Assessment of microbiological contamination in saengshik products from the Korean market and identification of the irradiation status

This study investigated the prevalence of microbiological contamination in commercial Saengshik products (samples SP-1 to SP-12) from the Korean market, and identified their irradiation status. SP-2, SP-8, and SP-12 showed less than 3.66 and 1.10 log colony forming units (CFU)/g in total plate and coliforms counts, respectively, while the remaining samples showed more than 4.70 and 2.35 log CFU/g, respectively. Four samples were positive on some of foodborne pathogenic bacteria (Clostridium perfringens, Escherichia coli O157:H7, and Bacillus cereus). SP-2, SP-8, and SP-12 contained no pathogenic bacteria and were suspected to have been irradiated. They were confirmed as positive using photostimulated luminescence (PSL) analysis. PSL positive results on samples SP-2, SP-8 and SP-12 were finally confirmed by the authentic thermoluminescence (TL) analysis on the basis of TL glow curve shape, intensity, temperature range of TL peak maxima and TL ratio (TL₁/TL₂).