Chapter 41 - Lactic Acid Bacteria in Table Olive Fermentation

Abstract

Freshly picked olives contain phenols and oleuropein, which makes the fruit bitter and unpalatable. There are many ways to de-bitter olives. Fermentation of olives in brine is one of the oldest methods of preserving and processing food known to man. Traditional methods of fermentation use the indigenous microflora (e.g. lactic acid bacteria; LAB), encouraging the growth of those that ferment the olive. The indigenous LAB involved in table olive fermentation mainly belong to the genus Lactobacillus. Lactic acid bacteria belonging to Leuconostoc, Streptococcus, Enterococcus, and Pediococcus genera are also present in smaller numbers. The main factor determining the quality of the olives produced is the LAB involved in fermentation. The use of starter cultures can accelerate and improve fermentation and also prevent the growth of undesirable microorganisms. Although table olive production remains an empirical process, interest in LAB starter cultures for processing olives is increasing. The selection of LAB for starter cultures focuses on several important criteria, including their ability to monitor the fermentation process and improve the safety of table olives. This chapter provides an overview of the LAB species involved in the preparation of table olives. Methods available for the detection and identification of LAB species involved in table olive fermentation are also described. The selection and use of LAB starter cultures to enhance fermentation and prevent the growth of undesirable microorganisms are discussed.