Effect of harvest time on physicochemical quality parameters, oxidation stability, and volatile compounds of extra virgin olive oil

The aim of this study was to determine the changes in some physicochemical properties of olives (fruit weight, water content and oil content) and olive oils (total chlorophyll, carotenoid, pheophytin a, peroxide value and free acidity), and in the chemical properties (fatty acids, tocopherols, phenolics, oxidation stability and volatile profiles) of oils during ripening.Ripening indices (RI) of olive samples were 1.93 (unripe), 4.28 (ripe) and 5.89 (overripe). Most of the mentioned features changed with ripening. During ripening there was a sharp decrease in total chlorophyll, carotenoid and pheophytin a contents. An increase in oleic and linoleic acids and a decrease in palmitic acid were found in the fatty acid composition. Olive oils showed strong relations among oxidation stability, tocopherol content, total phenols content, and antiradical actvity of phenol extracts and these parameters decreased with maturation. Nevertheless, higher amounts of trans-2-hexenal were found in the oil from ripe olives than from unripe and overripe olives. On the other hand, the highest concentration of hexanal was found in the oil from overripe olives.In general, significant differences were observed in fruit weight, pigments, free acidity, fatty acid, tocopherol, and total phenolics contents, radical scavenger activity, oxidation stability, phenolic profile and volatile profile between the olive oils from the Gemlik cultivar at different stages of maturation

Synthesis of axially disubstituted silicon phthalocyanines and investigation of their in vitro cytotoxic/phototoxic anticancer activities

In this study, two SiPcs have been selected and the photodynamic therapy potentials were evaluated of the Pcs. Synthesis of Axially 2-decyn-1-oxy disubstituted Es-SiPc-2 was newly synthesized by the reaction of SiPcCl2 with 2-decyn-1-ol in the presence of NaH in toluene. Furthermore, their nuclear imaging potentials were evaluated in human colon adenocarcinoma (HT-29) and human lung fibroblast cell (WI-38) cell lines. The uptake results have indicated that Es-SiPc labeled with 131I radionuclide (131I-Es-SiPc) was approximately 2-fold higher in the HT-29 cell line than the WI-38 cell line. In other words, the target/non-target tissue ratio is defined as two in the HT-29/WI-38 cell lines. Besides, the uptake values of 131I-Es-SiPc were found to be higher than 131I-Es-SiPc-2. 131I-Es-SiPc and 131I-Es-SiPc-2 are promising for imaging or treating colon adenocarcinoma. In vitro photodynamic therapy (PDT) studies have shown that both compounds are suitable and can be used in this field. Also, Es-SiPc has been shown to have higher phototoxicity than Es-SiPc-2. © 2020 World Scientific Publishing Company

Characterization of Aegean olive oils by their minor compounds

This study presents combined approach of establishing cultivar difference between Aegean olive oils, obtained from economically important olive oil producing cultivars (cv..Ayvalık and Memecik), based on chemometric evaluation of their content and in particular composition of minor compounds. Evaluation of minor compounds with principal component analysis (PCA) and linear discriminant analysis (LDA) indicated differentiation according to the cultivars. LDA produced a 100 % correct group classification. Moreover, stigmasterol, apparent β-sitosterol and total sterols were found to have the highest discriminating power. Memecik oils were characterized by the highest content of antioxidant compounds (α-tocopherol, phenolic compounds and total phenolic compounds). On the other hand, Ayvalık oil had the highest level of total sterols. The data were analyzed statistically to evaluate the differences according to variety and crop season. The minor compounds of Ayvalık and Memecik oils presented statistically significant differences (p < 0.01) according to variety, except for the hydroxytyrosol and clerosterol content. The amount of α-tocopherol, total phenolic compounds, apparent β-sitosterol and total sterols varied with respect to crop season. A good correlation was observed between the amount of α-tocopherol, total phenolic compounds, apparent β-sitosterol and total sterols and some climatic variables

LC-ESI-MS characterization of phenolic profiles Turkish olive oils as influenced by geographic origin and harvest year

The purpose of this investigation was to evaluate and compare the differences in the phenolic fractions and antioxidant properties of virgin olive oils from the Nizip yaglik and Kilis yaglik olive varieties cultivated in native and different olive growing areas of Turkey. The phenolic composition of olive oils was carried out by HPLC-DAD and identifications were made by LC-MS. Fourteen phenolic compounds were identified and among these compounds elenolic acid, tyrosol and hydroxytyrosol were the most dominant. Based on the results, there was no difference in distribution of phenolic compounds, but the total phenolic content in oil from native regions was higher than in oil from Bornova regions. The antioxidant capacity of olive oil extracts was determined by two different methods, including DPPH and ABTS. In both methods, antioxidant capacity values were higher in oil from native regions. © 2013 AOCS.110O602, ZF-2010-D24Acknowledgments The authors thank the Scientific and Technical Research Council of Turkey (TUBITAK) and Cukurova University Research Fund (ZF-2010-D24) for financial support for this research project (Project No. 110O602)