Monofloral citrus honeys: the use of near infrared spectroscopy (nir) and volatile composition to use as markers of botanical origin.

TAMAÑO, G. ; BONINI, A.; FARIÑA, L.; FAGUNDEZ, G.; DANERS, G.; BOIDO, E.; GIUDICI, V.

Campiñas

Simposio; 11º Simposio Latinoamericano de Ciencia de Alimentos. SLACA 2015.; 2015

olatile organic compounds in honey are obtained from diverse biosynthetic pathways. These compounds, grouped into different chemical categories, represent a fingerprint of a specific honey. Therefore they could be used to differentiate between monofloral honeys from different floral sources, providing valuable information concerning the honey?s botanical and geographical origin. Elucidation of the aroma compounds along with floral origins of a particular honey can help to standardize its quality contributing to the labeling of the product.Argentina and Uruguay are countries producing high quality honeys, from which about 95% is exported to markets where the botanical and geographical origins differentiate the products. Usually, the assessment of honey?s botanical and geographical origin is very complex. In particular, citrus honeys present a limited number of pollen granules making difficult the interpretation of the results of microscopic analysis.In this work, the volatile compounds of honeys from two vicinal citrus producing regions of Argentina (Concordia) and Uruguay (Salto), were analysed to identify volatile marker compounds specific for citrus honeys. The qualitative analysis of their pollen contents allowed to characterize their association with Citrus sp., Echium plantagineum, Eucalyptus sp., Schinus sp., Acicarpha tribuloides and Baccharis sp. The volatile compounds were extracted by solid-phase extraction and analyzed by gas chromatography-mass spectrometry (Shimadzu GC-MS 5050), where higher concentrations of terpenes (cis- and trans-8-hidroxilinalol) furanoids and shikimic acid derivatives (methyl anthranilate) were evidenced. The use of gas chromatography-olfactometry (GC-O) allowed identifying sensory active compounds whose descriptors were associated to pleasant aromas as floral, caramel, spices and others less pleasant, as medical and animal. Finally, NIR was evaluated for the authentication of different honey types previously classified using traditional methods (chemical, pollen, and sensory analysis). Chemometric evaluation of the spectra by applying principal component analysis showed that NIR spectra were closely related, allowing to differentiate the citrus honeys.