NMR Characterization of Saccharides in Italian Honeys of Different Floral Sources

Abstract

The saccharide profiles of 5 different botanical species in 86 Italian honey samples were investigated by ¹H and ¹H-¹³C NMR spectroscopy. Nineteen saccharides were identified in the aqueous extracts, namely, fructose, glucose, gentiobiose, isomaltose, kojibiose, maltose, maltulose, melibiose, nigerose, palatinose, sucrose, turanose, erlose, isomaltotriose, kestose, maltotriose, melezitose, raffinose, and maltotetraose. PCA performed on NMR spectral regions, in particular between 4.400 and 5.700 ppm and the fructose signal at 4.050 ppm, revealed a partial sample grouping. The score contribution plots derived from PCA performed using the mean values for the buckets of the anomeric region for each floral source allowed the identification of saccharides characterizing different honeys. OPLS-DA models were further evaluated to confirm the previous findings. OPLS-DA models were also built to highlight differences between polyfloral and high mountain polyfloral honeys and between high mountain polyfloral and rhododendron honeys, both collected at high altitude; S-plots highlighted the characteristic saccharides.

Evaluation of saffron (Crocus sativus L.) adulteration with plant adulterants by 1H NMR metabolite fingerprinting

“…The complexity of NMR data in food metabolomics studies is clearly the primary impetus for the coupling of NMR spectroscopy with multivariate statistical methods, capable of gathering samples with similar features Tomassini, Capuani, Delfini, & Miccheli, 2013). Among them, supervised methods that may enhance classification performance, such as orthogonal projection to latent structures -discriminant analysis (OPLS-DA) and its bidirectional modifications (O2PLS-DA) (Bylesjö, Rantalainen, Cloarec, Nicholson, Holmes, & Trygg, 2006), have shown great potential to determine the authenticity of various foodstuffs, mainly on the basis of their geographical or botanical origin (Consonni, Cagliani, & Cogliati, 2012a, 2012bConsonni, Cagliani, Stocchero, & Porretta, 2009Fotakis et al, 2013).…”

1H and13C NMR-based sugar profiling with chemometric analysis and antioxidant activity of herbhoneys and honeys

“…In particular, liquids such as fruit juices, wines and honeys can be easily examined by NMR . Italian honeys were successfully classified based on their NMR spectra and multivariate statistical analysis . It was suggested that the sugar profile could be used to characterize particular honey samples.…”

Recent Advances in NMR Studies of Carbohydrates

“…Included in the review are a survey of 21 common food polysaccharides, the current understanding of their structures, and the techniques used for their determination. In 2012, Consonni et al [152] characterized the profile of 5 different botanical species in 86 Italian honey samples by 1 H and 1 H-13 C NMR spectroscopy. They recognize and identify 19 saccharides in the aqueous extracts and suggest that the saccharides contest could be employed to characterize honey samples and to construct an identity card of saccharides for each floral source.…”