The roles of phenolics from olive oils as effective anticancer agents have been documented in various in vitro studies of different cancer cells lines, but the relationship between the phenolic profile of olive oil and its biological activity needs more elucidation. In this study, we analysed phenolic profiles of extra virgin olive oils (EVOOs) from different autochthonous cultivars from Croatia (Oblica, Bjelica, Buža, Žižolera) and investigated the biological effect of EVOO phenolic extracts (EVOO-PEs) on human cervical (HeLa) and human colon (SW48) cancer cell lines alone and in combination with cisplatin (cDDP), carboplatin (CBP), 5-fluorouracil (5-FU) and irinotecan. The quantitative evaluation of olive oil polyphenols was performed by HPLC-DAD and spectrophotometric analysis. The biological effect of EVOO-PEs alone and in combination with anticancer drugs was measured by MTT assay. Analysed EVOO-PEs differ in phenolic profile and inhibited HeLa and SW48 cells in a dose-dependent manner. Further, it is shown that EVOO-PEs (Oblica-Sea, Buža and Žižolera), in combination with anticancer drugs, increase the metabolic activity of HeLa and SW48 cells and have a protective role. These data imply careful consummation of olive oil during chemotherapy of cancer patients.

The harvesting time of olive (Olea europaea L.) fruit, which significantly affects the characteristics of virgin olive oil, is mainly determined empirically based on the fruit’s skin color. Developing objective methods such as electrical impedance spectroscopy (EIS) for assessing ripeness is essential. This study aimed to explore the potential of EIS as a rapid and objective technique for detecting the harvesting time of olives. Olive fruits from two varieties, ‘Picholine’ and ‘Buža momjanska’, were harvested in two periods and sorted into four color groups. EIS was applied to each color group to establish a relationship between fruit color and electrochemical properties. The distance of the coordinate at the top of the circular arc of the Cole–Cole plot from the origin (LTO) indicated tissue degradation. The LTO values varied depending on the olive variety, fruit color, and harvest date. The LTO values decreased from green to black fruits in both varieties, indicating textural changes in the olive fruit tissue. This study contributes to the knowledge and understanding of the electrical properties of olive fruit tissue during ripening. EIS shows potential as an innovative tool for determining the harvesting time of olives and for ‘in-field’ olive ripeness assessment.

In April 2015, dieback of young olive trees (Olea europaea L., cultivars Istarska bjelica and Buza) occurred in a private orchard near Vodnjan in Istria, Croatia. From total of 50 trees, 8 (16 %) showed symptoms of dieback, with branches that had vascular browning in cross section and attached light brown, downwardly curled leaves. A fungus, was consistently isolated from surface sterilized wood pieces of diseased branches, obtained in pure cultures on potato dextrose agar (PDA) by monohyphal isolation, and incubated at 25°C in darkness. Colonies grew slowly (1.9 mm/day), and the initial white color became gradually dark. Microscopic analysis showed hyaline, septate hypha with conidiophores bearing phialides in verticillate arrangement producing hyaline, single-celled, ovoid to ellipsoid conidia, 4.8 ± 0.7 µm x 2.4 ± 0.4 µm (n = 100). Dark parts of the colonies showed abundant dark-brown microsclerotia embedded in PDA. Solitary microsclerotia (rounded, elongated or irregular in shape) and their aggregates...

Olive growing in Croatia has a long tradition and is of great economic and social impact. The present study includes a set of 108 tree samples (88 samples corresponding to 60 presumed cultivars and 20 trees of unnamed ones) collected from 27 groves in the entire olive growing area, and is the most comprehensive survey to be conducted in Croatia. The genetic diversity, relationships, and structures of olive plants were studied using eight microsatellite loci. All loci were polymorphic and revealed a total of 90 alleles. A total of 74 different genotypes were detected that were subjected to further diversity and genetic relationship studies. The Fitch–Margoliash tree and Bayesian analysis of population structure revealed a complex relationship between the identified olive genotypes, which were clustered into three gene pools, indicating different origins of Croatian olive germplasms. Excluding the redundant germplasms, 44 different genotypes among the sampled trees of well-known cultivars and 16 new local germplasms were identified. In addition, we provide the etymology of 46 vernacular names, which confirms that the vast majority of traditional Croatian cultivars have common and widespread names. The results presented herein underline the importance of safeguarding local cultivars and conducting continuous surveys.

Within the framework of an incentive to provide labeled extra virgin olive oils as a food supplement in pharmacies, the phenolic profile analysis of extra virgin olive oils obtained from Croatian olive cultivars has been reported. With the aim of increasing the consumption of EVOO-s in northern Croatia, the varieties Bjelica, Buža and Italian Leccino have been studied involving two different agroclimatic locations, over two harvest years differing significantly in the amount of rainfall. The Croatian cultivars Plominka, Žižolera, Oblica and Lastovka, were also examined. Correlation tests and the insight from PCA reveal that the cultivars are highly individualized in character with regard to relationships among phenolic compounds. Some elements of an innovative labeling aimed to better present the authenticity, quality, excellence and uniqueness of the EVOO-s were suggested. En el marco de los incentivos que se han considerado para proporcionar el etiquetado de aceites de oliva virgen extra como suplemento alimenticio en farmacias, se reporta el análisis del perfil fenólico de aceites de oliva vírgenes extra obtenidos a partir de variedades croatas. Para ampliar el consumo de AOVE-s en el norte de Croacia, se han estudiado las variedades Bjelica, Buža y Leccino italiana procedentes de dos lugares agroclimáticos diferentes que difieren significativamente en la cantidad de lluvia y obtenidos en dos cosechas. Tambien fueron examinados los cultivares croatas Plominka, Žižolera, Oblica y Lastovka. Los test de correlación y los resultados de PCA revelan que las variedades están altamente individualizados en su carácter en lo que respecta a las relaciones entre los compuestos fenólicos. Se sugirieron algunos elementos innovadores para un etiquetado dirigido a presentar mejor la autenticidad, la calidad, la excelencia y la singularidad de los AOVE-s.

Leaf samples of 226 cultivated olive trees were collected from traditionally managed olive orchards and genotyped with eleven consensual SSR markers. The proportion of shared allele distance was used for the estimation of distances between olive genotypes. Cluster analyses were performed using a Fitch–Margoliash least-squares algorithm. The number of different genetic subgroups of olive genotypes (K) was investigated using STRUCTURE analysis. The standardization of allele lengths was performed to enable the comparison SSR profiles of Croatian olive genotypes with olive profiles obtained with the same SSR primers in OleaDB and WOGB databases. Overall, 73 SSR profiles of known Croatian varieties and 53 profiles of unknown olive genotypes were differentiated. Synonyms were detected in 18 varieties, and we found intra-varietal differences in 15 varieties. Three genetic subgroups of olive genotypes were determined. Following allele length standardization achieved using nine referral samples, the genetic profiles of 126 cultivated olive genotypes were compared to OleaDB and WOGB databases, out of which 92 genotypes were found to be unique to Croatian olive germplasm. The results revealed the wide genetic diversity of olive germplasm beyond the known, registered varieties. The FAZ_oliveDB database containing the profiles of 126 Croatian olive genotypes was created and made available for public use.