Microbiota of table olive fermentations and criteria of selection for their use as starters

Dilek Heperkan

doi:10.3389/fmicb.2013.00143

Abstract

Fermentation is one of the oldest methods for preserving of olives applied worldwide for thousands of years. However, olive processing is a speculative area where whether olives are fermented products or pickled products produced by organic acids and salt. Although lactobacilli and yeasts play a major role in the process, literature survey indicates that lactobacilli are less relevant at least in some types of natural green olives during fermentation. There have been significant advances recently in understanding the process to produce olives, especially the role of lactic acid bacteria and yeasts including biofilm formation on olive surfaces by these organisms. The purpose of this paper is to review the latest developments regarding the microbiota of olives on the basis of olive types, their role on the fermentation process, the interaction between both group of microorganisms and the olive surface, the possibility to use starter cultures and the criteria to select appropriate cultures.

Highlights

The addition of a starter culture in the production of fermented olives is not a common practice worldwide
USED FOR SELECTION OF APPROPRIATE STRAINS AS STARTER CULTURE Since lactic acid bacteria (LAB) and yeast play an important role in fermented olive production, microorganisms to be used as starter culture are preferably selected from LAB and yeast species already present in the olive microbiota
In recent studies, using culture-dependent methods, LAB or yeast cultures were isolated from olives and/or brine by using selective media such as de Man, Rogosa and Sharp (MRS) agar (Oxoid) and oxytetracyclineglucose-yeast extract (OGYE) agar (Oxoid), respectively

Summary

Introduction

The addition of a starter culture in the production of fermented olives is not a common practice worldwide. There are no reports published on food intoxication of fungal origin there are reports published on Clostridium botulinum type B and its neurotoxin detection in the conserved olives (Jalava et al, 2011). It is not usual, but there are several cases of food-borne botulism described linked to consumption of conserved olives (Cawthorne et al, 2005; Jalava et al, 2011). Interest in the development and use of starter cultures for table olive fermentation is increasing in order to achieve a more controlled process (Panagou et al, 2008; Randazzo et al, 2010; Corsetti et al, 2012)

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