Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 15Citation - Scopus: 16Formulation of Gluten-Free Cookies Utilizing Chickpea, Carob, and Hazelnut Flours Through Mixture Design(MDPI, 2023) Doğruer, Ilgın; Başer, Filiz; Güleç, Şükrü; Tokatlı, Figen; Özen, BanuLegume flours, which offer high nutritional quality, present viable options for gluten-free bakery products. However, they may have an objectionable flavor and taste for some consumers. In this study, it was aimed to improve the gluten-free cookie formulation by incorporating carob and hazelnut flours to pre-cooked chickpea flour and to investigate the techno-functional properties of the formulated cookies. The flours used in the formulations were assessed for their chemical and physical properties. This study employed a mixture design (simplex-centroid) to obtain the proportions of the flours to be used in the cookie formulations. The rheological characteristics of the doughs and the technological attributes of the baked cookies were determined. The addition of the hazelnut and carob flours had the overall effect of reducing the rheological characteristics of the cookie doughs. Furthermore, the textural attribute of the hardness of the baked cookies decreased as the ratio of hazelnut flour in the formulations was raised. The analysed results and sensory evaluation pointed to a formulation consisting of 30% pre-cooked chickpea/30% carob/30% hazelnut flours, which exhibited improved taste and overall acceptability scores. A total of 16.82 g/100 g of rapidly digestible starch, 5.36 g/100 g of slowly digestible starch, and 8.30 g/100 g of resistant starch exist in this particular cookie. As a result, combinations of chickpea, hazelnut, and carob flours hold promise as good alternatives for gluten-free cookie ingredients and warrant further exploration in the development of similar products.Article Citation - WoS: 16Citation - Scopus: 17Techno-Functional and in Vitro Digestibility Properties of Gluten-Free Cookies Made From Raw, Pre-Cooked, and Germinated Chickpea Flours(MDPI, 2023) Doğruer, Ilgın; Çoban, Başak; Başer, Filiz; Güleç, Şükrü; Özen, BanuChickpea flour, which is produced in various forms, has high protein and fiber content; therefore, it can be a good ingredient for gluten-free cookies. The objective of this study was to investigate and compare the properties of cookies formulated using raw (RCF), cooked (CCF), and germinated (GCF) chickpea flours. The techno-functional properties of these flours were determined, and scanning electron microscope images and mid-infrared spectra were obtained. The rheological properties of cookie doughs were measured along with their mid-infrared spectra. Baked cookies were analyzed for their technological properties as well as their in vitro digestion properties. Sensory analysis was also performed for all the cookies. The most significant difference among the flours was observed in their water retention capacity, and CCF had 119.7% higher water retention capacity compared to RCF. The dough made with CCF had quite different rheological properties from the others. The cookies baked with GCF had the highest baking loss and spread ratio. The CCF-containing cookies had the hardest structure. The cookies made from RCF had a higher resistant starch content followed by the cookies with GCF. All the cookies had similar scores in all aspects tested in the sensory analysis. The use of three different forms of chickpea flour in cookie formulations resulted in products with very different properties; however, their overall acceptability levels were close.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: 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 LtdArticle 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: 13Citation - Scopus: 17Characterization of Antimicrobial Activities of Olive Phenolics on Yeasts Using Conventional Methods and Mid-Infrared Spectroscopy(Springer, 2019) Canal, Canan; Özen, Banu; Baysal, Ayşe HandanOlive fruit is very rich in terms of phenolic compounds. Antimicrobial activities of various phenolic compounds against bacteria and fungi are well established; however, their effects on yeasts have not been examined. Aim of this study was to investigate the antimicrobial effects induced by olive phenolic compounds, including tyrosol, hydroxytyrosol, oleuropein, luteolin and apigenin against two yeast species, Aureobasidium pullulans and Saccharomyces cerevisiae. For this purpose, yeasts were treated with various concentrations (12.5-1000ppm) of phenolic compounds and reduction in yeast population was followed with optical density measurements with microplate reader, yeast colony forming units and mid-infrared spectroscopy. All phenolic compounds were effective on both yeasts, especially 200ppm and higher concentrations have significant antimicrobial activity; however, effects of lower levels depend on the type of phenolic compound. According to mid-infrared spectral data, significant changes were observed in 1200-900cm(-1) range corresponding to carbohydrates of yeast structure as a result of exposure to all phenolic compounds except tyrosol. Spectra of tyrosol and luteolin treated yeasts also showed changes in 1750-1500cm(-1) related to amide section and 3600-3000cm(-1) fatty acid region. Since phenolic compounds from olives were effective against yeasts, they could be used in food applications where yeast growth showed problem. In addition, FTIR spectroscopy could be successfully used to monitor and characterize antimicrobial activity of phenolic compounds on yeasts as complementary to conventional microbiological methods.Article Citation - WoS: 42Citation - Scopus: 47Effects of Malaxation Temperature and Harvest Time on the Chemical Characteristics of Olive Oils(Elsevier Ltd., 2016) Jolayemi, Olusola Samuel; Tokatlı, Figen; Özen, BanuThe aim of the study was to determine the effects of harvest time and malaxation temperature on chemical composition of olive oils produced from economically important olive varieties with a full factorial experimental design. The oils of Ayvalik and Memecik olives were extracted in an industrial two-phase continuous system. The quality parameters, phenolic and fatty acid profiles were determined. Harvest time, olive variety and their interaction were the most significant factors. Malaxation temperature was significant for hydroxytyrosol, tyrosol, p-coumaric acid, pinoresinol and peroxide value. Early and mid-harvest oils had high hydroxytyrosol and tyrosol (maximum 20.7 mg/kg) and pigment concentrations (maximum chlorophyll and carotenoids as 4.6 mg/kg and 2.86 mg/kg, respectively). Late harvest oils were characterized with high peroxide values (9.2-25 meq O2/kg), stearic (2.4-3.1%) and linoleic acids (9.3-10.4%). Multivariate regression analysis showed that oxidative stability was affected positively by hydroxytyrosol, tyrosol and oleic acid and negatively by polyunsaturated fatty acids.Article Citation - WoS: 27Citation - Scopus: 30Combination of Visible and Mid-Infrared Spectra for the Prediction of Chemical Parameters of Wines(Elsevier Ltd., 2016) Şen, İlknur; Öztürk, Burcu; Tokatlı, Figen; Özen, BanuRapid and environmentally friendly methods for the prediction of chemical compositions have been an interest in the wine industry. The objective of the study was to show the potentials of combined use of visible and mid-infrared (MIR) spectroscopies to improve the prediction of various chemical compounds of wine as opposed to using mid-infrared range only. Wine samples of twelve grape varieties from two harvest years were analyzed. The chemical composition of wine samples was related to MIR and visible spectra using orthogonal partial least square (OPLS) regression technique. The prediction abilities were tested with crossvalidation and independent validation sets. The coefficient of determination of validation (R2 val) for anthocyanin compounds of red wines were between 0.76 and 0.90, and that for total phenol content was 0.90. Range of R2 val for glycerol, glycerol/ethanol ratio, malic acid, o-coumaric acid and °Brix were between 0.77 and 0.96. The spectral ranges that played significant roles in the predictions were also determined. The validations with independent data sets showed that the combination of visible and MIR ranges with multivariate methods improved the prediction of anthocyanin compounds and total phenols; produced comparable results for the rest of the parameters as MIR. This is the first study in the literature that shows the practical use of visible spectra along MIR. The combined use of these spectral ranges with multivariate models can be applied for the rapid, on-line determination of quality parameters and chemical profiles of wines.Article Citation - WoS: 14Citation - Scopus: 17Phenolics 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, İlknurBACKGROUND: 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: 15Citation - Scopus: 16Comparison 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, İlknurSome 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.