Effect of ultrasonic treatment on the microstructure, antioxidant activities and metabolites of camellia bee pollen

Ultrasound is an efficient and eco-friendly friendly non-thermal technology for enhancing the extraction of bioactive ingredients from food. This study explored the impact of ultrasound on the microstructure and antioxidant properties of camellia bee pollen. Additionally, the impact of key contributors to antioxidant activity was examined through non-targeted metabolomics analysis. The results showed that ultrasonic exposure progressively degraded the cell walls of bee pollen, resulting in severe collapse of the intine. Notably, this degradation concurrently facilitated the release of polyphenols and flavonoids. The DPPH and ABTS radical scavenging capacity reached the highest after 40 and 60 min of ultrasonic treatment. After 40 min of ultrasonic treatment, the MDA content in camellia bee pollen exhibited a significant rise of 33.47 % compared to the control group, while it further escalated by 57.07 % after 60 min of ultrasonic treatment. Non-targeted metabolomics analysis identified a total of 7 differential metabolites that serve as potential biomarkers for ultrasonic-treated camellia bee pollen. Further analysis of the purine and nucleotide metabolism pathway indicated that the antioxidant defense systems within camellia bee pollen were activated by ultrasonic treatment, leading to a significant enhancement in its antioxidant capacity. These findings establish a solid foundation for the advancement of ultrasound treatment as a novel and green technology to improve the biological activities and qualities of bee pollen.