Coğrafi İşaretli Türk Zeytinyağlarının Kemometrik Ayırımında Fenolik Profil ve Yağ Asidi Kompozisyonunun Kullanımı

Abstract

A geographical indication (GI) of virgin olive oil (VOO) certifies the origin and production methodology within a determinative quality aspect. On the other hand, from the consumer perspective, VOO's with GI are expected to show a difference from other VOO's, even though it is not an official obligation. In this study, samples from seven different Turkish VOO's with GI were evaluated and possible discrimination among them was determined and justified using principal component analysis (PCA). Results revealed that saturated fatty acid (SAFA) content was a key factor for Nizip samples to discriminate from VOO's with GI. Samples of Southern Agean (Güney Ege) and Ayvalık had the highest amount of secoiridoids content. When phenolic profile was considered alone, Mut and Nizip samples were clearly separated while groupings among other samples were somehow overlapped. PCA using fatty acid composition revealed that Nizip and Güney Ege samples were located on different sides of the score plot. Regional distances among sample sets greatly affected the discrimination of the PCA plot when their fatty acid composition was involved.

Investigating the Quality and Purity Profiles of Olive Oils from Diverse Regions in Selçuk, İzmir

“…The highest and lowest values were found in the ES (47.41) and KK (25.28) groups, respectively (p < 0.05). The values found in our study were found to be lower than the TOTOX data obtained in the study in which olive oils with geographical indications in Turkey were examined [16]. Contrary to our study, no statistically significant differences were found between the samples in the same study.…”

“…They noted a significant impact of the variety; however, they also identified variations in luteolin contents and phenol concentrations of the same variety across different regions, a finding consistent with our study. Similarly, the oleocanthal values reported in Türkay et al's [16] studies on South Aegean olive oils of the Memecik variety, which we incorporated in our research, align with our findings. Additionally, Türkay et al [16] noted lower 3,4-DHPEA-EA values than those identified in our study.…”

“…Similarly, the oleocanthal values reported in Türkay et al's [16] studies on South Aegean olive oils of the Memecik variety, which we incorporated in our research, align with our findings. Additionally, Türkay et al [16] noted lower 3,4-DHPEA-EA values than those identified in our study. This observation suggests that this value could serve as a distinguishing characteristic of the Selçuk region.…”

“…However, our research contradicts this idea. Consistent with our findings, samples collected from various regions within the same province or different provinces were reported to exhibit differences in quality characteristics [8,16,21,30].…”

“…Our findings also indicate that this preference holds for consumers. The values found are lower than the acidity values of South Aegean olive oil with geographical marks, especially Milas olive oil, which is geographically registered by the European Union [16,21]. PV and panV are quality indicators that indicate the extent of oxidation in oil, offering insights into its oxidative degradation and estimated storage duration.…”