Determination of metal contents in sugar beet (Beta vulgaris) and its products: Empirical and chemometrical approach

Abstract

Multielements K, Na, Ca, Mg, Zn, Fe and Cu were estimated in 25 composite samples of sugar beet, extracted sugar beet pulp, dried sugar beet pulp, molasses, and white sugar collected during 50 days of the 2005 campaign in one beet sugar factory, and in 65 soil samples collected from the fields where beet was grown. Mean total contents of analyzed elements in sugar beet and different sugar beet based products were in the range: 18.11-37510 mg/kg dry matter (d.m.) for K, 6.54-8945 mg/kg d.m. for Na, 14.36-5220 mg/kg d.m. for Ca, 0.09-2550 mg/kg d.m. for Mg, 0.01-10.85 mg/kg d.m. for Zn, 0.42-360.4 mg/kg d.m. for Fe, and 0.07-7.09 mg/kg d.m. for Cu. Mean extractable amounts of these elements in the soils sampled in the fields where beet was cultivated were as follows: 207.6 mg/kg d.m., 60.3 mg/kg d.m., 14.4 mg/kg d.m., 404.7 mg/kg d.m., 1.44 mg/kg d.m., 9.89 mg/kg d.m. and 1.61 mg/ kg d.m., respectively. In order to get a better insight into the metal patterns of the investigated samples, three statistical techniques were used. Principal component analysis (PCA) and cluster analysis (CA) approved to be more powerful than Spearman's test in revealing the specific correlations among the variables (i.e. metal contents). PCA and CA pointed out the specific metal pattern of molasses on one hand and of sugar beet, extracted and dried sugar beet pulps on the other. Moreover, the chemometrical approach pointed out that main components that classified the metal behavior in the examined samples were the ones correlated with Na and K on one hand, and on the other hand with the remaining metals.