Use of Multivariate Analysis Techniques for Evaluation of Analytical Data—Determination of the Mineral Composition of Cabbage (Brassica oleracea)

Cabbage (Brassica oleracea) is a vegetable food that is found in red and white varieties, and it has been consumed worldwide as raw or cooked. In this paper, the mineral composition of cabbage collected in 24 Brazilian cities was determined and the results were evaluated using multivariate analysis. The samples were digested using nitric acid and hydrogen peroxide and were analyzed using inductively coupled plasma optical emission spectrometry. The accuracy of the method was confirmed by analysis of a certified reference material of spinach leaves, furnished by National Institute of Standard and Technology. The study involved 55 samples, being 31 of the white specie and 24 of the red specie. The results expressed as milligrams of element per kilogram of sample demonstrated that the concentration ranges varied from 1,602.9 to 4,068.3 for potassium, 217.5 to 766.2 for phosphorous, 221.9 to 744.7 for calcium, 67.2 to 286.0 for magnesium, 0.81 to 4.40 for manganese, 1.91 to 8.60 for iron, 0.01 to 0.24 for molybdenum, 1.17 to 5.10 for zinc, 27.2 to 591.0 for sodium, and 0.35 to 5.79 for strontium. The principal component analysis and hierarchical cluster analysis evidenced that the mineral composition of the red specie is not different of the white specie.