First comparative characterization of natural and commercial mannitol products: A multi-analytical approach

Manna is a traditional plant exudate obtained from Fraxinus species in Sicily and naturally contains mannitol as its predominant polyol. This study comparatively characterized natural manna (NM) and commercial mannitol products (CMP) through an integrated analysis of proximate composition, fatty acids, volatile compounds, and carbohydrates. Twelve commercial samples were investigated, including five NM and seven CMP. NM showed greater variability in proximate composition, particularly in moisture and ash contents, whereas CMP exhibited more homogeneous profiles. Fatty acid composition was broadly comparable between groups, with no significant differences in individual fatty acids or total SFA, MUFA, and PUFA. Volatile profiling revealed distinct compositional patterns and highlighted variables associated with sample distribution. The clearest distinction emerged from carbohydrate profiling. CMP contained predominantly mannitol (93.82–97.90 g/100 g), whereas NM contained an unresolved mannitol–glucose fraction (48.55–81.70 g/100 g, expressed as mannitol equivalents) together with fructose (3.51–8.29 g/100 g); sucrose remained below the limit of quantification. Fructose therefore emerged as a candidate compositional marker for distinguishing the investigated product categories. These findings provide an integrated comparative framework for the chemical characterization of NM and CMP and support further studies using larger independent sample sets to evaluate potential authenticity applications.