Disclosed is a method for removing one or more heavy metals from an aqueous plant extract, comprising: contacting the aqueous plant extract with, and sorbing at least a portion of the one or more heavy metals on, at least one sorbent selected from the group consisting of: one or more surface activated titanium oxide particles, one or more chitosans, one or more calcium phosphates, one or more mercaptoalkyl-substituted silica gels, one or more mercaptoalkyl-substituted mesoporous molecular sieves, one or more finely ground γ-aluminas, one or more photocatalytic titanium dioxide particles, one or more Au-anatases, ceria, and combinations thereof, to form a mixture of sorbent and heavy metal-depleted aqueous plant extract; and separating the sorbent from the mixture to provide a heavy metal-depleted aqueous plant extract.