The objective of this study was to determine the effects of different gums and their combination on quality and staling of breads baked in different ovens. In the first part of the study, the effects of gums (xanthan, guar, k-carrageenan, hydroxypropyl methylcellulose, locust bean gum and their blends) on quality of breads baked in infrared-microwave combination and conventional ovens were investigated. In addition, macro and micro-structure, dielectric and thermal properties and acrylamide content of breads were studied. Xanthan-guar blend addition improved bread quality with increasing specific volume and porosity values and decreasing hardness values of samples. More homogeneous closed-cell structure for conventionally baked control breads and channel formed cell structure for breads baked in infraredmicrowave combination oven were observed. Dielectric properties of breads were found to be a function of gum type. No acrylamide was formed in microwave baked breads. Breads baked in infrared-microwave combination oven had similar acrylamide content with conventionally baked ones. The second part of the study focused on staling. The hardness, retrogradation enthalpy, set back viscosity, FTIR outputs and crystallinity values of microwave-baked samples were found to be the highest. Infraredmicrowave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones and reduced the conventional baking time of breads by about 39%. Addition of xanthan-guar blend decreased hardness, retrogradation enthalpy and crystallinity values of breads. According to hardness data, in the presence of xanthan-guar blend staling of breads baked in all types of ovens was delayed for 1 day.

The main objective of this study was to optimize the roasting conditions of hazelnuts in microwave-infrared and microwave-convective heating combination ovens by using response surface methodology. It was also aimed to construct regression models for the prediction of quality parameters of hazelnuts as a function of processing conditions. The independent variables were microwave power (10, 30, 50, 70 and 90%), upper-lower infrared power (10, 30, 50, 70 and 90%) and roasting time (2, 3, 4, 5 and 6 min) for microwave-infrared combination roasting. Microwave power (70, 140 and 210W), air temperature (90, 150 and 210&deg / C) and roasting time (5, 15 and 25 min) were the independent variables of microwave-convective heating combination oven. As control, hazelnuts roasted in conventional oven at 150&deg / C for 20 min were used. The quality parameters were L* value, a* value, fracture force and moisture content of the hazelnuts for both microwave assisted ovens. The optimum roasting conditions of microwave-infrared combination oven were determined as 2.5 min of roasting time at 613.8W microwave power, 1800W upper infrared power, and 300W lower infrared power. Hazelnuts roasted at the optimum condition had comparable quality with the conventionally roasted ones. When micro- wave infrared combination oven was used, conventional roasting time of hazelnuts was reduced by 87.5%. Optimum roasting conditions of microwave-convective heating combination oven were 140 W microwave power, 150&deg / C air temperature and 20 min roasting time. High regression coefficients were calculated between the experimental data and predicted values showing that RSM is capable in predicting quality parameters of hazelnuts during microwave assisted roasting.

The main objective of this study was to investigate the effect of spouted bed and microwave assisted spouted bed drying on drying rates and quality parameters of bulgur. The drying experiments were performed at three air temperatures (50, 70, 90oC) and at two microwave powers (288 W, 624 W). Quality parameters were selected as bulk density, apparent density, apparent porosity, internal porosity, microstructure analysis, and color for dried cooked wheat / yield and water absorption capacity for bulgur. The drying rate increased with air temperature and microwave power. Microwave assisted spouted bed drying at microwave power of 288W and 624 W reduced drying time by at least 60% and 85%, respectively compared to spouted bed drying. The effective moisture diffusivities of bulgur in the spouted bed and microwave assisted spouted bed drying were found to be 2.356x10-10 and 8.398x10-10 m2/s on the average, respectively. The effect of air temperature on product quality except color was not significant in spouted bed drying. Interior kernel porosity, sphericity and L* value of dried cooked wheat increased with air temperature and microwave power. Yield and water absorption capacity of bulgur tended to decrease as microwave power increased. According to SEM analysis, more porous structure was observed in wheat samples dried in microwave assisted spouted bed compared to air dried ones. In microwave assisted spouted bed drying, lower water absorption capacity, bulk density and apparent density, higher sphericity and lighter color were observed as compared to spouted bed drying.

The objective of this study was to compare microwave assisted extraction (MAE) and conventional extraction methods for the extraction of total phenolic compounds (TPC) from tomato and sour cherry pomace. Antiradical efficiency (AE) of the extracts and also the concentration of phenolic compounds were determined. In MAE, the effects of microwave power (400 and 700 W), solvent type (water, ethanol and ethanol-water mixture at 1:1 v/v), extraction time (8-20 min) and solvent to solid ratio (10, 20 and 30 ml/g) were studied to observe the change of TPC and AE of the extracts. Conventional extraction was conducted for 6 h using different solvent to solid ratios (10, 20 and 30 ml/g) and solvent types (water, ethanol and ethanol-water mixture at 1:1 v/v). When the power increased from 400 W to 700 W, TPC and AE values increased. In MAE, maximum TPC and AE values were obtained at a solvent to solid ratio of 20 ml/g. The highest TPC and AE values were obtained when the ethanol-water mixture was used for both MAE and conventional extraction. The highest TPC and AE of tomato pomace extracts was determined as 3.76 mg gallic acid equivalent, GAE/g sample and 4.84 mg 1,1-diphenyl-2-picrylhydrazyl, DPPH/g sample, respectively in MAE using power level of 700 W, ethanol-water mixture, solvent to solid ratio of 20 ml/g and extraction time of 14 min. The major phenolic acids detected in tomato pomace extract were gentisic acid and vannilic acid. For sour cherry pomace extracts, the highest TPC and AE was found as 14.14 mg GAE/g sample and 28.32 mg DPPH/g sample, respectively in MAE using power level of 700 W, solvent to solid ratio of 20 ml/g, ethanol-water mixture and extraction time of 12 min. Epicatechin was found to be the major phenolic acid in sour cherry pomace. There was no significant difference in different extraction methods in terms of TPC. On the other hand, AE value and concentration of major phenolic acids of tomato and sour cherry pomace increased when MAE was used.

The aim of this current work is to analyze the behavior of OSL (Optically Stimulated Luminescence) signals of irradiated spices with respect to time, temperature, origin and the type. Throughout the experiments, 3 different type spices from four different origins were stored at 4&deg / C and 25&deg / C for six months after irradiation. During experiments, unirradiated red pepper, thyme and cumin samples were analyzed by using OSL technique in order to determine the background OSL signal values of samples. Samples were irradiated 10 kGy by Cobalt 60 gamma source in TAEK (Turkey Atomic Energy Association). After irradiation process, OSL signal values of different samples were analyzed according to the given parameters. In order to determine the effect of temperature on OSL signal loss, temperature (4&deg / C- 25&deg / C) was set as storage temperature. The analyses were made monthly. According to the statistical analyses (ANOVA- General Linear Model), origin and type of samples were detected as significant parameters of design experiment. Time and temperature effect on OSL signal loss changed with respect to origin and type of samples. After six months storage period, OSL signal was lost for most of the origin and sample type. At the end of sixth month, an ESR analysis was performed to detect the accuracy of the OSL technique. With respect to the results of these experiments, it was seen that, due to optical fading, most of the samples was observed as unirradiated by OSL technique, however ESR analyze the samples as irradiated at the end of sixth month. Irradiation had a detrimental effect on the microbiological load of the samples and resulted 6 log reduction on the microbial population. After irradiation, no colony formation was observed in total bacteria and yeast- mold count. During six month period, no injury recovery was observed.

Grape pomace is a valuable waste product and various end-products have been obtained after treatments. Recently, these have been commercialized due to their health-promoting effects. Drying is a crucial part of these treatments. This study aimed to analyze the drying kinetics of grape pomace parts, which are seeds and skins. Two grape types were used in this study, namely Emir and Bogazkere varieties of Vitis Vinifera species. Seeds and skins of each variety were dried in a tray dryer at an air velocity of 1 m/s with four different air temperatures / 40, 50, 55 and 60&deg / C. The drying curves showed that the drying r ate increased with the air temperature. Six different drying models were selected from the literature and the best fitted model was determined by application of appropriate statistical methods. It was found that for Bogazkere seeds / Modified Two Term Model, for Bogazkere and Emir skins / Modified Page Model and for Emir skins / Logarithmic Model gave the best fit. The effective moisture diffusivities of each type were found for each temperature and were determined by two different approaches, experimental and estimation. The values and variation of Deff / L2 with temperature were calculated and were found to be increasing with temperature and that the Deff / L2 values were larger for grape skins than grape seeds. Arrhenius type equation was used in order to explain the temperature dependency of Deff / L2.

The effects of edible chitosan coating on quality factors of pomegranate (Punica granatum) arils were investigated in the present research. For that purpose, pomegranate arils were treated with 0% (control) and 1% chitosan (extracted from shrimp shells and deacetylated (.75%)) solutions and stored at 4

Jerusalem artichoke has been cultivated in various regions without any special breeding technique. On the other hand, in food industry it does not have a wide usage area. Hence, in food industry its use as a potato substitute in some products is believed to be increasing its economical value. As a first attempt chips and crisps produced from Jerusalem artichoke was analyzed for texture, sensory, color, oil and moisture content. Jerusalem artichoke chips were fried in a bench top deep fat fryer for 120s, 180s and 240s at 160&deg / C, 170&deg / C, 180&deg / C and 190&deg / C. When microwave oven was used samples were cooked for 60s, 75s, 90s, 105s, 120s, 135s and 150s at 600 Watt and 900 Watt. Rheological properties of Jerusalem artichoke puree were investigated and Xanthan gum (2%wb) and sodium metabisulphite (1%wb) added for the desired puree consistence and color. After the production of puree Jerusalem artichoke flour was produced and water added to this flour then dough obtained again. Rheological behaviour of the original puree and these prepared from the containing 1- 4.5 and 1 - 5.0 part water were quite similar. In the light of the experimental results obtained as frying temperature and treatment time increased, moisture content and lightness of the Jerusalem artichoke products have decreased but a*and b* values, hardness, fracture and oil content increased. The best results for frying of Jerusalem artichoke seem to be 180&deg / C with about 240s treatment time for the chips and the same temperature for 180s for the crisps. As microwave power level and duration of treatment increased, moisture content and lightness of the microwave cooked Jerusalem artichoke products have decreased, but a* and b* values increased. Hardness and fracturability values of the products first increased with time and then decreased. When microwave oven was used, the best results were obtained for about 105s treatment time at 600W for the Jerusalem artichoke chips and about 60s processing time at 900W for the crisp. Since treatment time for cooking was significantly reduced when microwave cooking was used, this method could be recommended as an alternative to conventional deep fat frying, as oil is not used as well.

The primary objective of this study was to obtain nano-emulsion containing polyphenolic compounds extracted from sour cherry pomace and to investigate the effect of degritting of polyphenolic concentrates on the encapsulation efficiency and particle size distribution of capsules and emulsions. It was also aimed to study storage and baking stability of the capsules. Extracted polyphenolic concentrate was degritted at 10,000 rpm for 2 min. Purification reduced Sauter mean diameter (D[32]) of concentrated extract from 5.76 &mu / m to 0.41 &mu / m. Unpurified and purified concentrates were freeze dried for 48 h to obtain extracted phenolic powder (EPP) and purified extracted phenolic powder (PEPP), respectively. Powders were entrapped in two types of coating materials which contain 10% maltodextrin (MD) or 8% MD-2% gum arabic (GA). Samples were prepared by ultrasonication (160 W, 50% pulse) for 20 min. Emulsions containing EPP had D[32] of 1.65 and 1.61 &mu / m when they were entrapped in 10% MD and 8% MD-2% GA coating material solutions, respectively. It was possible to obtain nano-emulsions when purification step was performed. Emulsions prepared with PEPP and coated with 10% MD and 8% MD-2% GA had D[32] of 0.396 and 0.334 &mu / m, respectively. Encapsulation efficiency of the capsules increased significantly from 86.07-88.45% to 98.01-98.29% by means of degritting (p&le / 0.001). Loss of total phenolic content during storage at 43% and 85% relative humidities was smaller for encapsulated powders when compared to powders not entrapped in coating material. In addition, encapsulation significantly increased retention of phenolic compounds from 15.1-22.2% to 30.4-30.7% during baking (p&le / 0.05).

The main objective of this study was to extract phenolic compounds from caper and oleaster by using microwave. The effects of microwave power (400 and 700 W), extraction time (5-20 min), solid to solvent ratio (1:10, 1:20 and 1:30) and solvent type (water, ethanol and different ratios of ethanol-water mixture) on total phenolic content, antioxidant activity and concentration of the phenolic compounds in the extracts were investigated. In conventional extraction, extraction time and solvent type were used as independent variables. Microwave extraction was compared with conventional extraction. In caper and oleaster extracts that were obtained by using microwave, total phenolic compounds ranged between 5.0-52.4 and 2.6-43.0 mg GAE/g dry material while the antioxidant activity were between 0.5-2.0 and 0.2-3.7 mg DPPH/g dry material, respectively. Higher total phenolic content was observed with increasing solvent amount. The highest total phenolic content was obtained when 50% ethanol-water mixture was used as solvent. Microwave power did not affect total phenolic content significantly. The highest total phenolic contents were obtained when 400 W microwave power, 50% ethanol-water mixture and solid to solvent ratio of 1:30 were used in the extraction from both caper and oleaster. The best extraction time for caper was 5 min while it was 15 min for oleaster. The main constituents were rutin and kaempferol for both caper and oleaster extracts. For caper and oleaster there was no difference between extraction methods in terms of concentration of phenolic compounds. However, extraction time decreased significantly by using microwave, as compared to conventional extraction.