Microbiological Aspects of Table Olives

Table olives are the most important fermented vegetables because of their worldwide economic importance. The three main techniques for table olive production used in Italy concern 82% green olives, 16% black olives and 2% processed at the cherry ripened stage (UNAPROL, 2008). There are three main trade preparations of table olives: Spanish-style olives, Californian-style olives and naturally black or turning colour olives (GarridoFernández et al., 1997). The Spanish processing method includes treatment with sodium hydroxide solution, washing, brining, fermentation and packaging. The Greek-style method is milder and includes washing, natural fermentation in brine, air-oxidation for colour improvement, and packing. The Californian method includes lye treatment, washing, ironsalt treatment and air-oxidation, canning and heat treatment. This last method includes a final sterilization, so it is usually considered as a more safe production. Besides these most prominent preparations, there are many other traditional table olive elaboration recipes that are less known in the international market (Panagou et al., 2003) but very relevant at local market level, where they are frequently sold in in glass jars or plastic pouches.