SCI和EI收录∣中国化工学会会刊

›› 2017, Vol. 25 ›› Issue (4): 426-432.DOI: 10.1016/j.cjche.2016.09.005

• Separation Science and Engineering • Previous Articles     Next Articles

Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment

Mehdi Torki-Harchegani, Davoud Ghanbarian, Vida Maghsoodi, Ahmad Moheb   

  1. 1 Young Researchers and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran;
    2 Department of Mechanical Engineering of Biosystems, Shahrekord University, Shahrekord, Iran;
    3 Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, P. O. Box 11155-9465, Iran;
    4 Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
  • Received:2016-04-05 Revised:2016-08-29 Online:2017-06-03 Published:2017-04-28
  • Supported by:
    Corresponding author at:Department of Mechanical Engineering of Biosystems,Shahrekord University,Shahrekord,Iran.

Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment

Mehdi Torki-Harchegani, Davoud Ghanbarian, Vida Maghsoodi, Ahmad Moheb   

  1. 1 Young Researchers and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran;
    2 Department of Mechanical Engineering of Biosystems, Shahrekord University, Shahrekord, Iran;
    3 Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, P. O. Box 11155-9465, Iran;
    4 Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
  • 通讯作者: Mehdi Torki-Harchegani
  • 基金资助:
    Corresponding author at:Department of Mechanical Engineering of Biosystems,Shahrekord University,Shahrekord,Iran.

Abstract: Saffron is the most precious and expensive agricultural product.A dehydration treatment is necessary to convert Crocus sativus L.stigmas into saffron spice.To the best of our knowledge,no information on mass transfer parameters of saffron stigmas is available in the literature.This study aimed at investigating the moisture transfer parameters and quality attributes of saffron stigmas under infrared treatment at different temperatures (60,70,…,110℃).It was observed that the dehydration process of the samples occurred in a short accelerating rate period at the start followed by a falling rate period.The effective moisture diffusivity and convective mass transfer coefficient were determined by using the Dincer and Dost model.The diffusivity values varied from 1.1103×10-10 m2·s-1 to 4.1397×10-10 m2·s-1 and mass transfer coefficient varied in the range of 2.6433×10-7-8.7203×10-7 m·s-1.The activation energy was obtained to be 27.86 kJ·mol-1.The quality assessment results showed that the total crocin content increased,when the temperature increased up to 90℃ but,in higher temperatures,the amount of crocin decreased slightly.The total safranal content of the samples decreased slightly when drying temperature increased from 60℃ to 70℃ and then continuously increased up to 110℃.Also,the amount of picrocrocin increased from 83.1 to 93.3 as the drying temperature increased from 60℃ to 100℃

Key words: Saffron, Infrared drying, Effective diffusivity, Mass transfer coefficient, Chemical composition

摘要: Saffron is the most precious and expensive agricultural product.A dehydration treatment is necessary to convert Crocus sativus L.stigmas into saffron spice.To the best of our knowledge,no information on mass transfer parameters of saffron stigmas is available in the literature.This study aimed at investigating the moisture transfer parameters and quality attributes of saffron stigmas under infrared treatment at different temperatures (60,70,…,110℃).It was observed that the dehydration process of the samples occurred in a short accelerating rate period at the start followed by a falling rate period.The effective moisture diffusivity and convective mass transfer coefficient were determined by using the Dincer and Dost model.The diffusivity values varied from 1.1103×10-10 m2·s-1 to 4.1397×10-10 m2·s-1 and mass transfer coefficient varied in the range of 2.6433×10-7-8.7203×10-7 m·s-1.The activation energy was obtained to be 27.86 kJ·mol-1.The quality assessment results showed that the total crocin content increased,when the temperature increased up to 90℃ but,in higher temperatures,the amount of crocin decreased slightly.The total safranal content of the samples decreased slightly when drying temperature increased from 60℃ to 70℃ and then continuously increased up to 110℃.Also,the amount of picrocrocin increased from 83.1 to 93.3 as the drying temperature increased from 60℃ to 100℃

关键词: Saffron, Infrared drying, Effective diffusivity, Mass transfer coefficient, Chemical composition