Microwave heat treatment of spinach: Drying kinetics and effective moisture diffusivity

DADALI G., Demirhan E., Ozbek B.

DRYING TECHNOLOGY, cilt.25, sa.10, ss.1703-1712, 2007 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 25 Sayı: 10
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1080/07373930701590954
  • Dergi Adı: DRYING TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1703-1712
  • Anahtar Kelimeler: activation energy, drying kinetic, effective moisture diffusivity, microwave drying, porosity, spinach, HOT AIR, LAYER, QUALITY, CARROT, MODEL, APPLE, DEHYDRATION, PREDICTION, PARAMETERS, MACARONI
  • Yıldız Teknik Üniversitesi Adresli: Evet

Özet

The effect of microwave drying technique on moisture content, moisture ratio, drying rate, drying time, effective moisture diffusivity, and porosity of spinach (Spinacia oleracea L.) were investigated. By increasing the microwave output powers (180-900 W) and the sample amounts (25-100 g), the drying time decreased from 18 to 3.5 min and increased from 7.7 to 25 min, respectively. To determine the kinetic parameters, the drying data were fitted to various models based on the ratios of the differences between the initial and final moisture contents and equilibrium moisture content versus drying time. Among of the models proposed, Page's model gave a better fit for all drying conditions applied. The activation energy was calculated using an exponential expression based on Arrhenius equation. The relationship between the drying rate constant and effective moisture diffusivity was also estimated and gave a linear relationship.