Browsing by Author "Tavman, S"

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    Ultrasound assisted extraction of polysaccharides from hazelnut skin
    Yilmaz, T; Tavman, S
    In this study ultrasound assisted extraction (UAE) of polysaccharides from hazelnut skin has been studied. Optimum sonication time has been evaluated depending on responses such as amount of carbohydrate and dried sample and thermogravimetric analysis. Chemical and structural properties of extracted material have been determined by Fourier transform spectroscopy attenuated-total reflectance (FTIR-ATR) spectroscopy. Pretreated hazelnut skin powders were extracted in distilled water. Mixture was sonicated by ultrasonic processor probe for 15, 30, 45, 60, 90, and 120min. The results of UAE showed that maximum ethanol insoluble extracts in 60min and the highest dry matter content could be obtained in 120min extraction. Although total carbohydrate content of ethanol insoluble dry extract decreased with time, total carbohydrate in ethanol soluble fraction increased. Polysaccharides extracted from hazelnut skin were assumed to be pectic polysaccharide according to the literature survey of FTIR analysis result. Application time of UAE has an important effect on extraction of polysaccharide from hazelnut skin. This affect could be summarized by enhancing extraction yield up to critical level. Decrease of the yield in ethanol insoluble part could be explained by polymer decomposition. Most suitable model was hyperbolic model by having the lowest root mean square error and the highest R-2 values.
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    Ultrasound assisted extraction of lycopene from tomato processing wastes
    Kumcuoglu, S; Yilmaz, T; Tavman, S
    Tomato paste processing wastes, an important by-product of the paste industry, is rich in potentially health-promoting compounds such as lycopene. In this study, extraction yield of lycopene from tomato paste processing wastes by application of ultrasound assisted extraction (UAE) was compared with conventional organic solvent extraction (COSE) method. BHT (butylated hydroxytoluene) 0.05 % (w/v) added hexane:acetone:ethanol (2:1:1) mixture was used as solvent. Three different solvent solid ratios; 50:1, 35:1 and 20:1, (v/w) were used in both COSE and UAE. COSE experiments were performed at 20 A degrees C, 40 A degrees C and 60 A degrees C for 10, 20, 30 and 40 min. 50, 65 and 90 W of ultrasonic power were applied in UAE for 1, 2, 5, 10, 15, 20 and 30 min. Lycopene contents of the samples were determined by spectrophotometric method. The effects of different factors, including the temperature, solvent solid ratio and ultrasonic power on lycopene yield were investigated. It was determined that the most efficient application for COSE was extracting samples by 50:1 solvent solid ratio at 60 A degrees C for 40 min run, for UAE, 35:1 (v/w) solvent solid ratio, 90 W ultrasonic power for 30 min run. It was showed that UAE of lycopene requires less time, lower temperature and lower solvent than COSE.
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    Large Amplitude Oscillatory Shear (LAOS) analysis of gluten-free cake batters: The effect of dietary fiber enrichment
    Ozyigit, E; Eren, I; Kumcuoglu, S; Tavman, S
    The aim of this study is to investigate the effect of dietary fiber enrichment on non-linear viscoelastic behavior of gluten-free cake batters by using Large Amplitude Oscillatory Shear (LAOS) analysis. Textural properties and specific volume of gluten-free cakes were also determined to investigate the possible correlations with LAOS parameters. Gluten-free cake batters were formulated by replacing buckwheat flour with two different dietary fiber sources, namely orange fiber (OF) and orange pomace powder (OPP) at five different levels (0%, 4%, %8, %12 and 16%). All gluten-free cake batter samples exhibited linear viscoelastic properties at small strain amplitudes but Theological properties enters the non-linear region by increasing strain amplitude. The Lissajous-Bowditch curves revealed that stored energy increased by increasing dietary fiber amount and gluten-free cake batters became more elastic in the non-linear region. The normalized elastic Chebyshev coeffients (e(3)/e(1)) indicated the strain hardening behavior of cake batters at small strain amplitudes shifted to strain softening in the non-linear region. The e(3)/e(1) and v(3)/v(1) ratios as a function of strain amplitude indicated that non-linearity is more pronounced in the elastic component compared to the viscous component. The S and T values calculated at 50% strain amplitude showed strong correlation with water retention capacity, hardness and specific volume of gluten-free cakes enriched with OF whereas softer correlations were obtained for the OPP-containing ones due to elastic instability of the batters. Principal component (PCA) and hierarchical cluster analysis (HCA) were performed to provide basic graphical comparison of the differences/similarities between non-linear Theological properties of gluten-free cake batters by considering LAOS parameters. The viscoelastic properties of the cake batters containing 16% OPP were found to be suitable for high gas retention capacity since the highest cake specific volume was obtained.
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    ULTRASOUND-ASSISTED EXTRACTION OF LYCOPENE AND β-CAROTENE FROM TOMATO-PROCESSING WASTES
    Yilmaz, T; Kumcuoglu, S; Tavman, S
    Ultrasound-assisted extraction (UAE) of lycopene and beta-carotene from tomato-processing wastes were investigated. Hexane: acetone: ethanol (2:1:1 v/v/v) including 0.05% (w/v) butylated hydroxyl toluene (BHT) was used as a solvent, with 1:35 w/v solid liquid ratio at 15 +/- 5 degrees C. Ultrasonic power (50, 65, 90W) was applied in UAE for 1-30 min. Conventional organic solvent extraction (COSE) was applied under the same solvent and temperature conditions for 10-40 min. UAE was more effective and required a shorter time than COSE. Maximum lycopene and beta-carotene yields were obtained using 90W ultrasonic power for 30 and 15 min, respectively.
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    CHARACTERIZATION OF PECTIC POLYSACCHARIDES EXTRACTED FROM HAZELNUT SKIN BY HOT WATER
    Hromádková, Z; Kostálová, Z; Yilmaz, T; Tavman, S
    Turkey is the largest producers of hazelnuts (Corylus avellana L.). Hazelnut skin: is a by-product from the hazelnut processing. The objective of the present workwas to isolate and characterize the non-cellulosic components of hazelnut skin and evaluate the classical and ultrasound extractions with respect to the yield, chemical composition and antioxidant activity of the obtained polysaccharide fractions. The structure of pectic polysaccharides from the hot water extraction has been characterized by FT-IR and NMR. spectroscopic techniques.
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    MODELING AND OPTIMIZATION OF ULTRASOUND ASSISTED EXTRACTION PARAMETERS USING RESPONSE SURFACE METHODOLOGY FOR WATER SOLUBLE POLYSACCHARIDE EXTRACTION FROM HAZELNUT SKIN
    Yilmaz, T; Tavman, S
    The aim of this study is to evaluate optimum process conditions for water soluble polysaccharides (WSP) of plant waste materials such as hazelnut skin by using response surface methodologies (RSM). Polysaccharides from hazelnut skin were extracted by means of probe type sonication system using distilled water as a solvent with several sonication time, temperature and amplitude. Response surface models were applied by both Box-Behnken Design (BBD) and Central-Composite Design (CCD) for determining optimal condition which satisfies both maximizing polysaccharide yield and minimizing applied energy for sonication. Results showed that both BBD and CCD models represented the system with high regression coefficient (R-2>0.95) and optimum conditions are 16.15min, 45C, 50.29% amplitude with 0.733 desirability, 15.97min, 45C, 47.27% amplitude with 0.712 desirability, respectively, for designs. Results of given conditions are 1.74% yield and 78.75 kJ consumption for BBD and 1.64% yield and 71.68 kJ for CCD. These results were validated by comparing experimental results at 15min, 45C, 50% amplitude. As a consequence, it was observed that selected statistical models represent the system with a high accuracy and associating scores of each optimal condition is close enough to experimental results.
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    Investigating the physical and quality characteristics and rheology of mayonnaise containing aquafaba as an egg substitute
    Ozcan, I; Ozyigit, E; Erkoc, S; Tavman, S; Kumcuoglu, S
    This paper aimed to examine the effect of using aquafaba in different ratios (25%, 50%, 75%, 100%) as an egg yolk substitute on the physical, structural, and rheological properties of mayonnaise. Large amplitude oscillatory shear analysis (LAOS) parameters (eta L ' , eta M ' , G'L , G'(M) , e(3) , e(1) , v(3) , v(1)) were evaluated to determine the rheological properties of mayonnaise samples. The droplet size of samples significantly increased and the stability of the emulsion decreased after 50% substitution ratio. The density of mayonnaise significantly increased with increased aquafaba substitution. According to Lissajous curves, egg yolk substitution with aquafaba leads to a decrease in stress values. Aquafaba affected the microstructure of samples and decreased the dissipated and stored energies. The LAOS parameters showed that the sample's behavior is strain stiffening and shear thinning in the nonlinear region. Textural parameters decreased with increased ratio of aquafaba. Significant differences were observed for L*, a*, b* and Delta E values.