Biochemical composition of freshwater mussels in Malaysia: a neglected nutrient source for rural communities

Nutrient deficiency is still prevalent in Southeast Asia. Freshwater mussels (Unionida) are widespread and consumed by low-income, rural and indigenous communities, but their biochemistry is poorly known. We assessed concentrations of nutrients and harmful heavy metals in Malaysian freshwater mussels. Three replicate batches of 5–10 specimens of native Pilsbryoconcha compressa and non-native Sinanodonta woodiana were collected from one and three habitats, respectively, i.e. a rice paddy channel (both species), a lake and an abandoned mining pool (only S. woodiana). Macro- and micronutrient concentrations were determined on freeze-dried, ground mussel meat powder using established methods, including inductively coupled plasma mass spectrometry and direct mercury analyser. Concentrations differed significantly between and within species, but all populations were excellent sources of essential micronutrients. A serving of six mussels on average covered >100% of the recommended daily intake for adults of chromium, iron and manganese, and about 40–60% of calcium, copper, selenium and zinc. However, three of the four populations exceeded permissible levels of some heavy metals, especially arsenic and lead. Protein levels were low with 5–9 g 100 g−1 wet weight. Freshwater mussels may therefore represent an important nutrient source for rural, low-income communities, but should not be eaten in large quantities.