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Öğe Effects of Filtration on the Quality Properties of Extra Virgin Olive Oils during Storage(Wiley, 2019) Koseoglu, Oya; Sevim, Didar; Kadiroglu, PinarIn this study, the effects of filtration on quality parameters, chemical characteristics, antioxidant activity, and oxidative stability (OS) of Turkish olive oils during the storage period of 12 months were investigated. The olive oil free acidity (% oleic acid per 100 g of olive oil) (free fatty acidity, FFA), peroxide values (PV) (meq O-2 kg(-1) oil), and UV spectrophotometric indices (K-232 and K-270 measurements) were used for evaluating the quality parameters of olive oils. alpha-tocopherol analysis, total phenolic content (TPC), total chlorophyll and carotenoid analyses, and 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) radical-scavenging activity (RSA) assays were carried out. Chromatographic methods were applied to determine the fatty-acid and triacylglycerol (TAG) composition, the content of methyl and ethyl esters (FAEE and FAME), and the content of fatty acids of olive oils. Univariate and multivariate statistical methods were performed to evaluate results. Univariate data analysis results showed that filtration of Ayvalik, Memecik, and Domat olive oils had no considerable influence on quality parameters, antioxidant compounds, FAEE and FAME, antioxidant activity, and OS, except TPC (P < 0.05). A significant difference between the samples was determined regarding storage times of the olive oils. Principal component analysis (PCA) analysis revealed that olive oils were grouped according to storage periods of the olive oils regarding fatty-acid and triacylglycerol (TAG) composition while there was no clear separation among the samples according to the filtration process. However, qualitative and quantitative changes took place on minor and major components of olive oils during the storage period.Öğe Improvement of Olive Oil Quality with Innovative Olive Cleaning System(Sidas Medya A.S., 2022) Sevim, Didar; Köseoğlu, Oya; Şumnulu, Uğur; Kadiroğlu, Pınar; Erdan, Mehmet; Tosun, Mehmet; Vardin, Aslı YıldırımTurkey is considered the homeland of olives and is one of the important olive oil producers of the world. With the increasing number of trees, the necessity to complete olive harvest in a short time, like 3-4 months, makes mechanization necessary. The use of mechanical devices during olive harvest causes an increase in the number of leaves, shoots, and branches in the harvested product. Leaf separation systems used in cleaning non-olive materials in olives are generally inadequate in cleaning olives containing dense leaves obtained due to the use of new generation harvesting machines. For this reason, to develop an innovative sorting/cleaning prototype to provide more efficient cleaning, it is necessary to determine the machine efficiency, oil efficiency, olive oil quality and composition of machines. Total phenolics, chlorophyll and carotenoid contents, induction period and DPPH antioxidant activity values of olive oil obtained after traditional suction fan system (TSFS) application were higher than olive oils obtained after new generation blown and drum sieve system (NGBDSS) application. However, the ?-tocopherol content of olives was low in the samples obtained by TSFS. The fatty acid composition of olive oils obtained from both applications was similar. Our study determined that there were 13 volatile compounds in the olive oil obtained after applying the TSFS, and there were 6 volatile compounds in the olive oil obtained with the application of NGBDSS. When the sensory properties of olive oils were analyzed, it was found that olive oils obtained from both applications were similar to the fruitiness, bitterness, and pungency of olive oils obtained after applying NGBDSS. © 2022 by the Author(s).Öğe Oxidative stability of olive oils with supercritical carbon dioxide extracts of olive leaf(Innovhub Ssi-Area Ssog, 2022) Sevim, Didar; Koseoglu, Oya; Pazir, Fikret; Ova, Gulden; Kadiroglu, Pinar; Alper, YukselIn this study, quality parameters and oxidative stability of olive oils added with olive leaf (OL), an agricultural by-product extracted by the supercritical carbon dioxide (SCD) method, were evaluated. The SCD OL extraction method was applied at 100 degrees C, 100 bar and 80 minutes. Extracts containing phenolic substances obtained from olive leaves were added to refined olive oil (ROO) (E) at concentrations of 350 (A), 200 (B), 150 (C) and 60 mg CAE/kg oil (D). Olive oil samples were stored in clear glass bottles for 12 months under light (L) and dark (D) conditions. Samples were analysed at 0, 3, 6, 9 and 12 months of storage period. The results of the analyses revealed that the amount of free fatty acid values (FFAV), peroxide value (POV), total phenolic content (TPC), chlorophyll (TChl) and carotenoid (TCar) content and oxidative stability index (OSI) increased as the olive leaf extract (OLE) addition ratio increased. When the effect of OLE concentration on the amount of a- tocopherol was examined, it was determined that the amount of a- tocopherol was higher in ROO (E) and this amount decreased with the addition of OLE. In the samples which OLE was added, odours like alcohol, henna and dried herbs were detected as a result of sensory analysis. Principal component analyses (PCA) indicated that olive oils were discriminated clearly based on the concentrations of OLEs. As a result, it was determined that the TPC, TChl and TCar content and OSI values were the highest in the A sample, which was stored in the dark and had the highest OLE content. Sample A, which is rich in antioxidant components, can be said to be the best example enriched with OLE, apart from sensory properties. In terms of the content of AT, which is equivalent to vitamin E, we can say that the E sample stored in the dark has the best properties except for the sensory properties.Öğe Oxidative stability of olive oils with supercritical carbon dioxide extracts of olive leaf(INNOVHUB - Stazioni Sperimentali per l'Industria S.r.l - Area Oli e Grassi, 2022) Sevim, Didar; Köseoğlu, Oya; Pazir, Fikret; Ova, Gülden; Kadiroğlu, Pınar; Alper, YükselIn this study, quality parameters and oxidative stability of olive oils added with olive leaf (OL), an agricultural by-product extracted by the supercritical carbon dioxide (SCD) method, were evaluated. The SCD OL extraction method was applied at 100°C, 100 bar and 80 minutes. Extracts containing phenolic substances obtained from olive leaves were added to refined olive oil (ROO) (E) at concentrations of 350 (A), 200 (B), 150 (C) and 60 mg CAE/kg oil (D). Olive oil samples were stored in clear glass bottles for 12 months under light (L) and dark (D) conditions. Samples were analysed at 0, 3, 6, 9 and 12 months of storage period. The results of the analyses revealed that the amount of free fatty acid values (FFAV), peroxide value (POV), total phenolic content (TPC), chlorophyll (TChl) and carotenoid (TCar) content and oxidative stability index (OSI) increased as the olive leaf extract (OLE) addition ratio increased. When the effect of OLE concentration on the amount of ?-tocopherol was examined, it was determined that the amount of ?-tocopherol was higher in ROO (E) and this amount decreased with the addition of OLE. In the samples which OLE was added, odours like alcohol, henna and dried herbs were detected as a result of sensory analysis. Principal component analyses (PCA) indicated that olive oils were discriminated clearly based on the concentrations of OLEs. As a result, it was determined that the TPC, TChl and TCar content and OSI values were the highest in the A sample, which was stored in the dark and had the highest OLE content. Sample A, which is rich in antioxidant components, can be said to be the best example enriched with OLE, apart from sensory properties. In terms of the content of AT, which is equivalent to vitamin E, we can say that the E sample stored in the dark has the best properties except for the sensory properties. © 2022, INNOVHUB - Stazioni Sperimentali per l'Industria S.r.l - Area Oli e Grassi. All rights reserved.Öğe Quality characteristics and antioxidant properties of Turkish monovarietal olive oils regarding stages of olive ripening(Elsevier Sci Ltd, 2016) Koseoglu, Oya; Sevim, Didar; Kadiroglu, PinarThe aim of this study was to discriminate the extra virgin olive oils (EVOO) based on quality characteristics, chemical composition and antioxidant activity according to ripening stages of olives. Two different olive varieties (Memecik and Gemlik) were obtained at different stages of ripening based on skin color (green, purple and black). Quality properties of olive oils; free fatty acidity, peroxide value, K-232 and K-270, purity properties; fatty acid and triacylglycerol (TAG) composition and antioxidant compounds like total phenol, carotenoid and chlorophyll content and antioxidant activity (oxidative stability, ABTS radical scavenging activity) analyses were performed. Higher amount of oleic, linoleic and palmitic acids were observed in olive oils. Oleic acid amount of olive oils decreased, linoleic acid increased with ripening. The most abundant TAG of olive oils were ECN 48, OOO, SLO + POO, ECN 46 and LOO/PLO. Olive oils were clearly classified by principal component analysis based on fatty acid and TAG composition. (C) 2016 Elsevier Ltd. All rights reserved.
