Preservation of green table olives fermented with lactic acid bacteria with probiotic potential under modified atmosphere packaging

- Green olives were fermented by two potential probiotic Lactobacillus strains.
- The fermented olives were stored for a year at 4 and 20 °C under modified atmospheres.
- The initial and final LAB population was 5.6-5.9 and 5.8-6.4 log CFU/g respectively.
- Both strains were recovered with higher percentages after 6 months at 4 °C.
- A shelf life of 6 months at 4 °C could be proposed for a promising functional food.

Green olives cv. Halkidiki previously fermented by the potential probiotic Lactobacillus pentosus B281, Lactobacillus plantarum B282, or the indigenous microbiota were packed under modified atmospheres (70% N2-30% CO2) and stored at 4 and 20 °C for 12 months. The populations of lactic acid bacteria (LAB) and yeasts as well as the physicochemical characteristics of olives (pH, water activity, colour, acidity, salt content and firmness) were monitored. The LAB population was 5.6-5.9 at the beginning of the storage and reached 5.8-6.4 log CFU/g after one year. Pulsed-field gel electrophoresis revealed survival rates of 100% for L. pentosus B281 and 46.7% for L. plantarum B282 at the beginning of storage. Both strains were recovered in high percentages (64.7% for B281 and 94.1% for B282) after 6 months and in lower survival rates after one year (35.0% for B281 and 13.3% for B282) at 4 °C. Lower rates were also observed during storage at 20 °C. Moreover, the product was organoleptically more acceptable after 6 than 12 months of storage at both temperatures. Thus, a shelf life of six months at refrigerating temperature could be proposed as the best studied condition to deliver a promising probiotic food to the consumer.