Naturally fermented black olives of Taggiasca variety (Olea europaea L.)

Abstract

For the first time, a natural fermentation of black Taggiasca variety (Olea europaea L.) olives was studied. This cultivar is typical of Western Liguria (NW of Italy), where it is mainly used for olive oil production. Beside the traditional process, three slightly different processes were taken into account. The fermentation was carried out in 200 litre barrels left at environmental temperature (7-25ºC) and took about 6 months to be complete. At the end the olives were pasteurised and stored for a further 6 month period to equilibrate. Throughout the process, pH, NaCl, acidity, free biophenol content and microbiological analysis (Colony count, Coliforms (Klebsiella spp., Enterobacter spp., Citrobacter spp., Escherichia coli), Lactobacilli (25ºC, 36ºC, 45ºC), Pseudomonas (P. fluorescens, P. cepacia), Yeasts (Candida spp.), Moulds (Penicillum spp., Clostridium spp., Vibrio spp.) of brines were performed. The results showed that an initial pH correction is recommended and no long soaking of the olives in water (3+3 days) is advisable, except a short washing just before brining.