Fast field Cycling NMR for quality characterization of typical sicilian honeys.

Proton NMR relaxometry with fast field cycling (FFC-NMR) setup is developing as a very promising tool for the characterization of agro-food matrices. In fact, some papers have been published reporting on differences among balsamic vinegars, porous properties of oil-water emulsions and quality of meat-products. In the present study, quality of some typical Sicilian honey samples has been evaluated by traditional wet-chemical analyses and FFC-NMR. Nine wet-chemical parameters have been measured such as water content, pH, acidity (free, lactonic and total acidity), fructose, glucose, saccharose, electrical conductivity, diastase activity and colour. Results showed that 84% of the samples were correctly classified, whereas about 16% of them revealed some defects primarily due to erroneous industrial production practices and/or wrong storage conditions. In order to differentiate honey samples according to their botanical and geographical origins, correlation times were measured by FFC- NMR and related to the wet-chemical properties by statistical evaluations. The statistical analysis revealed that water content affected correlation times. Moreover, honeys having similar botanical origin showed differences in their chemical composition, mainly attributable to the geographical areas of production. The present study reported for the first time quality evaluation of honeys by FFC-NMR, thereby confirming the great potentiality of this technique for agro-food characterization.