Cold plasma and tea polyphenols: Synergistic impact on microbial quantity and quality of mutton

Abstract

To investigate the synergistic effects of in-package cold plasma (CP) and tea polyphenols (TP) on microbial quantity and quality of mutton, the mutton was sealed in tray with gas mixture inside (O2: N2: CO2 = 65:25:10) after soaked in TP solution, and treated with CP system at 75 kV for 150 s. Results showed that TP-CP treatment reduced the colony amounts of total viable count (TVC), psychrotrophic bacteria count, Enterobacteriaceae count, and Pseudomonas spp. count effectively. The TVC of mutton was 5.95 log CFU/g in the TP-CP group after 13 d, still acceptable. A synergistic inhibit effect of TP and CP was found on the TVB-N values. The CP treatment significantly (P < 0.05) increased the values of thiobarbituric acid-reactive substance (TBARS), while TP diminished the increase of TBARS caused by CP. Similarly, higher values of carbonyls and sulfhydryl content were found in the CP groups, and lower values were displayed in the TP-CP groups. In conclusion, the TP combined with CP treatment was efficient in inhibiting the growth of microorganisms, mitigating the oxidations of both lipid and protein, delaying the color changes, and helpful in maintaining the quality and extending the shelf-life of mutton.