Tarım Bilimleri Dergisi Tar. Bil. Der. Dergi web sayfası: www.agri.ankara.edu.tr/dergi Journal of Agricultural Sciences Journal homepage: www.agri.ankara.edu.tr/journal TARIM BİLİMLERİ DERGİSİ — JOURNAL OF AGRICULTURAL SCIENCES 24 (2018) 12-21 An Evaluation of the Performance of Forced Air Cooling on Cooling Parameters in Transient Heat Transfer at Different Layers of Pomegranate Mohammad-ALI BEHAEEN a , Asgar MAHMOUDI a , Seyed-FARAMARZ RANJBAR b a Tabriz University, Faculty of Agriculture, Department of Biosystem Engineering, Tabriz, IRAN b Tabriz University, Faculty of Mechanical Engineering, Department of Mechanical Engineering, Tabriz, IRAN ARTICLE INFO Research Article DOI: 10.15832/ankutbd.446362 Corresponding Author: Mohammad-ALI BEHAEEN, E-mail: Ali_behaeen@yahoo.com, Tel: +98 (41) 333 92 779 Received: 22 July 2015, Received in Revised Form: 30 November 2015, Accepted: 11 September 2017 ABSTRACT The quality of horticultural products can be promoted using high techniques. One of these methods is precooling applied before storage and leads to increased shelf and storage life of the fruit. For this reason, the effect of forced air cooling was conducted to investigate the cooling rate at the center (aril), spongy tissue (peel) and leathery skin (rind) of pomegranate (Punica granatum L.). Airfow velocity as an effective factor in cooling products at three levels of 0.5, 1, and 1.3 m s -1 and temperature of 7.2 °C was considered. Cooling parameters including lag factor and cooling coeffcient were calculated from experimental data. Then, half-cooling time and seven-eighths cooling time were obtained at different layers of pomegranate. Cooling heterogeneity was analyzed at different air velocity and at different layers of pomegranate. The results showed that increase in air velocity from 0.5 to 1.3 m s -1 , reduced the half-cooling time and seven-eighths cooling time. After 5000 seconds, the change of air velocity had a slight infuence on decreasing temperature of different layers of pomegranate. Cooling heterogeneity at the air velocity of 0.5 m s -1 was low and then increased at the air velocity of 1 m s -1 . Finally, at the air velocity of 1.3 m s -1 , it was declined. The overall results illustrate that the applied methodology in this research, which explains unsteady heat transfer in the cooling process, can be performed in pomegranate or similarly shaped fruits. Keywords: Precooling; Forced air cooling; Heat transfer; Pomegranate Nar’ın Farklı Katmanlarında Geçici Isı Transferindeki Soğutma Parametreleri Üzerinde Zorlanmış Hava ile Soğutma Performansının Değerlendirilmesi ESER BİLGİ Araştırma Makalesi Sorumlu Yazar: Mohammad-ALI BEHAEEN, E-posta: Ali_behaeen@yahoo.com, Tel: +98 (41) 333 92 779 Geliş Tarihi: 22 Temmuz 2015, Düzeltmelerin Gelişi: 30 Kasım 2015, Kabul: 11 Eylül 2017