In order to discriminate the two groups and screen the characteristic element, PLS-DA was carried out based on thirteen element composition of pork samples. As shown in Fig. 1,
the scatter 3D plot which included three components indicated that the two groups could be clearly classified by the element data.
Variable importance values were shown in Fig. 2. Five elements (Rb, Se, Cr, Cu andMn) were calculated to possess higher importance values; meanwhile, these five elements were significantly different between organic and conventional pork.