Changes in the Taste and Texture of the Foot of the Surf Clam (Pseudocardium sachalinensis) during Storage and Cooking

Abstract

Changes in the taste and texture of the surf clam foot due to cold storage (5°C) and cooking were analysed. During cold storage, the weight of the surf clam foot gradually decreased by up to 90% after 10 days. The changes in the total content of free amino acids in raw surf clam foot during cold storage were not statistically significant. However, the concentration of ornithine increased significantly after 10 days, which indicates decomposition. The ATP content of raw samples started decreasing after 3 days in cold storage, and their K' value, which is a freshness indicator, was 48% after 5 days.

Cooking the surf clam foot for 30 min reduced the weight by up to 65% of the original weight. The levels of free amino acids, as well as ATP and related compounds, were higher in the cooked samples than the raw samples. Shear force, piercing force, and thickness measurements of the cooked samples were higher than those of the raw samples; these parameters were the highest in samples cooked for 30 min. The sensory evaluation of three surf clam foot samples, namely, raw, cooked for 15 s, and cooked for 10 min, revealed a stronger fishy odor in raw samples than the cooked ones. The samples cooked for 10 min were harder to bite and had greater elasticity (chewiness) compared with those cooked for 15 s. Raw samples were inferior to those cooked for 15 s in overall preference.