Aydogdu A., Sumnu G., ŞAHİN S.

9th Baltic Conference on Food Science and Technology - Food for Consumer well-being, (Foodblatt 2014), Jelgava, Latvia, 8 - 09 May 2014, pp.202-205 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Jelgava
  • Country: Latvia
  • Page Numbers: pp.202-205
  • Middle East Technical University Affiliated: Yes


The main objective of this study is to investigate the effects of hot air drying and microwave-infrared combination drying on porous structure of eggplants. Hot air drying was performed in a tray dryer at 50 degrees C with an air velocity of 1.5 m s(-1). In microwave-infrared combination oven, different microwave powers (30%, 40% and 50%) were combined with different infrared powers (10%, 20%). During drying process, initial moisture content decreased from 14 kg water kg(-1) dry solid to approximately 0.13 kg water kg(-1) dry solid for eggplants. Pore size distributions of dried samples were analyzed with mercury porosimetry. Pores in different samples were characterized by cumulative intrusion curves which showed total volume of mercury intruded the poresin any size range and the threshold diameter. Cumulative intrusion curves had a sharp rise that indicated existence of macro pores on the surface. Unlike microwave infrared combination dried eggplants, hot air dried eggplants did not have pores above 200 gm size. Threshold diameter of eggplants dried in microwave-infrared combination oven were in the range of 48.86-73.42 gm which were greater than that of hot air dried eggplant, 42.47 mu m. Microwave-infrared combination drying provided more porous structure than hot air dried ones due to higher internal pressure. As infrared and microwave power increased, threshold diameter increased and eggplants with more porous structure were obtained.