科研之友
微信
新浪微博
Facebook
分享链接
摘要
Water-soluble dietary fiber (WSDF), water-insoluble dietary fiber (WIDF) from wheat bran, and the carboxymethylated product of WIDF (CIDF), all having low contents of protein, ash, and phytic acid, were evaluated for their scavenging capacity far three heavy metals, Hg, Cd, and Pb. The results showed that WIDF had higher BCmax (maximum amount of bound heavy metal ions) and BCmin, values (minimum concentration of heavy metal ions below which the ions cannot be bound by dietary fibers) than WSDF at two pH conditions (pH 2.0 and 7.0). Carboxymethylation of WIDF improved its binding capacity for heavy metals (increase in BCmax and decrease in BCmin). The pH value significantly affected the binding capacity for heavy metals; BC,, sharply increased and BCmin sharply decreased for each heavy metal ion for all of the dietary fibers when the pH was raised fi om 2.0 to 7.0. The binding capacity of dietary fibers for heavy metals was slightly affected by amino acids, calcium, iron, and zinc but significantly affected by copper. Colon fermentation released part of the heavy metal ions from dietary fibers. From the results it can be! concluded that dietary fibers from wheat bran can effectively bind all three tested metal ions to prevent the body from being affected by their toxicity.
