Synephrine - A potential biomarker for orange honey authenticity

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Agricultural Science

Background:

• Honey authenticity is crucial for consumer trust and economic value.
• Distinguishing monofloral honeys requires reliable analytical markers.
• Synephrine is a known compound in citrus plants.

Purpose of the Study:

• To develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying synephrine.
• To establish synephrine as a biomarker for authenticating orange honey.
• To compare the sensitivity of synephrine analysis with pollen analysis for detecting citrus nectar.

Main Methods:

• Sample extraction using 5% trichloroacetic acid (TCA).
• Florisil column for sample cleanup, achieving 83.7% recovery.
• LC-MS/MS analysis using specific ion transitions (168→135.0 for quantification, 168→107.0 for identification).
• Determination of method limits of detection (0.66 ng/g) and quantification (1.0 ng/g).

Main Results:

• Synephrine was detected in orange honey at concentrations ranging from 79.2 to 432.2 ng/g.
• Synephrine was absent in other monofloral honeys but present in some wildflower honeys (9.4-236.5 ng/g), indicating citrus pollen contribution.
• Synephrine levels up to 43.8 ng/g in honey showed no corresponding citrus pollen, suggesting higher sensitivity of synephrine analysis.
• Synephrine was found in citrus flowers but not in other common apiculture flora.

Conclusions:

• Synephrine serves as a reliable botanical marker for differentiating and verifying the authenticity of orange honey.
• LC-MS/MS analysis of synephrine offers superior sensitivity compared to pollen analysis for identifying citrus nectar sources.
• The developed method provides a robust tool for quality control in the honey industry.