The effect of thermal processing conditions on flavor compounds and active components in Peony seed kernels

Peony seed kernels (Paeonia suffruticosa Andrews) face limited food application because of their bitterness and astringency. Roasting, a well-established technique for flavor enhancement, presents a viable strategy to improve their sensory characteristics. This study investigated the effects of thermal processing on the flavor compounds and bioactive components of Peony seed kernels.

Using a Box-Behnken design coupled with response surface methodology, the optimal processing conditions were determined to be drying at 70 °C for 60 min followed by roasting at 200 °C for 8 min, achieving a tannin inhibition rate of 63.8%. HPLC-tandem mass spectrometry analysis revealed a significant reduction (50.53-69.85%) in the content of paeoniflorin, a key bitter component. Principal component analysis and hierarchical clustering analysis effectively discriminated the flavor profiles, demonstrating a clear clustering of samples based on their flavor components.

Thermal processing not only effectively mitigated bitterness and astringency, but also modulated the bioactivity of peony seed kernels. In vitro activity assays confirmed that roasting influenced the total phenolic and flavonoid content, alongside the antioxidant capacities, thereby positively impacting their potential for human metabolic regulation. This study provides a theoretical foundation for the industrial development of peony seed kernels as palatable and functional food ingredients. © 2025 Society of Chemical Industry.