This may be due to the rapid decomposition property Selleck 3 Methyladenine of ozone. Therefore, we analyzed residual ozone by the indigo method which is commonly used to determine the concentration of ozone in water. After ozone treatment, residual ozone concentration in all samples decreased to below 0.4 mg/l when maintained at 4 °C for 6 h. We also confirmed that residual ozone increased as the treatment temperature decreased, correlating with the result of a previous study (Achen and Yousef, 2001). They reported that the concentration of residual ozone was greatest at 4 °C, not at 22 or 45 °C. It has been reported that ozone treatment is more effective when microorganisms are

suspended in pure water or buffers containing less ozone demanding materials than in complex food systems

composed of organic compounds (Cho et al., 2003). Ozone concentration in treated apple juice couldn’t be determined by the indigo method (data not shown) because of the intrinsic color of juice, but residual ozone in Pictilisib manufacturer distilled water could be analyzed. Even though we obtained results about residual ozone by using distilled water instead of apple juice, low concentrations of residual ozone may occur in apple juice due to various ozone consuming compounds compared to distilled water. There are organic compounds such as sugars, pectic substances, and antioxidants in apple cider and orange juice. These compounds may react with ozone (Kim et al., 1999 and Williams et al., 2004). Antioxidant compounds like polyphenols, phenolic acids, flavonoids and ascorbic acid are ozone consuming materials having an effect on ozone chelation in apple juice (Liao et al., 2007). Therefore, application of the indigo method in Thymidine kinase this study is considered reasonable for judging the concentration of residual ozone in apple juice by inference through results obtained from distilled water. In conclusion, the combination of ozone and heat treatments can be used as a novel technology for the inactivation of foodborne pathogens in apple juice. We found a combination effect when apple juice is treated with

both ozone and heat simultaneously and a clear synergistic effect at 50 °C. Also, this treatment is effective in that the color of the juice was maintained and the concentration of residual ozone in the juice might decrease to below 0.4 mg/l after ozone treatment. If this intervention is to be used in the food industry, processing for more rapid ozone decomposition is necessary and specific treatment conditions such as temperature, time and ozone concentration should be established considering the inactivation of pathogens and maintenance of sensory quality in apple juice. This research was supported by the Public Welfare & Safety research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2012M3A2A1051679).