Fluidized bed and microwave-assisted fluidized bed drying of seed grade soybean
Ayushi Anand, Yvan Gareipy, Vijaya Raghavan
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.