Browsing by Author "Dogan, Ismail Sait"

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Determination of Simultaneous Heat and Mass Transfer Parameters of Tulumba Dessert During Deep-Fat Frying
(Wiley, 2017) Erim Kose, Yagmur; Dogan, Ismail Sait
The heat transfer ( h) of "Tulumba" dough was investigated depending on the water loss during frying at 150-180C. The plots of dimensionless temperature and concentration ratios against time were used to determine heat and mass transfer parameters. The mechanism of moisture transfer was studied. Effective mass transfer coefficient increased linearly, whereas effective moisture diffusivity increased exponentially with rising frying temperature. Moisture diffusivity were 1.77, 2.15, 2.69 and 3.59 x 10(-7) m(2)/s, and mass transfer coefficient were 3.009, 3.225, 3.445 and 3.695 x 10(-6) m/s for 150, 160, 170 and 180C, respectively. An Arrhenius type of relationship was found between temperature and the effective moisture diffusivity, so activation energy was calculated at 36.58 kJ/mol. On the other hand, higher oil temperature decreased the effective heat transfer coefficient during deep-fat frying. The maximum value was determined 182.41 W/m(2) C at 150C and the minimal value as 125.715 W/m(2) C at 180C.
Determination of Stickiness Values of Different Flour Combinations
(Walter de Gruyter Gmbh, 2012) Yildiz, Onder; Meral, Raciye; Dogan, Ismail Sait
Throughout the process of bakery production, dough stickiness is a widespread problem and is influenced by many factors. Reliable, quick and quantitative methods are needed for measurement of dough stickiness in baking industry. In this study, three different flours were used (F1, F2 and F3) and 12% wheat starch and 2% vital gluten were added to those flours to widen protein content of each flour sample. Stickiness values of prepared doughs were measured using SMS/Chen-Hoseney unit at different resting times (0, 20 and 40 mins) Stickiness (g), work of adhesion (g.s) and dough strength/cohesivenes (mm) values were measured for comparison. Obtained data from dough with F1 was significantly different from other flours (P<0.05). Protein content and resting time have changed dough stickiness value. A positive relationship was found between farinograph water absorption and dough stickiness of flour. Stickiness value increased with water uptake of flour.
Determination of the Bread-Making Quality of Flours Using an Automatic Bread Machine
(Tubitak Scientific & Technological Research Council Turkey, 2012) Dogan, Ismail Sait; Yildiz, Onder; Tasan, Burhan
In this study, the possibility of bread machine utilization as a quality control tool in the baking industry was investigated. Three different flour samples (F-1, F-2, and F-3) having different protein contents were obtained and then 12% wheat starch and 2% vital gluten were added to these flours to adjust protein ratios. The physicochemical and rheological properties of these flour combinations were analyzed. Specific volume, crumb grain attributes, crust and crumb color, and bread firmness in terms of compressibility (g) were measured. Specific volumes changed between 5.22 and 6.69 mL g(-1) and between 4.87 and 6.29 mL g(-1) for hearth and machine bread, respectively. Crumb firmness values of hearth bread made from F-1, F-2 and F-3 flours were 174.2, 259.4, and 180.3 g, whereas the mean firmness values of machine breads made from those flours were 91.2, 157.58, and 154.98 g, respectively. The F-2 flour had the poorest performance in both baking methods with regard to the evaluated features. At the same time, the bread machine performances were different, but displayed similar responses with changing flour quality. The effects of protein content were not observed in hearth bread. However, these changes affected specific volume and crumb features in bread machine baking. The study showed that bread machines with an optimized formula could be successfully employed for determining flour quality in bread making.
Effects of Varying Nixtamalization Conditions on the Calcium Absorption and Pasting Properties of Dent and Flint Corn Flours
(Wiley, 2017) Argun, Mustafa Samil; Dogan, Ismail Sait
In the present study it was examined how different nixtamalization conditions applied on dent and flint corn varieties affect the calcium absorption and pasting properties of corn flours. Results showed that with the increase of the Ca(OH)(2) amount used in nixtamalization process to 1.2%, while ash content, peak, setback and final viscosity values increased, gelatinization temperatures decreased in all corn varieties (P<0.01). Results also showed that the peak, setback and final viscosity values of dent corn varieties were higher than those of flint corns. However, the increase in the setback and final viscosity values of flint corns were higher than the increase observed in dent corns with the increase of the Ca(OH)(2) amount, indicating that flint corns are subjected to more retrogradation than dent corn in consequence of nixtamalization. The ash content of the all samples reached the maximum value at the end of a steeping time of 6 h. The increase in cooking time had a negative effect on peak, setback and final viscosity values and a positive effect on gelatinization temperatures of both types of corn varieties (P<0.01). Practical ApplicationsNixtamalization process causes some physical and chemical changes in flour attributes. The improvement in corn flour after nixtamalization needs to be investigated. The study showed that pasting properties and calcium content have been changed in nixtamalized corn flour (nixtamal) at varying rates depending on the type of corn varieties. Free niacin content of corn flour has increased and phytic acid content has reduced after nixtamalization process. Corn flour is included in many gluten-free formulations with some deficiency. Nixtamal has expected a potential use to improve the textural, sensorial and nutritional values of gluten-free applications.
Grape Seed as a Functional Food Ingredient in Bread-Making
(Taylor & Francis Ltd, 2013) Meral, Raciye; Dogan, Ismail Sait
The objective of this study was to determine the effects of grape seed (GS) on the rheological and bread-making properties, antioxidant activity and phenolic composition of bread. Wheat flour was replaced with GS at levels of 2.5%, 5.0% and 7.5%. GS increased the dough development time at a level of 5.0% but did not change it at levels of 2.5% and 7.5%. The dough stability value increased from 6.4 to 12.3 min with the increase of GS content from 0% to 7.5%. Mixing tolerance index decreased from 41.1 to 6.4 Brabender Units Equivalent. Extensibility of dough containing GS was higher than that of the control dough. The antioxidant activities of the bread increased significantly with the increased GS substitution. Gallic acid and catechin content increased in the bread containing GS. It was concluded that GS could be added to the formulae to improve functionality of the bread.
Optimization of Corn, Rice and Buckwheat Formulations for Gluten-Free Wafer Production
(Sage Publications Ltd, 2016) Dogan, Ismail Sait; Yildiz, Onder; Meral, Raciye
Gluten-free baked products for celiac sufferers are essential for healthy living. Cereals having gluten such as wheat and rye must be removed from the diet for the clinical and histological improvement. The variety of gluten-free foods should be offered for the sufferers. In the study, gluten-free wafer formulas were optimized using corn, rice and buckwheat flours, xanthan and guar gum blend as an alternative product for celiac sufferers. Wafer sheet attributes and textural properties were investigated. Considering all wafer sheet properties in gluten-free formulas, better results were obtained by using 163.5% water, 0.5% guar and 0.1% xanthan in corn formula; 173.3% water, 0.45% guar and 0.15% xanthan gum in rice formula; 176% water, 0.1% guar and 0.5% xanthan gum in buckwheat formula. Average desirability values in gluten-free formulas were between 0.86 and 0.91 indicating they had similar visual and textural profiles to control sheet made with wheat flour.
Optimization of Gluten-Free Cake Prepared From Chestnut Flour and Transglutaminase: Response Surface Methodology Approach
(Walter de Gruyter Gmbh, 2014) Yildiz, Onder; Dogan, Ismail Sait
In this study, the possible usage of chestnut flour in gluten-free cake formulation was investigated. Response surface methodology was used to evaluate the effects of water, xanthan and guar gum mixture and potato starch. Crust and crumb attributes, sensory and textural properties of the cake samples were investigated. Considering all cake properties, better results were obtained by increasing xanthan gum in the gum blend. Increasing the amount of potato starch in the chestnut flour-potato starch blend decreased the batter density, consistency, hardness and chewiness, but increased the specific volume, cohesiveness and scores of the interior and exterior attributes. Optimum concentration of gum mixture was found as 0.225% xanthan gum, 0.075% guar gum and ratio of chestnut flour to potato starch was 7:3. Then, four different levels of transglutaminase were added to control and optimized gluten-free cake formula. The highest desirability value was obtained in gluten-free formula containing 0.25% transglutaminase. According to the results of the sensory analyses, no significant difference was observed between control and gluten-free cake.
Spread and Microwave Oven Baking Test for Bread Making Quality
(Friends Science Publ, 2010) Dogan, Ismail Sait; Yildiz, Onder; Tasan, Burhan
Spread ratio test of dough and microwave-baked bread were used to study the effects of various flour sources and addition of 2% vital gluten and 12% wheat starch. Before fermentation and at 30, 60 and 90 min of proof time, the width (W) and height (H) of fermented dough was measured and the spread ratio (W/H) was calculated as an indicator of spreading. At the end of each proof time, the dough was baked in a microwave oven at the setting of 600 W for 150 s. At the end of baking, specific volume and ratio of pore area to the total area (proportion), form factor of microwave-baked bread were compared with the mentioned attributes of control bread. Spread ratios of dough and microwave-baked breads were also compared with each other. Addition of gluten and starch to flours and proof time significantly altered the spread ratios of dough, but only proof time significantly affected the spread ratio of microwave-baked bread (P< 0.001). Only flour source significantly altered the specific volumes and proportions of both microwave-baked and control breads. A combination of spread ratio and microwave baking test has potential for flour quality evaluation for bread-making. (c) Friends Science Publishers