Changes in olive properties and oil quality, oxidative stability, phenolic and chemical composition of two common Turkish varieties (Memecik and Edremit) during maturation were investigated. Olive samples were collected in their own growing region for five different harvest dates and processed to oil with a laboratory scale mill. Metabolic behaviors of these two varieties along with the maturation were different in terms of some compositional parameters. Oleic acid, triolein, b-sitosterol, oleuropein, hydroxytyrosol, and tyrosol contents of olive or olive oils fluctuated with maturation. However, changes in average weight, flesh/pit ratio, water and oil contents of the olives were observed. Phenolics such as trans cinnamic acid contents of both olive fruits decreased whereas cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside anthocyanins increased. Free fatty acids of virgin olive oils were found independent of maturity although some slight changes were determined in peroxide value, dien and trien conjugations. Some compositional parameters such as pigment concentration, tocopherols, stearic acid, linolenic acid, palmitodiolein and monounsaturated/polyunsaturated fatty acid ratio decreased while linoleic acid, dioleolinolein, palmitooleolinolein and D-5-avenasterol percentages increased with the maturation. A clear discrimination was observed with principal component analysis. The data obtained can also be considered useful for providing information to determine the ideal maturity stage.

The effects of microwave heating for 3, 6, and 9 min at a frequency of 2450 MHz on fatty acid composition, tocopherols, iodine value, free fatty acids (%), peroxide value, conjugated dienes and trienes, and hexanal contents of refined hazelnut, soybean, sunflower, and virgin olive oils were investigated. A significant (p < 0.05) decrease was observed in linoleic and linolenic acids contents of soybean oil during exposure to microwave heating. Tocopherol contents of oil samples significantly decreased (p < 0.05) during microwave heating. Free fatty acids of the samples slightly increased and iodine value showed reduction throughout the process. Conjugated dienes contents of samples showed an increasing trend up to the 6 min, followed by a reduction at 9 min. Conjugated triene fatty acids of all the samples significantly increased (p < 0.05) throughout the application. While peroxide value showed increasing trend up to the 3 min and sharply decreased at 9 min, hexanal contents of refined hazelnut, virgin olive, soybean, and sunflower oils increased 63, 28, 55, and 389 fold, respectively, after 9 min exposure to microwave heating. Kinetic analysis of data showed that the reaction orders for peroxide and hexanal formation were zero and first order, respectively, and in the tested oils the reaction rate followed the order: soybean oil ˃ sunflower oil ˃ hazelnut oil ˃ virgin olive oil for peroxide, and sunflower oil ˃ soybean oil ˃ hazelnut oil ˃ virgin olive oil for hexanal formation. It was concluded that hexanal could be considered as a parameter for evaluation of the quality of oils exposed to microwave heating.

The first objective of this study was to reveal the effect of temperature and time on the production of CLA isomers from safflower oil. For this purpose, CLA production was conducted at different temperatures (80–240 °C) and over different time durations (1–10 h). Alkali isomerisation gave a total conversion of 87.8% under the optimal conditions of 240 °C and 8 h (for maximum beneficial isomers), and produced 41.0% trans-10, cis-12, 40.4% cis-9, trans-11, and 6.4% undesirable CLA isomers. The second aim of this study was to determine the effect of temperature and solvents on the purification of CLA isomers. To achieve this, CLA solutions containing different solvents (acetone, methanol, and petroleum ether) were crystallized at several temperatures (0 to –85 °C). It was determined that although the highest CLA purities (94%) were obtained at –55 °C using acetone as the solvent with a yield of 38.1%, the highest yield (89.6%) was determined using petroleum ether at –85 °C with a purity of 88.1%. This paper presents methods to utilize safflower oil and low temperature crystallization process to inexpensively obtain beneficial CLA.

The aim of this study is to investigate the effects of various particle sized and different amount of plant fibers as fat mimetic for biscuit formulations instead of biscuit fat. The fibers with different particle sizes were obtained from wheat bran and used instead of fat in biscuit formulations. The texture, rheology and quality analyses of low-fat biscuit (30, 20 and 10% fat) were performed and compared with those of the full-fat control sample (40% fat). Results showed that wheat bran fiber with bigger particle size (Long Fiber, LF) were more favorable in terms of textural properties of the dough and the quality parameters of biscuits while the fibers with smaller particle size (Medium Fiber, MF and Small Fiber, SF) improved viscoelastic properties of dough similar to the control. Although the use of these fibers in the production of low-fat biscuits were suitable in terms of workability of dough increasing fiber content and/or reducing fiber size resulted in harder biscuits with lower spread ratio. This study showed that the texture of biscuits was greatly dependent on the texture of the dough.

The fatty acid, tocopherol and sterol contents of the oils of several poppy seeds were investigated. The main fatty acids in poppy seed oils were linoleic (687.6-739.2 g kg^-1), oleic (141.3-192.8 g kg^-1) and palmitic (76.8-92.8 g kg^-1). The oils contained an appreciable amount of -tocopherol (195.37-280.85 mg kg^-1), with a mean value of 261.31 mg kg^-1 and α-tocopherol (21.99-45.83 mg kg^-1), with a mean value of 33.03 mg kg^-1. The concentrations of total sterol ranged from 1099.84 mg kg^-1 (K.pembe) to 4816.10 mg kg^-1 (2. sınıf beyaz), with a mean value of 2916.20 mg kg^-1. The major sterols were -sitosterol, ranging from 663.91 to 3244.39 mg kg^-1; campesterol, ranging from 228.59 to 736.50 mg kg^-1; and Δ⁵-avenasterol, ranging from 103.90 to 425.02 mg kg^-1. The studied varieties of poppy seeds from Turkey were found to be a potential source of valuable oil.

El contenido en ácidos grasos, tocoferoles y esteroles de aceites de varias semillas de adormidera fueron investigadas. Los principales ácidos grasos en el aceite de semilla de adormidera fueron el ácido linoleico (687.6-739.2 g kg^-1), ácido oleico (141.3-192.8 g kg^-1) y ácidos palmítico (76.8- 92.8 g kg^-1). Los aceites contienen una cantidad apreciable de -tocoferol (195.37-280.85 mg kg^-1), con un valor medio de 261.31 mg kg^-1 y α-tocoferol (21.99-45.83 mg kg^-1), con un valor medio de 33.03 mg kg^-1. La concentración total de esteroles varió desde 1099.84 mg kg^-1 (K.pembe) a 4816.10 mg kg^-1 (2. sınıf beyaz), con un valor medio de 2916.20 mg kg^-1. El principal esterol fue el -sitosterol, que varió desde 663.91 a 3244.39 mg kg^-1; el campesterol, que varió desde 228.59 a 736.50 mg kg^-1; y el Δ⁵-avenasterol, que varió desde 103.90 a 425.02 mg kg^-1. Las semillas estudiadas de las diferentes variedades de adormidera de Turquía pueden ser una fuente potencial de aceites con valor añadido