Comparison of mineral and trace element contents between organically and conventionally grown fruit

摘要

Introduction. Many consumers buy organic foods because of their alleged greater nutritional benefits. However, studies investigating the effect of the agricultural farming system on minerals and toxic elements content are scarce. This study compared the content of minerals (P, Ca, Mg, Na and K) and trace elements (Fe, Mn, Cu, Cr, Se, Zn, Mo, Ni, Cd and Al) of four organically and conventionally grown fruits in Brazil. Materials and methods. Mango (Mangifera indica L., var. Palmer), persimmon (Diospyros kaki L., var. Rama Forte), acerola (Malpighia punicifolia L., var. Olivier) and strawberry (Fragaria vesca L., var. Oso Grande) were produced by organic and conventional farming in the same geographic region, under the same climatic conditions and same type of soil. Mineral analysis was performed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Results and discussion. Organic mango contained higher amounts of Mg and K, and Cr content was higher in conventionally grown mangos. Organic persimmon contained higher amounts of Cu and Zn, and Mg, P, Na, and K concentration was higher in conventional persimmon. Conventionally grown acerola contained higher amounts of Ca, Fe, Mn, Mo, Al, and Ni than the organic acerola. The concentrations of Mo and Al were higher in organic strawberry when compared to conventional strawberry. Conclusion. Organic farming did not result in a clear superiority of the mineral quality of fruit nor did it provide fruit free of toxic elements.