Energy consumption and quality improvement of frozen pork using NaCl refrigerant with three amino acids in contact immersion freezing

Maintaining low-energy consumption and improving the quality of frozen pork contribute to the sustainability of the meat industry. This study used a 23.5 % sodium chloride (NaCl) solution as the control refrigerant (NIF). It investigated the effects of substituting 10 % of NaCl in the refrigerant with three amino acids (l-lysine, l-proline, or l-arginine) on energy consumption and pork quality improvement in contact immersion freezing. Results indicated that l-proline among three amino acids could mitigate the increase in specific heat capacity, the decrease in thermal conductivity, and the unfrozen water content of pork caused by the reduction of NaCl via mitigating the increase in specific heat capacity, the decrease in thermal conductivity, and the thermal diffusion coefficient of the refrigerant, thus maintaining the freezing energy conservation and efficiency (reduced freezing time) of the NIF group. The incorporation of l-proline also effectively reduced NaCl infiltration into the pork and improved its color quality. This study provides a new refrigerant for contact immersion freezing in the meat industry, offering low-energy consumption and improved frozen meat quality.