Optimizing microwave drying parameters for rhododendron bee pollen: effects on antioxidant potential, polyphenols, and proteins

Monofloral Rhododendron spp. bee pollen is a remarkable bee product due to its functional components as well as its potential pharmacological effects. In this study, Rhododendron spp. bee pollen was dried by the microwave method as an alternative to the conventional drying method. Different combinations of microwave powers (140, 210 and 280 W) and sample weights (10, 20 and 30 g) applied during microwave drying (MWD) were determined by Central Composite Design. Drying time, total protein, total carotenoid, total phenolic-flavonoid compounds, and proanthocyanidin yields of dried pollen were determined and antioxidant activity tests (CUPRAC and DPPH•) were performed. The analysis results were optimized by response surface methodology (RSM) and the optimum drying conditions were obtained when the microwave power was 280 W and the sample weight was 30 g. The optimal conditions have been established to reduce drying time and enhance the content of bioactive compounds. As a result of optimization, the composite desirability (d) was found to be 0.8. Experimental and predicted values were close to each other. In conclusion, MWD has demonstrated efficacy as a drying technique by significantly reducing drying time while maintaining and enhancing the yields of bioactive compounds in monofloral Rhododendron spp. bee pollen. In comparison to conventional techniques, the application of MWD in the drying process of monofloral Rhododendron spp. bee pollen is demonstrably more efficient and sustainable.