Volatile markers as a reliable alternative for the correct classification of citrus monofloral honey

The pollen analysis to classify monofloral honey is an unresolved challenge specially when the pollen is under-represented as the case of citrus honey. Thus, this study assesses the validity of the volatile fraction to differ-entiate types of honey, with special attention to markers compounds of citrus honey that could permit their distinction. Unsupervised analysis (PCA and HCA) showed that the volatile fraction of honey containing Citrus sp. pollen, undoubtedly differentiates it from other types of honey. An OPLS model focused on citrus honey selected 5 volatile compounds (of the 123 found in all samples by GC-MS) as significant predictors of the currently used value of methyl anthranilate obtained by HPLC. The joint detection of 4 lilac-aldehydes and the volatile methyl-anthranilate has the advantage of providing more precise information. Therefore, it could be proposed as a consistent marker to ensure the correct classification of citrus honey, fostering its labelling reliability.

Automated summary

This study evaluates the validity of volatile compounds in differentiating types of honey, with a focus on markers of citrus honey. Unsupervised analysis shows that the volatile fraction of honey containing Citrus sp. pollen clearly distinguishes it from other types of honey. An OPLS model identifies 5 significant volatile compounds as predictors of the currently used marker compound, methyl anthranilate. The detection of 4 lilac-aldehydes and volatile methyl-anthranilate provides more precise information and can be proposed as consistent markers for accurate classification and labeling of citrus honey.