Effect of Steam Shucking on the Biochemical Composition of Black Clam (Villorita cyprinoides)

Abstract

The present study investigates the effect of shucking on the biochemical composition of black clam meat (Villorita cyprinoides). The clams were subjected to steaming and the nutritional quality parameters including proximate composition, fatty acid profile and lipid quality indices were estimated. There was an increase in protein content from 5.54% to 12.96%, fat content from 1.33% to 2.56%, and ash content from 0.64% to 1.19% along with a reduction in moisture content after steaming. The alpha amino acid content increased from 210mg% to 224mg% and the non-protein nitrogen content increased from 78mg% to 95mg% by steaming. The lipid oxidation index, thiobarbituric acid reactive substances increased from 0.25 to 0.66mg malonaldehyde/Kg in shucked clam. The palmitic acid and docosahexaenoic acid (DHA) were the major fatty acids present both in fresh and shucked clam meat. However, the saturated fatty acid content (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) had no significant change in their proportion. The PUFA content was 30% in both samples with ~66% constituted by n3 PUFA and ~33% constituted by n6 PUFA. The artherogenic index of fresh meat was 0.72 and shucked meat was 0.79 and thrombogenic index of both shucked and unshucked clam was ~0.29. It can be concluded that steam aided shucking preserves the proximate composition and fatty acids of black clam meat and hence can well be suggested for shucking.