Effect of Low Temperature Vacuum Slow Cooking on Muscle Quality Characteristics of Half Shell Scallop

This study utilized half-shell Chlamys farreri as the primary material to investigate the effects of different sous vide (SV) cooking temperatures (60, 65, 70, 75, 80 ℃) and cooking times (30, 45, 60, 75 min) on the quality attributes of the Chlamys farreri muscle. Sensory quality, drip loss, moisture content, water activity, texture, myofibrillar protein extraction, and microstructure were evaluated as key indicators. The results showed that as the cooking temperature and time increased, the sensory scores of SV Chlamys farreri initially rose and then declined, with the highest sensory score observed at 70 and 75 ℃ after 30 minutes of cooking. The drip loss of SV Chlamys farreri increased between 60 and 75 ℃ without significant differences (P<0.05), but significantly increased at 80 ℃ (P<0.05). In the temperature range of 60~70 ℃, there was no significant difference in moisture content with extended cooking time (P<0.05), while between 75 and 80 ℃, the moisture content significantly decreased with prolonged cooking (P<0.05). When the temperature exceeded 70 ℃, the hardness of the scallops reduced with an increase in temperature for the same cooking time (P<0.05). Shear force significantly increased with longer SV cooking time and higher temperatures (P<0.05). The extraction rate of myofibrillar protein decreased with the increase of temperature. No significant decrease was found in myofibrillar protein extraction rate at 75 and 80 ℃ for prolonged cooking time (P>0.05). Scanning electron microscopy and HE staining illustrated that as the cooking temperature increased, myofibrils underwent breakage, boundaries became indistinct, fractured myofibrils were cross-linked, and the disorder level escalated, ultimately leading to the aggregation of broken myofibrils into large masses. In conclusion, the optimal sensory quality of the scallops was achieved at 70 and 75 ℃ with 30 minutes of SV cooking, where drip loss and elasticity were lower than those in the control group (100 ℃, 15 min), while moisture content, water activity, hardness, and myofibrillar protein extraction rate were higher than those in the control group.