Chrysanthemum morifolium Ramat., known as Hangbaiju (HBJ), is a high-value edible, medicinal product where the flowers are infused in hot water and drunk as tea. Its quality and efficacy are closely related to its geographical origin. Consequently, it is vulnerable to fraudulent substitution by other lower-value Chrysanthemum products. In this study, cultivation (variety and different growth stages) and isotopic fractionation between the flower, stem, and leaf were studied. Samples from four different HBJ varieties were characterized using stable isotopes (δ¹³C, δ¹⁵N, δ²H, δ¹⁸O, %C, and %N) across three producing regions in Zhejiang province, China. The results showed that there were no significant differences in stable isotopic compositions for different HBJ varieties, but there were significant differences for different plant tissues (flower, stem, leaf, etc.). Furthermore, the stable isotopic composition altered dramatically at different growth stages. The δ¹⁵N (r = 0.6809) and δ²H (r = 0.6102) correlations between stems and leaves (SL) and flowers (F) of HBJ were relatively good, the δ¹³C correlation (r = 0.2636) between SL and F was weak, but δ¹⁸O correlation (r = 0.01) had almost no correlation. A supervised multivariate statistical model (partial least squares discriminant analysis, PLS-DA) was used to discriminate three different producing regions with high accuracy (66.7%, 66.7%, and 100%, respectively). Our findings show that stable isotopes combined with multivariate statistical analysis provide an effective method for the geographical identification of HBJ.

China is the world’s largest consumer and second largest producer of bananas. This strong domestic demand consistently provides a reliable income for Chinese banana growers. The geographical origin of food is usually associated with product quality and safety, and this is especially noted for Hainan origin-labeled bananas, which are grown offshore on China’s largest tropical island. Hainan banana is recognized as a premium variety within China’s banana market, but there have been recent impacts on branding, profits, and a reduction in income for banana farmers due to the fraudulent in-market substitution of non-Hainan bananas. In this study, stable isotope and elemental chemometric models were used to differentiate bananas grown in Hainan province (HN) from non-Hainan provinces (NHN). The results showed that HN bananas had a specific isotopic and elemental fingerprint compared to NHN bananas. Bananas sampled from HN and NHN regions showed significant differences in δ¹³C values (HN: −22.2‰ to −27.7‰, NHN: −22.3‰ to −24.3‰), Al content (HN: 0.00 mg/kg to 0.10 mg/kg, NHN: 0.00 mg/kg to 0.02 mg/kg), Na content (HN: 0.00 mg/kg to 0.09 mg/kg, NHN: 0.00 mg/kg to 0.07 mg/kg), and other elements (p < 0.05). Overall, 14 key variables reflecting climate and soil properties were selected from a group of 53 variables to improve a partial least squares discriminant analysis (PLS-DA) chemometric model. The discrimination accuracy of the test set increased from 84.60% to 90.93% after variable reduction. The use of stable isotopes and elements combined with PLS-DA models provided an effective method for distinguishing Chinese HN bananas from NHN bananas and would be useful as a screening or regulatory tool to confirm instances of origin fraud.

Tetrastigma hemsleyanum Diels et Gilg is a high-value edible and medicinal homologous plant, routinely grown under conventional field or greenhouse production systems across Asia. However, mislabeling of conventional products as the rarer (and more expensive) wild version may occur for financial gain. In this study, stable isotopes (δ¹³C, δ¹⁵N, δ²H, and δ¹⁸O) and metal contents (Cr, Cu, Ni, As, Cd, Pb) were used to characterize plant tissues (tuber root, stem, leaf) and corresponding soils originating from simulated-wild-cultivated (WC) and greenhouse-cultivated (GC) pot trials using the same soil. Carbon and nitrogen isotopes served as key indicators for distinguishing GC and WC products. Specifically, δ¹³C values of GC plant tissues were 1.4 to 2.4‰ more positive than those of WC plant tissues (p < 0.05), and δ¹⁵N values in GC tissues were 2.7 to 4.6‰ more positive than δ¹⁵N in WC tissues (p < 0.01). Lower δ¹⁵N values observed in WC products indicate slower nitrogen turnover compared with GC products. Soil metal concentrations had significant differences between the two cultivation systems, but only limited effects on metal bioconcentration factors (BCFs) and translocation factors (TFs) in T. hemsleyanum tissues. Pb and Cd concentrations in root tissues had large differences between cultivation systems, and carbon dynamics in GC plants were more negatively affected by Pb levels in soils. These findings provide the first investigation of T. hemsleyanum grown under different cultivation practices and establish a scientific basis for distinguishing other wild or simulated-wild labeled food and medicinal plant products from conventionally grown products in future studies.