Discrimination of garlic and onion and their geographical origin using fsLA-ICP-MS with chemometrics analysis

Abstract

Garlic and onions are popular ingredients and spices around the world because of their unique flavor. Femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fsLA-ICP-MS) provides an alternative for elemental analysis of small samples without pretreatment, and a total of 28 elements were identified in garlic and onion. For discrimination analysis, orthogonal partial least-squares discriminant analysis (OPLS-DA) and canonical discriminant analysis (CDA) were employed. In the OPLS-DA results, the R2, Q2, and area under the curve (AUC) values of garlic were 0.957, 0.928, and 1, and those of onion were 0.789, 0.725 and 1, respectively. CDA used structural scores to identify influential factors, and the resulting accuracies were 100 % and 98.33 % for garlic and onion, respectively. Finally, the R2, Q2, and AUC of the OPLS-DA model for distinguishing garlic and onion were 0.874, 0.762, and 1, respectively. These results highlight the potential of fsLA-ICP-MS for elemental analysis in geographical origin determination.