Elemental composition of yerba mate (Ilex paraguariensis A.St.-Hil.) under low input systems of southern Brazil

Authors: MOTTA, ANTONIO - Universidade Federal Do Parana; BARBOSA, JULIERME - Federal University Of Minas Gerais; MAGRI, EDERLAN - Universidade Federal Do Parana; PEDREIRA, GUILHERME - Universidade Federal Do Parana; SANTIN, DELMAR - University Of Santa Catarina; Prior, Stephen - Steve; CONSALTER, RANGEL - Universidade Federal Do Parana; YOUNG, SCOTT - University Of Nottingham; BROADLEY, MARTIN - University Of Nottingham; BENEDETTI, ELIZIANE - University Of Santa Catarina

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2020
Publication Date: 6/1/2020
Citation: Motta, A., Barbosa, J., Magri, E., Pedreira, G., Santin, D., Prior, S.A., Consalter, R., Young, S.D., Broadley, M.R., Benedetti, E. 2020. Elemental composition of yerba mate (Ilex paraguariensis A.St.-Hil.) under low input systems of southern Brazil. Science of the Total Environment. 736:139637. https://doi.org/10.1016/j.scitotenv.2020.139637.
DOI: https://doi.org/10.1016/j.scitotenv.2020.139637

Interpretive Summary: Yerba mate leaves (Ilex paraguariensis) have been used in various products (food, beverage, cosmetic, and pharmaceutical). This study determined elemental background levels of yerba mate in the primary production areas of southern Brazil for comparison to established maximum acceptable limits (MAL) of metals in consumption products. Under varied geologic formations, mature leaves were collected from thirty native sites and analyzed with and without washing (to assess foliar deposition) for 32 elements. Values of As, Ag, Be, Cs, Cr, Li, Se, Tl, U, and V indicated low toxicity potential for the consumer. Washing decreased Fe, Ti, As, Mo, Li, V, and Pb levels suggesting atmospheric/dust deposition. Soil parent material affected composition with basalt providing more Mn, P, and Co while Rhyodacite provided more K and Na. All samples had Pb values below the MAL, but 25% of samples had Cd levels close to or above the MAL. Study results indicated that Cd MAL values for yerba mate in southern Brazil should be reassessed.

Technical Abstract: Elemental composition of food can be used to determine nutritional potential as well as guiding legislation for establishing maximum acceptable limits (MAL) of metals in consumption products. This study aimed to determine the elemental background of yerba mate (Ilex paraguariensis A.St.-Hil.) under varied geologic formations in southern Brazil, in reference to actual legislation. Mature leaves were collected from thirty native sites in three states and analyzed for 32 elements. Since yerba mate is not washed to obtain the final product, leaves were analyzed with and without washing to assess foliar deposition. Concentration values of As, Ag, Be, Cs, Cr, Li, Se, Tl, U, and V were near detection limits, indicating low potential as a source and/or toxicity to the consumer. Washing decreased concentrations of Fe, Ti, As, Mo, Li, V, and Pb, suggesting atmospheric contributions/dust deposition. Concentrations were very high for Mn and high for Zn and Ni, emphasizing the importance of leaves as a source of these elements. Soil parent material affected elemental composition with basalt providing higher concentrations of Mn, P, and Co while Rhyodacite provided higher concentrations of K and Na. All samples exhibited Pb values below the MAL of 0.6 mg kg-1, but 25% of samples had Cd concentrations close to or above the MAL value of 0.4 mg kg-1. Study results indicated that Cd MAL values for yerba mate in southern Brazil should be reassessed.