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Pre-dried 2-phase olive pomace was dried until 8% moisture content of it by tray dryer. the effect of tray dryer's process conditions in terms of drying temperature (70-90 degrees C), air velocity (0.5-1.8 m/s), and sample thickness (0.5-1.5) on the quality of olive pomace and system energy efficiency were investigated. Moreover, tray dryer process parameters were optimized considering of minimum drying time, minimum quality loss of olive pomace, and maximum system energy efficiency. the optimum tray dryer conditions were 85.2 degrees C of drying temperature, 1.72 m/s of air velocity, and 0.5 cm of sample thickness as specified by using the Design Expert packaged software. the effects of drying temperature, air velocity, and sample thickness on the physical and chemical properties of dried 2-phase olive pomace (free fatty acid and specific absorption value [K-232, K-270]) and the system's energy efficiency (in terms of the moisture extraction rate and specific energy consumption) were examined., Council of Scientific Research ProjectsEge University [16-MUH-024], The authors acknowledge Ege University, Council of Scientific Research Projects (Project Number: 16-MUH-024) for financial support.

The aim of this study was to evaluate the effect of moisture on the glass transition temperature (T g ), flow properties, color, and morphology of spray-dried powdered egg. Powdered egg was stored under environments with different relative humidities at 25°C and the moisture sorption isotherm was determined. The Guggenhiem-Anderson-de Boer (GAB) model fitted the isotherm data well. A differential scanning calorimeter was used to determine the T g of samples with different water activities. The T g data were satisfactorily correlated by the Gordon-Taylor model. The results showed that the glass transition temperature of powdered egg decreased with increasing water activity. The changes in flowability based on the Carr index (CI) and cohesiveness based on the Hausner ratio (HR) with water activity were defined. At low water activity values, the powder had poor flowability and high cohesiveness. These flow properties were also supported with scanning electron microscope (SEM) images.

Moisture adsorption isotherms of spray-dried whole egg, microencapsulated with gelatin (G), lactose (L), pullulan (P), and their mixtures at equal ratios (gelatin+lactose [GL] and gelatin+pullulan [GP]), were determined using the standard static-gravimetric method at 25 degrees C. The data were fitted to the various sorption models and the constants were estimated by nonlinear regression analysis. Among the sorption models tested, the Guggenheim-Andersen-de Boer (GAB) and Ferro Fontan equations were recommended for characterizing the adsorption behavior of spray-dried whole egg, either microencapsulated or unencapsulated, in the water activity range of 0.11-0.84. It was indicated that all of the egg powders were stable up to a water activity of 0.43. The oxidative stability of microencapsulated powders was investigated under storage conditions of 20 degrees C and 50% relative humidity (RH). The microencapsulation process resulted in a decrease in the cholesterol oxidation level of egg powder during storage, where it followed a zero-order reaction kinetics and the trej value representing the time required to reach total cholesterol oxidation products (TCOP) 384.2 mu g/g egg fat as the upper limit of acceptability for fat oxidation was calculated as 1,124 days at 20 degrees C for egg powder microencapsulated with lactose. The relations among glass transition temperatures, oxidation rate constants, and monolayer moisture content values obtained by the GAB model are also highlighted.

Moisture adsorption isotherms of spray-dried yogurt powder were determined at 10, 25, and 40 degrees C using the standard, static-gravimetric method. Experimental data were fitted to five mathematical models (Guggenheim-Anderson-de Boer [GAB], Brunauer-Emmett-Teller [BET], Halsey, modified Oswin, and modified Henderson). A nonlinear regression analysis method was used to evaluate the constants of the sorption equations. The shelf-life of yogurt powder was predicted based on the relationship between permeability coefficient of the packaging material and moisture adsorbed by the powder determined by the GAB equation. Furthermore, the storage stability of spray-dried yogurt powder in terms of quality parameters including moisture content, water activity, color change, and thiobarbituric acid (TBA) value was studied in aluminum laminated polyethylene (ALPE) pouches under storage conditions of 25 degrees C and 50% relative humidity (RH).

Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150-180 degrees C) and outlet air temperatures (60-90 degrees C) and the feed temperature (4-30 degrees C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171 degrees C, air outlet temperature of 60.5 degrees C, and feed temperature of 15 degrees C as the optimum processing condition. The mathematical optimum condition was experimentally verified.

The drying mechanism of fermented sausages (sucuks) that were cylindrical rod shaped, 40 cm long and 4 cm diameter, during ripening under natural convection conditions at different temperatures (15 to 30°C) was examined. To simulate the experimental drying curves, three empirical models and a diffusional model assuming negligible external mass transfer resistance were evaluated. The drying rate curves of sucuk samples were also simulated taking into account the influence of the external mass transfer resistance. The equation was solved using the trial-and-error solution algorithm developed in this study and the mass transfer coefficient, k c , and effective moisture diffusivity, D eff , were simultaneously determined (1.44 × 10−8 to 1.93 × 10−8 m/s and 4.30 × 10−10 to 6.85 × 10−10 m2/s, respectively). The proposed model considering the effect of external resistance allowed the accurate simulation of the experimental drying data of sucuks at different temperatures.