Abstract: This study investigated the effect of radio frequency plasma activated water (RF-PAW) treatment on myoglobin color and the color development of cooked ham, and compared the efficacies of sodium nitrite solution and RF-PAW as color fixatives as well as the levels of residual nitrite in hams produced with the color fixatives. The results showed that PAW treatment for up to 6 min did not have significant influence on the color of metmyoglobin (metMb), but caused gradual oxidation of oxygenated myoglobin (oxyMb) into metMb, resulting in color change from bright red to reddish-brown. Naked eye observation showed that both RF-PAW and nitrite solution promoted the color development of ham but the former was more effective than the latter with its active substances causing no adverse effects on ham color. The results of color difference analysis showed that the ham cured with PAW had higher a* and C* values and lower b* values, and it had higher content of nitrosomyoglobin pigment (43.52%), thus showing a deeper red color. The level of residual nitrite in nitrite cured ham was 54.45 mg/kg, and that in PAW cured ham was 52.79 mg/kg, both of which were less than the national standard limit of 70 mg/kg. These findings may provide a theoretical basis and scientific guidance for the application of cold plasma in preservation and curing of meat products.

Key words: plasma activated water; myoglobin; color; nitrite; ham color development