Screening Capsicum chinense fruits for heavy metals bioaccumulation

Abstract

Elevated concentrations of heavy metals in edible plants could expose consumers to excessive levels of potentially hazardous chemicals. Sixty-three accessions (genotypes) of Capsicum chinense Jacq, collected from 8 countries of origin were grown in a silty-loam soil under field conditions. At maturity, fruits were collected and analyzed for seven heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, and Mo) concentrations. The main objectives of this investigation were: 1) to determine the concentrations of seven heavy metals in the soil and monitor their accumulation in mature fruits, 2) to categorize the pepper accessions as low or high heavy metal accumulators, and 3) to determine if heavy metal content of the pepper fruit was lower than the permitted limits. Concentrations and relative proportions of heavy metals in pepper fruits of C. chinense varied among accessions. Fruits of Plant Introduction (PI) 355820 accumulated significant concentrations of Cd (0.47 μ g g⁻¹dry fruit). PI-260522 accumulated the highest concentration of Pb (2.12 μ g g⁻¹ dry fruit) among the 63 accessions tested. This accession (PI-260522) contained about twice the Pb limit on a fresh weight basis. Among the 63 accessions analyzed, PI-238051 contained the highest levels of Ni (17.2 μ g g⁻¹). We concluded that high accumulator genotypes may be useful for phytoremediation, while, low accumulator accessions might be appropriate selections for growing on Cd-, Pb-, or Ni-contaminated soils to prevent potential human exposure to heavy metals and health hazards through the food chain.

Keywords:

• Hot peppers
• Cd
• Pb
• Ni
• high accumulator genotypes
• low accumulator genotypes

Acknowledgments

We thank Jami Rogers and Yoon Hu for their assistance in preparing pepper crude extracts. This investigation was supported by two grants from the United States Department of Agriculture/Cooperative State Research, Education, and Extension Service (USDA/CSREES) to Kentucky State University under agreements No. KYX-2004-15102 & No. KYX-10-08-43P.

Notes

† Each value in the table is an average of 3 replicates ± SE.

† Each value in the table is an average of 3 replicates ± SE.

† Each value in the table is an average of 3 replicates ± SE.

† Each value in the table is an average of 3 replicates ± SE.

† Each value in the table is an average of 3 replicates ± SE.

† Each value in the table is an average of 3 replicates ± SE.