Effects of Lactiplantibacillus plantarum 11 and Chloride Sodium on Biochemical and Microbiological Quality of Table Olives during Fermentation

Background: Table olives are nutritionally a complete food and considered as one of the oldest fermented products. This study aimed to evaluate the effect of Lactiplantibacillus plantarum 11 as a starter culture on the fermentation of table olives at two incubation temperatures 22 and 30 °C and different salt concentrations (0, 4, 8, and 12% m/v) of sodium chloride (NaCl). Methods: The fermentation of table olives was carried out according to the Spanish style. L. plantarum 11 was inoculated as a starter culture (106 Colony Forming Unit (CFU)/ml), and Listeria monocytogenes CECT 4032 was used as an indicator strain. Under the same experimental conditions, the fermentation of olives without the inoculation of starter culture was used as a control. Then, biochemical and microbiological quality of each experimental batch was tested. Results: Unlike the incubation temperature of 22 °C, the pH values ​​obtained in salted batches and incubated at 30 °C were all below the marketing limits for table olives. At the end of the process, the maximum load of yeasts and molds (>5 log CFU/ml) was recorded in the batches incubated at 22 °C. At 22 °C, Listeria was absent in inoculated fermenters at a concentration greater than or equal to 8% (w/v) of NaCl. However, at 30 °C, Listeria was not detected in treatment groups and in the control group with 12% NaCl.  Conclusion: L. plantarum 11 could be potentially considered as a probiotic starter culture during the fermentation of black table olives.