Study of microbiological quality of controlled atmosphere packaged 'Ambrunés' sweet cherries and subsequent shelf-life

The objectives of this study were to evaluate the effect of different controlled atmospheres, containing 3% O2 + 10% CO2, 5% O2 + 10% CO2 and 8% O2 + 10% CO2, on changes in microbial population of 'Ambrunés' sweet cherries throughout storage during 30 days and subsequent shelf-life, as well as to identify the main genera of yeast, mould, lactic acid bacteria, Staphylococcus spp., Pseudomonas spp., Enterobacteriaceae spp., and coliforms. The results indicated that controlled atmospheres with 5% O2 + 10% CO2 and 8% O2 + 10% CO2 were highly effective to control the growth of mesophilic aerobic bacteria, psychrotrophs, Pseudomonas spp., yeasts, and moulds after 15 days of storage, showing, in the case of yeasts and moulds, counts that ranged between < 1 and 1.75 log CFU/g. The genera of yeasts, moulds, lactic acid bacteria, Enterobacteriaceae spp., and coliforms identified were Aureobasidium spp., Penicillium spp., Leuconostoc spp., and Rahnella spp., respectively. In addition, the genera Staphylococcus spp. and Pseudomonas spp. were also identified. On the other hand, cherries of Stage 3 ripening presented the highest counts for all microbial groups.