Lonicera japonica Flos (LJF) is widely used in pharmaceuticals and functional foods, with its bioactive constituents significantly influenced by processing methods. This study characterized the dynamic changes in chemical components in LJF under different maceration and decoction durations. Using UPLC-Q-TOF-MS and molecular networking, a total of 260 metabolites were unambiguously identified or tentatively characterized, including 66 iridoids, 42 flavonoids and 49 phenolic acids. Among these, 11 phenolic acids and 3 flavonoids were absent in the macerated samples. Twenty-two representative compounds were quantified using calibration curves. Most secondary metabolites, particularly phenolic acids, exhibited lower levels in the macerated samples than the decocted samples (e.g., 5-O-caffeoylquinic acid: 65.67–106.41 μg/g during maceration vs. 32,783.05–55,754.68 μg/g during decoction). The decoction process significantly enhances the extraction of active constituents. Notably, certain iridoids (e.g., 7-O-methyl morroniside: 92.91–354.59 μg/g during maceration vs. 50.43–171.40 μg/g during decoction) were better preserved under maceration, highlighting its advantage for retaining heat-sensitive bioactive components. During the decoction process, 5-hydroxycinnamoylquinic acids tended to transform into 3- and 4-hydroxycinnamoylquinic acid isomers. Most di-hydroxycinnamoylquinic acids and flavonoids significantly decreased after 30 min. Nitrogen-containing seco-iridoids declined rapidly after 15 min. To balance extraction efficiency with the preservation of heat-sensitive bioactive components, a decoction time of 15–30 min is recommended. The study systematically elucidates the dynamic changes in bioactive components under two preparation methods, offering critical insights and a scientific foundation for the precision utilization of LJF in pharmaceutical and functional food industries.
Ding et al. (Sun,) studied this question.