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Spontaneous fermentation by native strains of lactic acid bacteria has traditionally been used to preserve table olives, by taking advantage of a proactive and competitive reduction of growth of unwanted microorganisms. Starter cultures have proven effective in stabilizing fermentation processes at large. Despite the many starter cultures available commercially, few have originated on the native microflora – and table olives have seldom been processed via deliberate inoculation with them. This study screened variables relevant for the growth of Lactobacillus plantarum AFS13 originally obtained from brines in Alto Douro (Portugal); and for preservation thereof as the starter, should it prove appropriate. A 2 I V 6 − 2 factorial design was used to assess six parameters (and their interactions): 19 fermentation batches were carried out to ascertain growth rates. Temperature and aeration degree were the most significant processing parameters. Maximum growth rate, 0.356 h−1, was attained under anaerobic conditions, at 37 °C, and in the absence of NaCl; ca. 9 log10 CFU mL−1 was reached by 6 h. Glucose concentration, pH, and stirring rate proved not significant, so economic considerations should fix their optimum levels. The starter culture could be preserved for up to 4 mo after freeze-drying in sucrose, with an acceptable reduction in cell viability.

Spontaneous fermentation constitutes the basis of the chief natural method of processing of table olives, where autochthonous strains of lactic acid bacteria (LAB) play a dominant role. A thorough literature search has unfolded 197 reports worldwide, published in the last two decades, that indicate an increasing interest in table olive-borne LAB, especially in Mediterranean countries. This review attempted to extract extra information from such a large body of work, namely, in terms of correlations between LAB strains isolated, manufacture processes, olive types, and geographical regions. Spain produces mostly green olives by Spanish-style treatment, whereas Italy and Greece produce mainly green and black olives, respectively, by both natural and Spanish-style. More than 40 species belonging to nine genera of LAB have been described; the genus most often cited is Lactobacillus, with L. plantarum and L. pentosus as most frequent species-irrespective of country, processing method, or olive type. Certain LAB species are typically associated with cultivar, e.g., Lactobacillus parafarraginis with Spanish Manzanilla, or L. paraplantarum with Greek Kalamata and Conservolea, Portuguese Galega, and Italian Tonda di Cagliari. Despite the potential of native LAB to serve as starter cultures, extensive research and development efforts are still needed before this becomes a commercial reality in table olive fermentation. info:eu-repo/semantics/publishedVersion