Acid Composition Of Olive Oil Research Articles

Debittering of “Ayvalık” and “Gemlik” olives with caustic, brine, and NaOH solutions affects oil content and fatty acid profiles at the beginning and end of fermentation

The oil results of the scratched “Ayvalık” and “Gemlik” olive varieties on the 0th day of fermentation were determined between 50.01 (lye) and 67.57% (NaOH) to 57.35 (salt) and 72.95% (NaOH), respectively. The oil results of scratched “Ayvalık” and “Gemlik” olives on the 60th day of fermentation were determined between 61.04 (salt) and 64.03% (water) to 55.89 (salt) and 61.95% (NaOH), respectively. While the oil contents of “Ayvalık” and “Gemlik” olive cultivars that were scratched and crushed at the beginning of fermentation (0 day) were higher than the control, the oil results of whole olives were lower than the control. Significant changes were observed in the fatty acid compositions of olive oils depending on the olive variety and the bittering process (p < 0.01). The dominant fatty acids of the oils obtained from olives on the 0th and 60th days of fermentation were oleic, palmitic and linoleic acid. The fatty acid composition of the oils depending on the applied process and olive types differed at days 0 and 60 of fermentation. It can be said that on the 0th and 60th days of fermentation, the oleic acid results of olives of both varieties increased compared to the control. The oleic acid contents of the oils obtained from “scratched” olives of “Ayvalık” varieties at the beginning and end of fermentation varied between 70.10 (NaOH) and 71.66% (lye) to 64.91 (NaOH) and 71.51% (normal water), respectively. It can be seen that debittering processes significantly reduced the amounts of unsaturated fatty acids. In general, it has been observed that olive oils have higher oil contents and better fatty acid compositions.Graphical abstractThe oil content and fatty acid profile distributions of the olives, which give taste and flavor to the olives, must also be monitored before and after fermentation. Research work was carried out to investigate the oil results and fatty acid compositions of the oils obtained from “Ayval?k” and “Gemlik” olives debittered with different solutions and fermented.

Integrated lipidomic and transcriptomic analysis reveals diacylglycerol accumulation in olive of Longnan (China).

Olive (Olea europaea L.) oil accumulate more diacylglycerols (DAG) than mostly vegetable oils. Unsaturated fatty acids-enriched DAG consumption enhanced wellness in subjects. However, the mechanism of DAG accumulation is not yet fully understood. In this study, gene network of DAG accumulation and fatty acid composition in the two olive mesocarps ("Chenggu 32" (CG) and "Koroneiki" (QJ)) were investigated by integrating lipidome and transcriptome techniques. A total of 1,408 lipid molecules were identified by lipidomic analysis in olive mesocarp, of which DAG (DAG36:3, DAG36:4 and DAG36:5) showed higher content, and triacylglycerols (TAG54:3, TAG54:4) exhibited opposite trend in CG. Specifically, DAG was rich in polyunsaturated fatty acids (especially C18:2) at the sn-2 position, which was inconsistent with TAG at the same positions (Primarily C18:1). Transcriptomic analysis revealed that phospholipase C (NPC, EC 3.1.4.3) were up-regulated relative to QJ, whereas diacylglycerol kinase (ATP) (DGK, EC 2.7.1.107), diacylglycerol acyltransferase (DGAT, EC 2.3.1.20), and phospholipid: diacylglycerol acyltransferase (PDAT, EC 2.3.1.158) were down-regulated. We speculated that the non-acyl coenzyme A pathway played a significant role in DAG biosynthesis. Additionally, fatty acyl-ACP thioesterase B (FATB, EC 3.1.2.14), stearoyl [acyl-carrier-protein] 9-desaturase (SAD, EC 1.14.19.2) and omega-6 fatty acid desaturase (FAD2, EC 1.14.19.6) were highly expressed in CG and may be involved in regulating fatty acid composition. Meanwhile, phospholipase A1 (LCAT, EC 3.1.1.32) involved in the acyl editing reaction facilitated PUFA linkage at the sn-2 position of DAG. Our findings provide novel insights to increase the DAG content, improve the fatty acid composition of olive oil, and identify candidate genes for the production of DAG-rich oils.

Improvement of Olive Oil Quality with Innovative Olive Cleaning System

Turkey 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 α-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.

The combined effects of ripening degree and fermentation process on biochemical properties of table olives and oils of Ayvalık and Gemlik varieties

Abstract The purpose of this study was to investigate the effect of variety, ripening degree, and also fermentation process on the bioactive compounds of olives, and on the fatty acid compositions of olive oils. The highest oil content was determined in fermented green olives (70.02% in Gemlik variety; 66.87% in Ayvalık variety). The fermentation process caused a notable reduction in both total phenolic content (from 2558.30–2894.40 to 699.10–1087.00 mg/kg), and antioxidant activity values (from 81.46–81.20 to 26.00–63.75%) of green olives in brine. Verbascoside was identified as the main phenolic compound (1150.95–1311.25 mg/kg). It was observed that oleuropein, hydroxytyrosol, tyrosol, and rutin contents of olives decreased after fermentation process. Concerning the fatty acid compositions of olive oils, oleic (70.13–75.47% for Gemlik; 67.36–70.22% for Ayvalık) and linoleic acid (6.18–11.13% for Gemlik; 10.13–12.94% for Ayvalık) contents showed differences regarding variety and maturation degree. However, there are minor variations in fatty acid composition according to fermentation.

The Oleic/Linoleic Acid Ratio in Olive (Olea europaea L.) Fruit Mesocarp Is Mainly Controlled by OeFAD2-2 and OeFAD2-5 Genes Together With the Different Specificity of Extraplastidial Acyltransferase Enzymes.

Fatty acid composition of olive oil has an important effect on the oil quality to such an extent that oils with a high oleic and low linoleic acid contents are preferable from a nutritional and technological point of view. In the present work, we have first studied the diversity of the fatty acid composition in a set of eighty-nine olive cultivars from the Worldwide Olive Germplasm Bank of IFAPA Cordoba (WOGBC-IFAPA), and in a core collection (Core-36), which includes 28 olive cultivars from the previously mentioned set. Our results indicate that oleic and linoleic acid contents displayed the highest degree of variability of the different fatty acids present in the olive oil of the 89 cultivars under study. In addition, the independent study of the Core-36 revealed two olive cultivars, Klon-14 and Abou Kanani, with extremely low and high linoleic acid contents, respectively. Subsequently, these two cultivars were used to investigate the specific contribution of different fatty acid desaturases to the linoleic acid content of mesocarp tissue during olive fruit development and ripening. Fatty acid desaturase gene expression levels, together with lipid analysis, suggest that not only OeFAD2-2 and OeFAD2-5 but also the different specificities of extraplastidial acyltransferase enzymes are responsible for the variability of the oleic/linoleic acid ratio in olive cultivars. All this information allows for an advancement in the knowledge of the linoleic acid biosynthesis in different olive cultivars, which can impact olive breeding programs to improve olive oil quality.

The Effect of Plant Essential Oil and Extracts on Fatty Acid Profile of Virgin Olive Oil Stored in Different Packaging Materials.

In this study, the combined effect of different packaging materials (transparent PET, transparent glass, glass-PET bottle and tin), some aromatic herbs (thyme, rosemary, sage and olive leaf) and also their essential oils (thyme, rosemary and sage) on fatty acid composition of virgin olive oil was investigated during storage period. The initial amounts of the main fatty acids as oleic, palmitic and linoleic acids were determined as 72.89%, 11.89% and 8.96%, respectively. The addition of aromatic plants and essential oils did not effect the fatty acid profile. Also, packaging materials had a minor influence on fatty acids. In the 6th month of storage, the oleic acid contents of olive oils showed the increase in all of samples. The highest increase was observed in olive oil stored in glass-PET (74.30-75.01%), followed by stored in glass bottle (73.41-74.82%). Generally, during the storage, the differences of fatty acid contents were in minor level. The fatty acid composition of olive oils stored under different essential oil and extract concentrations showed partial differences depending on the extract type and concentration.

Fatty acid composition of olive oil in response to fruit canopy position and artificial shading

The fatty acid composition of olive oil is greatly affected by geographical origin, and olive oil is often promoted by health experts because of its high oleic acid concentration. Unfortunately, recent evidence has shown that oleic acid (%) can be low in many non-Mediterranean regions due to high temperatures. Thus, management tools related to irrigation, fertilization, and canopy management are being sought that might improve fatty acid composition in such regions. The objectives here were to: 1) evaluate the relationships between fatty acid composition in fruit at different canopy positions and both the photosynthetically active radiation (PAR) and red-to-far red ratio (R/FR) measured at these same positions; and 2) determine the response functions of the fatty acid concentrations to PAR using multiple shading levels applied at different fruit growth phases. Fruit samples were taken from 60 canopy positions in a large olive hedgerow (cv. Arbequina) to achieve the first objective, and different shading levels (3, 20, 40, 70% PAR) were applied using shade cloth over the northern portion of large individual trees (cv. Arbequina) for the second objective. The oleic acid concentration (%) showed a significant exponential decay with increasing daily PAR values obtained from the different canopy positions. Maximum values of about 60% oleic acid were observed at low PAR and minimum values of 50% occurred at high PAR. Based on the artificial shading treatments, the high oleic acid at shaded canopy positions appeared to be related to less fruit maturation. The other main fatty acids did not differ by canopy position, and no significant relationships between individual fatty acids and R/FR ratio were found. However, severe artificial shading under shade cloth did increase stearic and linolenic acid concentrations. Despite oleic acid being about 10% higher in the more shaded parts of the canopy, cultivating olive trees at low PAR values in order to meet international olive oil trade standards would likely not be commercially feasible due to low flowering and yields. Careful cultivar selection, early harvesting when fruit are less mature and oleic acid is higher, and blending of oils from different cultivars are recommended to improve fatty acid composition in warm regions.

Zeytinyağının Bazı Fiziko-Kimyasal Özellikleri Üzerine, Ticari Antioksidan ve Esansiyel Yağ Bileşenlerinin Etkilerinin Belirlenmesi

Bu çalışmada, 60oC de birkaç baharat esansiyel yağının ve bazı bileşenlerin % 0.1 seviyesinde, zeytinyağının oksidatif stabilitesi üzerindeki antioksidan aktivitesi belirlenmiştir. Araştırma sonuçlarına göre, zeytinyağına farklı ilaveler ile yağın serbest yağ asitliği değerleri, birinci haftadan dördüncü haftaya kadar sırasıyla % 1.61-2.01, % 1.81-2.17, % 1.67-2.23, %1.79-2.62 arasında değişmiştir. Peroksit sayısı değerleri, birinci haftadan dördüncü haftaya kadar sırasıyla 11.98-15.10 meq O2/kg, 15.48-19.64 meq O2/kg, 18.22-27.50 meq O2/kg, 18.70-39.60 meq O2/kg arasında değişmiştir. Viskozite değerleri, 39.90-55.45 m.Pas, 53.35-59.60 m.Pas, 33.10-54.70 m.Pas, 34.00-50.80 m.Pas arasında değişmiştir. Araştırmanın ilk haftasında yağın peroksit değerleri 11.98 meq O2 / kg ile 15.10 meq O2 / kg (p <0.05) arasında değişmiştir. En zayıf etki, sater yağında belirlenmiştir. Thujene en yüksek antioksidan etkiyi göstermiş olup, ardından okaliptol, ocimene, mersin beyazı, BHA (bütillenmiş hidroksianisol) ve rezene izlemiştir. Zeytinyağlarının yağ asidi bileşimleri, esansansiyal yağlardan (% 0.1) ve buna karşılık gelen bazı bileşenlerden (% 0.01) kısmen etkilenmiştir. Zeytin yağının toplam yağ asidi miktarı % 96,86 ile% 99,99 arasında değişmiştir. En çok etkilenen yağ asitleri linoleik asit, ardından oleik ve linolenik asitler olmuştur.

SULAMA İŞLEMİNİN ZEYTİN VE ZEYTİNYAĞININ ÖZELLİKLERİNE ETKİSİ

The aim of the study was to identify the changes in olive and corresponding olive oil characteristics in response to irrigation. Five olive cultivars (Halhalı, Sarı ulak, Nizip Yağlık, Kilis Yağlık and Karamani) from Turkish origin were harvested from their own traditional growing region (Mardin, Mersin, Gaziantep, Kilis and Hatay respectively) from both irrigated and non-irrigated trees (rain-fed) for two consecutive crop years. Olives were processed to oil with a laboratory scale system. Olive fruits were analyzed for their physico-chemical properties and phenolic composition and olive oils were analysed for fatty acid, triacylglycerol and sterol composition. Results have shown that average weight, flesh/pit ratio of olives were lower and dry matter and oil content were higher in rain-fed trees than irrigated ones. Phenolic content and composition of fruits were cultivar dependent and responded differently to water supplement. Fatty acid composition of olive oils mainly remained unchanged, however the concentration of individual triacylglycerols behaved in distinct ways. Total sterol and β-sitosterol contents increased and decreased for various cultivars whereas Δ-5-avenasterol increased in all cases. Sarı ulak variety was well separated from other varieties by principal component and hierarchical cluster analysis both in rain-fed and irrigated treatments.

Effect of the Planting Location (Elevation) on the Composition of Fatty Acids in Olive Oil

In Jordan there are different environments and altitudes that have an effect on olive oil properties and fatty acid composition, which therefore affect its quality. Taking into account that there are no previous similar studies in this field, this study investigates the ratios and composition of the main fatty acids in mixed olive oil from different areas in Jordan (above and below the sea level); namely the Jordan Valley, Subaihi, Kufranja and Madaba areas where the elevation ranges between (-230 m) below sea level and (+785 m) above sea level. The study measures the impact of the location of olive orchards on the fatty acid composition of olive oil and of its quality. Three olive oil samples were collected from the &amp;ldquo;Nabali Muhasan&amp;rdquo; and &amp;ldquo;Baladi&amp;rdquo; varieties from each area. They were analyzed in the National Agriculture Research Center (NARC) laboratories using GAS Chromatography. The results showed that the ratios of fatty acids are significantly affected by the degree of above elevation of the olive trees sea level. This confirms the impact of the geographical and climatic environment, which is reflected on the olive oil quality due to differences in the ratios of fatty acids in the four planting areas. This shows that the mean concentration of the fatty acids in the olive oil in these four planting areas is not equal. In general, there is a significant difference in the fatty acid concentrations compared to the standard concentration because of the planting location of olive trees, given that olive oil fatty acids in each location work together in a balanced integrative relationship.

Effects of the storage of Turkish Gemlik olives under CO2 and N2 on the phenolic compounds and fatty acid compositions of olive oils

Because of the limited number and size of the oil extraction opportunities, olives are generally piled and stored at ambient temperatures for weeks before processing. Under these conditions biochemical changes could result a negative affect on the olive quality. The changes in the olive result poor stability in olive oil because of the oxidation and decomposition of bioactive compounds such as phenolic substances. Indeed, it is known that polyphenols are a large family of compounds found in plant tissues, which show strong antioxidant activity. The healthy characteristic of the phenolic compounds is associated to their radical scavenging activities. In this study, Gemlik olives cultivated from Osmaniye area were stored for 25 days at 5 °C under three different conditions (20 kPa CO2 atmosphere, 20 kPa N2 atmosphere and air). Olive oil was extracted following of 0, 5, 15 and 25 days of olive fruits storage. Qualtiy markers (free fatty acidity, peroxide value, K270 and K232) together with the phenolic compounds and fatty acid compositions of oils were determined. The physical properties of olives (flesh/pit ratio, average weight and fruit firmness) were well-preserved under CO2 and N2 atmospheres. The phenolics (tyrosol, syringic acid, vanilin, p-coumaric acid, oleuropein, cinnamic acid and luteolin) and fatty acids (palmitic, palmiteloic, heptadecanoic, heptadecenoic, stearic, oleic, linoleic, linolenic, arachidic, behenic, docosadienoic and lignoceric acids) composition were generally unchanged during storage. Oleuropein, the bitter principle of olives disapperead faster in the oils obtained through storage under N2 than other storage conditions.

Isıtma İşleminin Çekişte Zeytinyağının Kalite, Oksidatif Stabilite ve Yağ Asidi Bileşimine Etkisi

Çalışmanın amacı Çekişte çeşidi zeytinlerden elde edilen zeytinyağlarının ısıtma işlemi sırasında temel kalite kriterleri, oksidatif stabilite ve yağ asidi bileşiminde meydana gelen değişimlerin belirlenmesidir. Bu amaçla Aydın ilinden 2017 yılında hasat edilmiş olan Çekişte çeşidi zeytinlerden elde edilmiş olan zeytinyağı, 100°C sıcaklıkta ve 20 L/saat hava akışı altında toplamda 50 saat süreyle ısıtılmıştır ve 10 saatlik aralıklarla serbest yağ asidi oranı, peroksit sayısı, dien ve trien (K232 ve K270) değerleri, toplam fenol miktarı, antioksidan aktivite, klorofil ve karotenoid miktarları ile yağ asidi kompozisyonları yönünden analiz edilmiştir. Ayrıca örneklerin indüksiyon periyodu olarak ifade edilen oksidatif stabiliteleri belirlenmiştir. Çalışma sonunda temel kalite parametrelerinden serbest yağ asidi miktarı, peroksit sayısı, dien ve trien (K232 ve K270) değerlerinin ısıtma işlemi ile birlikte artış gösterdiği saptanmıştır. Örneklerin toplam fenol, antioksidan aktivite, klorofil ve karotenoid miktarları ise ısıtma süresinin artmasıyla birlikte kademeli olarak azalmıştır. Benzer şekilde indüksiyon periyodunun da işlem süresinin artmasıyla birlikte azaldığı tespit edilmiştir. Zeytinyağı örneklerinde tespit edilen yağ asitlerinden linolenik asit miktarının ise işlem sonunda önemli düzeyde arttığı, oleik asit miktarının ise işlem öncesine göre azalma eğiliminde olduğu saptanmıştır.

First study of correlation between oleic acid content and SAD gene polymorphism in olive oil samples through statistical and bayesian modeling analyses

BackgroundVirgin olive oil is appreciated for its particular aroma and taste and is recognized worldwide for its nutritional value and health benefits. The olive oil contains a vast range of healthy compounds such as monounsaturated free fatty acids, especially, oleic acid. The SAD.1 polymorphism localized in the Stearoyl-acyl carrier protein desaturase gene (SAD) was genotyped and showed that it is associated with the oleic acid composition of olive oil samples. However, the effect of polymorphisms in fatty acid-related genes on olive oil monounsaturated and saturated fatty acids distribution in the Tunisian olive oil varieties is not understood.MethodsSeventeen Tunisian olive-tree varieties were selected for fatty acid content analysis by gas chromatography. The association of SAD.1 genotypes with the fatty acids composition was studied by statistical and Bayesian modeling analyses.ResultsFatty acid content analysis showed interestingly that some Tunisian virgin olive oil varieties could be classified as a functional food and nutraceuticals due to their particular richness in oleic acid. In fact, the TT-SAD.1 genotype was found to be associated with a higher proportion of mono-unsaturated fatty acids (MUFA), mainly oleic acid (C18:1) (r = − 0.79, p < 0.000) as well as lower proportion of palmitic acid (C16:0) (r = 0.51, p = 0.037), making varieties with this genotype (i.e. Zarrazi and Tounsi) producing more monounsaturated oleic acid (C18: 1) than saturated acid. These varieties could be thus used as nutraceuticals and functional food.ConclusionThe SAD.1 association with the oleic acid composition of olive oil was identified among the studied varieties. This correlation fluctuated between studied varieties, which might elucidate variability in lipidic composition among them and therefore reflecting genetic diversity through differences in gene expression and biochemical pathways. SAD locus would represent an excellent marker for identifying interesting amongst virgin olive oil lipidic composition.

Comparison of the Characteristics of Two Kinds of Tea Seed Oils: Oil-tea Seed Oil and Green-Tea Seed Oil

Physicochemical properties, fatty acid composition, antioxidant compounds and oxidative stability of oil-tea seed oil (Camellia oleifera Abel.) and green-tea seed oil (Camellia sinensis O. Ktze.) were investigated. The refractive index, saponification value, iodine value, acid value, peroxide value, unsaponifiables were determined to assess the quality of the oils. The major fatty acids of green-tea seed oil and oil-tea seed oil were oleic acid, linoleic acid and palmitic acid. Green-tea seed oil was typical oleic-linoleic-oil with 52.13% oleic acid and 24.32% linoleic acid level, whereas oil-tea seed oil was typical oleic-oil with very high oleic acid level (73.67%). The amount of total phenols, α-tocopherol and β-carotene of green-tea seed oil were 8.68 mg/kg, 160.33 mg/kg, 3.20 mg/kg, respectively, whereas they were 17.90 mg/kg, 85.66 mg/kg, 1.18 mg/kg in oil-tea seed oil, respectively. Green-tea seed oil contained high amounts of α-tocopherol which was nearly twice that of oil-tea seed oil. The initial induction period (IP) values of green-tea seed oil and oil-tea seed oil were 6.55h and 6.08h at 110 oC by OSI method, respectively, which shows the oxidative stability of two kinds of tea seed oils were preferable. Therefore, oil-tea seed oil could be a good dietary supplement with high level of monounsaturated fatty acids and similar fatty acid composition of olive oil. Green-tea seed oil was a new oil resource which is rich in α-tocopherol in China.

Fatty Acid Compositions of Olive Oils from Six Cultivars from East and South-Western Algeria

The aim of this work is to characterize olive oils from six algerian cultivars (Azeradj, n=4); Blanquette, n=7; Bouricha, n=2; Chemlal, n=5; Limli, n=3; Sigoise, n=1) by determining their fatty acid compositions. The fatty acid composition of oils is determined using gas chromatography of methyl esters obtained by transesterification of triacylglycerols with 2M KOH/MeOH. Fourteen fatty acids and squalene are identified in all the samples. Oleic acid (18:1ω9), palmitic acid (16:0), linoleic acid (18:2ω6) and stearic acid (18:0) are the major fatty acids commonly found in olive oils. Palmitoleic acid (16:1ω7), hypogeic acid (16:1ω9), oleic acid (18:1ω9) and cis-vaccenic acid (18:1ω7) are considered as separate entities by the European regulation, unlike the Codex Alimentarius which identifies them as a single component. Six minor fatty acids namely margaric acid (17:0), margaroleic acid (17:1ω8), arachidic acid (20:0), gondoique acid (20:1ω9), behenic acid (22:0) and lignoceric acid (24:0) are identified. These acids, although minor, are important for the characterization of cultivars. Oils of different cultivars are characterized by different fatty acid compositions. All the values of fatty acid compositions are in compliance with the regulations of the International Olive Oil Council and Codex Alimenta-rius. A radial plot enables the analysis and characterization of each variety as a morphotype by creating a morphogramme . The morphogramme is designed as a radial representation of each fatty acid (n=14) using an Excel ® spreadsheet, and each axis represents the change in the variable with respect to the mean. The morphotypes are real fingerprints of different oil cultivars. Thus, the oils of Azeradj, Blanquette, Chemlal, Limli and Sigoise cultivars have specific morphotype . The morphotype of the Bourricha cultivar is very similar to the Chemlal cultivar. In addition, the Blanquette morphotype is identical to that of the tunisian cultivar Chetoui. This mode of representation is particularly effective for the rapid visual identification of characteristics of olive oils.

Determination of Fat – Soluble Vitamins and Natural Antioxidants in Seventeen Vegetable Oils

The fat – soluble vitamins (A, D, E and K) and the most natural antioxidants ( T.polyphenols, tocopherols, chlorophylls, carotenoids, δ – oryzanol, phenolic and flavonoid compounds) of seventeen vegetable oils (olive, corn crystal, corn lecuir, sunflower, palm olein, soybean, linseed, cottonseed, sesame, rice bran, peanut, blending, wheat germ, safflower, rapeseed, castor and coconut oils) were estimated. Results showed that, parameters established ( acidity, peroxide value, K232 and 270nm.) to measure level of quality and fatty acid composition of olive oil were the best compared to other studied oils and also were in side the range reported by the Egyptain standareds for olive oil and International Olive Oil Cuoncel (IOOC).All vegetable oils contain a great amounts from vitamin E, especially corn lecuir, sesame, safflower, soybean and coconut oils was 36661, 30811,22540, 20334 and 16384 ppm., respectively, contrary with vitamin K recorded a lower values in all studied vegetable oil, it was ranging from 0.3 ppm in soybean oil to 6.1 ppm in rapeseed oil. On the other side safflower oil contained a higher amount from vitamin A (336.9 ppm), while linseed oil contained a considerable amount from vitamin D (46.5 ppm) followed that, rapeseed oil 23.3 ppm then corn crystal oil 22.9 ppm and wheat germ oil 21 ppm. Olive oil had a higher amount from T.polyphenols 324.91 ppm. Also results showed that, corn lecuir oil contained the highest value from T. tocopherols (212.53 ppm) compared to other vegetable oils. Carotenoids was the highest value in wheat germ oil 10.03 ppm, followed that in linseed oil 4.76 ppm , in rapeseed oil 4.5 ppm and in olive and castor oils were 2.28 and 2.05 ppm respectively. All studied vegetable oils had nearly amounts from chlorophylls, it was ranging from 0.538 ppm in corn crystal to 2.517 ppm in olive oil. δ – oryzanol contents found to be higher values in rice bran and wheat germ oils, (0.365 and 0.203 %, respectively,) but it was the lowest value in linseed oil (0.002 %) compared with other oils. This results indicated that, all vegetable oils enriched with the most identified phenolic compounds. Also it is clear from results narerigin compound was the highest value in some vegetable oils under study compared to other flavonoid compounds, whearas recorded the highest value in sesame oil (39.5 ppm.), followed by corn crystal oil (5.9 ppm.) then in corn lecuir oil (4.5 ppm.).

The Effects of Geographic Region, Cultivar and Harvest Year on Fatty Acid Composition of Olive Oil.

In this study, the effect of cultivar, harvest year (2010 and 2011) and the geographic regions (Mediterranean, Aegean, Southeastern Anatolia, Marmara and Black Sea) on fatty acid compositions of olive oil was investigated. The proportions of palmitic acid and linoleic acid, which comprised most of the amount of fatty acids after oleic acid, showed variations according to the region and cultivar. The amount of linoleic acid was found higher in some cultivars than that of palmitic acid. In the Aegean, Marmara and Mediterranean Regions, no significant difference was observed between olive cultivars for oleic and linoleic acids. The highest linoleic and lowest oleic acid content were determined in the Black Sea Region. One cultivar (Butko) showed an oleic acid proportion below 55% in this region. The effect of the harvest year on the fatty acid composition of the samples was also found significant. In oils harvested in the second year, a decrease in the amount of linoleic acid was observed, while the amount of oleic acid increased. The highest oleic acid proportion was found in olive oils produced from harvests in the Aegean and Mediterranean regions.

Comparison of thermal stability, antioxidant properties and fatty acid composition of olive oil and Pomegranate seed oil

In this study after oil extraction of Pomegranate seeds and olives, Fatty acid composition of two oil types GC/Mass were identified. most of The fatty acid Compounds of two oil, Oleic acid, linoleic acid and Palmitic acid were all of saturated fatty acids (SFA)in olive oil, Most of saturated fatty acids the pomegranate seed oil were. Oil thermal stability was measured with rancimat. Thermal stability of olive oil were (6/4 ± %17). Thermal resistance of pomegranate seed oil were (%788 ± %19). Olive oil contains more antioxidant properties and is stable against oxidation. Percentage of omega 6 in pomegranate seed oil was higher in omega 6 than those found in olive oil pomegranate is used for the extraction of oil were collected from Shiraz (Fars-Iran). Olive oil used was obtained from company Etka. Thermal stability and fatty acid composition properties of both samples, pomegranate seed oil and olive oil were compared and discussed.

Blends of olive oil and sunflower oil: Characterisation and olive oil quantification using fatty acid composition and chemometric tools

A method capable of recognising the percentage of olive oil in a blend is required to verify whether its labelling complies with the statements set out by the Commission Regulation (EC) No. 1019/2002. In this study an analytical methodology was developed in order to define blends of olive oil and sunflower oil, which contain 50% of olive oil, compared to blends with 40% and 60% of it, respectively. Methyl esters of fatty acids were analysed by GC-FID and processed through chemometric tools (PCA, TFA, SIMCA and PLS). A strong differentiation of blends according to the amount of olive oil contained and a quantification model with a standard error of prediction of 1.51% were obtained. As this issue represents a significant analytical challenge, variability associated with the fatty acid composition of olive oil was first studied.

The effect of early harvest on infestation rate of Bactrocera oleae (Gmelin) (Diptera: Tephritidae) as well as yield, acidity and fatty acid composition of olive oil

The olive fruit fly, Bactrocera oleae (Gmelin) (Diptera: Tephritidae), is one of the most important olive pests in Turkey, as well as throughout the olive growing regions in the world. The aims of the study are to determine infestation rate of B. oleae and to asses the effects of pest infestation on yield, hundred fruit weight, maturation index, acidity and fatty acid composition of olive oil at different harvest times. This study was carried out in five selected olive orchards in Kucukkuyu-Ayvacik (Canakkale), representing the Edremit Gulf Region, where aerial spraying is not being applied. Only trees representing cv. Ayvalik, the main cultivars of the region, were selected for the experiment. Adults were monitored with yellow sticky traps from the beginning of July to the end of December in 2005. Samples were collected at five different dates in the five orchards. The results showed that the level of B. oleae adults population was low during July and August and reached the highest level at the end of October. The infestation rates of B. oleae at all harvesting dates were observed parallel to the adult population densities in all five orchards. The puncture rate considerably increased after mid November, therefore, early harvest definitely contributed to the preventing the fruit from B. oleae infestation. There were no statistical differences in hundred fruit weight among different harvest times. Oil yield increased rapidly until 10th of November. After that time, the increase rates gradually stopped and there were no statistical differences between oil yields. Therefore, fruit harvest should be carried out starting from mid-November to obtain the highest oil yield and avoid higher infestation rates. It is obvious that the olive oil acidity is affected by B. oleae infestation but in presented study, the results haven’t complied with this due to a considerable percentage of fly-damaged fruits that would cause high acidity dropped prior to early November. The fatty acid composition was affected by olive ripening. Although it was effectively proved through previous research on the fatty acid composition, the effects of B. oleae infestation haven’t been determined because the analysis was carried out on the fruits hanging on the trees as suggested by International Olive Oil Council (IOOC). According to the results the harvest should be done when olives are turning purple or have purple skin for minimizing the damage caused by B. oleae. Regarding to the above criteria, the suitable harvest time was found as the mid of November, when fruit maturation index is between 2.5 and 3.5. Results indicate that the B. oleae infestation could be significantly reduced by the implementation of early harvest.