Influence of temperature and modified atmosphere on the microbial profile of packed Gemlik dry-salted olives

Abstract

The effect of a chlorine wash on microbial growth in packed (vacuum and MAP), dry-salted olives of the Gemlik variety stored at 4C and 20C was studied for 7 months. The study was based on microbiological changes occurring in dry-salted olive samples during their shelf life. The microbiota were comprised of total viable bacteria, LAB and yeasts, mold, Enterobacteria and Pseudomonads. At 4 and 20C, the population of yeasts increased steadily in control samples during the shelf-life period (with and without chlorine exposure). At 20C, neither of the packaging methods was effective in suppressing total viable and LAB growth. The count of TYM increased in the MAP samples after the third month at 20C; therefore, different combinations of chlorine and CO(2) and N(2) (or combinations of chlorine with only CO(2) or N(2)) can be used to control yeast-mold growth. The combination of a 35% CO(2) and 65% N(2) (with a 10-ppm chlorine wash) at 4C was the most effective at controlling the growth of total viable, LAB and TYM. No Enterobacteria and Pseudomonads were detected since the high salt content is not favorable for their growth.