Mathematical modeling of microwave dried celery leaves and determination of the effective moisture diffusivities and activation energy

Alibas I.

FOOD SCIENCE AND TECHNOLOGY, cilt.34, sa.2, ss.394-401, 2014 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 34 Sayı: 2
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1590/s0101-20612014005000030
  • Dergi Adı: FOOD SCIENCE AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.394-401
  • Anahtar Kelimeler: activation energy, effective moisture diffusivity, microwave drying, celery, thin-layer drying models, LAYER DRYING CHARACTERISTICS, KINETICS, AIR, FRUITS, SYSTEM
  • Bursa Uludağ Üniversitesi Adresli: Evet

Özet

Celery (Apium graveolens L. var. secalinum Alef) leaves with 50 +/- 0.07 g weight and 91.75 +/- 0.15% humidity (similar to 11.21 db) were dried using 8 different microwave power densities ranging between 1.8-20 W g(-1), until the humidity fell down to 8.95 +/- 0.23% (similar to 0.1 db). Microwave drying processes were completed between 5.5 and 77 min depending on the microwave power densities. In this study, measured values were compared with predicted values obtained from twenty thin layer drying theoretical, semi-empirical and empirical equations with a new thin layer drying equation. Within applied microwave power density; models whose coefficient and correlation (R-2) values are highest were chosen as the best models. Weibull distribution model gave the most suitable predictions at all power density. At increasing microwave power densities, the effective moisture diffusivity values ranged from 1.595 10(-10) to 6.377 10(-12) m(2) s(-1). The activation energy was calculated using an exponential expression based on Arrhenius equation. The linear relationship between the drying rate constant and effective moisture diffusivity gave the best fit.