Nutritional and physicochemical characteristics of Asiatic hard clam powder prepared by different cook-drying...

Asiatic hard clam (Meretrix meretrix) is an underutilized bivalve resource. This study discusses dried clam powders prepared from this resource to enhance its utilization and improve nutritional security in protein-deficient populations. Dried clam powder was prepared from Asiatic hard clam and the effects of different pre-cooking methods (boil-dried clam powder, BDCP; steam-dried clam powder, SDCP; and microwave-dried clam powder, MDCP) on nutritional (proximate composition, amino acid profiling, mineral profiling, fatty acid profiling) and physicochemical qualities were investigated.

Different pre-cooking methods significantly influenced the characteristics of the clam powder. The MDCP sample showed the highest concentration of amino acids, polyunsaturated fatty acids, Na, K, Ca and Mg content compared to BDCP and SDCP. The boiling process led to a loss of nutritional quality in terms of amino acids and macrominerals. The MDCP displayed the highest solubility in water (30.10%) but its oil and water absorption characteristics were the lowest among all the samples. Boil-cooked clam powder displayed the highest oil binding (2.03 mL g^-1 protein) capacity. Boiling and steaming processes resulted in malondialdehyde generation compared to microwaving. Different pre-cooking processes did not influence the colour attributes significantly, but the control sample prepared without pre-cooking (CCP) had a significantly lower L* value (32.34), resulting in a darker product. In vitro digestibility of the clam powder varied in the order MDCP > SDCP > BDCP > CCP.

The study demonstrated that nutritionally rich protein powder can be prepared from Asiatic hard clam. Based on the results, microwave pre-cooking is considered the best pre-cooking method to preserve the nutritional qualities of clam powder. © 2024 Society of Chemical Industry.