Evaluation of Molluscs as Dietary Sources of Iron: Heme and Non-Heme Iron Content of Clams and Oysters Consumed in the Asia-Pacific Region

Abstract

Iron deficiency is the most prevalent nutrient deficiency in the world. Limited bivalve data indicates discrepancies in iron and heme iron concentration. Therefore, fresh Manila clams, Pacific oysters, canned blood clams (A. granosa), canned akagai (A. broughtonii), and frozen blood clams were assayed and compared to beef liver as a reference food rich in heme iron. Heme iron ranged from 0.53 ± 0.08 to 5.77 ± 0.34 mg/100 g edible portion in Manila clams and blanched frozen blood clams, respectively. Non-heme iron ranged from 4.47 ± 0.44 to 9.81 ± 0.58 and total iron ranged from 4.35 ± 0.85 to 12.28 ± 0.44 mg/100 g EP in Manila clams and canned blood clams, respectively. Frozen blood clams had significantly more heme and total iron compared to the liver reference. Although these data indicate that clams could be a reasonable iron source, some samples contained potentially toxic amounts of cadmium.