Exploring bitter characteristics of blue honeysuckle (Lonicera caerulea L.) berries by sensory-guided analysis: Key bitter compounds and varietal differences

The taste of blue honeysuckle (Lonicera caerulea L.) berries is wrapped in bitterness, and awareness about the essence of bitterness is lacking. In the current study, 7-ketologanin, sweroside and loganin were isolated and identified as key bitter compounds using sensory-guided analysis. The bitterness thresholds of these compounds were determined to be 11.9 μg/mL, 33.5 μg/mL and 60.2 μg/mL. Subsequently, the differences in bitterness among 16 blue honeysuckle varieties were evaluated. The wild varieties A1 and A2 exhibited the highest bitter intensity. 7-Ketologanin, with the highest concentration of 34.70-37.11 mg/100 g and taste activity values of 29.16-31.18 in A1 and A2, was first identified as a bitter contributor in blue honeysuckle. There was no significant difference in bitter intensity between the reconstitution model and the original sample, confirming the contribution of the three bitter compounds. This study lays the foundation for the bitter improvement and variety selection of blue honeysuckle resources.