Fecal descriptor in honey: indole from a floral source as an explanation

Animal odor, is one of the most common aroma defects described in the honey odor aroma wheel. It comprises two secondary descriptors: 'fecal' and 'cowshed'. However, the compounds responsible for these honey defects have not been fully identified. In this context, the aim of this work was to identify the compounds responsible for the aromatic defect 'fecal' in Uruguayan honeys by means of gas chromatography coupled to olfactometry (GC-O).

Samples of honey described by beekeepers as having fecal aroma were analyzed by GC-O and gas chromatography coupled to mass spectrometry (GC-MS). Through GC-O, it was possible to establish the region of the chromatogram corresponding to the fecal descriptor, while the GC-MS analysis allowed to identify indole as the compound responsible for the fecal descriptor. The content of indole in the analyzed samples ranged between 132 and 414 μg kg^-1 . The melissopalynological analysis indicated the presence of Scutia buxifolia ('quebracho' or 'coronilla') pollen in all samples studied. The volatile profile of Scutia buxifolia flowers was evaluated during the full day, enabling the identification of indole as one of its components. The detection threshold value for indole in honey was experimentally determined as 64 μg kg^-1 of honey, a value lower than the concentration found in the evaluated samples.

Results from the study allowed the identification of indole as the compound responsible for the 'fecal' aroma defect in Scutia buxifolia honeys. © 2022 Society of Chemical Industry.