytase molecules are in direct contact with the outside world, and are easily affected by other components in the feed, and there are certain problems in preservation.

With the improvement of the domestic phytase technology level, domestic enterprises have successfully produced phytase of pellets and coated dosage forms. The advent of pellets and coated phytase marks the international advanced level of domestic phytase processing. The pellet phytase is obtained by mixing the treated fermentation broth and the carrier in a certain ratio, molding by low temperature, and drying to obtain a product. It is equivalent to blocking the phytase molecules in several cells, which isolates the contact between the molecules and the outside world, and is more conducive to the preservation of phytase. Phytase is also more easily distributed throughout the feed due to the guaranteed particle size distribution and particle count. There is no longer a problem with dust during use. The key to the pellet phytase technology is the choice of carrier and drying method. In the selection of the carrier, it is first required that the produced particles have a certain hardness, and the particles can rapidly disintegrate in water, releasing the phytase molecules therein and functioning. Secondly, the chosen carrier must ensure stability in the feed. It is guaranteed that after mixing into the feed, it will not interact with the feed and affect the stability of the phytase. Finally, because the carrier has an effect on the enzyme activity, the determination of the carrier requires a lot of calculations and tests to get the correct results. The evaluation index of the quality of the pellet phytase includes the number of particles per unit weight and the particle size distribution. The number of particles per unit weight indicates the ability of the pellets to be distributed in the feed. If the number of particles is small, it is difficult to ensure uniform distribution after adding the feed. The more the number of particles, the greater the chance of distribution in the various parts of the feed, in order to ensure the uniform distribution of phytase in the feed, in order to ensure the feeding effect of the animal. The particle size distribution shows the uniformity of the product size. The more concentrated the particle size, the more uniform the particle size of the product, and the better the phytase distribution in the feed when mixed into the feed.

The coating uses a coating agent for the formed particulate phytase to form a strong and easily soluble film on the surface, which separates the phytase particles from the outside air and moisture. It is more conducive to the stability of phytase, the high temperature resistance level is also improved, and the use range is wider. The coating agent is divided into two types of water-soluble and fat-soluble. It is best to use a water-soluble coating to ensure rapid dissolution in the digestive tract and release the phytase. If a fat-soluble coating agent is used, such as various fats or stearates, on the one hand, it needs to be released by lipase to release a large amount; on the other hand, fat or stearate is easily oxidized in the feed, affecting planting. The retention rate of acid enzymes. The coating process must form a strong film on the surface, which has the function of moisture proof and air isolation. This requires specific requirements for the coating time and process.

For the evaluation of the quality of the coated phytase product, the number of particles per unit weight and the particle size distribution are similar to those of the granule phytase. Whether the coating is complete or not requires microscopic examination.