Effect of Ozone Technology on Microbial Characteristics of the Processed Olive and its Comparison with Sorbic Acid

Ozone molecules have antimicrobial activity through attacking the cell wall of microorganisms and oxidizing sulfhydryl groups of proteins, resulting in rupturing of the wall and outer membrane followed by inactivation of microorganisms. In this study, effect of ozone technology on microbial characteristics of the processed olives and its comparison with sorbic acid were investigated.
In this study, ozone and sorbic acid were used at concentrations of 2.5 ppm and 100 ppm, respectively. Samples were treated for 1, 2 and 4 minutes. The effect of ozone and sorbic acid was studied separately on thermophilic and mesophilic aerobic bacteria with producing lactic acid activity, mold and yeast. Microbiological characteristics of processed olive samples were measured for 75 days at 4 °C on day zero, ten, twenty, thirty, forty-five, sixty and seventy-five. The least significant difference (LSD) method was used to compare differences between treatments and the data analysis was performed by SAS software.
In general, ozone treatment at different times and also sorbic acid reduced molds, yeasts and lactic acid-producing bacteria (thermophilic and mesophilic aerobics) populations in the processed olives compared to the control sample. Ozone injection time of 4 min had better properties and also resulted in similar efficiency of antimicrobial activity and sometimes higher than the samples containing sorbic acid.
•The results of the present study showed that the use of ozone can be an acceptable alternative to sorbic acid as an antimicrobial agent in packaged processed olives.