Multivariate data reduction and discrimination of black and green teas due to the physical fractionation pattern of selected metals determined in their infusions

• Physical fractionation of 12 metals in black and green teas infusions done.
• High and low molecular weight metals fractions being the most distinctive.
• Metals bioaccessibility indirectly assessed upon their fractionation patterns.
• PCA and LDA used to classify teas due to molecular weight metals fractionations.

An analytical scheme for the physical fractionation of Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Sr and Zn in black and green teas infusions was proposed. It was based on the ultrafiltration/centrifugation through five membranes having molecular weight cut-offs of 100, 50, 30, 10 and 5 kDa. The concentrations of the studied metals in the highest and the lowest molecular weight fractions were found to classify and discriminate the analyzed teas infusions much better than the total metals concentrations. The differences in the physical fractionation patterns of these metals assessed for both tea varieties was profound and let to simply classify the infusions of different black and green teas by principal component analysis and linear discriminant analysis.

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