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    Fatty acid, triacyl glycerol, phytosterol, and tocopherol variations in kernel oil of Malatya apricots from Turkey
    (Amer Chemical Soc, 2007) Turan, Semra; Topcu, Ali; Karabulut, Ihsan; Vural, Halil; Hayaloglu, Ali Adnan
    The fatty acid, sn-2 fatty acid, triacyglycerol (TAG), tocopherol, and phytosterol compositions of kernel oils obtained from nine apricot varieties grown in the Malatya region of Turkey were determined (P < 0.05). The names of the apricot varieties were Alyanak (ALY), Cataloglu (CAT), Cologlu (COL), Hacihaliloglu (HAC), Hacikiz (HKI), Hasanbey (HSB), Kabaasi (KAB), Soganci (SOG), and Tokaloglu (TOK). The total oil contents of apricot kernels ranged from 40.23 to 53.19%. Oleic acid contributed 70.83% to the total fatty acids, followed by linoleic (21.96%), palmitic (4.92%), and stearic (1.21%) acids. The sn-2 position is mainly occupied with oleic acid (63.54%), linoleic acid (35.0%), and palmitic acid (0.96%). Eight TAG species were identified: LLL, OLL, PLL, OOL + POL, OOO + POO, and SOO (where P, palmitoyl; S, stearoyl; 0, oleoyl; and L, linoleoyl), among which mainly 000 + POO contributed to 48.64% of the total, followed by OOL + POL at 32.63% and OLL at 14.33%. Four tocopherol and six phytosterol isomers were identified and quantified; among these, gamma-tocopherol (475.11 mg/kg of oil) and beta-sitosterol (273.67 mg/100 g of oil) were predominant. Principal component analysis (PCA) was applied to the data from lipid components of apricot kernel oil in order to explore the distribution of the apricot variety according to their kernel's lipid components. PCA separated some varieties including ALY, COL, KAB, CAT, SOG, and HSB in one group and varieties TOK, HAC, and HKI in another group based on their lipid components of apricot kernel oil. So, in the present study, PCA was found to be a powerful tool for classification of the samples.
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    Human milk fat substitute produced by enzymatic interesterification of vegetable oil blend
    (Faculty Food Technology Biotechnology, 2007) Karabulut, Ihsan; Turan, Semra; Vural, Halil; Kayahan, Mummer
    Palm oil, palm kernel oil, olive oil, sunflower oil, and marine oil blend, formulated in the mass ratio of 4.0:3.5:1.0:1.5:0.2, was subjected to interesterification catalyzed by lipase from Thermomyces lanuginosa (Lipozyme(R) TL IM) for obtaining a product that contains similar triacylglycerol (TAG) structure to that of human milk fat (HMF). Reactions were carried out in a double jacketed glass vessel equipped with magnetic stirrer at 60 degrees C for 21 4, 6, 8, 12 and 24 h. The blend was analyzed for fatty acid composition of both total fatty acids and those at the sn-2 position after pancreatic lipase hydrolysis. After interesterification, TAGs were purified by thin layer chromatography and TAG species were determined according to the carbon number (CN) by high-temperature gas chromatography. Enzymatic interesterification generated significant differences for all TAG species from CN30 to CN54. Concentrations of some TAG species (CN30, 32, 34, 36, 38, 50, 52 and 54) decreased, while some (CN40 to 48) increased after 24 h. TAG species with higher CN reached maximum levels at the end of 6 h of reaction time. The predominant TAGs of the reaction product after 24 h were CN46, 48, 50, 52 and 54 with ratios of 13.8, 18.2, 13.9, 17.8, and 12.1%, respectively. These TAG species contain mainly 1,3-diunsaturated-2-saturated structure, like HMF.
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    Thermal Oxidation Kinetics of Refined Hazelnut Oil
    (Wiley, 2018) Solak, Rukiye; Turan, Semra; Kurhan, Sebnem; Erge, Hande S.; Karabulut, Ihsan
    In this study, oxidation kinetics of refined hazelnut oil heated at the temperature range from 80 to 180 degrees C was evaluated. The changes in peroxide value, p-anisidine value, polymer triglyceride content, -tocopherol content, and color values during oxidation were best fitted to zero-order kinetic model. The rate constants for the p-anisidine value, polymer triglyceride content, and degradation of -tocopherol of hazelnut oil increased at the temperatures between 80 and 160 degrees C, while the rate constant for peroxide value decreased at the temperatures between 80 and 140 degrees C. The activation energies for the formation of peroxides (at 80-140 degrees C), secondary oxidation products such as alkenals, the polymer triglycerides, and degradation of -tocopherol were found as 47.49, 29.95, 52.65, and 14.22kJmol(-1), respectively. The induction period of hazelnut oil was observed to reduce with increasing oxidation times. The increase in the b* value with the oxidation time and temperature was attributed to the fact that the heating process intensified the yellow color of the oil.
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    Utilization of activated carbons produced from some natural materials in the purification of used frying oil
    (Wiley, 2021) Turan, Semra; Akmil Basar, Canan; Onal, Yunus
    The activated carbons (ACs) from shells of horse chestnut, chestnut, acorn, pistachio, apricot kernel, and wood shavings were evaluated to recover used oil (UO). The effects of the amount of AC, adsorption time, and temperature on the purification of the UO were investigated using the apricot kernel shells due to the high apricot production of Turkey. The kinetic evaluation was also done. The percentage improvements (PIs) in total polar materials (TPM), free fatty acids (FFA), p-anisidine value (p-AV), conjugated diene content (CD), and color of UO were found as 100, 56, 92, 51, and 90% for the apricot kernel AC in the column treatment. The most effective other ACs in decreasing FFA, p-AV, CD, and color were the horse chestnut (59%), chestnut (74%), chestnut (43%), and pistachio (72%), respectively. Consequently, these ACs can be used for the purification of UO. Practical applications Industrial wastes cause environmental pollution if they are ejected into river, sea, and soil. Therefore, they should be purified or treated for different purposes. In this study, the industrial wastes from the food and forest industries were used for the production of activated carbon to purify the used oil. The results showed that these activated carbons could be utilized for the regeneration of used oils. The most economical treatment is to blend the activated carbon with used frying oil for a certain time and remove it through centrifugation and filtration. The purified oil has the potential to be used in the biodiesel production.