*2.1. Honey Samples*

Twenty-seven pine honey samples from diverse locations in Greece (Figure 1) were selected from samples collected in the framework of the national Emblematic Action "The Honeybee Routes". The classification as pine honey was based on the organoleptic, microscopic (honeydew elements) and electrical conductivity (>0.9 mS/cm) measurement (Table S1, Figure S1).

**Figure 1.** Locations of collected pine honey samples across Greece.

All samples were stored in glass containers at −18 ◦C until analysis. Before all assays, the samples were homogenized by stirring thoroughly for at least 3 min. Crystalized samples were liquefied in gentle heat of less than 40 ◦C for 5 min. Manuka honey UMF 24+ (MGO 1122) (Steens™, New Zealand, LOT 20NZH18) was used as reference honey to compare antibacterial activity of pine honey samples.
