Lactic fermentation during the storage of 'Alorena' cultivar untreated green table olives

The development of lactic fermentation processes for the storage of directly brined olives (Aloreña cultivar) was investigated by three procedures: (1) a modification of the traditional method with an initial brine containing 9% (w/v) NaCl and 0.2% (w/v) acetic acid; (2) induced lactic fermentation with 6% NaCl and 0.2% acetic acid; and (3) conservation in acidified brine containing 6% NaCl and 0.6% acetic acid. In all cases, strains of Lactobacillus plantarum and Pediococcus spp. were present in each, indicating the great tolerance of these micro-organisms to high levels of lactic and acetic acids. They also appeared in an altered sequence. Counts of Pediococcus remained moderate (higher than Lact. plantarum ) throughout the last part of the preservation period. A commercial starter improved colonization by Lact. plantarum. Yeasts coexisted with the lactic bacteria throughout the preservation period although their importance in the fermentation process was very limited. The brine characteristics obtained after fermentation were suitable for assured product preservation. There was no spoilage. These results encourage research on the mechanism of lactic acid bacteria inhibition in brines and the development of lactic fermentation processes for directly brined olives from other olive cultivars.