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Öğe Influence of different antioxidants and pack materials on oxidative stability of cold pressed poppy seed oil(Innovhub Ssi-Area Ssog, 2017) Ogutcu, M.; Yilmaz, E.The aim of this study was to determine the oxidative stability of cold pressed poppy seed oil (PSO) samples. The PSO samples prepared by adding BHA, tocopherol and oryzanol, were also filled into polyethylene terephthalate (PET), amber glass (AG) and transparent glass (TG) packaging materials. The samples were stored at 4 and 20 degrees C for 9 months and the color differences, free fatty acidity, peroxide value (PV), UV absorbance (K-232 and K-270) and oxidative induction time (OIT) were monitored. As expected, the oil oxidation process was affected by storage temperature, hence the samples stored at 20 degrees C oxidized faster than the samples stored at 4 degrees C. This study revealed that BHA was more effective against oxidation than the other antioxidant additives. Moreover, the samples packaged with AG materials had lower PV values and higher OIT values than the other samples. There was high correlation between PV and OIT (r = 0.88; p = 0.01) and K-232 and OIT (r = 0.84; p = 0.01) measurements. In conclusion, the OIT values obtained from DSC measurements can be applied as an accurate and effective method just as standard titration and UV absorbance methods.Öğe Oleogels of virgin olive oil with carnauba wax and monoglyceride as spreadable products(Inst Grasa Sus Derivados, 2014) Ogutcu, M.; Yilmaz, E.The oleogels of virgin olive oil with carnauba wax and monoglyceride were prepared to determine the most suitable spreadable product. The oil binding capacities of monoglyceride oleogels were higher than those of the carnauba wax oleogels. There was no true crystalline structure with carnauba wax at 3%. Although the highest solid fat content was in the 10% monoglyceride oleogel (9.38%), it was 12.15% in the commercial breakfast margarine at 20 degrees C. The peak melting temperature of the margarine was 47.11 degrees C, and among all oleogels, monoglyceride oleogel at 7% addition had the closest value (48.70 degrees C). The melting enthalpies of the oleogels ranged from 1.25 to 103.97 J.g(-1), while it was 94.19 J-g(-1) for the margarine sample. The firmness and stickiness values were usually lower in the oleogel samples than those of the margarine sample. There was no significant change in the texture parameters during storage, indicating good structural stability. The polarized light microscopy pictures revealed rod-like crystals for carnauba wax and rosette-like aggregates for monoglyceride oleogels. X-ray diffraction patterns of the samples have revealed a beta-type polymorphic structure for the oleogels. These oleogels can be used in a spreadable, breakfast margarin-like product to promote new consumption habits for this healthy oil.Öğe Preventing oil leakage with natural wax additions during the storage of tahini halva(Innovhub Ssi-Area Ssog, 2018) Ogutcu, M.; Arifoglu, N.; Temizkan, R.; Yilmaz, E.Tahini halva, a famous traditional Turkish dessert, is a food product with a high oil content and when stored an oil leakage may occur leading to unpleasant appearance. In this study, to restrict oil migration, sunflower, shellac and beeswax were used at 3% (w/w) in tahini halva and the effects of these natural waxes were comparatively investigated during a 6-month storage period at 25 and 35 degrees C against control samples containing no additives and halva containing 3% hydrogenated palm stearine (HPS). The physico-chemical, textural, and sensorial characteristics were monitored and the results revealed that natural wax addition led not only to successful restriction of oil leakage, but also the samples, especially sunflower wax and HPS containing samples preserved their textural and sensory characteristics throughout storage. According to the samples XRD patterns, the crystal structure of the natural wax containing samples did not change during storage, but that of the tahini halva containing no additive extremely changed, mostly related with oil leakage during storage. The data on oxidative induction time, peroxide values, and free fatty acid contents of the samples, were within the legal limits during storage. It can be concluded that sunflower wax was more suitable in replacing commercially used HPS in terms of restricting oil leakage and preserving textural and sensory properties of traditional tahini halva than the other natural waxes.Öğe Textural properties and storage stability of organogels prepared from pomegranate seed oil with beeswax and sunflower wax(Innovhub Ssi-Area Ssog, 2016) Yilmaz, E.; Ogutcu, M.Organogels from pomegranate seed oil (PO) with beeswax (BW) and sunflower wax (SW) were produced and followed for their textural and oxidative stabilities for 3 months storage. Organogel properties like oil binding capacity, gelation time, solid fat content, color, thermal properties, textural properties, X-ray diffraction measurement, polarized light microphotographs and peroxide values were measured. It was shown that both SW and BW have yielded stable, uniform and smooth gels with no increase in solid fat content. SW organogels had higher melting temperatures (59.27-64.06 degrees C) and enthalpies (8.46-19.00 J/g) than that of BW organogels (45.78-51.29 degrees C and 3.40-11.70 J/g). Generally, as added wax concentration increased, the firmness and stickiness were enhanced. The conclusions showed that the textural and oxidative stability of the organogels was good enough for practical applications. Hence, nutritionally important oil, pomegranate seed oil, can be utilized in spreadable fat and margarine formulations in the plastic fat form of the organogels.
