Synephrine - A potential biomarker for orange honey authenticity

•Orange honey is one of the most appreciated monofloral honeys.•LC-MS/MS method was developed and validated for synephrine in honey.•Synephrine can help discriminate orange honeys.•Synephrine was detected in orange and wildflowers honey and citrus flowers.

A LC-MS/MS method for synephrine as a biomarker for orange honey authenticity was developed and validated. The sample was extracted with 5% TCA and cleaned up with Florisil providing 83.7% recoveries. Ions transitions for quantification and identification were 168 → 135.0 and 168 → 107.0, respectively. The limits of detection and quantification were 0.66 and 1.0 ng/g, respectively. Synephrine was detected in orange honey at levels from 79.2 to 432.2 ng/g, but not in other monofloral honeys. It was also present in some wildflower honeys (9.4-236.5 ng/g), showing contribution of citrus to this polyfloral honey. Results were confirmed by qualitative pollen analysis. No citrus pollen was detected in honey containing synephrine levels ≤43.8 ng/g, suggesting that synephrine in honey is more sensitive compared to pollen analysis. Synephrine was found in citrus but not in other apiculture flowers. Therefore, synephrine is a botanical marker to differentiate and attest authenticity of orange honey.