Effects of microwave assisted pulse fluidized bed freeze-drying (MPFFD) on quality attributes of Cordyceps militaris

Abstract The effect of microwave assisted pulse fluidized bed freeze-drying (MPFFD) on the quality of dried Cordyceps militaris was studied. To highlight the effect, the freeze-drying (recognized for its high-quality products) and hot air dying (the most commonly used) were also evaluated to compare the drying based on the drying characteristics, sensory qualities, volatile compounds and antioxidant activities of dried products. Results indicated that MPFFD helped to lower the rehydration time and shrinkage of dried samples. Furthermore, the rehydration ratio, color attributes, crispness, volatile compounds and antioxidant activities of dried samples were also conserved as compared to those obtained using hot air drying. Not only were the effects of MPFFD on the quality of C. militaris similar to those of freeze-dried samples, but the drying time of MPFFD was reduced by 71.9% when compared to freeze-drying. Therefore, MPFFD provides a potential method for achieving high-quality dried C. militaris with a faster drying time.