Fatty acid composition and stability of vegetable oils have taken more attention as an essential source of biologically active compounds in a good balanced diet. The purpose of the study was to determine peroxide value, free fatty acids, unsaponifiable matter, total carotenoid content, iodine value and fatty acid composition of sunflower, rapeseed, mustard, peanut and olive oils. Rapeseed and peanut oils had the highest peroxide values, while sunflower oil had the lowest peroxide values. The free fatty acid value of the tested oils varied between 0.43 and 1.36% oleic. The peanut oil had the highest free acid value and the mustard oil had the lowest one. Total carotenoid contents of mustard and rape seed oil were higher than those of the other oils tested. Palmitic acid (C16:0), oleic acid (C18:1) and stearic acid (C18:0) were the common main fatty acid components of the vegetable oils tested. Followed by linoleic acid, the amount of oleic acid was the highest among other fatty acid components. Mustard oil had the highest erucic acid (C22:1) with the amount of 11.38%, indicating that it cannot be used for human consumption. Among the oils investigated, sunflower and mustard oils were more stable than rapeseed, peanut and olive oils.

This study was carried out to determine the effect of three ripening stages (green, spotted and ripe) on fatty acid, sterol composition and antioxidant activity of olive oils from three olive varieties (Sarı Hasebi, Gemlik and Halhalı) widely grown in the eastern Mediterranean region of Turkey. The variety had a significant effect on the fatty acids, sterols and total phenolic content. Halhalı oil had the lowest oleic acid content (67.28%), while Sarı Hasebi oil had the highest (75.61%). Total phenolic content varied between 163.02 mg GAE/kg oil and 749.28 mg GAE/kg oil. Halhalı oil showed the highest antioxidant activity (IC = 66 µg/ml) whereas Sarı Hasebi oil showed the lowest one (IC = 2617 µg/ml). The total content of sterols in olive oils ranged from 358 mg/kg in Sarı Hasebi to 1092.33 mg/kg in Halhalı. The β-sitosterol content of olive oils varied between 80.72 (Sarı Hasebi) and 87.81% (Halhalı). ∆-5-avenasterol content ranged between 3.34 (Halhalı) and 7.30% (Gemlik). Variety and ripening degree significantly affected the β-sitosterol, ∆-5-avenasterol and erythrodiol + uvaol contents of oils. Finally, these results showed that sterol and fatty acid compositions can be used as indicators of variety and ripening degree among virgin olive oils.

Chemical properties, fatty acid and sterol compositions of olive oils extracted from Gemlik and Halhalı varieties grown in Hatay and Mardin provinces in Turkey were investigated during four maturation stages. The olive oil samples were analyzed for their chemical properties such as free acidity, peroxide value, total carotenoid, total chlorophyll, total phenolic contents, antioxidant activity, fatty acid and sterol compositions. Chemical properties, fatty acids and sterol profiles of olive oil samples generally showed statistically significant differences depending on the varieties, maturation and growing areas (p < 0.05). As free fatty acid contents and total phenolic contents increased, total carotenoid and chlorophyll contents decreased throughout the maturity stages. Total carotenoid and chlorophyll contents of oil samples from Mardin were higher than those of Hatay. The total phenolic compounds of olive oil samples ranged from 20.62 in Gemlik to 525.22 mg GAE/kg oil in Halhalı from Hatay. In general, the phenolic contents and antioxidant activities of olive oil samples were positively associated. Oleic acid content was the highest 71.53 % in H1 samples in Hatay. Total sterol contents were 1194.33 mg/kg in Halhalı and 2008.66 mg/kg in Gemlik from Hatay. Stigmasterol contents of oils obtained from Hatay were lower than those of Mardin. Oleic acid, palmitic acid, β‐sitosterol, ∆‐5‐avenasterol and campesterol contents fluctuated with maturation for each of variety from both growing regions. These results showed that the variety, growing area and maturation influence the chemical properties, fatty acid and sterol compositions.

Aim: The aim of this study was to determine the influence of two different extraction methods on the fatty acid composition, total phenolic content and antioxidant activity of grape seed oils obtained from 5 different varieties. Materials and Methods: The seeds of the Syrah, Merlot, Sangiovese, Cabernet Sauvignon, Sauvignon Blanc grape varieties were used in this study. Oil extraction was carried out by Soxhlet extraction and coldpressed extraction methods. Results: The most abundant fatty acids in the grape seed oils that were obtained were linoleic acid, oleic acid and palmitic acid ranging from 64.80 to 68.64%, 18.41 to 21.58% and 7.08 to 8.23%, respectively. The linoleic and palmitic acid values that were determined in the grape seed oils obtained by solvent extraction were higher than those for the grape seed oils obtained from the cold-pressed samples. The total phenolic content and antioxidant activity of the grape seed oils varied between 115.68 and 317.71 mg GAE/kg, 7.14 and 34.46% as DPPH radical scavenging activities, respectively. Conclusion: The total phenolic content and antioxidant activity values for the grape seed oils obtained by solvent extraction were higher than those determined in the grape seed oils obtained by cold-pressing.

No abstract

A field trial was conducted to observe the effects of different irrigation strategies on the yield and the water use, oil content and marginal return of sunflower which was irrigated by means of a drip system during 2010 and 2011 under Çukurova condition of Turkey. The irrigation strategies include three irrigation intervals (A 1 : 25 mm; A 2 : 50 mm; A 3 : 75 mm of cumulative pan evaporation) and six water levels (WL) based upon the percentages of cumulative pan evaporation (WL 1 = 0.50, WL 2 = 0.75, WL 3 = 1.00 and WL 4 = 1.25). In addition, WL 5 = PRD50 and WL 6 = PRD75 treatments were evaluated. They obtained water from alternative laterals 50% and 75% of the WL 3 treatment. Additionally, a nonirrigated treatment (NI) was included as control plot in the experiment. In each of the experimental years, the largest and the smallest average yields were acquired from the A 2 WL 4 and NI treatments, respectively. The oil content and fatty acid composition were significantly affected by irrigation strategies. The oil content increased with the increasing amount of irrigation. Among all irrigation intervals, PRD-50 (WL 5) treatment provided the largest water use efficiency (WUE) and irrigation water use efficiency (IWUE) values in both growing seasons. In order to attain higher yields and a generated the marginal return, A 2 WL 4 irrigation regime is suggested for sunflower production in the Mediterranean region. A 2 WL 3 water strategy is proposed for an acceptable marginal return in case of water shortage.

There is a considerably interest on some fruits and leaves extracts such as olive leaf, due to their beneficial health effects. Olive leaf has been consumed as tea for many years. However, the studies on volatile compounds (VCs) of leaves are scarce. Therefore, this study was aimed to evaluate of VCs in the leaves collected from 'Gemlik', 'Halhalı' and 'Sarı Hasebi' olive trees varieties grown in Hatay province. The VCs were analyzed by gas chromatography-mass spectrometry (GC-MS) using solid phase micro-extraction (SPME). The 97 out of 127 VCs identified were found common in all the olive leaves. Terpenes, aldehydes, alcohols and ketones were identified in the olive leaves as major VCs groups, which accounted for about 36-60%, 20-28%, 6-14% and 4-8% of total VCs identified in leaves, respectively. The relative proportions of these chemical groups showed considerably differences among olive leaves. α-Cubebene was found as major VC followed by transcaryophyllene, α-farnesene, trans-2-hexenal, benzeneethanol, nonanal, trans,trans-2,4-heptadienal, cycloisosativene, trans-4,8-dimethyl-1,3,7-nonatriene, 2,4-heptadienal, α-humulene, α-muurolene and benzaldehyde. These compounds accounted for 56-75% of total VCs identified in the olive leaves. While 'Halhalı' olive leaf had highest (p<0.01) levels of α-cubebene (31.79%), cycloisosativene (7.69%) and α-muurolene (4.05%), 'Sarı Hasebi' had trans-caryophyllene (23.16%), trans-4,8-dimethyl-1,3,7-nonatriene (4.65%), αhumulene (3.64%) and 'Gemlik' had benzeneethanol (6.93%), nonanal (5.07%), and benzaldehyde (2.17%) at the highest levels. This study has showed that olive leaves from each variety are a good terpene source that makes them important in terms of beneficial effects on health.

Bu çalışmada, Hatay'da yetiştirilen Halhalı, Sarı Haşebi ve Gemlik zeytin çeşitlerinden iki fazlı mekanik yöntemle (kırma-ezme, yoğurma ve santrifüj) elde edilen zeytinyağı örneklerinde sterol ve yağ asidi kompozisyonları ile diğer kalite kriterleri (serbest yağ asitleri, peroksit sayısı, toplam klorofil ve toplam karotenoid) belirlenmiştir. Zeytinyağlarında oleik asit, palmitik asit, linoleik asit, stearik asit, palmitoleik asit, linolenik asit ve araşidik asitler başlıca yağ asitleri olarak tespit edilmiştir. Zeytinyağı örneklerinde oleik asit içerikleri %66,25-76,14 arasında belirlenmiştir ve en yüksek oleik asit içeriğine sahip çeşit Sarı Haşebi olarak saptanmıştır. Zeytinyağı örneklerinde sterol ve yağ asidi kompozisyonları çeşitlere göre önemli farklılıklar göstermiştir. Toplam sterol içerikleri 1025-1686 mg/kg arasında saptanmıştır ve toplam sterol içeriği en yüksek olan çeşit Gemlik en düşük olan çeşit Sarı Haşebi olarak belirlenmiştir. Toplam beta-sitosterol (beta-sitosterol, delta-5-avenasterol, delta-5-24-stigmastadienol, klerosterol, sitostanol) içerikleri %92,96-94,63 olarak saptanmıştır. En yüksek ve en düşük toplam betasitosterol içerikleri sırasıyla Halhalı ve Sarı Haşebi çeşitlerine ait yağlarda tespit edilmiştir. Başlıca sterol bileşenleri beta-sitosterol %83,08-88,21, delta-5-avenasterol %4,82-6,97, kampesterol %2,28-3,43 olarak tanımlanmıştır. Zeytinyağlarında eritrodiol + uvaol içerikleri %1,68-2,71 arasında belirlenmiş olup, bu değerler Türk Gıda Kodeksi'nde belirtilen sınırlar arasında yer almaktadır.