Fluidized bed and microwave-assisted fluidized bed drying of seed grade soybean

Abstract

Soybean seeds were dried under fluidized bed drying (FBD) and microwave-assisted fluidized bed drying (MFBD) conditions in this study. During FBD, the effect of air temperature (30–50 °C) and air velocity (1–7 m/s) on drying parameters and some quality attributes (viz. vigor index, germination, fissure and cracking percentage, and seed coat hardness) of dried seeds were analyzed through response surface method. In MFBD, the effect of air temperature and microwave power levels was studied on the drying kinetics and quality parameters at a constant air velocity of 7 m/s. A face-centered central composite design with three levels of each variable was used to generate models for the responses. The study showed that the drying of seeds under two methods resulted in high germination percentage (>77%) and low cracking percentage (<20%). However, an increase in the germination time as depicted through the vigor index was found in the dried seeds. Also, the seed coat was highly damaged during drying and resulted in fissures (∼100%) and a decrease in hardness of the seed coat.

Keywords:

• Seed drying
• fluidized bed dryer
• microwaves
• germination
• seed quality

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful to the Natural Sciences and Engineering Research Council of Canada and Le Fonds Quebecois de la Recherche sur la Nature et les Technologies for financial assistance for this study.