Abstract:

The microwave intermittent drying process of ginkgo fruits was optimized in this study. Microwave power,
heating time and interval time were selected as experimental factors, and average power consumption, average drying rate
and sensory score as response variables. Quadratic regression orthogonal design was adopted to optimize these independent
variables. A quadratic regression mathematical model for each response variable was established by utilizing backWard
analysis method and analyzed response surface analysis. The results showed all the selected factors had significant effects
on the drying process and the decreasing order of significance was as follows: heating time, microwave power, and interval
time. Meanwhile, these factors also had significant interactive effects. The optimal parameters from response surface
optimization were obtained as follows: microwave power of 4.5 W/g, heating time of 6.5 s and interval time of 80 s. Under
these conditions, the average drying rate was 0.157 kg/(h·kg), the average energy consumption was 65.54 kJ/g and the
sensory score was 8.5. These results will provide a reference for improving microwave drying equipment and drying process
of ginkgo fruits.

Key words: ginkgo fruit, microwave intermittent drying, orthogonal regression, response surface methodology