Optimization of Malaxation Process using Major Aroma Compounds in Virgin Olive Oil

ABSTRACT Optimization of major aroma compounds in olive oils produced from fruits at three maturity stages wasstudied. A central composite design was used for the optimization of malaxation conditions of temperature and times, each at five levels with 13 runs including five central points. The responses of interest were trans-2-hexenal and hexanal, which were investigated and their contents were optimized. A full quadratic second order regression model including the linear, quadratic, and two factor interaction effects was proposed to explain the variation in the contents of target compounds depending on the malaxation conditions. Adequacies of models were evaluated by checking regression coefficients for each model. Models were found to work with high success for trans-2-hexenal prediction for oils from fruits at both purple and black stages, whereas the model for hexanalwas only in black stage oil. Their regression coefficients were higher than 0.86. Influences of time and temperature for the malaxation process were found to be significant for the transition of major aroma compounds from the fruit matrix to olive oil. The optimum conditions of temperature and time pairs to maximize trans-2-hexenal and hexanal was found to be 23°C/31 minutes for black olive and to maximize only trans-2-hexenal was also 29°C/41 minutes for purple olive

Fatty acid and sterol composition of fenugreek seed (Trigonella foenum-graecum L.)

Oil content, fatty acid and sterol composition of fenugreek seeds obtained from three different provinces were investigated. Oil was obtained from fenugreek seeds by solvent extraction and oil content was determined between 7.01-8.82%. Fenugreek seed oils were determined to be rich of unsaturated fatty acids according to gas chromatography results. Especially, linoleic acid was the most important of the fatty acids and varied between 45.10-46.19%. Total sterol content of oils varied from 8 681.54 to 9 591.70 ppm. The major sterol was β- sitosterol, and it was found to be between 59.94-68.24% of the total sterols

Determination of six-carbon volatile aroma components in aegean region olive oils

Yağ üretimi açısından önemli olan Ege bölgesi illerinden (Muğla, Aydın, İzmir ve Manisa) Gemlik, Memecik, Ayvalık, Uslu ve Domat zeytin çeşitlerinden 2007-2008 ve 2008-2009 dönemi olmak üzere 2 yıl hasat edilmiştir. Hasat edilen zeytinler laboratuvar tipi santrifüj sistem kullanılarak yağa işlenmiştir. Tepe boşluğukatı faz mikroekstraksiyon (HS-SPME) yöntemi yardımı ile yağlardan uçucu aroma bileşenleri ekstrakte edilerek gaz kromatografi-kütle spektrometre (GC-MS) cihazı ile bileşenlerin kalitatif ve kantitatif analizi yapılmıştır. Bu çalışmada, zeytinyağı kalitesi ile ilişkili olan altı karbonlu bileşenler belirlenmiştir. E-2-hekzenal ve hekzanal, çalışılan yağ örneklerinde en fazla oranda bulunan bileşenlerdir. 2007-2008 ve 2008-2009 hasat döneminde E-2-hekzenal bileşeninin sırası ile % 13.05-67.15 ve % 23.03-52.44 aralığında olduğu belirlenirken aynı hasat dönemlerinde % 6.70-39.34 ve % 11.23-59.81 arasında tespit edilen hekzanal bileşeninin, en yüksek salınan uçucu bileşenler arasında ikinci sırada yer aldığı görülmüştür.Gemlik, Memecik, Ayvalık, Uslu and Domat olive cultivars were harvested from Aegean region provinces (Muğla, Aydın, İzmir ve Manisa) being important in terms of the oil productions of the Aegean region for two harvest periods as 2007-2008 and 2008-2009. The olives harvested are processed to olive oils using laboratory scale centrifuge system. With the aid of the headspace-solid phase microextraction (HS-SPME) technique the qualitative and quantative analyses of compounds were accomplished with the gas chromatography-mass specrometer (GC-MS) by extracting the volatile compounds of oils via. In the present study, C6 compounds related to the quality of olive oil were determined. E-2-hexenal and hexanal were found to be most abundant compounds in the oil samples studied. In 2007-2008 and 2008-2009 harvest periods, E-2-hexenal (the most found component) was determined to be in a range of 13.05-67.15% and 23.03-52.44%, respectively whereas hexanal detected between 6.70-39.34% and 11.23-59.81% in the same harvest periods was observed to take the second place among the highest released volatile compounds

Ege Bölgesi Zeytinyağlarının Fenolik Bileşenleri

Bu çalışmada, Türkiye’de başlıca zeytin yetiştiriciliği yapan Ege bölgesinin bazı illerinden (Muğla, Aydın, İzmir ve Manisa) 2 hasat dönemi (2007-2008 ve 2008-2009) süresince yerli zeytin çeşitlerinin (Gemlik, Memecik, Ayvalık, Uslu ve Domat) yağı incelenmiştir. Bu yağların toplam fenolik madde ve fenolik bileşimi belirlenmiştir. Yağların toplam fenolik madde içeriği, 2007-2008 hasat dönemi örneklerinde 23,69-153,64 mg kafeik asit/kg, 2008-2009 hasat dönemi örneklerinde 16,18-136,22 mg kafeik asit/kg aralığında belirlenmiştir. Tüm zeytinyağı örneklerinde tespit edilen fenolik maddeler; tirozol, oleuropein, 4-hidroksifenil asetik asit, luteolin, vanilik asit, hidroksitirozol, rutin, sinnamik asit, verbaskozit, hidroksi fenilkarboksilik asit, sirinjik asit, 3,4-dihidroksibenzoik asit, kafeik asit, ferulik asit, p-kumarik asit, taksifolin ve apigenindir. Tirozol ve oleuropeinin, 2007-2008 hasat döneminde 1,80-13,39 mg/kg, 1,26-19,50 mg/kg ve 2008-2009 hasat döneminde ise 1,76-11,66 mg/kg, 0,20-13,12 mg/kg aralığında en fazla miktarda değişen bileşenler olduğu saptanmıştır