Journal of Agriculture and Food Science

Objective Honey adulteration is a prominent issue of food fraud, severely undermining consumer rights and market fairness. This study aimed to establish an untargeted metabolomics approach based on liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) for the efficient and accurate discrimination of pure and adulterated honey. Methods Pure honey samples from different botanical origins (acacia, vitex, jujube) were collected, and simulated adulterated samples were prepared by adding common adulterants (rice syrup, beet syrup) at different ratios (10%, 20%, 30%, 50%, w/w). The metabolic profiles of all samples were acquired using LC-Q-TOF-MS. Pattern recognition was performed using principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) to screen for differential markers and construct identification models. Results PCA and OPLS-DA models effectively distinguished pure honey from adulterated honey. Fifteen significant differential compounds were screened out as potential chemical markers through variable importance in projection (VIP > 1.5) and t-test (p < 0.05), including oligosaccharides, amino acids, phenolic acids, and flavonoids. Among them, markers for rice syrup (e.g., specific isomers of maltooligosaccharides) and beet syrup (e.g., trehalose, raffinose) were significantly up-regulated in adulterated samples, while some characteristic plant-derived compounds of honey were significantly down-regulated. The discriminant model established based on these markers achieved an accuracy of 98.5% for the validation set. Conclusion The untargeted screening method established in this study can overcome the limitations of traditional targeted methods, effectively identifying the presence of exogenous syrup adulteration in honey without pre-defined targets, and suggesting possible adulteration sources. It provides a powerful technical support for honey authenticity identification.

Honey adulteration; Untargeted screening; High-resolution mass spectrometry; Chemical markers; OPLS-DA