New process for production of fermented black table olives using selected autochthonous microbial resources.

Gianluca Bleve,Francesco Grieco,Maria Tufariello,Vittorio Falco,Francesca A Ramires,Antonio F Logrieco,Giovanni Mita,Miriana Durante,Maria Tasioula-Margari,Ezio Perbellini,Luca Tommasi

doi:10.3389/fmicb.2015.01007

Abstract

Table olives represent one important fermented product in Europe and, in the world, their demand is constantly increasing. At the present time, no systems are available to control black table olives spontaneous fermentation by the Greek method. During this study, a new protocol for the production of black table olives belonging to two Italian (Cellina di Nardò and Leccino) and two Greek (Kalamàta and Conservolea) cultivars has been developed: for each table olive cultivar, starter-driven fermentations were performed inoculating, firstly, one selected autochthonous yeast starter and, subsequently, one selected autochthonous LAB starter. All starters formulation were able to dominate fermentation process. The olive fermentation was monitored using specific chemical descriptors able to identify a first stage (30 days) mainly characterized by aldehydes; a second period (60 days) mainly characterized by higher alcohols, styrene and terpenes; a third fermentation stage represented by acetate esters, esters and acids. A significant decrease of fermentation time (from 8 to 12 months to a maximum of 3 months) and an significant improvement in organoleptic characteristics of the final product were obtained. This study, for the first time, describes the employment of selected autochthonous microbial resources optimized to mimic the microbial evolution already recorded during spontaneous fermentations.

Highlights

Table olives represent one important fermented product in Europe and their demand is nowadays increasing throughout both EU and the world and producer countries are the most important consumers (International Olive Council (IOC), 2014)
We previously reported that in several cultivars of black table olives yeasts were present during the fermentation, whereas Lactic Acid Bacteria (LAB) resulted associated only to the last stage of the process produced (Bleve et al, 2014, 2015a)
Microbial Strains and Growth Conditions The yeast strains used in this study were: Saccharomyces cerevisiae LI 180-7 isolated from Leccino, Pichia anomala CL 3029 isolated from Cellina di Nardò, S. cerevisiae KI 30-16 isolated from Kalamàta, Debaryomyces hansenii A 15-44 isolated from Conservolea

Summary

Introduction

Table olives represent one important fermented product in Europe and their demand is nowadays increasing throughout both EU and the world and producer countries are the most important consumers (International Olive Council (IOC), 2014). Conservolea and Kalamàta represent the most economically important cultivars in Greece for domestic and foreign market (Garrido-Fernandez et al, 1997); whereas, among Italian table olive cultivars, Leccino is the most important olive variety used for dual-purpose in the world (Vossen, 2007) and Cellina di Nardò is a very promising table olive cultivar in Salento (Apulia, Southern Italy), highly appreciated for its peculiar organoleptic and sensorial features (Bleve et al, 2015a). Bleve et al (2014, 2015a) studied the evolution of several compounds (sugars, organic acids, alcohols, mono and polyphenols and volatiles) associated with yeasts and bacteria fermentative metabolism of during the spontaneous fermentation process of these Italian and Greek olive cultivars By this approach, chemical compounds deriving by microbiological activities during the fermentation process were proposed as chemical descriptors to monitor the fermentation process

Methods

Results

Conclusion