WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Access Right: Open AccessAuthor: search.filters.author.Aktaş, Ayşe Burcu

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 6
    Citation - Scopus: 8
    Chemical and Physical Properties of Fats Produced by Chemical Interesterification of Tallow With Vegetable Oils
    (CSIC Consejo Superior de Investigaciones Cientificas, 2021) Aktaş, Ayşe Burcu; Özen, Banu
    This study aims at manufacturing structured lipids by chemical interesterification (CI) of beef tallow with corn, canola and safflower oils individually at various tallow blend ratios (60, 70, 80%) and catalyst concentrations (0.75, 0.875, 1%). Several physical and chemical properties of interesterified products were determined and data were analyzed using univariate and multivariate statistical techniques. Interesterified lipids were more spreadable and showed plastic behavior due to their lower consistency and solid fat contents. Decreases in melting points to a temperature range of 26.5-45.5 degrees C regardless of oil type were observed. Interesterified fats displayed mostly beta' and beta'+ beta crystal forms. The CI of tallow did not result in the formation of significant amounts of trans-fatty acids. Samples interesterified with corn oil had lower free fatty acid contents (1.87-3.9%) and higher oxidation induction times (3.82-12.25h) than other lipids. Therefore, fats containing corn oil-tallow could be used in the baking industry due to their potentially good aeration properties and smooth texture.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 10
    Ir Spectroscopy and Chemometrics for Physical Property Prediction of Structured Lipids Produced by Interesterification of Beef Tallow
    (Academic Press, 2019) Aktaş, Ayşe Burcu; Alamprese, Cristina; Fessas, Dimitrios; Özen, Banu
    The aim of this study was the application of infrared spectroscopy and chemometrics to predict slip melting point (SMP), melting points at different melted fat percentages (MP85, MP90, MP95), and consistency of structured lipids to provide fast and reliable methods for their characterization. Tallow was chemically or enzymatically interesterified with corn, canola, or safflower oils, at different ratios. Fourier-transform mid-infrared (FT-IR) and near-infrared (FT-NIR) spectra of melted and solid samples were collected. Partial-least-square regression models constructed after different spectra pre-treatments and variable selection were satisfactory. The best models were obtained with solid sample FT-NIR spectra: in cross-validation, determination coefficients and root mean square errors were, respectively, 0.85 and 1.7 degrees C for SMP, 0.85 and 2.8 degrees C for MP90, and 0.91 and 14 MPa for consistency. Infrared spectroscopy can be considered a promising tool to determine physical properties of interesterified fats.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 17
    Phenolics Profile of a Naturally Debittering Olive in Comparison To Regular Olive Varieties
    (John Wiley and Sons Inc., 2014) Aktaş, Ayşe Burcu; Özen, Banu; Tokatlı, Figen; Şen, İlknur
    BACKGROUND: Hurma, an olive variety that grows in a specific area in Turkey, loses its bitterness before harvesting, and therefore does not need further processing steps for the production of table olives. The total phenol content and phenolic profiles of (1) this naturally debittered olive type, Hurma; (2) the same olive variety, but not a naturally debittered type, Erkence; and (3) another variety, Gemlik, which is commonly consumed as table olive, were determined during their maturation period for two harvest years. RESULTS: The total phenol content of Hurma is the lowest compared to the other types regardless of harvest year, which has a significant effect on the phenolic content and composition of individual components for all olive types. All three olive types can be differentiated from each other especially during the late phase of maturation using the phenolics profile in combination with principal component analysis. CONCLUSION: The natural debittering phenomenon of Hurma olive on the tree involves a decrease in phenol content and a change in phenol composition. The differentiation in phenol composition especially becomes very significant in the late of period of maturation.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 16
    Comparison of Some Chemical Parameters of a Naturally Debittered Olive (olea Europaea L.) Type With Regular Olive Varieties
    (Elsevier Ltd., 2014) Aktaş, Ayşe Burcu; Özen, Banu; Tokatlı, Figen; Şen, İlknur
    Some olives grown in Karaburun peninsula in the west part of Turkey and mostly coming from Erkence variety lose their bitterness while still on the tree and are called Hurma among locals. This olive type does not require further processing to remove the bitter compounds. In this study, sugar, organic acid and fatty acid profiles of Hurma, Erkence (not naturally debittered) and Gemlik (commonly consumed as table olive) olives were determined throughout 8 weeks of maturation period for two consecutive harvest seasons, and the results were analysed by principal component analysis (PCA). PCA of sugar and organic acid data revealed a differentiation in terms of harvest year but not on variety. Hurma olive is separated from others due to its fatty acid profile, and it has higher linoleic acid content compared to others. This might be an indication of increased desaturase enzyme activity for Hurma olives during natural debittering phase.