Differences in metal concentrations and total antioxidant capacity were compared to assess potential risks of consumption amongst four locally sourced and imported crops in Saskatchewan, Canada. Total antioxidant capacity was significantly greater in locally sourced strawberry and red peppers. Concentrations of cadmium, copper, nickel, and zinc were significantly higher in imported crops as opposed to locally sourced crops, measured by inductively coupled plasma mass spectroscopy. Imported and locally sourced lettuce cadmium concentrations exceeded the hazard quotient consumption safety threshold. A field experiment evaluating metal concentrations in the edible tissues of five field grown lettuce cultivars identified that all cultivars exceeded the cadmium safety threshold. ‘Pandero’ and ‘Iceberg’ cultivars exceeded the consumption safety threshold for nickel and ‘Grand Rapids 08’ exceeded the consumption safety threshold for aluminum. Antioxidant capacity differed significantly amongst cultivars. Correlation analysis was conducted to determine if antioxidant capacity can be used as a proxy for trace metal concentrations. When comparing all field lettuce, there was a significant correlation between copper and nickel concentrations and antioxidant capacity. This research reinforces the need to screen for cultivar-specific metal accumulation and the identification of markers for cadmium accumulation in lettuce.
Canadian Journal of Plant Science
Vol. 97 • No. 2
Vol. 97 • No. 2
évaluation des risques