A comparative study on exergetic performance assessment for drying of broccoli florets in three different drying systems

This article deals with the exergy analysis and evaluation of broccoli in three different drying systems. The effects of drying air temperature on the exergy destruction, exergy efficiency, and exergetic improvement potential of the drying process were investigated. The exergy destruction rate for the drying chamber increased with the rise in the drying air temperature at 1.5 m/s, both in the tray and the heat pump dryer. The highest exergy efficiency value was obtained as 90.86% in the fluid bed dryer in comparison to the other two drying systems and the improvement potential rate was the highest in the heat pump dryer during drying of broccoli at the drying air temperature of 45°C and the drying air velocity of 1.0 m/s. © 2010 Taylor & Francis Group, LLC

Retroperitoneal Malignant Fibrous Histiocytoma Can Mimic a Hydatid Cyst

Malignant fibrous histiocytoma is the second most common soft-tissue sarcoma in adults. After the extremities, the retroperitoneal space is the second most common site of this tumor. A 50-year-old man presented with a right retroperitoneal, thick-walled, cystic multilocular mass measuring 10 × 10 cm that was thought to be a type CE 5 hydatid cyst preoperatively. However, the postoperative histopathology did not agree with the radiological findings and instead showed a malignant fibrous histiocytoma. The computed tomography and ultrasound/Doppler ultrasound findings of this retroperitoneal mass mimicked a type CE 5 hydatid cyst. We present this case because the surgical management of these two lesions differs and misdiagnosis can be problematic

Zeytin yaprağının sıcak hava ile kurutulmasının modellenmesi, optimizasyonu ve ekserji analizi

Zeytin yaprağı içerdiği değerli fenolik maddeler ve yüksek antioksidan kapasitesiyle önemi her geçen gün artan bir üründür. Günümüzde tıpta, ilaç ve kozmetik sanayinde kullanılmakla beraber gıda sanayinde henüz yaygınlaşmamıştır. Gıda sanayi açısından da kullanılma potansiyeline sahip olan zeytin yaprağı, zeytincilik sektörü açısından dünyadaki konumu düşünüldüğünde ülkemiz için özel öneme sahiptir. Zeytin yaprağının işlenmesinde uygulanan en temel işlem kurutmadır. Bu çalışmada zeytin yaprakları sıcak hava ile kurutma prensibiyle çalışan tepsili kurutucu ve ısı pompalı kurutma sisteminde kurutulmuştur. Tepsili kurutucu sistemin belirsizlik analizi yapılmıştır. Zeytin yaprağının kuruma davranışları belirlenmiştir. Sıcaklık, hava hızı ve süre işlem değişkenleri olarak alınmış toplam fenolik madde kaybı, toplam antioksidan madde kaybı, son ürün nem içeriği ve kurutma işleminin ekserjetik verimliliği yanıt olarak değerlendirilmiştir. Zeytin yaprağının kurutulmasının optimizasyonu yanıt yüzey metodu ile her iki ekipman için de gerçekleştirilmiştir. Bu amaçla gerekli deneysel veriler “merkezi karma dönel tasarım (CCRD)” deneme planı seçilerek belirlenmiştir. Zeytin yaprağının kurutulması işleminin ekserjetik analizi yapılmış, ısı pompalı sistemde ekserji analizi tek tek sistem bileşenlerinden hareketle gerçekleştirilmiştir. Sonuçta, zeytin yaprağının kuruma davranışlarını en iyi açıklayan modelin Modeifiye Henderson ve Pabis olduğu tespit edilmiştir. Son ürün nem içeriği %6’nın üzerinde olmamak şartıyla, hammaddeye göre toplam fenolik madde kaybı ve antioksidan kapasite kaybı en düşük ve ekserjetik verimliliği en yüksek işlem koşulları optimizasyon sonucu belirlenmiştir. Buna göre tepsili kurutucuda 51,15 °C, 1,01 m/s, 298,92 dak işlem koşullarının, ısı pompalı kurutucuda ise 53,43 °C, 0,64 m/s, 288,32 dak işlem koşullarının optimum olduğu belirlenmiştir. Isı pompalı sistemin ekserjetik verimliğinin tepsili kurutucuya göre daha yüksek olduğu ve ısı pompalı kurutucunun verimliliğinin kompresör ve kondenserde yapılabilecek geliştirmelerle çok daha yükselebileceği görülmüştür

THIN-LAYER DRYING BEHAVIORS OF OLIVE LEAVES (OLEA EUROPAEA L.)

WOS: 000275757400006Recently, interest in olive leaves has increased because of their high phenolic contents. Although the critical process in olive leaf treatment is drying, the drying behavior of olive leaves has not been known yet in the literature. In this study, olive leaves were dried in a tray drier at the temperature range of 50-70C and velocity range of 0.5-1.5 m/s. Eleven different semitheoretical thin-layer drying curve models were used to characterize the drying behavior of olive leaves. Effects of drying air temperature and velocity on model coefficients were determined by multiple regression analysis. The correlation coefficient (r), the reduced chi square (chi 2) and the root mean square error (RMSE) were taken as the statistical criteria parameters for model comparisons. It was found that the modified Henderson and Pabis model represented drying characteristics best with r = 0.9955. Effective diffusivity was computed by taking account of temperature and air velocity. The temperature- and velocity-temperature-dependent activation energies were 60.97 +/- 3.21 and 75.98 kJ/mol, respectively. It was concluded that olive leaves could be dried successfully by thin-layer drying procedure, and the drying rate was influenced mainly by drying air temperature. PRACTICAL APPLICATIONS Olive trees are important plants covering similar to 8 million hectares in the whole world. Recent studies have shown that olive leaves have higher amounts of phenolic contents such as oleuropein and hydroxytyrosol. Oleuropein is especially a very valuable component in food, medicines and in the drug industry. Although the importance of olive leaves has been discussed in several scientific studies, there have been few studies for using olive leaves industrially. Because the main process in olive leaf treatment is drying, modeling and determining the drying behavior is an important step for designing and optimizing the olive leaf treatment. Unfortunately, there has been no study ever carried out explaining the drying behavior of olive leaves in open literature to the best of the authors' knowledge.Ege University Scientific ResearchEge University [2007/MUH/30]This study is a part of the MSc thesis named as "The investigation of modeling, optimization, and exergetic analysis of drying of olive leaves," and is supported by Ege University Scientific Research project no. of 2007/MUH/30

Energetic, Exergetic, and Exergoeconomic Analyses of Spray-Drying Process during White Cheese Powder Production

WOS: 000301846300013In this study, white cheese powder was produced using a pilot-scale spray dryer. Drying experiments were carried out with an inlet drying air temperature range of 160-230 degrees C, an outlet drying air temperature range of 60-100 degrees C, and an atomization pressure range of 294.2-588.4 kPa. The performance of the spray-drying process and the effects of process conditions on the process performance were evaluated using energetic, exergetic, and exergoeconomic analyses. The performance assessment was performed by using energy and exergy efficiencies, improvement potential ((I) over dotP) rate, total cost, and exergoeconomic factor terms. A comprehensive parametric study was conducted to investigate the effect of varying dead-state temperatures on exergetic and exergoeconomic performance parameters for the drying process. Correlations between the performance parameters and dead-state temperatures were developed. Exergetic efficiency values and (I) over dotP rates were found to vary between 2.66 and 6.00% and 7.54 and 10.96 kW, respectively, and total costs and exergoeconomic factors were in the range 7.30-7.82 TL/h (Turkish lira per hour) and 76.09-81.93%, respectively.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109O093]The authors are grateful for the financial support provided for the project entitled "The Optimization of White Cheese Powder Production and the Determination of Changes in Quality Characteristics during Storage" under Project No. 109O093 from the Scientific and Technological Research Council of Turkey (TUBITAK); to Sutas, Dairy Company for providing cheese; to the Yildiz Group for providing the atomizer; and to Kipa Chemical Company for providing the emulsifying salt

Optimization of hot air drying of olive leaves using response surface methodology

WOS: 000263196300006Recently, the interest in olive leaves has increased due to its high phenolic content. Olive leaves have a high potential for industrial exploitation in the food industry and drying is the main process in olive leaf treatment. In this Study, response surface methodology was used to optimize operating conditions of the drying of olive leaves in a tray drier and desirability function used as the methodology for the optimization. Optimization factors were air temperature (40-60 degrees C), air velocity (0.5-1.5 m/s) and process time (240-480 min) while investigated responses were total phenolic content (PC) and antioxidant activity loss (AC), final moisture content (MC), and exergetic efficiency (eta). The optimum conditions for drying of olive leaves in a tray drier were determined to obtain the criteria; minimum PC and AC, and maximum eta for MC value below 6% and the optimum condition was found to be the temperature of 51.16 degrees C with the air velocity of 1.01 m/s for the process time of 298.68 min. At this optimum point, PC, AC, MC and eta were found as 10.25%, 41.88%, 6.0% and 65.50%, respectively. (C) 2008 Elsevier Ltd. All rights reserved.Ege University Scientific ResearchEge University [2007/MUH/30]This Study is a part of the MSc thesis named as "The investigation of modeling, optimization, and exergetic analysis of drying of olive leaves", and is supported by Ege University Scientific Research Project No. of 2007/MUH/30