RESUMO
Cassava is a main cultivated tropical crop in China, its rich starch roots are often used to produce fuel ethanol in recent years, so it's a kind of hot biomass energy crops. But cassava's byproducts such as leaves, stems and peels are regarded as waste, and are not fully utilized. Cassava's byproducts contain many nutrients, and can be used to process high value food products. The contents of mineral elements and heavy metals in cassava's byproducts were studied by ICP-MS. The results showed that cassava's byproducts contained many elements necessary to human health, the sequence of macroelements was K>Ca>P> Mg>S>Mn>Zn>Na>Fe>B>Cu, particularly, the contents of Fe, Mn, Zn and B ranged from 10 to 800 microg x g(-1) (DW), while the contents of microelements including Mo, Co, Se and Ge ranged from 0.01 to 0.2 microg x g(-1) (DW), which are important to human health. Besides macroelements and microelements, the contents of heavy metals (As, Cr, Pb and Hg) were also important to identify the quality of farm products, and the results showed that cassava's byproducts contained little heavy metals except Pb (2.19 microg x g(-1) (DW) in stalk peels). All the data showed that cassava's byproducts accorded with the national hygiene standards.
