Stable Isotope Ratios of Herbs and Spices Commonly Used as Herbal Infusions in the Italian Market

Stable isotope ratio analysis has been widely used for traceability and authenticity purposes in relation to various food commodities, but only in a limited number of herb and spice species. This study explored the stable isotope ratios of carbon, nitrogen, sulfur, oxygen, and hydrogen (δ13C, δ15N, δ34S, δ18O, and δ2H) of 119 herbs and spices belonging to 116 plant species and 57 plant families collected from the Italian market for the first time. The characteristic value ranges of δ13C, δ15N, δ34S, δ18O, and δ2H of the herbs and spices went from -31.0 to -11.6, -4.7 to 12.0, -5.0 to 22.0, 14.7 to 46.0, and -158 to -12‰, respectively. The isotopic profiles within and between common botanical families and their similarity/dissimilarity between herbs and spices belonging to the common botanical families are also discussed here. The results of this exploratory work highlight the possibility of characterizing herbs and spices and suggest widening the scope of the survey through more extensive sampling and focusing on specific plant species.