Abstract: In order to evaluate the effect of lactic acid (LA)-assisted low-temperature plasma on the preservation of yellow-feathered broiler carcass, single factor experiments and response surface methodology were used to investigate total viable count (TVC), coliform count (CC) and fat oxidation value as a function of three variables, namely LA concentration (V/V), discharge voltage, and discharge time. Microbiological, physicochemical, and quality indicators of chicken were determined during storage after sterilization under optimized conditions. The results showed that the optimal sterilization parameters were LA concentration of 2.0%, discharge voltage of 150 kV, and discharge time of 115 s. Under these conditions, the TVC and CC on the surface of chicken and its fat oxidation value were 3.02, 1.00 (lg(CFU/g)) and 0.58 mg/kg, respectively. On the 7th day of storage, the inhibitory effects of LA-assisted low-temperature plasma on TVC and CC increased by 26.75% and 19.72% compared with those of LA, by 34.51% and 24.87% compared with those of low-temperature plasma, respectively, and the combination decreased the total volatile basic nitrogen (TVB-N) content by 27.35% and 12.25% compared with single treatments with LA and low-temperature plasma, respectively. In addition, the combination treatment delayed the increase in pH of chicken during storage, improved the texture, and significantly slowed down the deterioration of sensory quality (P < 0.05). Low-temperature plasma treatment increased the fat oxidation value at the early stage (from day 1 to 3) of storage, but did not have a significant impact on the sensory evaluation of meat in terms of odor or color. Overall, LA combined with low-temperature plasma was more effective in preserving yellow-feathered broiler carcass than either alone.

Key words: low-temperature plasma; lactic acid; yellow-feathered broiler carcass; response surface methodology optimization; preservation effect