engleski

Differentiation between Unfiltered and Filtered Oblica and Leccino cv. Virgin Olive Oils

The quality parameters, a variety of microcomponents and the sensory characteristics of Oblica and Leccino cv. virgin olive oils (VOOs) were evaluated before and after filtration process adopted in order to estimate the individual varietal compositional changes. The dynamics of the formation of hydrolytic and oxidative changes in unfiltered (UF) and filtered (F) oils was asses by comparing level of free fatty acids (FFA), peroxide value (PV) and spectrophotometric indices periodically during one year of oil storage. An analysis of phenolics, tocopherols and fatty acids was determined by chromatographic (HPLC and GC) and spectrometric methods, oxidative stability by Rancimat method while sensory analyses of obtained olive oils were performed by a trained professional panel. Single monovarietal VOO loses phenols in different rate with the applied filtration. Total secoiridoids decreases significantly in ‘Oblica’ VOOs while no changes in their concentrations were found between unfiltered and filtered ‘Leccino’ oils. Intensity of desired sensory properties decreases with filtration. In ‘Leccino’ VOOs decrease of oxidative stability was more pronounced. After twelve months of storage, filtered ‘Leccino’ VOOs had significantly lower FFA values than observed for the unfiltered counterparts. Further, there were no significant changes in PV and K270 values between unfiltered and filtered oils of both studied varietal oils. Storage time influenced more studied quality parameters than filtration, during which PV of unfiltered oils faster deteriorate. The highest changes between stored and corresponding fresh samples were exhibited in unfiltered ‘Oblica’ VOOs.

filtration ; phenolic composition ; sensory profile ; oxidative stability ; fatty acid composition ; storage

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