WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 28Citation - Scopus: 29Detection of Vinegar Adulteration With Spirit Vinegar and Acetic Acid Using Uv–visible and Fourier Transform Infrared Spectroscopy(Elsevier, 2022) Çavdaroğlu, Çağrı; Özen, BanuVinegar is one of the commonly adulterated food products, and variations in product and adulterant spectrum make the detection of adulteration a challenging task. This study aims to determine adulteration of grape vinegars with spirit vinegar and synthetic acetic acid using different spectroscopic methods. For this purpose, grape vinegars were mixed separately with spirit vinegar and diluted synthetic acetic acid (4%) at 1–50% (v/v) ratios. Spectra of vinegars and mixtures were obtained with UV–visible and Fourier-transform infrared (FTIR) spectrometers. Data were evaluated with various chemometric methods and artificial neural networks (ANN). Correct classification rates of at least 94.3% and higher values were obtained by the evaluation of both spectroscopic data along with their combination with chemometric methods and ANN for discrimination of non-adulterated and adulterated vinegars. UV–vis and FTIR spectroscopy can be rapid and accurate ways of detecting adulteration in vinegars regardless of adulterant type.Article Citation - WoS: 6Citation - Scopus: 8Chemical 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, BanuThis 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: 13Citation - Scopus: 14Uv-Vis Spectroscopy for the Estimation of Variety and Chemical Parameters of Olive Oils(Springer, 2021) Jolayemi, Olusola Samuel; Tokatlı, Figen; Özen, BanuOlive oils produced in different years from different varieties were studied with UV-Vis spectroscopy for classification and prediction. Multivariate models were created with second derivative spectral data, and tested with external validation sets. For varietal classification, orthogonal partial least square discriminant analysis resolved oil samples into various classes with correct classification rate more than 89% for validation set (n = 20). A sample of fresh and stored oils were also classified with a correct classification rate more than 90% for validation set (n = 20). In the predictions of chemical parameters (70 for calibration, 30 for validation), the combination of UV-Vis spectroscopy with orthogonal partial least square regression models showed potential for simultaneous quantification of chlorophylls (0.6-5.6 mg/kg; R-val(2) , 0.79; RPD, 1.97); carotenoids (0.6-3.3 mg/kg; R-val(2), 0.80; RPD, 2.38); ratio of mono to polyunsaturated fatty acids (3.6-8.8; R-val(2) , 0.77; RPD, 1.90), oleuropein derivatives (1.2-62.3 mg/kg; R-val(2) , 0.66; RPD, 1.77), and total phenol content (62.2-505 mg/kg; R-val(2) , 0.67; RPD, 1.74), although showed poor to moderate results for the quantification of free fatty acid (0.3-5.4%; R-val(2), 0.67; RPD, 1.64); monounsaturated fatty acids (66-76.5%; R-val(2) , 0.71; RPD, 1.67); polyunsaturated fatty acids (8.6-18.2%; R-val(2) , 0.73; RPD, 1.65). The models were unable to estimate oxidative stability, saturated fatty acids, and individual phenolics such as hydroxytyrosol, pinoresinol, luteolin, total phenolic acids (R-val(2) , 0.26-0.64; RPD, 0.60-1.52). Results showed the capacities of UV-Vis spectroscopy for classification of olive oils, and prediction of total pigments and phenol content and ratio of mono to polyunsaturated fatty acids.Article Citation - WoS: 1Citation - Scopus: 2Fatty Acid Alkyl Ester and Wax Compositions of Olive Oils as Varietal Authentication Indicators(Springer, 2021) Uncu, Oğuz; Özen, BanuMinor components of olive oils can be good markers for their authenticity, which is a significant quality issue for this product. It was aimed to determine individual and total fatty acid alkyl esters and waxes as minor constituents of olive oil and to investigate their novel varietal authentication capability separately and in combination for three main olive cultivars grown in three distinct locations of Aegean Region of Turkey. In addition, basic quality and purity parameters as free fatty acid, K values and fatty acid profiles were also determined for the characterization of the samples. Olive oil samples from different cultivars had different fatty acid profiles and two of these varieties had similar quality parameters. Statistical analyses were conducted with orthogonal partial least squares discriminant analysis (OPLS-DA) to differentiate varieties with respect to their individual and combined parameters of fatty acid alkyl esters and waxes. For calibration sets, use of individual fatty acid alkyl esters profile resulted in 80% correct classification rate while waxes alone was 67% successful in classifying the olive oils according to variety. It was found that alkyl esters in combination with waxes were more effective in discrimination of olive oils with respect to cultivar compared to their individual forms and the correct classification rate for the generated model is 92% for calibration set. Since fatty acid alkyl esters along with waxes have effect on cultivar differentiation, they could have a potential as authentication tools for olive oil besides their known quality characteristics.Article Citation - WoS: 13Citation - Scopus: 13Authentication of Turkish Olive Oils by Using Detailed Pigment Profile and Spectroscopic Techniques(John Wiley and Sons Inc., 2020) Uncu, Oğuz; Uncu, Oğuz; Özen, Banu; Özen, Fatma Banu; Tokatlı, Figen; Tokatlı, FigenBACKGROUND Minor compounds of olive oil could have discriminatory characteristics in the authentication of this product. It was aimed to determine the detailed pigment profiles of Turkish olive oils and use them in differentiation of the samples in comparison to fast, reliable, and environmentally friendly Fourier-transform infrared (FTIR) and ultraviolet (UV)-visible spectroscopic techniques. Pigment contents of 91 olive oils obtained from different locations for two consecutive harvesting years were determined with chromatographic analysis and FTIR and UV-visible spectra of these samples were also obtained. All data were analyzed with orthogonal partial least-squares discriminant analysis to investigate the differentiation ability of these methods with regard to their detailed pigment and spectroscopic profiles. RESULTS Pheophytin a (2.78-8.98 mg kg(-1)) and lutein (1.19-4.07 mg kg(-1)) were the major pigments in all samples. Pigment profiles provided successful classification of olive oils with respect to their designated origins and harvesting year with average correct classification rates of 97%. UV-visible spectroscopy has quite similar results with pigment profiles in terms of its discriminatory power. In addition, FTIR and fused data were slightly better in discrimination of the samples, and the fused dataset has the highest correct classification rate of 100%. CONCLUSION Use of detailed pigment profiles is quite promising in authentication of olive oils. However, UV-visible and FTIR spectroscopic techniques could be reliable alternatives for the same purposes. All of the techniques studied have great potential in 'protected designation of origin' certification studies. (c) 2020 Society of Chemical IndustryArticle Citation - WoS: 25Citation - Scopus: 30Prediction of Chemical Parameters and Authentication of Various Cold Pressed Oils With Fluorescence and Mid-Infrared Spectroscopic Methods(Elsevier Ltd., 2021) Doğruer, Ilgın; Uyar, H. Hilal; Uncu, Oğuz; Özen, BanuIt was aimed to compare the performances of two spectroscopic methods, fluorescence and mid-infrared spectroscopy, in terms of their adulteration detection and estimation of several chemical properties for various cold pressed seed oils. Spectroscopic profiles, fatty acid, free fatty acid and total phenol contents of pumpkin seed, grape seed, black cumin oil, and sesame seed oils were determined and these oils were mixed with sunflower oil at 1–50% (v/v). Both spectroscopic techniques provided comparable results for determination of adulteration of each oil type and the most successful prediction was obtained for pumpkin seed oil at levels >%1. Combined data set of oils resulted in successful quantification of their free fatty acid value, total phenol and major fatty acids contents with both spectroscopic methods regardless of oil type. Both techniques could be used as reliable, fast and environmentally friendly alternatives in the analyses of different types of seed oils. © 2020 Elsevier LtdConference Object Bioethanol Production From Low Cost Agro-Industrial Waste Products(Elsevier, 2012) Evcan, Ezgi; Tarı, Canan; Özen, BanuIn recent years, the rapid increase in environmental problems, greenhouse gas emissions, fuel prices and the unlimited consumption of limited fossil fuel stocks made people search for some alternative energy sources. Bioethanol is one of the most popular alternative source with its many beneficial features. Besides, bioethanol which will be obtained from low cost raw materials will be more attractive. Bioethanol produced from lignocellulosic biomass sources, such as agricultural residues, offers unique environmental and economic benefits.Article Citation - WoS: 11Citation - Scopus: 10Ir 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, BanuThe 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: 61Citation - Scopus: 70Use of Ftir and Uv-Visible Spectroscopy in Determination of Chemical Characteristics of Olive Oils(Elsevier, 2019) Uncu, Oğuz; Özen, Banu; Tokatlı, FigenIt was aimed to predict fatty acid ethyl ester (FAEE), wax, diacylglycerol (DAG) and color pigment contents of olive oils by using rapid and non-destructive spectroscopic techniques (FTIR and UV-vis) individually and in combination. Prediction models were constructed by using partial least squares (PLS) regression with cross and external validation. FAEEs were estimated best with FTIR + UV-Vis spectroscopy (R-cv.(2) = 0.84, R-pred(2) = 0.90, and RPD = 3.0). PLS model with R-cv.(2) = 0.79, R-pred(2) = 0.71, and RPD = 1.9 was obtained for the estimation of 1,2 DAG using FTIR spectral data. Major pigments, lutein, pheophytin a and their derivatives and total xanthophylls were quantified successfully by FTIR + UV-Vis with a range of R-cv.(2) of 0.71-0.85, R-pred(2) of 0.70-0.84, and RPD = 1.5-2.5 values but the prediction of the rest of the pigments were poor (R-cv(2) = 0.60-0.76, R-pred(2) = 0.42-0.62, and RPD = 1.2-1.5). Combination of two spectral data resulted in average prediction of wax content of oils (R-cal(2) = 0.95, R-pred(2) = 0.75, and RPD = 1.9). FTIR and UV-vis spectroscopic techniques in combination with PLS regression provided promising results for the prediction of several chemical parameters of olive oils; therefore, they could be alternatives to traditional analysis methods.Article Citation - WoS: 34Citation - Scopus: 42Importance of Some Minor Compounds in Olive Oil Authenticity and Quality(Elsevier Ltd., 2020) Uncu, Oğuz; Özen, BanuBackground: Consumption and production of olive oils have been increasing steadily worldwide mainly due to proven health benefits and sensorial characteristics of olive oil. M the same time, rising demand makes it harder to protect olive oil genuineness; therefore, inauthentic products have been always a serious problem in olive oil industry. Scope and approach: Some minor compounds such as pigments (chlorophylls and carotenoids) including their derivatives pyropheophytins (PPPs), diacylglycerols (DAGs) and fatty acid ethyl esters (FAEEs) are all prominent compounds with their discriminatory and descriptive properties. Among several different approaches, use of these components to differentiate genuine and adulterated olive oils could be a promising choice since it is harder to mimic these compounds in fake mixtures. Recent studies focus on these compounds as authentication and quality tools for olive oil and potential of these compounds are aimed to be reviewed. Key findings and conclusions: Results from literature indicated that these parameters could be used in both authenticity and quality determination of olive oils with some limitations. Pigments were found to be more promising in geographical and/or varietal classification. All of the discussed components have successful applications in determination of olive oil quality with respect to storage history and oil grades. However, in detection of certain types of adulteration techniques such as soft deodorization, reviewed parameters did not work effectively alone. Regulations could be updated with these findings and use of combined parameters including discussed compounds could be further investigated for unsolved authentication problems.