## 4 Discussion  
Soybean seeds, when subjected to microwave drying at temperatures of 40 to 50 \({}^{\circ}\)C and microwave power above 0 to 0.5 W/g, may have their drying time reduced by up to eight times. The process is safe for water contents below 21%, as shown by the results of this experiment.  
Several studies report gains in reducing drying time or other advantages using microwaves and other electromagnetic energies [2; 3; 41; 42]. However, studies that report gains in seed quality are still incipient. Recently, it was proved in a study on the use of magneto  
Figure 8: Water absorption curve of soybean seeds for conventional drying and microwave drying.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Temperature** & **Power** & **a** & **b** & **c** & **r** & **R2 * \\ \hline
40 & 0.0 & 3.46 \(\times\) 10\({}^{-1}\) & 1.71 \(\times\) 10\({}^{-1}\) & 8.64 \(\times\) 10\({}^{-4}\) & 5.6 \(\times\) 10\({}^{-1}\) & 0.99 \\
40 & 0.5 & 3.72 \(\times\) 10\({}^{-1}\) & 2.06 \(\times\) 10\({}^{-1}\) & 3.69 \(\times\) 10\({}^{-4}\) & 5.8 \(\times\) 10\({}^{-1}\) & 0.99 \\ \hline \hline \end{tabular} \({}^{*}\)Significance level of 0.05.  
\end{table}
Table 5: Parameters of the exponential plus linear model given by y = a + br* + cx and adjusted for the water absorption curve in soybean seeds for conventional drying and microwave drying.  
priming in soybean seeds they can promote biostimulation and carry out the removal of water from the seeds [33].  
In this study, soybean seeds were submitted to different drying conditions, which led to a region of exploration of potential gains in bio stimulus by microwaves. The gain in seed vigor observed in the physiological tests indicates a large area of study to be explored as new post-harvest technologies for seeds. Similar results have already been shown in previous studies [43; 44; 45; 46; 47], but little is known about the biological or biophysical reasons related to this phenomenon.  
In other types of food products, the MW power can minimize the nutritional degradation influencing the oxidation effect of different products; in samples of sugarcane juice, it was verified that the lower power of the lesser antioxidant activity verified through the elimination of free radicals (DPPH), being the device an efficient technique for concentrate juice [48]. The same antioxidant effect was observed in peas treated at a power of 100 W; there was a decrease in DPPH and an increase in flavonoid levels [49]. In jelly processing, the microwave had an advantage, such as higher DPPH, phenolic content, and ascorbic acid content over the conventional use of the open pan [50]. Despite this, these products are no longer like soybean seeds--the antioxidant effect shown by these studies could explain a possible similar effect on seeds during drying.  
This study corroborates the data presented in [51], which using a power of 0.13 W/G, identified that it is possible to dry soybean seeds without damage to germination with greater speed and efficiency of the process. Microwave drying is still a field of study that needs many exploratory studies to certify, over a wide range of drying conditions, the safety and benefits of this process. This study demonstrated that we have a reach region for drying, considering the binomial temperature and power that can not only be safe but also promising for the performance of seeds in the field.