Dehydration Kinetics and Infusion Attributes of Microwave Dried Olive Leaves

Olive leaves have been catching consumers’ and researchers’ great interest because of benefits on human health. In this study, the olive leaves were dried by microwave method at different powers (52, 90, 167, 290, 347 W real effective power levels) and drying kinetics of olive leaves were examined to find the best mathematical model. Page model was the most suitable model rather than the others. Diffusion coefficients were ranged between 2.65×10-10 to 6.87×10-10 m2/s and an increment in power level promoted moisture diffusivities. Dried olive leaves were used to get leave tea and different infusion temperatures were investigated to recover the total polyphenols (mg GAE/kg) and radical scavenging activities (%). Rising in infusion temperature, especially at 100°C enhanced the extraction levels of polyphenols from leave tea. Olive leaves dried at 167 W had higher phenolic contents (2282.9 mg GAE/kg) among all samples

Thin layer drying of zucchini in solar dryer located in Osmaniye region

In this study, the dehydration behavior of zucchini using solar assisted drying system was examined according to 22 thin layer drying models available in literature. The correlation coefficient (R2), chi-square (χ2) and root mean square error (RMSE) values were calculated to check the suitability of models by non-linear regression analysis. It was found that Cubic and Modified Midilli-1 models were the most suitable equations and their R2 values were calculated as 0.99963. χ2 and RMSE values of related mathematical expressions were 1.89343×10‒5, 1.91692×10‒5 and 0.01685×10‒3, 0.01721×10‒3 respectively. In addition, heat transfer, mass transfer and diffusion coefficients, which were important parameters in design of drying systems were also determined as 5.18124 W/m2°C, 1.57129×10‒7 m/s and 2.335718×10‒9 m2/s respectively

Gıda Mühendisliğinde Hesaplamalı Akışkanlar Dinamiği Uygulamaları

Computational fluid dynamics (CFD) analyses systems including heat transfer, fluid flow and chemical reactions by means of computer based simulations. CFD codes have been developed within the scope of numerical algorithms for solving nonlinear partial differential equations. Experimental data are generally used to validate CFD solutions through comparing magnitudes that are found experimentally and numerically. CFD analysis is completed with drawing images, lines, vectors and/or animations after creating geometry and mesh (grid), customizing physical model, determining boundary counditions and increasing the model accuracy by numerical options stages. Today, CFD applications have become indispensable in system design in food industry because of having advantages for both consumers and environment. Various processes (e.g. packaging, cold storage, freezing, baking, sterilization, drying and designing) and analyses of systems (e.g. heat exchanger and agitated vessel) have been already benefited from CFD technology.Hesaplamalı akışkanlar dinamiği (HAD), bilgisayar temelli simülasyonlar sayesinde ısı transferi, akışkan akışı ve kimyasal reaksiyonlar içeren sistemleri analiz eder. HAD kodları lineer olmayan kısmi diferansiyel denklemleri çözen nümerik algoritmalar çerçevesinde geliştirilmiştir. Sayısal ve deneysel olarak bulunan genel büyüklüklerin karşılaştırılması yoluyla HAD çözümlerini doğrulamak için çoğunlukla deneysel veriler kullanılır. Geometri ve meş (ağ) oluşturma, fiziksel modeli özelleştirme, sınır koşullarını belirleme, nümerik seçeneklerle modelin kesinliğini arttırma aşamalarından sonra çözüme geçilir ve şekil, doğru, vektör çizimi ve/veya animasyonlarla HAD analizi tamamlanmış olur. Günümüzde hem tüketiciler hem de çevre için bilinen yararlarından ötürü HAD uygulamaları, gıda endüstrisinde sistem tasarımında vazgeçilmez hale gelmiştir. Hâlihazırda, gıda maddelerinin ambalajlanması, soğukta depolanması, dondurulması, fırında pişirilmesi, sterilizasyon ve kurutma gibi pek çok proses ile ısı değiştirici, karıştırmalı kazan gibi sistemlerin tasarım ve analizinde hesaplamalı akışkanlar dinamiği teknolojisinden yararlanılmaktadır