Green olive fermentation using spontaneous and Lactobacillus plantarum cultures

Abstract

The aim of this work was to evaluate the performance of spontaneous and Lactobacillus cultures in Spanish style fermentation of olive fruits. A fermentation with Lactobacillus plantarum ATCC 8014 was carried out for comparison. Fermentation was performed at room temperature during 120 days in two different concentrations of NaCl (2.4–13.6 % w/v) and sucrose (0–0.82 % w/v) in the brines. The pH, chlorides, lactic acid, reducing sugar and lactic bacteria in selective medium were investigated during the olive fermentation. After 120 days of fermentation, the formulation with 12 % NaCl in the brine hampered the growth of lactic bacteria, avoiding the consumption of reducing sugars. However, low salt concentrations (≤4 %) promoted a decrease in pH, an increase of the lactic acid and the growth of lactic bacteria, providing best environmentally suitable for the fermentation process. Whereas using concentrations of 12 % NaCl and 0.7 % sucrose showed better chemical conditions, ensuring the safety of the product produced. Multivariate analysis showed that the olives with both cultures were in close relation to lactic acid and reducing sugar and different from lactic bacteria.