Impact of Solar Drying Temperatures on Total Polyphenols and Antioxidant Activity of Bee Pollen from the Mantaro Valley, Peru

Abstract

Bee pollen is a functional food highly valued for its content of bioactive compounds, especially polyphenols, known for their antioxidant properties and their role in preventing oxidative stress and chronic non-communicable diseases. However, during processing— particularly the drying stage—these compounds can be affected. This study aimed to evaluate the influence of different solar drying temperatures (40, 50, and 60 °C) on the total polyphenol content and antioxidant capacity of bee pollen collected in the Tarma region, Junín, Peru. A completely randomized experimental design was applied using analysis of variance (ANOVA), followed by Tukey’s test to determine significant differences among treatments. The samples were dehydrated in an automated solar dryer under controlled temperature and humidity conditions. Polyphenols were determined using the Folin-Ciocalteu method, and antioxidant activity was assessed using the DPPH assay. The results showed a significant increase (p < 0.05) in both polyphenol content and antioxidant capacity as the drying temperature increased, reaching the highest values at 60 °C. These findings suggest that, contrary to some technical regulations limiting drying temperatures to 45 °C, higher temperatures may favor the release of bound polyphenols or induce structural changes in the pollen matrix that enhance their bioavailability. As a limitation, this study only evaluated polyphenols and antioxidant activity, without considering other relevant bioactive compounds. The practical implications of this research include the optimization of solar drying processes under controlled conditions to preserve and even enhance the functional properties of bee pollen, which is beneficial for both the food industry and the nutraceutical sector. Furthermore, it provides evidence that could support the revision and updating of technical standards related to pollen processing.