Abstract:In order to explore the effect of plasma electric field assisted freezing on the quality and freezing process of mutton, the longissimus dorsi muscles of sheep was selected as the experimental material, the effect of the auxiliary plasma electric field of different field strength (1, 3 kV/m and 5 kV/m) on the freezing velocity of mutton and the distribution of ice crystal and the diameter and roundness of ice crystal in the frozen meat were studied, and the thermodynamic theory was used to analyze it. The results showed that the meat samples in the auxiliary 5 kV/m plasma field environment had the shortest time to pass the maximum ice crystal generation zone at -20 ℃ and -35 ℃, 70 min and 40 min, respectively, with significant differences compared with the control group (P < 0.05); the tissue sections showed the smallest ice crystal area and grain size formed at -35 ℃ assisted 5 kV/m plasma field freezing, and -20 ℃ assisted the roundness of ice crystals was the highest in 5 kV/m plasma field freezing, with a mean value of 0.88, and the above indexes were significantly different from the control group (P < 0.05). The entropy of the system was analyzed using Boltzmann's formula, and the results showed that the entropy of the meat samples frozen by the assisted 5 kV/m plasma electric field was the smallest at -20 °C and -35 °C, with significant differences compared with the control group (P < 0.05). It proved that the auxiliary 5 kV/m plasma electric field could significantly improve the system frozen meat moisture vitrification degree, could make the crystallization process more controllable, the electric field assisted freezing required less energy to improve the subcooling degree, accelerate the freezing rate of meat samples, and the larger the field strength the more significant the effect. Based on the experimental results and energy-saving requirements, it was considered that -20 ℃ assisted 5 kV/m voltage freezing can be used as a new freezing method in production.