Chelating effect of leek (Allium tuberosum Rottler ex Sprengel) containing chlorophyll on Cd, Pb, and As

Abstract

Effect of leek (Chinese chive) on bioaccessibility of arsenic (As), cadmium (Cd), and lead (Pb) was determined in comparison with sodium copper chlorophyllin (SCC) using in vitro digestion model. Leek (0, 6, 12, 60, and 120 mg) and SCC (0, 1, 5, 10, and 50 mg) were digested with equal concentration (10 ppm) of As, Cd, and Pb. Concentration of each heavy metal in aqueous phase following in vitro digestion was measured using an inductively coupled plasma optical emission spectrometer. Changes in absorbance spectra of chlorophyll extracted from leek and SCC by heavy metals were measured at 0, 1, 2, and 3 h after mixing. Results showed that the concentration of each heavy metal in aqueous phase decreased with increasing amounts of leek and SCC. At the highest level of leek (120 mg), the concentrations of As, Cd, and Pb decreased to 93.9, 87.1, and 58.2%, respectively. Absorbance of chlorophyll drastically decreased after 1 h of mixing with each As, Cd, and Pb, and no difference in the absorbance was observed after 2 and 3 h. This result indicates that mixing chlorophyll extracted from leek with each heavy metal for 1 h was sufficient for chelating As, Cd, and Pb ions. On the other hand, SCC and each heavy metal showed a decreasing pattern of absorbance without any significant difference for 3 h, indicating that chlorophyll from leek was more effective than SCC, a commercial grade chlorophyll derivative, in chelating As, Cd, and Pb. Results showed leek reduces heavy metals in humans.