Combination effect of ozone and heat treatments for the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in apple juice

Abstract

We investigated the combination effect of ozone and heat treatments in apple juice for the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes. Apple juices inoculated with the three pathogens were treated with gaseous ozone and heat simultaneously for up to 1 min. Gaseous ozone treatment was progressed at a flow rate of 3.0 l/min with a concentration of 2.0-3.0 g/m³ and heat treatment was performed at temperatures of 25, 45, 50, and 55 °C. Populations of surviving pathogens decreased in all samples as treatment temperature increased from 25 to 55 °C. Heat treatment alone (25, 45, 50 and 55 °C) resulted in 0.20, 0.37, 2.16 and 2.54 log CFU/ml reductions of E. coli O157:H7, respectively, in apple juice. Combination treatment of ozone and heat for 1 min reduced this pathogen by 1.50 and 1.60 log CFU/ml, respectively, at 25 and 45 °C, and below the detection limit (1 log CFU/ml) at 50 and 55 °C. We found a synergistic effect in the inactivation of pathogens in apple juice treated with ozone and heated at 50 °C. The reduction trend of S. Typhimurium and L. monocytogenes in apple juice was similar to that of E. coli O157:H7. There were no significant changes of Hunter color values when apple juices were treated with heat only and the combination of ozone and heat. Residual ozone was measured following ozone treatment. In all ozone treated samples, the concentration of residual ozone was reduced to under acceptable levels (<0.4 mg/l). In conclusion, the combination treatment of ozone and heat was significantly effective in the inactivation of foodborne pathogens while maintaining acceptable apple juice quality.

Inactivation ofEscherichia coliO157:H7,SalmonellaTyphimurium andListeria monocytogenesin apple juice at different pH levels by gaseous ozone treatment

“…Schematic diagram of the ozone treatment apparatus at Seoul National University (Seoul, Republic of Korea) (Sung et al . ).…”

Impact of ozone processing on microbiological, physicochemical, and bioactive characteristics of refrigerated stored Cantaloupe melon juice

“…Thermal processes are traditionally applied and their effectiveness on fruit juices decontamination has been widely studied (Torlak, ). However, high temperatures dramatically impact sensorial attributes (e.g., color and flavor) and the concentration of important bioactive and nutritional compounds, such as vitamins and phenolics, are also negatively affected (Fonteles et al, ; Sung, Song, Kim, Ryu, & Kang, ). To avoid these problems, several nonthermal technologies are being exploited to guarantee fruit juices safety and retention of quality and nutritional characteristics (Miller, Silva, & Brandão, ).…”

Tracing interactions among column height, exposure time and gas concentration to dimension peanut antifungal ozonation

“…On the other hand, although the results of the analysis of variance indicates a significant change in color hue due to the interaction between ozone concentration and exposure time, the regression coefficients were not significant (p > 0.05). It is noteworthy that the color is an important indicator of product quality and also has influence on consumer perceptions (Carvalho, Chagas, & Souza, 1997) being used to assess the quality of ozonated food (Liew & Prange, 1994;Nadas, Olmo, & García, 2003;Sung, Song, Kim, Ryu, & Kang, 2014). Alencar et al (2011) observed significant variation in color difference of peanut kernels as a function of ozonation.…”