ÖMER FARUK GAMLI, ÖZGE SÜFER, TÜLİN EKER

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.

Mikrodalga ile Kurutulmuş Zeytin Yapraklarının Kurutma Kinetikleri ve Demleme Özellikleri

Zeytin yaprakları, sağlık üzerindeki olumlu etkilerinden dolayı araştırmacıların ve tüketicilerin ilgisini çekmektedir. Bu çalışmada, zeytin yaprakları mikrodalga uygulaması ile 52, 90, 167, 290, 347 W gerçek etkin güç seviyelerinde kurutulmuş ve kurutma kinetikleri, kurutma davranışını en iyi betimleyen matematik modelin belirlenebilmesi maksadıyla incelenmiştir. Page model, diğerlerinin içerisinde en uygun model olarak tespit edilmiştir. Difüzyon katsayıları 2,65×10-10 – 6,87×10-10 m2/s aralığında hesaplanmış olup, güç düzeyindeki artışın, difüzyon katsayısında da artışa sebep olduğu görülmüştür. Kurutulmuş zeytin yaprakları çay elde etmek amacıyla kullanılmış ve farklı demleme sıcaklıklarının, çayın toplam polifenol (mg GAE/kg) ve radikal süpürme aktivitesi (%) üzerindeki etkileri araştırılmıştır. Demleme sıcaklığındaki artışın, özellikle 100°C’de polifenollerin özütlenmesini arttırdığı görülmüştür. 167 W’da kurutulmuş olan zeytin yapraklarının (2282,9 mg GAE/kg) diğer güçlerde kurutulanlara oranla daha fazla fenolik içeriğine sahip olduğu açığa çıkmıştır.

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