What are the key points of freezing technology for frozen rabbit

1. Freezing facilities

Currently, frozen rabbit processing in China mostly uses mechanized or semi-mechanized operations, and its process level and hygiene standards have reached international levels.

The freezing processing rooms mainly include cooling rooms, cold storage rooms and freezing rooms, etc. In medium-sized frozen rabbit meat processing plants, since the slaughtering room is generally located on the top floor of the building, the meat cooling room should also be located on the top floor so as to be connected to the slaughtering room, followed in sequence by the cold storage room and the freezing room, while the freezing room should be located on the ground floor so that it can be directly shipped or used for temporary storage by other processing rooms. Cooling, cold storage and freezing rooms should be equipped with crane monorails, and the distance between rails is generally 600-800 mm, and the height of the freezing room is 3-4 m. In order to reduce the degree of microbial contamination on the carcass, in addition to attention that must be paid during the slaughtering process, good hygiene conditions should also be maintained for the air, facilities, floor, walls and even workers in the freezing room. During the freezing process, hooks, iron trays, cloth covers, etc. that come into direct contact with the carcass should only be used once, and before repeated use, they must be cleaned, disinfected, and dried before use.

2. Cooling conditions

This mainly refers to temperature, humidity, air velocity and cooling time, etc. In rabbit meat freezing, the first thing is the freezing of water and meat juice in the muscle fibers; however, the quality of frozen rabbit meat has a great relationship with freezing temperature and speed. According to experiments, under different low-temperature conditions, the degree of freezing of rabbit meat is different. Usually, the water in fresh rabbit meat begins to freeze at -0.5 to -1°C, and is completely frozen at -10 to 15°C.

According to measurements, throughout the cooling process, because the temperature difference between the cooling medium (air) and the carcass is relatively large in the early cooling stage, the cooling speed is relatively fast, and the amount of water evaporated from the carcass surface in the first 1/4 of the time accounts for about 1/2 of the total evaporation. Therefore, the relative humidity of the air is also required to be divided into two stages: in the first 1/4 of the cooling period, it is appropriate to maintain the relative humidity above 95%; in the latter 3/4 of the cooling period, the relative humidity should be maintained at 90%-95%; near the end of cooling, it should be controlled at about 90%. Air velocity is another important factor affecting cooling time and degree. Generally, when frozen rabbit meat is cooled, an air velocity of 2 m per second is appropriate.

3. Cooling methods

At present, frozen rabbit meat processing plants in China all use the quick-freezing cooling method. The temperature in the quick-freezing room should be below -25°C, and the relative humidity should be 90%. The quick-freezing time generally does not exceed 72 hours, and when the measured meat temperature reaches -15°C, it can be transferred to cold storage.

Small processing plants without cooling facilities should be equipped with an appropriate number of fans and exhaust fans. In hot seasons, every effort must be made to keep the meat temperature below 20°C, and then it should be sent directly to the quick-freezing room for quick freezing, so that the water in the muscle fibers and the meat are completely frozen. In order to speed up the temperature drop, the Shanghai frozen rabbit meat processing plant uses the open-box quick-freezing method, compressing the original 72-hour quick freezing to 36 hours, which not only saves electricity but can also improve the quality of frozen rabbit meat. It is an effective measure. The plant's specific method is to open the box cover, send it to the pipe rack for quick freezing, and after quick freezing, pack it and transfer it to cold storage.