Drying Properties and Quality Parameters of Dill Dried with Intermittent and Continuous Microwave-convective Air Treatments

Abstract

In this study, influence of various microwave-convective air drying applications on drying kinetics, color and sensory quality of dill leaves (Anethum graveolens L.) were investigated. In general, increasing the drying air temperature decreased the drying time, and increased the drying rate. Increasing microwave pulse ratio increased the drying time. Page, Logarithmic, Midilli et al, Wang & Singh and Logistic models were fitted to drying data and the Page model was found to satisfactorily describe the microwave-convective air drying curves of dill leaves. Comparing to the fresh dill, lightness (L*), greenness (-a*) and yellowness (+b*) decreased for all drying applications. The deviation from fresh product color (∆E*) increased as pulse ratio increased and drying air temperature decreased. Considering the product quality, continuous microwave-convective air drying combinations gave better results than intermittent microwave-convective air drying in terms of color and sensory evaluation results. 

Keywords

• Microwave drying
• Dill
• Anethum graveolens
• Drying kinetics
• Color

Kesikli ve Sürekli Mikrodalga-Taşınım Hava Uygulamaları ile Kurutulan Dereotunun Kuruma Özelliklerinin ve Kalite Parametrelerinin Belirlenmesi

Abstract

Bu çalışmada, farklı mikrodalga-taşınım sıcak hava kurutma uygulamalarının dereotu yapraklarının (Anethum graveolens) kuruma kinetiği, renk kalitesi ve duyusal kalitesi üzerine etkileri araştırılmıştır. Kurutma işleminde uygulanan hava sıcaklığı arttıkça kuruma süresi kısalmış, kuruma hızı ise artmış ve kesiklilik oranı arttıkça kuruma süresi uzamıştır. Deneysel olarak elde edilen kuruma eğrileri Page, Logarithmic, Midilli et al, Wang & Singh ve Logistic eşitlikleri kullanılarak modellenmiştir. Dereotu yapraklarının mikrodalga-taşınım hava kuruma eğrilerinin matematiksel olarak ifade edilmesinde Page modeli tatmin edici bulunmuştur. Taze ürünle kıyaslandığında, mikrodalga-taşınım hava ile kurutulan ürünlerin tamamında renk parlaklığı (L*), renk yeşilliği (-a*) ve renk sarılığı (+b*) azalmıştır. Mikrodalga kesiklilik oranı arttıkça ve kullanılan hava sıcaklığı düştükçe taze ürün renginden sapma (∆E*) artmıştır. Renk ve duyusal değerlendirme sonuçlarına göre ürün kalitesi dikkate alındığında, sürekli mikrodalgataşınım hava kurutma uygulamaları kesikli mikrodalga-taşınım hava uygulamalarına göre daha iyi sonuç vermiştir. 

Keywords

• Mikrodalga kurutma
• Dereotu
• Anethum graveolens
• Kuruma kinetiği
• Renk

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