Study of microbiological and physicochemical characteristics of fermented table olives in Cyprus and the multifunctional properties of the predominant microbiota

Abstract

Table olives are one of the most well-known traditionally fermented vegetables and their global consumption is increasing exponentially. According to the directly brining method, table olives are produced spontaneously, without any pre-treatment. This process remains empirical and inconstant, since it is strongly affected by physicochemical attributes of the fruit and the microbiota coming from the olive fruit and the environment. Nowadays, process modernization is extremely recommended worldwide, aiming to innovative products and/or processes. The stabilization of fermentation and thus, increasing the added value of the final product is a highly needed innovation making one of the oldest traditional food processes and products highly modernized. Furthermore, the reduction levels of sodium chloride used during processing is one of the main industry’s challenges. In this regard, in the present thesis, the significant contribution of a commercial starter culture containing L. plantarum to both Cypriot and Picual table olives fermentation is illustrated, even in lower NaCl concentration (7%), supporting the application of starter cultures in table olives processing. Furthermore, considering microorganism acclimation to local conditions, industrial interest and consumers demand, for the development of indigenous starter cultures, several LAB and yeasts strains were isolated from Cypriot table olives and screened for interesting technological and potential probiotic features. Results indicated that Cypriot olives is a new source of probiotic microorganisms, as a series of them (including LAB and yeast strains) exhibited very promising multifunctional profile and thus, are recommended to be used as starter cultures at industrial scale fermentation process, in order to produce stable, novel and potentially functional table olives. Finally, the present thesis fully supports the concept of local microbial terroir and can potentially fingerprint the products.