Use of a lactic acid bacteria starter culture during green olive (Olea europaea L cv Ascolana tenera) processing

Among the Italian olive germplasm, ' Ascolana tenera ' is one of the best varieties for table olive production. This research addressed the impact of different processing types (Greek-style and Spanish-style) on the fermentation and phenolic composition of olive fruit. In particular, the effects of a lactic acid bacteria (LAB) starter culture on the fermentation of naturally green olives processed according to the traditional Greek method were studied. Results revealed that Spanish-style processing produced a dramatic loss of total phenolics, while natural olive processing favoured a higher retention of biophenols. Oleoside 11 -methylester, a phenol-related compound, and hydroxytyrosol, tyrosol, vaniflic acid, 3,4-dihydroxyphenylglycol, oleuropein and oleuropein aglycons, as the main phenols, were detected in olive fruit. More interestingly, this research indicated that inoculation with LAB affected the pH, total acidity, microbial profile and palatability of olives. Olives fermented with the LAB starter culture were perceived by panellists to be less bitter and more aromatic than those spontaneously fermented. Thus the use of LAB inoculants during olive fermentation could be applied with the currently available technology. (c) 2005 Society of Chemical Industry.