Effects of Ultrasonic Atomizing Humidification Technology on the Shelf Quality of Refrigerated Pork

【Objective】China is a large country of pork production and consumption in the world, but most fresh meat is sold extensively while little of them is sold in refrigeration condition. In order to improve the quality and prolong the shelf life of fresh meat, a refrigeration method based on ultrasonic atomizing humidification was proposed.【Method】Taking the pork sold in an open refrigerated display cabinet as the material, the influence of ultrasonic atomizing humidification on the shelf quality of pork was studied, and the changes of quality parameters such as shear force, color difference, cooking loss rate and pH of pork within 24 h in temperature control (TC) and temperature and humidity control (THC) conditions.【Result】The pork shear force changed little compared with the initial value after 12 h of TC condition, but rapidly decreased to 65.2N after 24 h of storage. The shear force of pork rapidly decreased within 12 h, and remained at around 86 N during 12-24 h in THC condition. In both conditions, L*, a* and b* showed similar trends over time, but L* in TC condition was higher than THC condition, while a* and b* were lower than THC condition. After 24 h refrigerated sales, the number of pork microorganisms under the two conditions were 28 000 and 149 713 CFU/mL, respectively. The change of pork microbial number during refrigerated sales was related to the change of color difference. The cooking loss rate showed similar trend under the two conditions over time, and there was little difference between them after 12 h. The cooking loss rate under two conditions were 26.2% and 24.6%, respectively. After 24 h refrigerated sales, the pH of pork under TC condition and THC condition decreased by 0.4 and 0.2, respectively, and the pork under THC condition belonged to the prime meat. The temperature and relative humidity in the refrigerated display cabinet under two working conditions showed similar trend of decreasing to rising in a single refrigeration cycle. The minimum temperature of TC condition in the cabinet was 1.2 ℃ higher than that of THC condition. The variation trend and amplitude of relative humidity under two working conditions were similar.【Conclusion】THC condition slowed down the shear force and pH drop rate of pork, reduce the cooking loss rate of pork, but the number of microorganisms in THC condition is 5.3 times of that in TC condition. The research results have a significant reference for improving the shelf quality of pork and optimizing the parameters of refrigerated display cabinet.